Common Information Model Power System Dynamics Standard

Common Information Model for

Power System Dynamics

Standard Dynamic Model Reference Document

DRAFT November 30, 2008

Page 2

Introduction ............................................................................................................................................................................. 4

Standard Interconnections ................................................................................................................................................... 5

Synchronous Generator Unit............................................................................................................................................................................. 5 Asynchronous (Induction) Generator Unit ................................................................................................................................................... 7 Large Synchronous Motor Unit ........................................................................................................................................................................ 8 Large Asynchronous (Induction) Motor Unit ............................................................................................................................................... 9 Aggregate Load.....................................................................................................................................................................................................10

Synchronous Generator Models......................................................................................................................................... 11

genSync - Synchronous Generator Model ..............................................................................................................................................13 genSync - RoundRotor Type....................................................................................................................................................................17 genSync - Salient Pole Type......................................................................................................................................................................19 genSync - Transient Type .........................................................................................................................................................................20 genSync - TypeF.............................................................................................................................................................................................20 genSync - TypeJ .............................................................................................................................................................................................21 genSync - CrossCompound Type...........................................................................................................................................................22

genEquiv - Equivalent (Classical ) Generator Model..............................................................................................................................24

Asynchronous Generator Models ...................................................................................................................................... 26

genAsync - Asynchronous Generator Model...........................................................................................................................................28

Large Synchronous Motor Models ..................................................................................................................................... 31

motorSync - Synchronous Motor Model....................................................................................................................................................33 motorSync - RoundRotor Type...............................................................................................................................................................38 motorSync - Salient Pole Type.................................................................................................................................................................40

Large Asynchronous Motor Models................................................................................................................................... 41

motorAsync - Asynchronous Motor Model...............................................................................................................................................42

Voltage Compensation Models .......................................................................................................................................... 45

vcompIEEE - IEEE Voltage Compensation Model....................................................................................................................................47 vcompCross – Cross-Compound Voltage Compensation Model.....................................................................................................48

Excitation System Models.................................................................................................................................................... 49

excAC1A - IEEE AC1A Model ............................................................................................................................................................................51 excAC2A - IEEE AC2A Model ............................................................................................................................................................................53 excAC3A - IEEE AC3A Model ............................................................................................................................................................................55 excAC4A - IEEE AC4A Model ............................................................................................................................................................................57 excAC5A - IEEE AC5A Model ............................................................................................................................................................................59 excAC6A - IEEE AC6A Model ............................................................................................................................................................................61 excAC7B - IEEE AC7B Model ............................................................................................................................................................................63

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excAC8B - IEEE AC8B Model ............................................................................................................................................................................65 excDC1A - IEEE DC1A Model............................................................................................................................................................................67 excDC2A - IEEE DC2A Model............................................................................................................................................................................69 excDC3A - IEEE DC3A Model............................................................................................................................................................................71 excDC4B - IEEE DC4B Model............................................................................................................................................................................73 excST1A - IEEE ST1A Model..............................................................................................................................................................................75 excST2A - IEEE ST2A Model..............................................................................................................................................................................77 excST3A - IEEE ST3A Model..............................................................................................................................................................................79 excST4B - IEEE ST4B Model..............................................................................................................................................................................81 excST5B - IEEE ST5B Model..............................................................................................................................................................................83 excST6B - IEEE ST6B Model..............................................................................................................................................................................85 excST7B - IEEE ST7B Model..............................................................................................................................................................................87 Other Excitation System Models To Be Added.........................................................................................................................................89

Power System Stabilizer (PSS) Models ............................................................................................................................... 90

pssIEEE2B - IEEE PSS2B Power System Stabilizer Model .................................................................................................................92 Other PSS Models To Be Added......................................................................................................................................................................94

Turbine-Governor Models ................................................................................................................................................... 95

govHydro1 – Hydro Turbine-Governor Model .........................................................................................................................................97 govSteam1 – IEEE Steam Turbine-Governor Model.............................................................................................................................99 govPID1 – General PID Governor and Prime Mover Model ...........................................................................................................102 Other Turbine-Governor Models That May Be Added .......................................................................................................................106

Aggregate Load Models..................................................................................................................................................... 107

loadStatic - Static Load Model...................................................................................................................................................................109 loadMotor - Aggregate Induction Motor Load ...................................................................................................................................111

Mechanical Load Models ................................................................................................................................................... 114

mechload1 - Mechanical Load Model 1 ................................................................................................................................................115

Page 4

Introduction The CIM standard dynamic models include most models for power system equipment that are commonly used for analysis of power system dynamic simulations in the transient and oscillatory stability time scale as defined by IEEE / CIGRE Standard Terms and Definitions for Power System Stability Analysis [ref]. Each of the models is described in this document, grouped by type of model.

Page 5

Standard Interconnections This section describes the standard interconnection of models for various types of equipment. These interconnections are understood by the application programs and therefore do not need to be communicated with the CIM data. In the interconnection diagrams, a dashed box means that a model does not have to be present.

Synchronous Generator Unit A synchronous generator and its related equipment models are associated with a generator in the static (power flow) data and have the standard interconnections shown in the following figure.

IfdExcitation

System

Efd

Turbine-Governor

Vcomp

speed

Pmech

PSSVs

Voltage Compensator

Etr, Eti

Itr, Iti

SynchronousGenerator

generatorterminal

bus

Network Algebraic Equations

Pref

PSS inputs

Itr2, Iti2

Generator#2

Vref

Pmech2

Notes:

1. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models.

2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant

at the initial value.

3. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) is held constant at the initial value.

4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any of several variables as inputs. The identification of the type of variable and its source is part of the data for the PSS model.

Page 6

5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the terminal voltage.

6. Generator #2 is the second unit of a cross-compound pair of generators and is usually connected to the same terminal bus. A single Turbine-Governor model determines the mechanical power for both units. A Voltage Compensator model that uses the currents from both units may be used. Therefore, the Turbine-Governor and Voltage Compensator models must have provision for being associated with two generating units.

7. The Vref and Pref variables are shown because they are standard inputs to the Excitation System and Turbine-Governor, respectively. These variables may be the output of non-standard models, e.g. for secondary voltage and frequency controls.

Page 7

Asynchronous (Induction) Generator Unit An asynchronous generator and its related equipment models are associated with a generator in the static (power flow) data and have the standard interconnections shown in the following figure. This is for a “squirrel-cage” induction machine or a wound-rotor induction machine with short-circuited field windings. Other models and interconnections are required for a wound-rotor machine with external connections to the field windings.

Turbine-Governor

speed

Pmech AsynchronousGenerator

generatorterminal

bus


Pref

Notes:

1. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models.

2. If no Turbine-Governor model is present for a unit, the generator mechanical power

(Pmech) is held constant at the initial value.

Page 8

Large Synchronous Motor Unit A synchronous motor and its related equipment models are associated with a generator (with negative Pgen) in the static (power flow) data and have the standard interconnections shown in the following figure.

IfdExcitation

System

Efd

Mechanical Load

Vcomp

speed

Pmech

PSSVs

Voltage Compensator

Etr, Eti

Itr, Iti

SynchronousMotor

generatorterminal

bus


PSS inputs

Vref

Notes:

1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models.

2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant


3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is held constant at the initial value.

4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any of several variables as input. The identification of the type of variable and its source is part of the data for the PSS model.

5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the terminal voltage.

Page 9

Large Asynchronous (Induction) Motor Unit An asynchronous motor and its related equipment models are associated with a generator (with negative Pgen) in the static (power flow) data and have the standard interconnections shown in the following figure. This is for a “squirrel-cage” induction machine or a wound-rotor induction machine with short-circuited field windings. Other models and interconnections are required for a wound-rotor machine with external connections to the field windings.

Mechanical Load

speed

Pmech Asynchronous Motor

generatorterminal

bus


Notes:

1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models.

2. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is

held constant at the initial value.

Page 10

Aggregate Load An aggregate load is associated with a load in the static (power flow) data and has the standard interconnection shown in the following figure.

Pload

Vbus, fbus

Load ModelQload

loadterminal

bus


Load Model Standard Interconnections

Notes: 1. The interface between the model and the network algebraic equations is application

dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other model.

a. For static (non-dynamic) load models, the P and Q consumption of the load is determined as a function of the magnitude and frequency of the voltage at the terminal bus.

b. For dynamic load models, the interface is similar to that of a generator model.

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Synchronous Generator Models For conventional power generating units (e.g., thermal, hydro, combustion turbine), a synchronous machine model represents the electrical characteristics of the generator and the mechanical characteristics of the turbine-generator rotational inertia. The standard interconnection variables between a synchronous generator model and other models are shown in the following figure and table:

Efd

SynchronousGenerator

Pmech

Network Equations

Turbine -Governor

Excitation System I fd

speedId, Iq*

E”d, E”q*

* Network interface variables may differ among application programs

angle

Synchronous Generator Interconnection Variables

The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection.

Synchronous Generator Interconnection Variables

Model Type Synchronous Generator

Inputs: Name

Units Description Source

Efd p.u. Field voltage on base of Ifag * Rfd (field resistance) Exciter Pmech p.u. Mechanical shaft power to the generator Turbine Outputs: Name Units Description Speed p.u. Generator (electrical) speed Angle radians Generator rotor angle relative to synchronously-rotating reference

frame Eppd p.u. Direct-axis subtransient voltage Eppq p.u. Quadrature-axis subtransient voltage Ifd p.u. Field current on Ifag base

Page 12

The following variables may be calculated in the generator model or in the network solution

depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Initialization Inputs: Name


Eterm p.u. Terminal voltage magnitude Power Flow busAngle radians Terminal voltage angle relative to system reference Power Flow Pgen MW Electrical power Power Flow Qgen MVAr Reactive power Power Flow Initialization Outputs: Name Units Description Speed p.u. Generator (electrical) speed (= 1.0 initially) Angle radians Generator rotor angle relative to synchronously-rotating reference

frame Efd p.u. Field voltage on base of Ifag * Rfd (field resistance) Ifd p.u. Field current on Ifag base (= Efd initially) Pmech p.u. Mechanical shaft power to the generator Notes:

1. Input/output variable units (except for angle) should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards.

2. The interface between the generator model and the network algebraic equations is

application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models.

3. If no Excitation model is present for a unit, the field voltage (Efd) should be held constant


4. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) should be held constant at the initial value.

References Most of the standard synchronous machine models are based on modeling practices described in IEEE Standard 1110-1991, “IEEE Guide for Synchronous Generator Modeling Practices in Stability Analysis.”

Page 13

genSync - Synchronous Generator Model A single standard synchronous model is defined for the CIM, with several variations indicated by the “model type” attribute. This model can be used for all types of synchronous machines (salient pole, solid iron rotor). A simplified model (genEquiv) is also defined below for representation of groups of generators that are not modeled in detail. All types of the genSync model use a subset of the same data parameters and input/output variables The input parameters are shown in the following table: Model Name genSync

Description Synchronous generator model with several variations

Parameters:

Parameter Usual CIM Typical Name Units Units?? Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Model Type None None See table below MVAbase MVA MVA MVA base for p.u. values kVbase kV kV kV base for p.u. values Ra p.u. 0.005 Stator resistance (>= 0.) Xl p.u. 0.15 Stator leakage reactance (> 0.) Xd p.u. 1.8 D-axis synchronous reactance (>= Xpdv) Xpdv p.u. 0.5 D-axis transient reactance (unsaturated) (>

=X”dv) Xppdv p.u. 0.2 D-axis sub-transient reactance (unsaturated) (>

Xl) Xq p.u. 1.6 Q-axis synchronous reactance (> =Xpq) Xpq p.u. 0.3 Q-axis transient reactance (> =Xppq) Xppq p.u. 0.2 Q-axis sub-transient reactance (> Xl) Tpdo sec. sec. 5.0 D-axis transient rotor time constant (> Tppdo) Tppdo sec. sec. 0.03 D-axis sub-transient rotor time constant (> 0.) Tpqo sec. sec. 0.5 Q-axis transient rotor time constant (> Tppqo) Tppqo sec. sec. 0.03 Q-axis sub-transient rotor time constant (> 0.) H (note 2) sec. 3.0 Inertia constant of turbine-generator (> 0.) D (note 3) none none 0.0 Damping factor S1 (note4) none none 0.02 Saturation factor at rated term. voltage (>= 0.) S12 (note 4) none none 0.12 Saturation factor at 120% of rated term.

voltage (>=S1) Ks none none 0.0 Saturation loading correction factor (>= 0.) Pfrac none none 1.0 Fraction of power flow generator P (>= 0.)

1. Generator parameters such as Xl, Xd, etc. are actually used as inductances (L) in the models, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the

Page 14

symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xppd refers to X”d.

2. H is the stored energy in the rotating mass of the generator plus all other elements (turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units).

3. D has units of power/speed but is regarded as a dimensionless factor resulting from

linearization of an exponential relationship between speed and power: ( )DoPP ω= . This value is often zero when the source of damping torques (generator damper windings, load damping effects, etc.) are modeling in detail. [ref]

4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1

E1

OPENCIRCUIT

VOLTAGE

OPEN CIRCUIT MAGNETIZATION

CURVE

MAGNETIZINGCURRENT

For generators E1 = 1.0 E2 = 1.2For Exciters E1, E2 are parameters

E2

A1 B1 A2 B2

AIR GAP LINE

0

OBi - OAi S(E) = --------------- OAi

Figure genSync1 -- Synchronous Generator Saturation Parameters

Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open circuit on the air gap (no saturation) line.

Page 15

Model Equations: The mechanical equations for all variatons of the genSync model are the same and can be represented by the following block diagram:

12Hs

∆ω

D

Tespeed

anglePmech

1. +

ωos

+

Σ+

_

_

ω

n/dn Tm

d

Σ

Σ

Figure genSync2 -- Synchronous Generator Mechanical Equation Block Diagram

All variables are per unit on generator MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations for all variations of the genSync model are based on the following equivalent circuit diagram for the direct and quadrature axes:

+

efd

Xl Xfd

Xkd

Xad

Rkd

Ra Rfd

d axis

Xl X1q

X2q

Xaq

R2q

Ra R1q

q axis

Figure genSync3 -- Synchronous Generator Equivalent Circuit

Page 16

In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor q). Models based on unequal mutual inductance are not normally used for stability analysis. The definition of d and q axis variables is based on the following phasor diagram (counter-clockwise rotation), for the case of an overexcited generator (generating Q):

q axis

Et

It

It (Ra + jX”)

E”

j It ( Xq-X”)

d axis

Network Reference

rotor angle

bus angle

Figure genSync4 -- Synchronous Generator Phasor Diagram

The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xad + Xl X’d = Xl + Xad * Xfd / (Xad + Xfd) X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd) T’do = (Xad + Xfd) / (wo * Rfd) T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd) Xq = Xaq + Xl X’q = Xl + Xaq * X1q / (Xaq+ X1q) X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q) T’qo = (Xaq + X1q) / (wo * R1q) T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q) The several variations of the genSync model described on the following pages differ in the following ways:

• The number of equivalent windings that are included • The way in which saturation is incorporated into the model.

Page 17

• Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented. • Whether or not multiple units (e.g. cross-compound set) are represented individually in the

static (power flow) data. Variations of the genSync model are identified by the “model type” attribute as shown in the table below, together with the corresponding model names in each application program. Each model type is described in detail on the following pages. CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model RoundRotor genrou GENROU ElmSym SalientPole gensal GENSAL ElmSym Transient (genrou) GENTRA ElmSym TypeF gentpf TypeJ gentpj CrossCompound gencc GENROU? Note: It is not necessary for each program to have separate models for each of the model types. The same model can often be used for several types by alternative logic within the model. Also, differences in saturation representation may not result in significant model performance differences so model substitutions are often acceptable.

genSync - RoundRotor Type The complete equivalent circuit is used with two rotor windings in each axis. Notes:

• Xppq is assumed to be equal to Xppd (no subtransient saliency) • Saturation is modeled in both the d and q axes as shown in the block diagram • The following input parameters are not used: Xppq, Ks, Pfrac

Block Diagram:

Page 18

Se

XlXdXlXq

−−

ψ" = sqrt(ψ"d2+ψ"d

2)ψ"d

ψ"q

do''sT1

2**)Xld'X(d''Xd'X

−− X'd-Xl d-AXIS

Efddo'sT

1Xld'X

d''Xd'X−

−

Xld'XXld''X

−−

Xd-X'dIfd

ψfdψkd

qo''sT1

2**)Xlq'X(q''Xq'X

−−

X'q-Xl q-AXIS

iq

qo'sT1

Xlq'Xq'Xq'X

−−

Xlq'XXlq''X

−−

Xq-X'q

ψ1qψ2q

ψ"q

iq

id

X''d

Ra

Eq

id

Σ

X''q

Ra

Ed

ψ"dΠ

ω

Π

ω

ΣΣ

ΣΣ

Σ

Σ

Σ Σ

ΣΣ Σ

Figure genSync5 -- genSync – RoundRotor Type Model Block Diagram

Page 19

genSync - Salient Pole Type The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes:

• Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency) • Saturation is modeled in the d axis only as shown in the block diagram • The following input parameters are not used: Xpq, Xppq, Tppqo, Ks, Pfrac

Block Diagram:

Se

do''sT1

2**)Xld'X(d''Xd'X


Efddo'sT

1Xld'X

d''Xd'X−

−

Xld'XXld''X

−−

Xd-X'dIfd

ψfdψkd

q-AXIS

iq

qo'sT1

Xq-X'q

ψ1q ψ"q

iq

id

X''d

Ra

Eq

id

Σ

X''q

Ra

Ed

ψ"dΠ

ω

Π

ω

Σ

Σ

Σ Σ

ΣΣ Σ

ψfd

Figure genSync6 -- genSync – SalientPole Type Model Block Diagram

Page 20

genSync - Transient Type The d-axis equivalent circuit has only the field winding. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes:

• ??? Xppq (=Xpq) is assumed to be equal to Xppdv (=Xpd) (no subtransient saliency) • Saturation is modeled in the d axis only as shown in the block diagram • The following input parameters are not used: Xppd, Xpq, Xppq, Tpdo, Tppqo, Ks, Pfrac

Block Diagram: Add figure later

Figure genSync7 -- genSync – Transient Type Model Block Diagram

genSync - TypeF This model has a similar level of detail to the RoundRotor type but permits subtransient saliency (Xppq ≠ Xppdv) and models saturation differently. The RoundRotor type can usually be substituted without significant loss of accuracy. Notes:

• Saturation is modeled in both the d and q axes as shown in the block diagram • The following input parameters are not used: Ks, Pfrac

Block Diagram:

Page 21

do''sT1

id

Efd do'sT1

d''Ld'Ld'LLd

−−

L’d - L”dd''Ld'Ld"LLd

−−

E’q

Se

SeE”q

)ag(LdLq.1Se

:exceptsimilarAxisQ

)ag(fsat.1Se

ϕ+=

−

ϕ+=

d"ϕ∑∑

Figure genSync9 -- genSync – TypeF Model Block Diagram

genSync - TypeJ This model is the same as TypeF but includes the effect of generator loading on saturation. Notes:

• Saturation is modeled in both the d and q axes as shown in the block diagram • The following input parameters are not used: Pfrac

Block Diagram:

Page 22

do''sT1

id

Efd do'sT1

d''Ld'Ld'LLd

−−

L’d - L”dd''Ld'Ld"LLd

−−

E’q

Se

SeE”q

))id(signItKisag(fsatLdLq.1Se

:exceptsimilarAxisQ

))id(signItKisag(fsat.1Se

∗∗+ϕ∗+=

−

∗∗+ϕ+=

d"ϕ

∑∑

Figure genSync10 -- genSync – TypeJ Model Block Diagram

genSync - CrossCompound Type This model is the same as RoundRotor Type but permits more than one genSync model to split the generator power from the power flow synchrounous machine model. This is most often used for representing the two untis of a cross-compound set which always operate together from the same steam supply. Notes:

• The parameter Pfrac is the fraction of the power flow Pgen and Qgen supplied by this unit. • Xppq is assumed to be equal to Xppd (no subtransient saliency) • Saturation is modeled in both the d and q axes as shown in the block diagram • The following input parameters are not used: Xppq, Ks

Block Diagram:

Page 23

Se

XlXdXlXq

−−


2)ψ"d

ψ"q

do''sT1

2**)Xld'X(d''Xd'X


Efddo'sT

1Xld'X

d''Xd'X−

−

Xld'XXld''X

−−

Xd-X'dIfd

ψfdψkd

qo''sT1

2**)Xlq'X(q''Xq'X

−−

X'q-Xl q-AXIS

iq

qo'sT1

Xlq'Xq'Xq'X

−−

Xlq'XXlq''X

−−

Xq-X'q

ψ1qψ2q

ψ"q

iq

id

X''d

Ra

Eq

id

Σ

X''q

Ra

Ed

ψ"dΠ

ω

Π

ω

ΣΣ

ΣΣ

Σ

Σ

Σ Σ

ΣΣ Σ

Figure genSync11 -- genSync – CrossCompound Type Model Block Diagram

Page 24

genEquiv - Equivalent (Classical ) Generator Model This model represents a synchronous generator as a constant internal voltage behind an impedance (Ra +jXpdv) as shown in the following equivalent circuit: Notes:

• Since internal voltage is held constant, there is no genEfd input and any excitation system model will be ignored. There is also no genIfd output.

• This model should never be used for representing a real generator except, perhaps, small generators whose response is insignificant.

• The model is often used for gross equivalents of parts of a system that are not represented in detail. In this case. the MVA rating would be the combined rating of all generators in the equivalenced area. Ra + jXpdv would be the short circuit equivalent impedance at the location of the equivalent generator on the generator MVA rating base. H and D would be typical or average values for the generators in the equivalenced area.

• The internal reactance may be labeled in different ways (Xp, Xpp, Xpd, Xppd) by different programs. The Xpdv value from the genSync input data is selected for use by the CIM model.

Block Diagram: The mechanical equations for the genEquiv model are the same as for genSync as shown in Figure genSync2. Add figure later

Figure genEquiv1 -- Equivalent (Classical) Model Block Diagram CIM PSLF PSS/E DigSilent Eurostag Model Name Model Model Model Model genEquiv gencls GENCLS ElmSym Parameters:

Parameter Usual CIM Typical Name Units Units?? Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Model Type None None See table below MVAbase MVA MVA MVA base for p.u. values kVbase kV kV kV base for p.u. values Ra p.u. ohms 0.005 Stator resistance (>= 0.) Xpdv p.u. ohms 0.5 D-axis transient reactance (unsaturated) (> 0.)

Page 25

H sec.* MW-sec. 3.0 Inertia constant of turbine-generator (> 0.) D none** none 0.0 Damping factor

1. Parameter Xpd is actually used as an inductance (L) in the model, but is commonly referred

to as a reactance since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter name is a substitution for a “prime” in the usual notation, e.g. Xpd refers to X’d.



linearization of an exponential relationship between speed and power: ( )DoPP ω= . This value is often zero when the source of damping torques (generator damper windings, load damping effects, etc.) are modeling in detail. [ref]

Page 26

Asynchronous Generator Models The standard interconnection variables between an asynchronous generator model and other models are shown in the following figure and table:

AsynchronousGenerator

Pmech

Network Equations

Turbine -Governor

speedId, Iq*

E”d, E”q*


Asynchronous Generator Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection.

Asynchronous Generator Interconnection Variables

Model Type Asynchronous Generator

Inputs: Name


Pmech p.u. Mechanical shaft power to the generator Turbine Outputs: Name Units Description Speed p.u. Generator (electrical) speed Eppd p.u. Direct-axis subtransient voltage Eppq p.u. Quadrature-axis subtransient voltage The following variables may be calculated in the generator model or in the network solution

depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude

Page 27

Initialization Inputs: Name


Eterm p.u. Terminal voltage magnitude Power Flow busAngle radians Terminal voltage angle relative to system reference Power Flow Pgen MW Electrical power Power Flow Qgen MVAr Reactive power Power Flow Initialization Outputs: Name Units Description Speed p.u. Generator (electrical) speed (= 1.0 initially) Pmech p.u. Mechanical shaft power to the generator Notes:

1. Input/output variable units should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards.

2. The interface between the generator model and the network algebraic equations is

application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models.

3. If no Turbine-Governor model is present for a unit, the generator mechanical power

(Pmech) should be held constant at the initial value.

Page 28

genAsync - Asynchronous Generator Model The genAsynch model represents an asynchrounous (induction) generator with no external connection to the rotor windings, e.g squirel-cage induction machine. Model Name genAsync

Description Asynchronous generator model

Parameters:

Parameter Usual CIM Typical Name Units Units?? Value Description Bus number Terminal bus number in power flow case Unit ID Motor (generator) ID in power flow case MVAbase MVA MVA MVA base for p.u. values kVbase kV kV kV base for p.u. values Rs p.u. 0.005 Stator resistance (>= 0.) Xls p.u. 0.15 Stator leakage reactance (> 0.) Xs p.u. 1.8 Synchronous reactance (>= Xp) Xp p.u. 0.5 Transient reactance (unsaturated) (> =Xpp) Xpp p.u. 0.2 Sub-transient reactance (unsaturated) (> Xl) Tpo sec. sec. 5.0 Transient rotor time constant (> Tppo) Tppo sec. sec. 0.03 Sub-transient rotor time constant (> 0.) H (note 2) sec. 3.0 Inertia constant of motor and mechanical load

(> 0.) D (note 3) none none 0.0 Damping factor S1 (note4) none none 0.02 Saturation factor at rated term. voltage (>= 0.) S12 (note 4) none none 0.12 Saturation factor at 120% of rated term.

voltage (>=S1)

1. Generator parameters such as Xls, Xs, etc. are actually used as inductances (L) in the model, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xpp refers to X”.



linearization of an exponential relationship between speed and power: ( )DoPP ω= . This value is often zero when the source of damping torques (damper windings, load damping effects, etc.) are modeling in detail. [ref]

4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above.

Page 29

Model Equations: The mechanical equations for the motorAsync model can be represented by the following block diagram:

12Hs

∆ω

D

Tespeed

Pmech

1. +

+

Σ+

_ω

n/dn Tm

d

Σ

Σ

slip_

+

Figure genAsync1 Asynchronous Generator Mechanical Equation Block Diagram

All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations of the genAsync model are based on the following equivalent circuit diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis:

Xls

Xlr2Xlr1

Xm

Rr1

Rs

Rr2

d axis

q axis – same as d-axis

Figure genAsync2 Asynchronous Generator Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the magnetizing reactance (Xm), and the resistance and leakage reactance of equivalent windings (Rr1, Xlr1, etc.) on the rotor. The relationships between the equivalent circuit parameters and the standard model parameters are as follows:

Page 30

Xd = Xm + Xls Xp = Xls + Xm * Xlr1 / (Xm + Xlr1) Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) Tpo = (Xm + Xlr1) / (wo * Rr1) Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1) If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled. CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model genAsync genind or

motor1 CIMTR1 CIMTR3

ElmAsm

A specific block diagram for an asynchronous generator model is not shown. There will be variations in modeling among the application programs which should not materially affect the results in the stability analysis time scale. (ref Krause book/papers)

Page 31

Large Synchronous Motor Models Large industrial motors or groups of similar motors may be represented by individual motor models (synchronous or asynchronous) which are represented as generators with negative Pgen in the static (power flow) data.

Model Interconnections Standard interconnection of synchronous motor models with other models are shown in Figure 7-1 and listed in Table 7-1.

Efd

Synchronous Motor

Pmech

Network Equations

Mechanical Load

Excitation System I fd

speed

Eterm

Id, Iq*

E”d, E”q*


angle

Synchronous Motor Interconnection Variables

The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection.

Synchronous Motor Interconnection Variables

Model Type Motor

Inputs: Name


Efd (note 1) p.u. Field voltage on base of Ifag * Rfd (field resistance) Exciter Pmech p.u. Mechanical shaft power drawn by mechanical load Mech. Load

Page 32

Outputs: Name Units Description Speed p.u. Motor (electrical) speed Angle radians Motor rotor angle relative to synchronously-rotating reference frame Eppd p.u. Direct-axis subtransient voltage Eppq p.u. Quadrature-axis subtransient voltage Ifd (note 1) p.u. Field current on Ifag base The following variables may be calculated in the motor model or in the network solution

depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Initialization Inputs: Name


Eterm p.u. Terminal voltage magnitude Power Flow busAngle radians Terminal voltage angle relative to system reference Power Flow Pgen MW Electrical power Power Flow Qgen MVAr Reactive power Power Flow Initialization Outputs: Name Units Description Speed p.u. Motor (electrical) speed Angle radians Motor rotor angle relative to synchronously-rotating reference frame Efd (note 1) p.u. Field voltage on base of Ifag * Rfd (field resistance) Ifd (note 1) p.u. Field current on Ifag base (= Efd initially) Pmech p.u. Mechanical shaft power drawn by mechanical load Notes:

1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models.

2. If no exciter model is present for a unit, the field voltage (Efd) should be held constant at

the initial value.

3. If no mechanical load model is present for a unit, the motor mechanical power (Pmech) should be held constant at the initial value.

Page 33

motorSync - Synchronous Motor Model A single standard synchronous motor model is defined for the CIM, with several variations indicated by the “model type” attribute. This model can be used for all types of synchronous machines (salient pole, solid iron rotor). All types of the motorSync model use a subset of the same data parameters and input/output variables The input parameters are shown in the following table: Model Name motorSync

Description Synchronous motor model with several variations

Parameters:

Parameter Usual CIM Typical Name Units Units?? Value Description Bus number Terminal bus number in power flow case Unit ID Motor (generator) ID in power flow case Model Type None None See table below MVAbase MVA MVA MVA base for p.u. values kVbase kV kV kV base for p.u. values Ra p.u. 0.005 Stator resistance (>= 0.) Xl p.u. 0.15 Stator leakage reactance (> 0.) Xd p.u. 1.8 D-axis synchronous reactance (>= Xpdv) Xpdv p.u. 0.5 D-axis transient reactance (unsaturated) (>

=X”dv) Xppdv p.u. 0.2 D-axis sub-transient reactance (unsaturated) (>

Xl) Xq p.u. 1.6 Q-axis synchronous reactance (> =Xpq) Xpq p.u. 0.3 Q-axis transient reactance (> =Xppq) Xppq p.u. 0.2 Q-axis sub-transient reactance (> Xl) Tpdo sec. sec. 5.0 D-axis transient rotor time constant (> Tppdo) Tppdo sec. sec. 0.03 D-axis sub-transient rotor time constant (> 0.) Tpqo sec. sec. 0.5 Q-axis transient rotor time constant (> Tppqo) Tppqo sec. sec. 0.03 Q-axis sub-transient rotor time constant (> 0.) H (note 2) sec. 3.0 Inertia constant of motor and mechanical load


voltage (>=S1)

1. Motor parameters such as Xl, Xd, etc. are actually used as inductances (L) in the models, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xppd refers to X”d.

Page 34

2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has units of MW-sec. Conventional units are per unit on the motor MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units).



4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure 7-2

E1

OPENCIRCUIT

VOLTAGE

OPEN CIRCUIT MAGNETIZATION

CURVE

MAGNETIZINGCURRENT

For generators E1 = 1.0 E2 = 1.2For Exciters E1, E2 are parameters

E2

A1 B1 A2 B2

AIR GAP LINE

0

OBi - OAi S(E) = --------------- OAi

Figure 7-2 Synchronous Motor Saturation Parameters

Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open circuit on the air gap (no saturation) line.

Page 35

Model Equations: The mechanical equations for all variatons of the motorSync model are the same and can be represented by the following block diagram:

12Hs

∆ω

D

Tespeed

anglePmech

1. +

ωos

+

Σ

+_

ω

n/dn Tm

d

Σ

Σ

+

Figure 7-2 Synchronous Motor Mechanical Equation Block Diagram

All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations for all variations of the motorSync model are based on the following equivalent circuit diagram for the direct and quadrature axes:

Page 36

+

efd

Xl Xfd

Xkd

Xad

Rkd

Ra Rfd

d axis

Xl X1q

X2q

Xaq

R2q

Ra R1q

q axis

Figure 7-3 Synchronous Motor Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor q). Models based on unequal mutual inductance are not normally used for stability analysis. The definition of d and q axis variables is based on the following phasor diagram (counter-clockwise rotation), for the case of a motor consuming P and overexcited (generating Q):

Page 37

q axis

Et

It

It (Ra + jX”)

E”j It ( Xq-X”)

d axis

Network Reference

rotor angle

bus angle

Figure 7-4 Synchronous Motor Phasor Diagram

The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xad + Xl X’d = Xl + Xad * Xfd / (Xad + Xfd) X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd) T’do = (Xad + Xfd) / (wo * Rfd) T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd) Xq = Xaq + Xl X’q = Xl + Xaq * X1q / (Xaq+ X1q) X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q) T’qo = (Xaq + X1q) / (wo * R1q) T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q) The several variations of the motorSync model described on the following pages differ in the following ways:

• The number of equivalent windings that are included • The way in which saturation is incorporated into the model. • Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented.

Variations of the motorSync model are identified by the “model type” attribute as shown in the table below, together with the corresponding model names in each application program. Each model type is described in detail on the following pages. CIM PSLF PSS/E DigSilent Eurostag

Page 38

Model Type Model Model Model Model RoundRotor genrou GENROU ElmSym SalientPole gensal GENSAL ElmSym Note: It is not necessary for each program to have separate models for each of the model types. The same model can often be used for several types by alternative logic within the model. Also, differences in saturation representation may not result in significant model performance differences so model substitutions are often acceptable.

motorSync - RoundRotor Type The complete equivalent circuit is used with two rotor windings in each axis. Notes:

• Xppq is assumed to be equal to Xppd (no subtransient saliency) • Saturation is modeled in both the d and q axes as shown in the block diagram • The following input parameters are not used: Xppq

Block Diagram:

Page 39

Se

XlXdXlXq

−−


2)ψ"d

ψ"q

do''sT1

2**)Xld'X(d''Xd'X


Efddo'sT

1Xld'X

d''Xd'X−

−

Xld'XXld''X

−−

Xd-X'dIfd

ψfdψkd

qo''sT1

2**)Xlq'X(q''Xq'X

−−

X'q-Xl q-AXIS

iq

qo'sT1

Xlq'Xq'Xq'X

−−

Xlq'XXlq''X

−−

Xq-X'q

ψ1qψ2q

ψ"q

iq

id

X''d

Ra

Eq

id

Σ

X''q

Ra

Ed

ψ"dΠ

ω

Π

ω

ΣΣ

ΣΣ

Σ

Σ

Σ Σ

ΣΣ Σ

Figure 7-5 motorSync – RoundRotor Type Model Block Diagram

Page 40

motorSync - Salient Pole Type The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes:

• Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency) • Saturation is modeled in the d axis only as shown in the block diagram • The following input parameters are not used: Xpq, Xppq, Tppqo

Block Diagram:

do''sT1

L'd - Ll

d-AXIS

id

Efd do'sT1

q-AXIS

iq

Pfd

Ld - L'd

qo''sT1

Lq - Lq”

L"d - LlL'd - Ll

L'd - L"dL'd - Ll

L'd - L"d(L'd - Ll) **2

SePfd

Lad ifd

Pkd

Pkq

P"d

P"q

Figure 7-6 motorSync – SalientPole Type Model Block Diagram

Page 41

Large Asynchronous Motor Models The standard interconnection variables between an asynchronous motor model and other models are shown in the following figure and table:

AsynchronousMotor

Pmech

Network Equations

Mechanical Load

speedId, Iq*

E”d, E”q*


Asynchronous Motor Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection.

Asynchronous Motor Interconnection Variables

Model Type Asynchronous Motor

Inputs: Name


Pmech p.u. Mechanical shaft power of motor load Mech. Load Outputs: Name Units Description Speed p.u. Motor (electrical) speed Eppd p.u. Direct-axis subtransient voltage Eppq p.u. Quadrature-axis subtransient voltage The following variables may be calculated in the motor model or in the network solution

depending on the particular application program: Pe p.u. Electrical power Qe p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude

Page 42

Initialization Inputs: Name


Eterm p.u. Terminal voltage magnitude Power Flow busAngle radians Terminal voltage angle relative to system reference Power Flow Pgen MW Electrical power Power Flow Qgen MVAr Reactive power Power Flow Initialization Outputs: Name Units Description Speed p.u. Motor (electrical) speed (= 1.0 initially) Pmech p.u. Mechanical shaft power to the generator Notes:

1. Input/output variable units should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards.

2. The interface between the motor model and the network algebraic equations is application

dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models.

3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech)

should be held constant at the initial value.

motorAsync - Asynchronous Motor Model The motorAsynch model represents an asynchrounous (induction) motor with no external connection to the rotor windings, e.g squirel-cage induction motor. Model Name motorAsync

Description Asynchronous motor model

Parameters:

Parameter Usual CIM Typical Name Units Units?? Value Description Bus number Terminal bus number in power flow case Unit ID Motor (generator) ID in power flow case MVAbase MVA MVA MVA base for p.u. values kVbase kV kV kV base for p.u. values Rs p.u. 0.005 Stator resistance (>= 0.) Xls p.u. 0.15 Stator leakage reactance (> 0.) Xs p.u. 1.8 Synchronous reactance (>= Xp) Xp p.u. 0.5 Transient reactance (unsaturated) (> =Xpp)

Page 43

Xpp p.u. 0.2 Sub-transient reactance (unsaturated) (> Xl) Tpo sec. sec. 5.0 Transient rotor time constant (> Tppo) Tppo sec. sec. 0.03 Sub-transient rotor time constant (> 0.) H (note 2) sec. 3.0 Inertia constant of motor and mechanical load


voltage (>=S1)

1. Motor parameters such as Xl, Xs, etc. are actually used as inductances (L) in the model, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xpp refers to X”.

2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has units of MW-sec. Conventional units are per unit on the motor MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units).



4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above.

Model Equations: The mechanical equations for the motorAsync model can be represented by the following block diagram:

12Hs

∆ω

D

Tespeed

Pmech

1. +

+

Σ

+_

ω

n/dn Tm

d

Σ

Σ

+

slip

Figure motorAsync1 Asynchronous Motor Mechanical Equation Block Diagram

All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems.

Page 44

The electrical equations of the motorAsync model are based on the following equivalent circuit diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis:

Xls

Xlr2Xlr1

Xm

Rr1

Rs

Rr2

d axis

q axis – same as d-axis

Figure motorAsync2 Asynchronous Motor Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the magnetizing reactance (Xm), and the equivalent windings (Rr1, Xlr1, etc.) on the rotor. The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xm + Xls Xp = Xls + Xm * Xlr1 / (Xm + Xlr1) Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) Tpo = (Xm + Xlr1) / (wo * Rr1) Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1) If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled. CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model motorAsync motor1 CIMTR2 ElmAsym A specific block diagram for a motor model is not shown. There will be variations in modeling among the application programs which should not materially affect the results in the stability analysis time scale.

Page 45

Voltage Compensation Models The voltage compensation model adjusts the terminal voltage feedback to the excitation system by adding a quantity that is proportional to the terminal current of the generator. It is linked to a specific generator by the Bus number and Unit ID

Model Interconnections Standard interconnection of voltage compensation models with other models are shown in Figure B-1 and listed in Table B-1.

VcEtr, Eti

Voltage Compensation Excitation System

Itr, It iNetwork

Itr2, Iti2

Figure B-1 Voltage Compensation Model Standard Interconnections

Table B-1 Voltage Compensation Model Standard Interconnections Inputs:

Name Units Description Source Etr p.u. Terminal voltage – real component see note 1 Eti p.u. Terminal voltage – imaginary component see note 1 Itr p.u. Terminal current – real component see note 1 Iti p.u. Terminal current – imaginary component see note 1 Itr2 p.u. Terminal current – real component – unit 2 see note 2 Iti2 p.u. Tterminal current – imaginary component – unit 2 see note 2 Outputs:

Name Units Description Vc p.u. Compensated terminal voltage Initialization Inputs:

Name Units Description Source Etr p.u. Terminal voltage – real component see note 1 Eti p.u. Terminal voltage – imaginary component see note 1 Itr p.u. Terminal current – real component see note 1 Iti p.u. Terminal current – imaginary component see note 1 Itr2 p.u. Terminal current – real component – unit 2 see note 2 Iti2 p.u. Tterminal current – imaginary component – unit 2 see note 2 Initialization Outputs:

Name Units Description

Page 46

Vc p.u. Compensated terminal voltage Notes: 1. Source of the generator complex voltage components is application dependent. It may come

from the generator or from the network equations. 2. Unit 2 is a second generator connected to the same terminal bus, usually the other unit of a

cross-compound pair. These inputs are not used by all voltage compensation models.

Page 47

vcompIEEE - IEEE Voltage Compensation Model Model Name vcompIEEE

Description IEEE Voltage Compensation Model

Inputs Etr, Eti, Itr, Iti Outputs: Vc

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Rcomp p.u. (gen. base) 0. Compensating (compounding) resistance Xcomp p.u. (gen. base) -0.1 Compensating (compounding) reactance. Notes: . Equation:

( ) )jItiItr(*)jXcompRcomp(jEtiEtrVcomp ++++=

CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model vcompIEEE Rcomp,

Xcomp IEEEVC COMP

drp_COMP

Notes: 1. PSLF does not have a separate Voltage Compensator model but permits the specification of

Rcomp and Xcomp (with opposite sign convention) for each generator as part of its generator model data.

Page 48

vcompCross – Cross-Compound Voltage Compensation Model Model Name vcompCross

Description Voltage Compensation Model for Cross-Compound Generating Unit

Inputs Etr, Eti, Itr, Iti, Itr2, Iti2 Outputs: Vc

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Rcomp p.u. (gen. base) 0. Self-Compensating (compounding) resistance Xcomp p.u. (gen. base) -0.1 Self-Compensating (compounding) reactance. Rcomp2 p.u. (gen. base) 0. Cross-Compensating (compounding) resistance Xcomp2 p.u. (gen. base) -0.1 Cross-Compensating (compounding) reactance. Notes: . Equation:

( ) )(*)()(*)( 2jIti2Itr2jXcomp2RcompjItiItrjXcompRcompjEtiEtrVcomp +++++++= CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model vcompCROSS none COMPCC

COMCC1

Notes: 1. Equation is based on convention in IEEE Std 421.5-2005. PSS/E model uses a different

convention which can be translated to/from CIM equation coefficients. 2. PSLF does not currently have a standard model for cross compensation.

Page 49

Excitation System Models The excitation system model provides the field voltage (Efd) for a synchronous machine model. It is linked to a specific generator by the Bus number and Unit ID. The data parameters are different for each excitation system model; the same parameter name may have different meaning in different models.

Model Interconnections Standard interconnection of excitation system models with other models are shown in Figure C-1 and listed in Table C-1.

Efd

LadIfd

Vref

Vs

VOE L

VUE L

Excitation SystemVc

Generator

VoltageCompensator

PSS

UEL

OEL

Figure C-1 Excitation System Model Standard Interconnections

Table C-1 Excitation System Model Standard Interconnections Inputs:

Name Units Description Source Vc p.u. Compensated generator terminal voltage see note 1 Vref p.u. Voltage reference see note 2 Ifd p.u. Generator field current Generator Vs p.u. Power system stabilizer (PSS) output PSS Voel p.u. Overexcitation limiter output OEL Vuel p.u. Underexcitation limiter output UEL

Page 50

Outputs: Name Units Description

Efd p.u. Generator field voltage Initialization Inputs:

Name Units Description Source Efd p.u. Genator field voltage Generator Ifd p.u. Generator field current Generator Vc p.u. Compensated generator terminal voltage Compensator Initialization Outputs:

Name Units Description Vref p.u. Voltage Reference Vs p.u. Power system stabilizer (PSS) output – initilialized to zero Voel p.u. Overexcitation limiter output – initialized to large negative value Vuel p.u. Underexcitation limiter output – initialized to large positive value Notes: 1. If a voltage compensation model is present, it is the source of Vc. If not, Vc = Eterm from the

generator model. (Note: PSS/E and PSLF handle compensation differently. In PSS/E, the compensator is a separate model, which may or may not be present. In PSLF, the compensating (compounding) impedance values (Rcomp, Xcomp) are included in the generator data. For CIM, separate compensating model is recommended.)

2. Vref may be modified by a user-written model.

References Most of the standard excitation system models are based on the 2005 version of the IEEE standard 421.5 “IEEE Recommended Practice for Excitation System Modeling for Power System Stability Studies”. Earlier versions of this standard in 1992, 1980, and 1968 are also referenced. Nearly all of the models described in these earlier versions can be adequately represented by models in the 2005 standard. Therefore, separate CIM standard models are not included for those earlier versions of the models. Legacy models in PSLF and PSS/E based on the earlier versions are still used in many databases but can translated into the new versions without loss of accuracy.

Page 51

excAC1A - IEEE AC1A Model Model Name excAC1A

Description IEEE (1992/2005) AC1A Model

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Tb sec. 0.0 TGR lag time constant (>= 0.) Tc sec. 0.0 TGR lead time constant Ka p.u. 400.0 AVR gain (> 0.) Ta sec. 0.02 AVR time constant (> 0.) Vamax p.u. 14.5 Maximum AVR output (> 0.) Vamin p.u. -14.5 Minimum AVR output (< 0.) Te sec. 0.8 Exciter time constant (> 0.) Kf p.u. 0.03 Rate feedback gain (>= 0.) Tf sec. 1.0 Rate feedback time constant (> 0.) Kc p.u. 0.20 Rectifier regulation factor (>= 0.) Kd p.u. 0.38 Exciter internal reactance (>= 0.) Ke p.u. 1.0 Exciter field resistance constant E1 p.u. 4.18 Field voltage value 1 (note d) (> 0.) S(E1) none 0.10 Saturation factor at E1 (note d) (>= 0.) E2 p.u. 3.14 Field voltage value 2. (note d) (> 0.) S(E2) none 0.03 Saturation factor at E2 (note d) (>= 0.) Vrmax p.u. 6.03 Maximum exciter control signal (> 0.) Vrmin p.u. -5.43 Minimum exciter control signal (< 0.) Notes: a) For modeling alternator-rectifier excitation system with non-controlled rectifiers and feedback

from exciter field current, e.g. Westinghouse Brushless system. b) Ka, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate

feedback, set Kf = 0. d) Saturation parameters are consistent with the IEEE saturation factor definition using the open

circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower.

Page 52

Block Diagram:

Kd

F( In )

F ex

Efd

Ke+Se (Ve ) Vfe

I fd

Vc+

+

+

-

0Vf

Vre f

In

Vrm a x

Vam in

Kc I fd / Ve

+

Vrm in

Vam ax

1 + sTb

1 + sTc1 + sTr

1 1

sTe

sKf

1+ sTf

1+ sTa

KaLV

GateVa Ve

Vs

Π

+

- Σ-

Σ

Σ

VOEL

VrHV

Gate

V U EL

Model Compatibility:

CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC1A esac1a ESAC1A vco_ESAC1A exac1* EXAC1* IEEX2A* IEET1A* vco_IEET1A* * These models can be represented by excAC1A by setting specific parameters to zero or large values.

Page 53


Description IEEE (1992/2005) AC2A Model (ref)

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Tb sec. 0.0 TGR lag time constant (>= 0.) Tc sec. 0.0 TGR lead time constant Ka p.u. 400.0 AVR gain (> 0.) Ta sec. 0.01 AVR time constant (> 0.) Vamax p.u. 8.0 Maximum AVR output (> 0.) Vamin p.u. -8.0 Minimum AVR output (< 0.) Kb p.u. 25.0 Exciter field current controller gain (> 0.) Vrmax p.u. 105.0 Maximum exciter control signal (> 0.) Vrmin p.u. -95.0 Minimum exciter control signal (< 0.) Te sec. 0.6 Exciter time constant (> 0.) Vfemax p.u. 4.4 Exciter field current limit parameter (>= 0.) Kh p.u. 1.0 Exciter field current feedback gain (>= 0.) Kf p.u. 0.03 Rate feedback gain (>= 0.) Tf sec. 1.0 Rate feedback time constant (> 0.) Kc p.u. 0.28 Rectifier regulation factor (>= 0.) Kd p.u. 0.35 Exciter internal reactance (>= 0.) Ke p.u. 1.0 Exciter field resistance constant E1 p.u. 4.4 Field voltage value 1 (note d) (> 0.) S(E1) none 0.037 Saturation factor at E1 (note d) (>= 0.) E2 p.u. 3.3 Field voltage value 2. (note d) (> 0.) S(E2) none 0.012 Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling high initial-response alternator-rectifier excitation system with non-controlled

rectifiers and feedback from exciter field current, e.g. Westinghouse HIR Brushless system. b) Ka, Kb, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are

bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate

feedback, set Kf = 0.

Page 54

d) Saturation parameters are consistent with the IEEE saturation factor definition using the open


. e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this

limit will not be enforced. The real system, the limiter is implemented by a low value gate just before Kb. The input to this LV gate is Kl * (Vlr – Vfe). If the values of Kl and Vlr are known, Vfemax can be calculated as Vlr*Kl*Kb / (1 + Kl*Kb).

Block Diagram:

Kd

F( In )

F e x

Efd

Ke +Se (Ve) Vfe

I fd

+

+

+

-

0Vf

Vre f

In

Vrm ax

Vam in

Kc I fd / Ve

+

Vrm in

Va m a x

1 + sTb

1 + sTc1 + sTr

1 1

sTe

sKf

1+ sTf

1+ sTa Ka

LVG at e

Vc Va Ve

Vs

Π

+

- Σ-

Σ

Σ

Vfem a x - Kd I fdKe + Se (Ve )

VOEL

VrHVGate

Σ

Kh

Kb-

+

Vh

VU EL]


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC2A esac2a ESAC2A vco_ESAC2A exac2* EXAC2* vco_EXAC2 * exac2a/EXAC2A are based on the 1981 IEEE standard. They can be converted to excAC2A by computing Vfemax parameter from Vlr, Kl as described in note e above.

Page 55



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Tb sec. 0.0 TGR lag time constant (>= 0.) Tc sec. 0.0 TGR lead time constant Ka p.u. 45.62 AVR gain (> 0.) Ta sec. 0.013 AVR time constant (> 0.) Vamax p.u. 1.0 Maximum AVR output (> 0.) Vamin p.u. -0.95 Minimum AVR output (< 0.) Te p.u. 1.17 Exciter time constant (> 0.) Vemin p.u. 0.84 Minimum field voltage limit (<= 0.) Kr p.u. 3.77 Field self-excitation feedback gain (> 0.) Kf sec. 0.143 Low level rate feedback gain (>= 0.) Tf p.u. 1.0 Rate feedback time constant (> 0.) Kn p.u. 0.05 High level rate feedback gain (>= 0.) Efdn p.u. 2.36 Rate feedback gain break level (> 0.) Kc sec. 0.104 Rectifier regulation factor (>= 0.) Kd p.u. 0.499 Exciter internal reactance (>= 0.) Ke p.u. 1.0 Exciter field resistance constant Vfemax p.u. 16 Exciter field current limit parameter (>= 0.) E1 p.u. 6.24 Field voltage value 1 (note d) (> 0.) S(E1) none 1.143 Saturation factor at E1 (note d) (>= 0.) E2 p.u. 4.68 Field voltage value 2. (note d) (> 0.) S(E2) none 0.1 Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling field-controlled alternator-rectifier excitation system with non-controlled, e.g.

GE Alterrex systems with static voltage regulators. b) Ka, Kr, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate

feedback, set Kf = Kn = 0.

Page 56

d) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower.

e) The upper limit on Ve is an approximate represention of the effect of the maximum field

current limiter. If Vfemax is zero, this limit will not be enforced. The lower limit (Vemin) on Ve is an approximate representation of the minimum field voltage limiter. If these limiters are specified in terms of their basic parameters (Kl1, Kfa, Vlv), the exac3a model should be used.

Block Diagram:

Kd

F( In )

F ex

Efd

Ke+Se (Ve)

Vfe

I fd

Vc+

+

+

-

VfVs

In

Va m in

Kc I fd / Ve

+

Vam ax

1 + sTb

1 + sTc

1 + sTr1 1

sTe

s

1+ sTf

1+ sTa

Ka

Va

Ve

Vre f

Π+

- Σ Σ

Σ

Vfem ax - Kd I fdKe + Se (Ve)

VrHVG ate Σ

-+

VU EL

X

Kr

Vem in

VnKn

Kf

E fdn

V n

E f d


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC3A esac3a ESAC3A vco_ESAC3A exac3* EXAC3* exac3a* vco_EXAC3A * exac3/EXAC3 are based on the 1981 IEEE standard and represent the exciter limit differently. Exac3a represents the exciter limit differently from either exac3 or esac3a. They may be convertible to excAC3A by computing Vfemax parameter from other model parameters.

Page 57



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Vimax p.u. 10.0 Maximum error signal ( > 0.) Vimin p.u. -10.0 Minimum error signal (< 0.) Tc sec. 1.0 Lead time constant Tb sec. 10.0 Lag time constant (>= 0.) Ka p.u. 100.0 Gain (> 0.) Ta sec. 0.02 Time constant (> 0.) Vrmax p.u. 5.64 Maximum controller output (> 0.) Vrmin p.u. -4.53 Minimum controller output (< 0.) Kc p.u. 0.0 Excitation system regulation (>= 0.) Notes: a) This model can be used to represent controlled rectifier systems in which the excitation power

is provided by a voltage-controlled source such as a shaft driven alternator with its own voltage regulator. The voltage droop of the a.c. excitation power source, if any, and the regulation of the rectifier are approximated by the parameter, Kc. Do not use this model to represent "bus-fed" excitation systems.

b) Ka and Ta must be non-zero. If Tr or Tb is zero, the respective block is bypassed.

Block Diagram:

Efd

S0

+

+

Vre f

1 + sT r1

-

Vim a x

Vim in

1 + sT a

Ka

1 + sT b

1 + sT c

Vrm a x - Kc I fd

Vrm in - Kc I fd

ΣVc

Vs

HVga te

Vue l


Page 58

CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC4A esac4a ESAC4A vco_ESAC4A exac4 EXAC4

Page 59



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Ka p.u. 400.0 Gain (> 0.) Ta sec. 0.02 Time constant (> 0.) Vrmax sec. 7.3 Maximum controller output (> 0.) Vrmin sec. -7.3 Minimum controller output (< 0.) Ke p.u. 1.0 Exciter field resistance line slope Te sec. 0.8 Exciter time constant, sec. (> 0.) Kf p.u. 0.03 Rate feedback gain (>= 0.) Tf1 sec. 1.0 Rate feedback lag time constant (> 0.) Tf2 sec. 0.8 Rate feedback lag time constant (>= 0.) Tf3 sec. 0.0 Rate feedback lead time constant E1 p.u. 5.6 Field voltage value 1 (note c) (> 0.) Se(E1) none 0.86 Saturation factor at E1 (note c) (>= 0.) E2 p.u. 4.2 Field voltage value 2. (note c) (> 0.) Se(E2) none 0.5 Saturation factor at E2 (note c) (>= 0.) Notes: a) Simplified model of a brushless, rotating rectifier excitation system.

b) Ka, Ta, Te, Tf1 must be greater than zero. Tr, Tf1, Tf2 may be zero. If Tr is zero, the block

is bypassed.

c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower .

Block Diagram:

Page 60

ΣΣ Efd

Se(Ve) + Ke

Vrmin

Vrmax

Vc

sTr11

+ sTa1Ka

+

)2sTf1()1sTf1()3sTf1(sKf

+++

sTe11

+

Vref Vs

++ +

−

−

−

Vr


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC5A esac5a ESAC5A vco_ESAC5A IEEET2 exdc2* IEEEX2*

* exdc2 and IEEEX2 have an extra (1+sTc) / (1+sTb) block before the Ka / (1+sTa) block. They can be converted to excAC5A if Tb = Tc or Tb = 0.

Page 61



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.02 Filter time constant Ka p.u. 536 Gain (> 0.) Ta sec. 0.086 Time constant (>= 0.) Tk sec. 0.18 Lag time constant (>= 0.) Tb sec. 9.0 Time constant (>= 0.) Tc sec. 3.0 Lead time constant Vamax p.u. 75.0 Maximum controller element output (> 0.) Vamin p.u. -75.0 Minimum controller element output (< 0.) Vrmax p.u. 44.0 Maximum exciter control signal (> 0.) Vrmin p.u. -36.0 Minimum exciter control signal (< 0.) Te sec. 1.0 Exciter time constant (> 0.) Kh p.u. 92.0 Exciter field current limiter gain (>= 0.) Tj sec. 0.02 Field current limiter time constant (>= 0.) Th sec. 0.08 Field current limiter time constant (> 0.) Vfelim p.u. 19.0 Exciter field current limit reference (> 0.) Vhmax p.u. 75.0 Maximum field current limiter signal (> 0.) Kc p.u. 0.173 Rectifier regulation factor (>= 0.) Kd p.u. 1.91 Exciter internal reactance (>= 0.) Ke p.u. 1.6 Exciter field resistance constant (note c) E1 p.u. 5.55 Field voltage value 1 (note c) (> 0.) S(E1) none 0.044 Saturation factor at E1 (note c) (>= 0.) E2 p.u. 7.4 Field voltage value 2. (note c) (> 0.) S(E2) none 0.214 Saturation factor at E2 (note c) (>= 0.) Notes: a) Ka, Te, Th must be non-zero. If Tr, Ta, Tb or Tc is zero, the respective block is bypassed. b) To disable the forward path gain reduction, set Tb = Tc = 0. This will also disable the non-

windup limits Vamax and Vamin. c) If Ke = 0., it is set during initialization to make Vr = 0.

Page 62

d) Saturation parameters is given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower.

Block Diagram:

Kd

F(In)

Fex

Efd

Ifd

+ +

In

Ve

+

Se

Ke

1sTe

0

+

+

Vc +

+−

Vs Vt Vrmax

Va m i n Vt Vrmin

Vam a x

Vref

1 + sTa

Ka (1 + sTk)

1 + sTb

1 + sTc Va

+Vr

Vhmax

1 + sTh

1 + sTj VhKh

+

Vfelim0

Kc Ifd / Ve

1

1 + sTrΠ

Vfe

Vil

Σ

Σ Σ Σ

Σ Σ

− −

−

Vuel

+


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC6A esac6a ESAC6A vco_ESAC6A exac6a

Page 63

excAC7B - IEEE AC7B Model Model Name excAC7B

Description IEEE (2005) AC7B Model (ref)

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Kpr p.u. 3.89 Regulator proportional gain (> 0. if Kir = 0.) Kir p.u. 3.89 Regulator integral gain (>= 0.) Kdr p.u. 0.0 Regulator derivative gain (>= 0.) Tdr sec. 0.0 Derivative gain washout time constant (>= 0.) Vrmax p.u. 6.74 Maximum regulator output (> 0.) Vrmin p.u. -6.74 Minimum regulator output (< 0.) Kpa p.u. 117.7 Amplifier proportional gain (> 0. if Kia = 0.) Kia p.u. 26.8 Amplifier integral gain (>= 0.) Vamax p.u. 1.0 Maximum amplifier output (> 0.) Vamin p.u. -0.95 Minimum amplifier output (< 0.) Kp p.u. 12.08 Exciter field voltage source gain (> 0.) Kl p.u. 10.0 Exciter field voltage lower limit parameter Te sec. 3.0 Exciter time constant, sec. (> 0.) Vfemax p.u. 15.2 Exciter field current limit parameter (note e) Vemin p.u. 0.0 Minimum exciter ouput voltage (<= 0.) Ke p.u. 1.0 Exciter field resistance constant Kc p.u. 0.13 Rectifier regulation factor (>= 0.) Kd p.u. 1.14 Exciter internal reactance (>= 0.) Kf1 p.u. 0.194 Field voltage feedback gain (>= 0.) Kf2 p.u. 0.0 Exciter field current feedback gain (>= 0.) Kf3 p.u. 0.0 Rate feedback gain (>= 0.) Tf sec. 1.0 Rate feedback time constant (> 0.) E1 p.u. 6.67 Field voltage value 1 (note d) (> 0.) S(E1) none 1.951 Saturation factor at E1 (note d) (>= 0.) E2 p.u. 5.0 Field voltage value 2. (note d) (> 0.) S(E2) none 0.156 Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling alternator-rectifier excitation system with either stationary or rotating rectifiers

with PID voltage regulator.

Page 64

b) Te and Tf must be non-zero. If Tr or Tdr are zero, the respective blocks are bypassed. Kpa and Kpi must not be zero if their corresponding integral gains are zero.

c) To disable the rate feedback, set Kf3 = 0. d) Saturation parameters are consistent with the IEEE saturation factor definition using the open


e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this

limit will not be enforced. f) In the IEEE Std 421.5 – 2005 document, the 1. / sTe block in the block diagram below is

shown as 1. / (1 + sTE), which is incorrect

Block Diagram:

Kd

F( In )

F e xEfd

Ke+Se(Ve )

Vfe

I fd

+

+

+

-

Vf

Vre f

In

Va m in

Kc I fd / Ve

+

-Kl Vfe

Va m a x

1 + sTr

1 1

sTe

s Kf 3

1+ sTf

Vc Va Ve+

- Σ-

Σ

Σ

Vfem a x - Kd I fdKe + Se (Ve )

VrΣ

-

Vem in

Π

Kp Vt

Σ

Vu e l

+

Kpa + Kias

+

+Kf 2

Kf 1

Π

Vs

+

Vrm a x

Vrm in

1+ sTdr

s KdrKpr +

Kirs

+


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC7B esac7b ESAC7B

Page 65

excAC8B - IEEE AC8B Model Model Name excAC8B

Description IEEE (2005) AC8B Model (ref)

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Voltage transducer time constant (>= 0.) Kpr p.u. 80.0 Voltage Regulator Proportional Gain (> 0. if

Kir = 0.) Kir p.u. 5.0 Voltage Regulator Integral Gain (>= 0.) Kdr p.u. 10.0 Voltage Regulator Derivative Gain (>= 0.) Tdr sec. 0.1 Voltage Regulator Derivative Time Constant

(> 0. if Kdr > 0.) Vrmax p.u. 35.0 Maximum controller output (> 0.) Vrmin p.u. 0.0 Minimum controller output (<= 0.) Ka p.u. 1. Amplifier gain (> 0.) Ta sec. 0.0 Amplifier time constant (>= 0.) Te sec. 1.2 Exciter field time constant (> 0.) Vfemax p.u. 6.0 Exciter field current limit parameter (note d) Vemin p.u. 0.0 Minimum exciter ouput voltage (<= 0.) Ke p.u. 1.0 Exciter field proportional constant Kc p.u. 0.55 Rectifier regulation factor (>= 0.) Kd p.u. 1.1 Exciter regulation factor (>= 0.) E1 p.u. 6.5 Field voltage value 1 (note c) (> 0.) S(E1) none 0.3 Saturation factor at E1 (note c) (>= 0.) E2 p.u. 9.0 Field voltage value 2. (note c) (> 0.) S(E2) none 3.0 Saturation factor at E2 (note c) (>= 0.) vtmult none 0. if not 0, multiply Vrmax and Vrmin by

terminal voltage (note e) Notes: a) This model represents a PID voltage regulator with either a brushless exciter or dc exciter. For

a dc exciter, Kc and Kd are set to zero. b) Te must be non-zero. If Tr is zero, the block is bypassed. If Ta is zero, the block is reduced to

multiplication by Ka. If Tdr is zero, the output of the derivative block is set to zero. Kpr must not be zero if Kir is zero.

Page 66

c) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower.

d) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this

limit will not be enforced. e) If vtmult is non-zero, the limits Vrmax and Vrmin are multiplied by the generator’s terminal

voltage to represent a thyristor power stage fed from the generator terminals. This parameter is not in the IEEE standard model.

Block Diagram:

Kd

F ( In )

F ex

Ke + Se

+

+

--

V emi n

+

+

Vrm in

++

+

I fe

In

sTdr1sKdr+

sTr11

+

VeIfdKc

sTe1

+sKir

Kp r

sTa1Ka

+

Vrm ax

Σ Σ Σ

Σ

Vc

Vre f

Vs

VrEfd

I fd

VeΠ

Vfem ax - Kd I fdKe + Se (Ve )


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excAC8B esac8b ESAC8B* vco_ESAC8B

* As of rev. 30, ESAC8B in PSS/E did not have the parameters Kc, Kd, Vfemax, Vemin of the IEEE model. Therefore, it can represent a dc exciter but not an ac/rectifier exciter.

Page 67

excDC1A - IEEE DC1A Model Model Name excDC1A

Description IEEE (1992/2005) DC1A Model (ref)

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Ka p.u. 40.0 Gain (> 0.) Ta sec. 0.1 Time constant (> 0.) Tb sec. 0.0 Lag time constant (>= 0.) Tc sec. 0.0 Lead time constant Vrmax p.u. 1.0 Maximum controller output (note d) Vrmin p.u. -1.0 Minimum controller output (< 0.) Ke p.u. 0.1 Exciter field resistance line slope (note c) Te sec. 0.5 Exciter time constant (> 0.) Kf p.u. 0.05 Rate feedback gain (>= 0.) Tf sec. 0.7 Rate feedback time constant, sec. (> 0.) E1 p.u. 2.8 Field voltage value 1 (note e) (> 0.) S(E1) none 0.08 Saturation factor at E1 (note e) (>= 0.) E2 p.u. 3.7 Field voltage value 2. (note e) (> 0.) S(E2) none 0.33 Saturation factor at E2 (note e) (>= 0.) uelin none 0 UEL input: if < 2, HV gate; if = 2, add to error

signal exclim none 0 If not 0, apply lower limit of 0. to exciter

output (note f) Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr, Tb or Tf are zero, the respective blocks are

bypassed. b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate

feedback, set Kf = 0. c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial

condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as non-zero, its value is used directly, without change.

Page 68

d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the control signal, Vr, has the value Vrmax when the exciter output is equal to E2.

e) Saturation parameters is given by the IEEE saturation factor definition using the open circuit

magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower value if the input value of Vrmax > 0; else E2 must > E1.

f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a

lower limit of zero is applied to integrator output.

Block Diagram:

Efd

Se + Ke

+Vrm in

+

Vrm ax

Vr

sTb1sTc1

++

sTaKa

+1 sTe1

sTf1sKf+

Vs

−ΣHV

Gate

Vref

sTr11

+

+

Σ

−

−

VU EL

+uel i n < 2uel i n = 2

Vc

Vf (no te f )


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excDC1A esdc1a ESDC1A vco_ESDC1A exdc1* IEEEX1* vco_IEEEX1 ieeet1* IEEET1* vco_IEEET1

* These models are based on early versions of the IEEE standard and can be converted to the excDC1A model without loss of data.

Page 69



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Ka p.u. 300.0 Gain (> 0.) Ta sec. 0.01 Time constant (> 0.) Tb sec. 0.0 Lag time constant (>= 0.) Tc sec. 0.0 Lead time constant Vrmax p.u. 4.95 Maximum controller output (note d) Vrmin p.u. -4.9 Minimum controller output (< 0.) Ke p.u. 1.0 Exciter field resistance line slope (note c) Te sec. 1.33 Exciter time constant (> 0.) Kf p.u. 0.1 Rate feedback gain (>= 0.) Tf sec. 0.675 Rate feedback time constant, sec. (> 0.) E1 p.u. 3.05 Field voltage value 1 (note e) (> 0.) S(E1) none 0.279 Saturation factor at E1 (note e) (>= 0.) E2 p.u. 2.29 Field voltage value 2. (note e) (> 0.) S(E2) none 0.117 Saturation factor at E2 (note e) (>= 0.) uelin none 0 UEL input: if < 2, HV gate; if = 2, add to error

signal exclim none 0 If not 0, apply lower limit of 0. to exciter

output (note f) Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr or Tb is zero, the respective block is

bypassed. If Tf is zero, the rate feedback block is not used. b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate

feedback, set Kf = 0 or Tf = 0. c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial


Page 70

d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the control signal, Vr, has the value Vrmax when the exciter output is equal to E2.

e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit


f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a

lower limit of zero will be applied to integrator output.

Block Diagram:

Efd

Se + Ke

+Vt * Vrm in

+

Vt * Vrm ax

Vr

sTb1sTc1

++

sTaKa

+1 sTe1

sTf1sKf+

Vs

−ΣHV

Gate

Vref

sTr11

+

+

Σ

−

−

VU EL

+uel i n < 2uel i n = 2

Vc

Vf (no te f )


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excDC2A esdc2a EXDC2A exdc2a* EXDC2*

* These models are based on early versions of the IEEE standard and can be converted to the excDC2A model without loss of data.

Page 71



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Trh sec. 20.0 Rheostat full range travel time (> 0.) Kv p.u. 0.05 Voltage error threshold min/max control action

(> 0.) Vrmax p.u. 5.0 Maximum control element output (> 0.) Vrmin p.u. 0.0 Minimum control element output (<= 0.) Te sec. 1.83 Exciter field time constant (> 0.) Ke p.u. 1.0 Exciter field resistance line slope (note b) E1 p.u. 2.6 Field voltage value 1 (note c) (> 0.) S(E1) none 0.1 Saturation factor at E1 (note c) (>= 0.) E2 p.u. 3.45 Field voltage value 2. (note c) (> 0.) S(E2) none 0.35 Saturation factor at E2 (note c) (>= 0.) exclim none 0 If not 0, apply lower limit of 0. to exciter

output (note d) Notes: a) Kv, Trh and Te must be greater than zero. b) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial


c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit

magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower.

d) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a

lower limit of zero will be applied to integrator output.

Block Diagram:

Page 72

Efd

Vre f

−

+

Vrmax

Vr

Vrh

Verr

STeKe1

+VrhVrelseminrVrV,vKerrVIf

maxrVrV,vKerrVIf

=

=−≤

=≥

Vx = Efd Se(Efd) Vx

Kv

−Kv

Vrmax−Vrmin

s Kv Trh

Vrmin

+

ΣsTr11

+ −Vc

(note d)

Σ


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excDC3A esdc3a IEEEX4 exdc4*

* exdc4 with it’s parameter Kr = 0 is the same as excDC3A

Page 73

excDC4B - IEEE DC4B Model Model Name excDC4B

Description IEEE (2005) DC4B Model

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Ka p.u. 1.0 Gain (> 0.) Ta sec. 0.2 Time constant (> 0.) Kp p.u. 80 Proportional gain (>= 0.) Ki p.u. 20 Integral gain (>= 0.) Kd p.u. 20 Derivative gain (>= 0.) Td sec. 0.01 Derivative time constant (> 0. If Kd > 0.) Vrmax p.u. 6.0 Maximum controller output (note d) Vrmin p.u. -2.7 Minimum controller output (<= 0.) Ke p.u. 1.0 Exciter field resistance line slope (note c) Te sec. 0.8 Exciter time constant (> 0.) Kf p.u. 0.0 Rate feedback gain (>= 0.) Tf sec. 0.0 Rate feedback time constant (>= 0.) E1 p.u. 1.75 Field voltage value 1 (note e) (> 0.) S(E1) none 0.08 Saturation factor at E1 (note e) (>= 0.) E2 p.u. 2.33 Field voltage value 2. (note e) (> 0.) S(E2) none 0.27 Saturation factor at E2 (note e) (>= 0.) Vemin p.u. 0. Exciter minimum output (<= 0.) OELin none 0 OEL input: if < 2, LV gate; if = 2, subtract

from error signal UELin none 0 UEL input: if < 2, HV gate; if = 2, add to error

signal Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr is zero, the block is bypassed. If Td or Tf are

zero, the respective blocks are not used. b) To disable the derivative path, set Kd = 0 or set Td = 0.. To disable the rate feedback, set Kf =

0.

Page 74

c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial condition value of Vc is zero. The zero value of Ke is not changed. If Ke is entered as non-zero, its value is used directly, without change.

d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the

control signal, Vc, has the value Vrmax when the exciter output is equal to E2. e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit


Block Diagram:

S4

Efd

Se + Ke

+Vt Vrm in

+

Vt Vrm ax

Vr

sTaKa

+1 sTe1

sTf1sKf+

Vs[vsig]

−ΣHV

Gate

Vref

sTr11

+

+

Σ

−

−

VU EL

+

uel i n < 2uel i n = 2

Vc

Vf (no te g )

LVGate

Π

−Vrm ax / Ka

Vrm in / Ka

1+ sTdr

s KdrKpr +

Kirs

+

VOEL oel i n < 2oel i n = 2

Vt


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excDC4B esdc4b **

** Not in PSS/E as of rev. 30

Page 75

excST1A - IEEE ST1A Model Model Name excST1A

Description IEEE (1992/2005) ST1A Model

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Voltage transducer time constant (>= 0.) Vimax p.u. 999. Maximum error (> 0.) Vimin p.u. -999. Minimum error (< 0.) Tc sec. 1.0 Lead time constant Tb sec. 10.0 Lag time constant (>= 0.) Ka p.u. 190.0 Gain (> 0.) Ta sec. .02 Time constant (>= 0.) Vrmax p.u. 7.8 Excitation voltage upper limit (> 0.) Vrmin p.u. -6.7 Excitation voltage lower limit (< 0.) Kc p.u. 0.05 Excitation system regulation factor (>= 0.) Kf p.u. 0.0 Rate feedback gain (>= 0.) Tf sec. 1.0 Rate feedback time constant (>= 0.) Tc1 sec. 0.0 Lead time constant Tb1 sec. 0.0 Lag time constant (>= 0.) Vamax p.u. 999. Maximum control element output (> 0.) Vamin p.u. -999. Minimum control element output (< 0.) Ilr p.u. 0.0 Maximum field current (note b) Klr p.u. 0.0 Gain on field current limit (note b) UELin none 0 = 2 – UEL input added to error signal

= 1 – UEL input HV gate with error signal = -1 – UEL input HV gate with volt. reg. output = 0 – ignore UEL signal

PSSin none 0 = 0 – PSS input (Vs) added to error signal ≠ 0 – PSS input (Vs) added to voltage regulator output

Notes: a) This model can be used to represent a controlled-rectifier excitation system whose a.c. power

source is a power transformer fed from the generator terminals. The voltage regulation of the excitation transformer and rectifier are approximated by the parameter Kc.

Page 76

b) The field current limiter (Klr, Ilr) is optional. If Klr = 0., the limiter is not used. c) Ka and Ta must not be zero. If Ta, Tr, Tb, or Tb1 are zero, the corresponding block is

bypassed. If Tf is zero, the output of the rate feedback block is zero.

Block Diagram:

I lr

Klr

Vam in

Vam a xVimax

Vimin

sTb1sTc1

++

1sTb11sTc1

++

Vt Vrm ax - Kc I fd

0

sTa1Ka

+sTr11

+

Vt Vrm in

sTfsKf+

Σ Σ

Σ

Vref

Vc Efd

lfd•

•++

+

+

−−

−

−

Va LVGate

HVGate

Voe l

+

VU EL

uel i n = 1uel i n = 2

HVGate

VU EL

uel i n = -1

Vs

+

ps s i n = 00sinps ≠

Vs

Ve

VU EL


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excST1A esst1a ESST1A vco_ESST1A exst1* EXST1* vco_EXST1

* Based on earlier (1981) IEEE standard. Can be converted to excST1A.

Page 77



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Ka p.u. 120.0 Gain (> 0.) Ta sec. 0.15 Time constant (> 0.) Vrmax p.u. 1.0 Maximum controller output (> 0.) Vrmin p.u. -1.0 Minimum controller output (< 0.) Ke p.u. 1.0 Time constant feedback Te sec. 0.5 Transformer saturation control time constant (> 0.) Kf p.u. 0.05 Rate feedback gain (>= 0.) Tf sec. 0.7 Rate feedback time constant (>= 0.) Kp p.u. 4.88 Potential source gain (>= 0.) Ki p.u. 8.0 Current source gain (>= 0.) Kc p.u. 1.82 Rectifier loading factor (>= 0.) Efdmax p.u. 99.0 Maximum field voltage (>=0.) UELin none 0 UEL input: if = 1, HV gate; if = 2, add to error signal Tb sec. 0.0 Time constant (>=0.) (note b) Tc sec. 0.0 Time constant (note b) Notes: a) Ka, Ta, Te must be greater than zero. If Tr or Tb are zero, the respective blocks are bypassed.

If Tf is zero, the rate feedback is disabled. b) The lead/lag block (Tc, Tb), which is not in the IEEE ST2A model, is included to match the

WECC FM exciter model. The block can be bypassed by omitting these parameters or by setting Tb to zero.

Block Diagram:

Page 78

ΠΣ Efd

Vref0

Efdmax

sTr11

+ sTe1

Vt

ItFex(In) Kc Ifd / Ve

Vrmin

Vrmax

sTa1Ka

+

Ve

Ke

sTf1skf+

Vs

Π

Σ

Ifd

tIijKtVpKVe +=

Vc Vr

Vb

In•

•

V U EL

uel i n = 1

HVGate

uel i n = 2

sTb1sTc1

++ +

+

++

−−

−


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excST2A esst2a ESST2A vco_ESST2A exst2* EXST2* exst2a* EXST2A* vco_EXST2A IEEEX3* IEEET3*

* Based on earlier IEEE standards. Can be converted to excST2A.

Page 79



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Voltage transducer time constant (>= 0.) Vimax p.u. 0.2 Maximum error (> 0.) Vimin p.u. -0.2 Minimum error (< 0.) Ka p.u. 200. AVR gain (> 0.) Ta sec. 0.0 AVR time constant (>= 0.) Tb sec. 6.67 AVR lag time constant (>= 0.) Tc sec. 1.0 AVR lead time constant Vrmax p.u. 10.0 Maximum AVR output (> 0.) Vrmin p.u. -10.0 Minimum AVR output (< 0.) Km p.u. 7.04 Inner loop forward gain (> 0.) Tm sec. 1.0 Inner loop time constant (> 0.) Vmmax p.u. 1.0 Maximum inner loop output (> 0.) Vmmin p.u. 0.0 Minimum inner loop output (<= 0.) Kg p.u. 1.0 Inner loop feedback gain (>= 0.) Kp p.u. 4.37 Potential source gain (> 0.) angp deg.. 20.0 Phase angle (θp) of potential source Ki p.u. 4.83 Current source gain (>= 0.) Kc p.u. 1.1 Exciter regulation factor (>= 0.) Xl p.u. 0.09 P-bar reactance (>= 0.) Vbmax p.u. 8.63 Maximum excitation voltage (> 0.) Vgmax p.u. 6.53 Maximum inner loop feedback voltage (>= 0.) Notes: c) Ka, Km and Tm must be greater than zero. If Tr, Ta or Tb is zero, the corresponding block

are bypassed Block Diagram:

Page 80

Vgmax

Ifd

Vs

sTr11

+

Vt


Vmmin

Vmmax

sTm1Km

+

VetI)lXpKiK(jtVpK ++

Vimax

Vimin

sTb1sTc1

++

Vbmax

Kg

pjepKpK

θ=

ΣΣ

Π

Π

Vref

Efd

Vb

In

Vc•

•

Vr Vm

++

+ −

−

Vrmin

Vrmax

sTa1Ka

+HV

Gate

Vuel

Vi


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excST3A esst3a ESST3A vco_ESST3A exst3* exst3a* EXST3A* * Based on earlier IEEE standard. Can be converted to excST3A.

Page 81

excST4B - IEEE ST4B Model Model Name excST4B

Description IEEE (2005) ST4B Model

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Voltage transducer time constant (>= 0.) Kpr p.u. 10.75 AVR proportional gain (note b) Kir p.u. 10.75 AVR Integral gain (note b) Ta sec. 0.02 AVR time constant (>= 0.) Vrmax p.u. 1.0 Maximum AVR output (> 0.) Vrmin p.u. -0.87 Minimum AVR output (< 0.) Kpm p.u. 1.0 Prop. gain of inner loop regulator (note a) Kim p.u. 0.0 Integral gain of inner loop regulator (note a) Vmmax p.u. 99. Maximum inner loop regulator output Vmmin p.u. -99. Minimum inner loop regulator output Kg p.u. 0.0 Inner loop feedback gain (>= 0.) Kp p.u. 9.3 Potential source gain (> 0.) Angp deg.. 0.0 Phase angle (θp) of potential source Ki p.u. 0.0 Current source gain (>= 0.) Kc p.u. 0.113 Exciter regulation factor (>= 0.) Xl p.u. 0.124 P-bar leakage reactance (>= 0.) Vbmax p.u. 11.63 Maximum excitation voltage (> 0.) Vgmax p.u. 999. Maximum inner loop feedback gain (>= 0.) Notes: a) The inner loop field voltage regulator parameters (Kpm, Kim and Kg) are used for modeling of

a compound power source static exciter. Any of these values can be zero, but either Kpm or Kim must be non-zero. To bypass the inner loop field voltage regulator, set Kpm = 1.0, and Kim and Kg to zero.

b) Either of the automatic voltage regulator AVR parameters (Kpr, Kir) may be zero but at least

one must be non-zero. c) Setting Ta or Tr to zero will bypass the corresponding block. If Ta is zero, a one time step

delay is included for this block.

Page 82

Block Diagram: Vgmax

Ifd

Vs

sTr11

+

Vt


Vmmin

Vmmax

VetI)lXpKiK(jtVpK ++

Vbmax

Kg

pjepKpK

θ=

ΣΣ

Π

Π

Vref

Efd

Vb

In

Vc•

•

Vr

Vm

+

+

+ −

−

Vrmin

Vrmax

sTa11

+

[voel]Voel

sKirKpr +

sKimKpm +

LVGate

Vuel

+


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excST4B esst4b ESST4B vco_ESST4B exst4b* *. Can be converted to excST4B.

Page 83



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant (>= 0.) Kr p.u. 200 Regulator gain (> 0.) T1 p.u. 0.004 Firing circuit time constant (>= 0.) Kc p.u. 0.004 Rectifier regulation factor (>= 0.) Vrmax p.u. 5.0 Maximum regulator output (> 0.) Vrmin p.u. -4.0 Minimum regulator output (< 0.) Tc1 sec. 0.8 Regulator lead time constant Tb1 sec. 6.0 Regulator lag time constant (>= 0.) Tc2 sec. 0.08 Regulator lead time constant. Tb2 sec. 0.01 Regulator lag time constant (>= 0.) Toc1 sec. 0.1 OEL lead time constant Tob1 sec. 2.0 OEL lag time constant (>= 0.) Toc2 sec. 0.08 OEL lead time constant Tob2 sec. 0.08 OEL lag time constant (>= 0.) Tuc1 sec. 2.0 UEL lead time constant. Tub1 sec. 10.0 UEL lag time constant (>= 0.) Tuc2 sec. 0.1 UEL lead time constant Tub2 sec. 0.05 UEL lag time constant (>= 0.) Notes: a) For modeling static systems such as ABB UNITROL D, P, F, or 5000 or Brush DCP. Similar

to IEEE Type ST1A but with alternative OEL and UEL inputs and transfer functions. b) Kr must not be zero. Any of the time constants may be zero. If any denominator time constant

is zero, the respective block is bypassed. c) If T1 is less than 4 times the integration time step, it’s block is replaced by a one time step

delay. Block Diagram:

Page 84

1sT11

+

Kc

Efd

S0

Vc +

Vref

Vrmin

+

Vrmax

Kr+

Vt Vrmax

sTr11

+

Vt VrminVs

•− Σ

Ifd

Vrmax/Kr

Vrmin/Kr

Vrmax/Kr

Vrmin/Kr

ΣΣ •HV

GateVuel

LVGate

Voel

Vrmax/Kr

Vrmin/Kr

+−

0+1

−1

jlim

if (Voel < Verr, jlim = +1if (Vuel > Verr, jlim = -1else jlim = 0

Verr

Vrmin/Kr

Vrmax/Kr

Vrmin/Kr

Vrmax/Kr

Vrmax/Kr

Vrmin/Kr

Vr

1+sTuc11+sTub1

1+sTob11+sToc1

1+sTc21+sTb21+sTb1

1+sTc1

1+sTub21+sTuc2

1+sToc21+sTob2


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model excST5B esst5b ** **. As of rev. 30, not in PSS/E.

Page 85



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.012 Filter time constant (>= 0.) Kpa p.u. 18. Regulator proportional gain (> 0.) Kia p.u. 45. Regulator integral gain (> 0.) Vamax p.u. 4.81 PI maximum output. (> 0.) Vamin p.u. -3.85 PI minimum output (< 0.) Kff p.u. 1.0 Feedforward gain (note b) Km p.u. 1.0 Main gain (note b) Kg p.u. 1.0 Feedback gain (>= 0.) Tg sec. 0.02 Feedback time constant (>= 0.) Vrmax p.u. 4.81 Maximum regulator output (> 0.) Vrmin p.u. -3.85 Minimum regulator output (< 0.) Vmult none 1.0 If non-zero, multiply regulator output by terminal voltage OELin none 0.0 OEL input selector: 1 – before UEL, 2 – after UEL, 0 – no

OEL input Ilr p.u. 4.164 Field current limiter setpoint (> 0.) Kcl p.u. 1.0577 Field current limiter conversion factor (> 0.) Klr p.u. 17.33 Field current limiter gain (> 0.) Ts sec. 0.0 Rectifier firing time constant (not in IEEE model) (>= 0.) Notes: a) For modeling static systems such as Siemens THYRIPOL or ECS2100. b) Kpa and Kia must not be zero. (Kff + Km) must not be zero. Any of the time constants may

be zero. If any time constant is zero, the respective block is bypassed. c) If Ts is less than 4 times the integration time step, its block is replaced by a one time step

delay. Block Diagram:

Page 86

EfdVc +

Vrmin

+

+

Vs

−

Σ •

sTgKg

+1

Vrmax+

sKiaKpa +Σ

+

−

Vamax

Vamin

KmΣ Σ+

−

Kff

LVGate

vmult1

01

Vt

Ilr

Klr

Ifd+

Kcl

Vrmin

−

VrVa•HV

GatesTr11

+

Vref

−

Vuel

VOELOELin=1 OELin=2

Vb

Π

Σ

sTs11

+



Page 87



Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Tr sec. 0.0 Filter time constant Kpa p.u. 40. Regulator proportional gain (> 0.) Kia p.u. 1. Feedback gain (>= 0.) Tia sec. 3.0 Feedback time constant (>= 0.) Tb sec. 1.0 Lead-lag denominator time constant (>= 0.) Tc sec. 1.0 Lead-lag numerator time constant (>= 0.) Tf sec. 1.0 Input lead-lag denominator time constant (>= 0.) Tg sec. 1.0 Input lead-lag numerator time constant (>= 0.) Kl p.u. 1.0 Low-value gate feedback gain (>= 0.) Kh p.u. 1.0 High-value gate feedback gain (>= 0.) Vrmax p.u. 5.0 Maximum field voltage output (> 0.) Vrmin p.u. -4.5 Minimum field voltage output (< 0.) Vmax p.u. 1.1 Maximum voltage reference signal (> 0.) Vmin p.u. 0.9 Minimum voltage reference signal (> 0.) UELin none 0.0 UEL input selector: 1 – add to Vref, 2 – input HV gate,

3 – output HV gate, 0 – no UEL input OELin none 0.0 OEL input selector: 1 – add to Vref, 2 – input LV gate,

2 – output LV gate, 0 – no OEL input Ts sec. 0.0 Rectifier firing time constant (>= 0.) (not in IEEE model) Notes: a) For modeling static systems such as Alstom Eurorec, Microrec K4.1 and ALSPA P320. b) Kpa must not be zero. Any of the time constants may be zero. If any time constant is zero, the

respective block is bypassed. c) If Ts is zero, its block is replaced by a one time step delay. Block Diagram:

Page 88

Kpa

EfdVc

+sTb1sTc1

++

sTs11

+sTr11

+

Vt * Vrm in

sTf1sTg1

++

+

VrefVs

−Σ

sTia1Kia

+

Vt * Vrm ax

+HV

GateLV

GateLV

GateHV

Gate

Kl

Σ

Σ Vt* Vrm ax+−

Σ

Kh

Vt * Vrm in−

+

Σ+

Vm in

Vm ax

HVGate

LVGateΣ

Voel

Vuel

+ ++

+

VuelVoel21 2

1 2

3

Vr•

•



Page 89

Other Excitation System Models To Be Added CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model exac1a EXAC1A vco_EXAC1A exdc4 IEEET4

IEEEX4 vco_IEEET4 vco_IEEEX4

IEET5A vco_IEET5A exbbc BBSEX1 vco_BBSEX1 exeli EXELI vco_EXELI exeli2 CELIN vco_CELIN expic1 EXPIC1 vco_EXPIC1 rexs REXSYS vco_REXSYS scrx SCRX vco_SCRX sexs SEXS vco_SEXS

Page 90

Power System Stabilizer (PSS) Models The PSS model provides an input (Vs) to the excitation system model to improve damping of system oscillations. A variety of input signals may be used depending on the particular design.

Model Interconnections Standard interconnection of PSS models with other models are shown in Figure D-1 and listed in Table D-1.

VsPower System Stabilizer (PSS)

Excitation System

speed

Networkfrequency

GeneratorPelec

Eterm

Pmech

Figure D-1 PSS Model Standard Interconnections

Table D-1 PSS Model Standard Interconnections Inputs:

Name Units Description Source speed p.u. Generator speed Generator frequency p.u. Terminal voltage frequency (note b) Network Pelec p.u. Generator electrical power Generator Pmech p.u. Generator mechanical power Generator Eterm p.u. Generator terminal voltage Generator Outputs:

Name Units Description Vs p.u. PSS signal to excitation system Initialization Inputs:

Name Units Description Source speed p.u. Generator speed Generator frequency p.u. Terminal voltage frequency Network Pelec p.u. Generator electrical power Generator Pmech p.u. Generator mechanical power Generator Eterm p.u. Generator terminal voltage Generator

Page 91

Vs p.u. PSS signal to excitation system (note a) Exc. System Notes: a) Vs is always initialized to zero by the excitation system model. b) If bus voltage frequency is not available from network, the model can calculate it as derivative

of the bus voltage angle.

Page 92

pssIEEE2B - IEEE PSS2B Power System Stabilizer Model Model Name pssIEEE2B

Description IEEE (2005) PSS2B Model

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case J1 none Input signal #1 code K1 none Input signal #1 remote bus number J2 none Input signal #2 code K2 none Input signal #2 remote bus number Vsi1max p.u. Stabilizer output max limit Vsi1min p.u. Stabilizer output min limit Tw1 sec. First washout on signal #1 Tw2 sec. Second washout on signal #1. Vsi2max p.u. Stabilizer output max limit Vsi2min p.u. Stabilizer output min limit. Tw3 sec. First washout on signal #2. Tw4 sec. Second washout on signal #2. T1 sec. Lead/lag time constant T2 sec. Lead/lag time constant T3 sec. Lead/lag time constant T4 sec. Lead/lag time constant T6 sec. Time constant on signal #1 T7 sec. Time constant on signal #2. T8 sec. Lead of ramp tracking filter T9 sec. Lag of ramp tracking filter T10 sec. Lead/lag time constant T11 sec. Lead/lag time constant. Ks1 p.u. Stabilizer gain Ks2 p.u. Gain on signal #2 Ks3 p.u. Gain on signal #2 input before ramp-tracking filter n none Order of ramp tracking filter m none Denominator order of ramp tracking filter Vstmax p.u. Stabilizer output max limit Vstmin p.u. Stabilizer output min limit a none Numerator constant Ta sec. Lead constant Tb sec. Lag time constant Notes:

Page 93

a) TW1 and TW3 must be greater than zero.

b) Setting TW2 or TW4 to zero will bypass the corresponding washout function.

c) T1, T2, T3, T4, T6, T7, T8, and T9 may be zero.

d) Set T9 = 0 or n = 0 to get a null effect from the ramp tracking filter.

e) The product of n*m cannot be greater than 10.

f) The input signal code, J, and the remote bus number, K, specify the input signal used by the

stabilizer. If K is zero, the signal is taken from the shaft or terminals of the generator on which the stabilizer is located. If K is non-zero, the signal is taken from bus number K ( for J = 1, 2, 3, 4, or 5 ).

g) The values of the input signal code, J, are as follows:

1 shaft speed 2 frequency of bus voltage 3 generator electrical power 4 generator accelerating power 5 amplitude of bus voltage 6 derivative of bus voltage amplitude

. Block Diagram:

Ks1

Ks3 Ks4Vstmax

Vstmin

Vs

Vsi2min

Vsi1max

Vsi1min

Input 1

Input 2

Σ Σ 1+sT2

a+sTa1+sTb

sTw2

1+sTw2

1+sT7

11+sT6

1+sT11

1+sT10

1+sT4

1+sT3

1+sT1

1

sTw1

1+sTw1

sTw31+sTw3

sTw41+sTw4

Vsi2max

( )

n

m9

8sT1sT1

+

+


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model pssIEEE2B pss2b pss2a PSS2A pss_PSS2A

Page 94

Other PSS Models To Be Added CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model pss1a PSS1A pss_PSS1A pss3b PSS3B pss4b PSS4B wsccst ST2CUT pss_ST2CUT psssb psssh expic1 EXPIC1 PTIST1 vco_PTIST1 PTIST3 vco_PTIST3 ieeest IEEEST vco_IEEEST

Page 95

Turbine-Governor Models The turbine-governor model determines the mechanical power (Pm) to the generator model.

Model Interconnections Standard interconnection of turbine-governor models with other models are shown in following figure and table:

Pmech

speed

Pref

Turbine-Governor

GeneratorAGC

Generator#2

Pmech2

Turbine-Goveror Model Standard Interconnections

Turbine-Governor Model Standard Interconnections Inputs:

Name Units Description Source speed p.u. Generator speed Generator Pref p.u. Load reference See note a Outputs:

Name Units Description Pmech p.u. Generator mechanical power Initialization Inputs:

Name Units Description Source speed p.u. Generator speed (= 1.) Generator Pmech p.u. Generator mechanical power Generator Initialization Outputs:

Name Units Description Source Pref p.u. Load reference See note a Notes:

Page 96

a) Pref is usually held constant for stability analysis, but may be deteremined by a user-written model or, for long-term dynamics, an area-wide automatic generation control (AGC) model.

Page 97

govHydro1 – Hydro Turbine-Governor Model Model Name govHydro1

Description Basic hydro turbine-governor model

Parameters:

Parameter Typical Name Units Value Description Bus number Generator terminal bus number Unit ID Generator ID MWbase MW Base for power values (> 0.) Rperm p.u. 0.04 Permanent droop (R) (> 0.) rtemp p.u. 0.3 Temporary droop (r) (> R) Tr sec. 5.0 Washout time constant (> 0.) Tf sec. 0.05 Filter time constant (> 0.) Tg p.u. 0.5 Gate servo time constant. (> 0.) Velm p.u./sec. 0.2 Maximum gate velocity. (> 0.) Gmax p.u. 1.0 Maximum gate opening (> 0.) Gmin p.u. 0.0 Minimum gate opening (>= 0.) Tw sec. 1.0 Water inertia time constant (> 0.) At p.u. 1.2 Turbine gain. (> 0.) Dturb p.u. 0.5 Turbine damping factor (>= 0.) qnl p.u. 0.08 No-load flow at nominal head (>= 0.) Notes:

a) Per unit parameters are on base of MWbase, which is normally the MW capability of the turbine.

b) The gates travel over a range of 1.0 per unit from fully closed to fully opened. The gate position is normally greater than zero at zero power and normally less than 1.0 when power is 1.0 p.u. Gmax and Gmin are operating limits.

c) Tr, Tf, Tg, Tw must be greater than zero.

d) Dturb has the dimensions ∆P(pu of mwcap) /∆speed(pu). Block Diagram:

Page 98

Pref

rsTrsTr1 +

Σ

sTf11

+

Dturb

sTg11

+

Atn/d ΣTws1

Pm

hdam qnl

Gmin

Gmax

R

rate limit = Velmω∆

gv(gate

position)

qH•

•

•gv

ω

•

•

•

1.

ω∆

n

d

(speed)Σ Σ

Π

Π

Π Σ


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model govHydro1 hygov HYGOV

Page 99

govSteam1 – IEEE Steam Turbine-Governor Model Model Name govSteam1

Description IEEE steam turbine/governor model (with optional deadband and nonlinear valve gain added)

Parameters:

Parameter Typical Name Units Value Description Bus number 1 Terminal bus number of first generator Unit ID 1 Generator ID of first generator Bus number 2 Terminal bus number of second generator Unit ID 2 Generator ID of second generator MWbase MW Base for power values (> 0.) K p.u. 25.0 Governor gain (reciprocal of droop) (> 0.) T1 Sec. 0.0 Governor lag time constant T2 sec. 0.0 Governor lead time constant T3 sec. 0.1 Valve positioner time constant (> 0.) Uo p.u./sec. 1.0 Maximum valve opening velocity (> 0.) Uc p.u./sec. -10.0 Maximum valve closing velocity, p.u./sec (< 0.) Pmax p.u. 1.0 Maximum valve opening (> Pmin) Pmin p.u. 0.0 Minimum valve opening (>= 0.) T4 sec. 0.3 Inlet piping/steam bowl time constant K1 0.2 Fraction of HP shaft power after first boiler pass K2 0.0 Fraction of LP shaft power after first boiler pass T5 sec. 5.0 Time constant of second boiler pass K3 0.3 Fraction of HP shaft power after second boiler pass K4 0.0 Fraction of LP shaft power after second boiler pass T6 sec. 0.5 Time constant of third boiler pass K5 0.5 Fraction of HP shaft power after third boiler pass K6 0.0 Fraction of LP shaft power after third boiler pass T7 sec. 0.0 Time constant of fourth boiler pas K7 0.0 Fraction of HP shaft power after fourth boiler pass K8 0.0 Fraction of LP shaft power after fourth boiler pass db1 Hz. 0.0 Intentional deadband width eps Hz. 0.0 Intentional db hysteresis db2 MW 0.0 Unintentional deadband GV1 p.u. 0.0 Nonlinear gain valve position point 1 Pgv1 p.u. 0.0 Nonlinear gain power value point 1 GV2 p.u. 0.4 Nonlinear gain valve position point 1 Pgv2 p.u. 0.75 Nonlinear gain power value point 1 GV3 p.u. 0.5 Nonlinear gain valve position point 1 Pgv3 p.u. 0.91 Nonlinear gain power value point 1 GV4 p.u. 0.6 Nonlinear gain valve position point 1 Pgv4 p.u. 0.98 Nonlinear gain power value point 1 GV5 p.u. 1.0 Nonlinear gain valve position point 1

Page 100

Pgv5 p.u. 1.0 Nonlinear gain power value point 1 GV6 p.u. 0.0 Nonlinear gain valve position point 1 Pgv6 p.u. 0.0 Nonlinear gain power value point 1 Notes: a) Per unit parameters are on base of MWbase, which is normally the MW capability of the

turbine. b) T3 must be greater than zero. All other time constants may be zero. c) For a tandem-compound turbine, Bus Number 2 and Unit ID 2 are omitted, and the parameters

K2, K4, K6, and K8 are ignored. For a cross-compound turbine, two generators are connected to this turbine-governor model.

d) Each generator must be represented in the load flow by data on its own MVA base. The values

of K1, K3, K5, K7 must be specified to describe the proportionate development of power on the first turbine shaft. K2, K4, K6, K8 must describe the second turbine shaft. Normally

K1 + K3 + K5 + K7 = 1.0 K2 + K4 + K6 + K8 = 1.0 (if second generator is present)

The division of power between the two shafts is in proportion to the values of MVA bases of the two generators. The initial condition load flow should, therefore, have the two generators loaded to the same fraction of each one’s MVA base.

g) The intentional input speed deadband follows the relationship shown in the following figures:

Add figures later

h) The unintentional deadband can be used to represent backlash hysteresis in the control components by the relationship shown in the following figure:

Add figure later

i) The nonlinear gain between gate position and power may be input with up to 6 points. The (0.,0.) and (1.,1.) points are assumed and need not be input. The output is not allowed to go beyond 0. and 1. However, if Pmax > 1., the input and output are scaled by Pmax.

If GV1 is input as a negative number, the default full-arc steam valve curve shown in the “typical data” will be used. If input is omitted or if all zero values are input, a straight line is used.

Page 101

Block Diagram:

Pgv

Σ

Pref

4sT11

+1sT1)2sT1(K

++

K1

Σ

Pmech2

Gv

db1 db2

3T1

s1

Pmin

Pmaxuo

uc

Pgv

5sT11

+

K3

6sT11

+

Σ

K5

7sT11

+

Σ

K7

K2 K4 K6 K8

Σ Σ Σ

Pmech1

Speed

Gv

eps


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model govSteam1 ieeeg1 WSIEG1 WSIEG1

Page 102

govPID1 – General PID Governor and Prime Mover Model Model Name govPID1

Description General model for any prime mover with a PID governor, used primarily for combustion turbine and combined cycle units.

Parameters:

Parameter Typical Name Units Value Description Bus number Generator terminal bus number Unit ID Generator ID MWbase MW Base for power values (> 0.) R p.u. 0.04 Permanent droop Rselect 1.0 Feedback signal for droop = 1 electrical power = 0 none (isochronous governor) = -1 fuel valve stroke ( true stroke) = -2 governor output ( requested stroke) Tpelec sec. 1.0 Electrical power transducer time constant, sec. (>0.) maxerr p.u. 0.05 Maximum value for speed error signal minerr p.u. -0.05 Minimum value for speed error signal Kpgov p.u. 10.0 Governor proportional gain Kigov p.u. 2.0 Governor integral gain Kdgov p.u. 0.0 Governor derivative gain Tdgov sec. 1.0 Governor derivative controller time constant Vmax p.u 1.0 Maximum valve position limit Vmin p.u 0.15 Minimum valve position limit Tact sec. 0.5 Actuator time constant Kturb p.u 1.5 Turbine gain (>0.) Wfnl p.u 0.2 No load fuel flow Tb sec. 0.5 Turbine lag time constant, sec. (>0.) Tc sec. 0.0 Turbine lead time constant, sec. Wfspd 1.0 Switch for fuel source characteristic = 0 for fuel flow independent of speed = 1 fuel flow proportional to speed Teng sec. 0.0 Transport time delay for diesel engine Tfload sec. 3.0 Load Limiter time constant (>0.) Kpload p.u. 2.0 Load limiter proportional gain for PI controller Kiload p.u. 0.67 Load limiter integral gain for PI controller Ldref p.u. 1.0 Load limiter reference value Dm p.u. 0.0 Speed sensitivity coefficient Ropen p.u./sec. .10 Maximum valve opening rate Rclose p.u./sec. -0.1 Minimum valve closing rate Kimw p.u. 0.002 Power controller (reset) gain Pmwset MW 80.0 Power controller setpoint Aset p.u./sec. 0.01 Acceleration limiter setpoint

Page 103

Ka p.u. 10.0 Acceleration limiter gain Ta sec. 0.1 Acceleration limiter time constant (>0.) db p.u. 0.0 Speed governor dead band Tsa sec. 4.0 Temperature detection lead time constant Tsb sec. 5.0 Temperature detection lag time constant Rup p.u. 99.0 Maximum rate of load limit increase Rdown p.u. -99.0 Maximum rate of load limit decrease Notes: a) Per unit parameters are on base of MWbase, which is normally the MW capability of the

turbine. b) This model can be used to represent a variety of prime movers controlled by PID governors. It

is suitable, for example, for representation of • gas turbine and single shaft combined cycle turbines • diesel engines with modern electronic or digital governors • steam turbines where steam is supplied from a large boiler drum or a large header whose

pressure is substantially constant over the period under study • simple hydro turbines in dam configurations where the water column length is short and

water inertia effects are minimal c) The range of fuel valve travel and of fuel flow is unity. Thus the largest possible value of

Vmax is 1.0 and the smallest possible value of Vmin is zero. Vmax may, however, be reduced below unity to represent a loading limit that may be imposed by the operator or a supervisory control system. For gas turbines Vmin should normally be greater than zero and less than Wfnl to represent a minimum firing limit.

The value of the fuel flow at maximum output must be less than, or equal to unity, depending on the value of Kturb. If the initial power requires a fuel flow greater than 1.0, a warning message is written and Kturb is increased to permit initialization with valve position = 1.0.

d) The parameter Teng is provided for use in representing diesel engines where there is a small

but measurable transport delay between a change in fuel flow setting and the development of torque. Teng should be zero in all but special cases where this transport delay is of particular concern.

e) The parameter Wfspd is provided to recognize that fuel flow, for a given fuel valve stroke, can

be proportional to engine speed. This is the case for GE gas turbines and for diesel engines with positive displacement fuel injectors. Wfspd should be set to unity for all GE gas turbines and most diesel engines. Wfspd should be set to zero where it is known that the fuel control system keeps fuel flow independent of the engine speed.

f) The load limiter module may be used to impose a maximum output limit such as an exhaust

temperature limit. To do this the time constant Tfload should be set to represent the time constant in the measurement of temperature (or other signal), and the gains of the limiter, Kpload, Kiload, should be set to give prompt stable control when on limit. The load limit can be deactivated by setting the parameter Ldref to a high value.

Page 104

g) The parameter Dm can represent either the variation of the engine power with the shaft speed or the variation of maximum power capability with shaft speed.

If Dm is positive it describes the falling slope of the engine speed verses power characteristic as speed increases. A slightly falling characteristic is typical for reciprocating engines and some aero-derivative turbines. If Dm is negative the engine power is assumed to be unaffected by the shaft speed, but the maximum permissible fuel flow is taken to fall with falling shaft speed. This is characteristic of single-shaft industrial turbines due to exhaust temperature limits.

h) This model includes a simple representation of a supervisory load controller. This controller is active if the parameter Kimw is non-zero. The load controller is a slow acting reset loop that adjusts the speed/load reference of the turbine governor to hold the electrical power output of the unit at its initial condition value. This value is stored in the parameter Pmwset when the model is initialized, and can be changed thereafter. The load controller must be adjusted to respond gently relative to the speed governor. A typical value for Kimw is 0.01, corresponding to a reset time of 100 seconds.

i) The parameters Aset, Ka, and Ta describe an acceleration limiter. Ta must be non-zero, but

the acceleration limiter can be disabled by setting Aset to a large value, such as 1. l) The parameter, db, is the speed governor dead band. This parameter is stated in terms of per

unit speed. In the majority of applications, it is recommended that this value be set to zero. m) The parameters, Tsa, Tsb, are provided to augment the exhaust gas temperature measurement

subsystem in gas turbines. For example, they may be set to values such as 4., 5., to represent the ‘radiation shield’ element of large gas turbines. If both parameters are omitted, they default to 1.0.

n) The parameters, Rup, Rdown, specify the maximum rate of increase and decrease of the

output of the load limit controller (Kpload/Kiload). These parameters should normally be set, or defaulted to 99/-99, but may be given particular values to represent the temperature limit controls of some GE heavy-duty engine controls. If both parameters are omitted, they default to 99 and –99.

o) The fuel flow command (fsr) is determined by whichever is lowest of fsrt, fsra, and fsrn.

Although not explicitly shown in the block diagram, the signals that are not in control track fsr so that they do not “windup” beyond that value. This represents GE gas turbine control practice but may not be true for other controller designs.

p) As shown in the block diagram, when Kpgov is non-zero, the governor PI control is

implemented to “track” fsr to prevent windup when fsr is limited by another signal (fsrt, fsra) or Vmax/Vmin. If Kpgov is zero, the integral path is implemented directly. The same applies to the load limiter PI control with regard to Kpload.

Page 105

Block Diagram:

Kpgov

sKdgov1+sTdgov

Kpload

11+sTfload

govervor outputvalve stroke

speed**Dmif Dm < 0Ldref

db-db

maxerr

minerr

1+sTsa1+sTsb

Π

speed1.0

Rclose

vmax

vminfsr

LowValueSelect

fsrt

fsra

fsrn+

++

1. Kturb

Wfnl

++

+

+

+

1.0

RupRdown

cfe

Tex

Tlim

Texm

1Tact

1s

Ropen

+

speedKa ∆t

s1+sTa

Aset

s8+ +

+

fsr

R

+

s6

+KigovKpgov

KiloadKpload +

Wfspd0 1

Wfnl

ΣPmech

1+sTc1+sTb

Kturb

e-sTeng

dmspeedif Dm > 0

+

11+sTpelec

Pe

Kimws

Pmwset

+

+ 1.1R

−1.1R

Pref +

+

1 - electrical power-1 - valve stroke-2 - governor output0 - isochronous

Rselect

1s

1s

Π

Σ

Σ

Σ

Σ Σ

Σ

Σ Σ

Σ

Σ

Σ Σ

Σ


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model govPID1 ggov1 GGOV1 Pss_GGOV1

Page 106

Other Turbine-Governor Models That May Be Added CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model ggov2 GGOV2 IEEEG2 ieeeg3 IEEEG3 IEEEG3 hyg3 WSHYGP WSHYGP hygov4 hygovr g2wscc WSHYDD WSHYDD gast GAST GAST GASTWD MELGAS gpwscc WSHYGP WSHYGP lfb1 LCFB1 pidgov PIDGOV PIDGOV tgov1 TGOV1 TGOV1 TGOV2 TGOV2 tgov3 TGOV3 TGOV3 crcmgv CRCMGV CRCMGV IEESGO IEESGO WPIDHY WPIDHY WEHGOV RAVGOV DUMGOV RAVGOV

Page 107

Aggregate Load Models The load models in this section are used to represent all or part of the real and reactive load from a load in the static (power flow) data. This load is usually the aggregation of many individual load devices. The load models are approximate representation of the aggregate response of the load devices to system disturbances. Models of loads for dynamic analysis may themselves be either static or dynamic. A static load model represents the sensitivity of the real and reactive power consumed by the load to the amplitude and frequency of the bus voltage. A dynamic load model can used to represent the aggregate response of the motor components of the load. Several standard models for agregate load are discussed in this section. Large industrial motors or groups of similar motors may be represented by individual motor models (synchronous or asynchronous) which are usually represented as generators with negative Pgen in the static (power flow) data. These models are discussed in earlier sections

Model Interconnections Standard interconnection of load models with other models are shown in the following figure and table:

Pload

Vbus, fbus

Load Model NetworkQload

Load Model Standard Interconnections

Load Model Standard Interconnections Inputs:

Name Units Description Source Vbus p.u. Terminal bus voltage magnitude Network fbus p.u. Terminal voltage frequency Network Outputs:

Name Units Description Pload p.u. Load real power

Page 108

Qload p.u. Load reactive power Initialization Inputs:

Name Units Description Source Pload p.u. Load real power Qload p.u. Load reactive power Vbus p.u. Terminal bus voltage magnitude Network Notes: 1. The application program converts the P and Q of the load into a current injection at the bus.

Page 109

loadStatic - Static Load Model Model Name loadStatic

Description General Static Load Model

Parameters:

Parameter Typical Name Units Value Description Model Type Exponential, ZIP1, ZIP2 Scope Type Bus, owner, zone, area, system Scope Value Bus number, area number, zone number Load ID Load ID for individual bus load Kp1 Kp2 Kp3 Kp4 Ep1 Ep2 Ep3 Kpf Kq1 Kq2 Kq3 Kq4 Eq1 Eq2 Eq3 Kqf Notes: Equations: Several variations of the static load model are used in various programs. The model type is used to specify these variations. Model type –Exponential

Page 110

( )

( )fK1VVK

VVK

VVKPQ

fK1VVK

VVK

VVKPP

qf

3Eq

03q

2Eq

02q

1Eq

01q0

pf

3Ep

03p

2Ep

02p

1Ep

01p0

∆+

+

+

=

∆+

+

+

=

.

.

Model type – ZIP1

( )

( )fK1VVK

VVK

VVKPQ

fK1VVK

VVK

VVKPP

qf0

3q

1

02q

2

01q0

pf0

3p

1

02p

2

01p0

∆+

+

+

=

∆+

+

+

=

.

.

Model type – ZIP2

( )

( )fK1KVVK

VVK

VVKPQ

fK1KVVK

VVK

VVKPP

qf4q0

3q

1

02q

2

01q0

pf4p0

3p

1

02p

2

01p0

∆++

+

+

=

∆++

+

+

=

.

.


CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model General

Exponential NONE IEELBL

IEELOW IEELZN IEELAR IEELAL

ZIP1 blwscc

zlwscc alwscc wlwscc

IEELBL IEELOW IEELZN IEELAR IEELAL

ZIP2 blwscc

zlwscc alwscc wlwscc

LDFRBL LDFROW LDFRZN LDFRAR LDFRAL

Page 111

loadMotor - Aggregate Induction Motor Load Model Name loadMotor

Description Aggregate Induction Motor Load

Parameters:

Parameter Typical Name Units Value Description Bus number Terminal bus number in power flow case Unit ID Generator ID in power flow case Pfrac none 0.3 Fraction of constant-power load to be represented

by this motor model (between 1.0 and 0.0) Lfac none 0.8 Loading factor – ratio of initial P to motor MVA base Ls p.u. 3.2 Synchronous reactance Lp p.u. 0.15 Transient reactance Lpp p.u. 0.15 Sub-transient reactance, p.u. Ra p.u. 0.0 Stator resistance, p.u. Tpo sec. 1.0 Transient rotor time constant Tppo sec. 0.02 Sub-transient rotor time constant, sec. H Sec. 0.4 Inertia constant, sec. D p.u. 2.0 Damping factor, p.u. Vt p.u. 0.7 Voltage threshold for tripping (default = 0), p.u. Tv sec. 0.1 Voltage trip pickup time (default = 999), sec. Tbkr sec. 0.08 Circuit breaker operating time (default = 999), sec. Notes: a) This model is used to represent a fraction of an ordinary load as "induction motor load". It

allows load that is treated as ordinary constant power in power flow analysis to be represented by an induction motor in dynamic simulation. Either a “one-cage” or “two-cage” model of the induction machine can be modeled. If Lpp = 0. or Lpp = Lp, or Tppo = 0., only one cage is represented. Magnetic saturation is not modeled. This model is intended for representation of aggregations of many motors dispersed through a load represented at a high voltage bus but where there is no information on the characteristics of individual motors.

b) This model treats a fraction of the constant power part of a load as a motor. During

initialization, the initial power drawn by the motor is set equal to Pfrac times the constant P part of the static load. The remainder of the load is left as static load. The reactive power demand of the motor is calculated during initialization as a function of voltage at the load bus. This reactive power demand may be less than or greater than the constant Q component of the load. If the motor's reactive demand is greater than the constant Q component of the load, the model inserts a shunt capacitor at the terminal of the motor to bring its reactive demand down to equal the constant Q reactive load.

Page 112

. c) If a motor model and a static load model are both present for a load, the motor Pfrac is

assumed to be subtracted from the power flow constant P load before the static load model is applied. The remainder of the load, if any, is then represented by the static load model.

d) The rotor time constant Tpo and inertia time constant H must be non-zero. e) Ls, Lp, Lpp must all be specified. f) D has the dimensions delta P/ delta speed. The initial value of Pmech or the value coming from

an separate mechanical load model, if used, is multiplied by speed raised to the power D to determine the effective mechanical load seen by the motor.

g) The parameters Vt and Tv define under-voltage tripping logic. A timer is started if the terminal

voltage falls below Vt per unit and continues to run until voltage rises above Vt. If voltage has not risen above Vt when the timer reaches Tv the motor is tripped immediately.

h) Per unit parameters are on the motor MVA base. The MVA base is calculated during

initialization as the initial motor P in MW divided by the loading factor (Lfac) parameter Block Diagram:

Page 113

Lp - Lpp

d-AXIS

id

E'q

Ls - Lp

E"q1Tppo s

Σ1

s

11Tpo

ωo SLIPωo SLIP Tpo

Lp - Lpp

q-AXIS

iq

E'd

Ls - Lp

E"d1Tppo s

1

s

11Tpo

ωo SLIPωo SLIP Tpo

12Hs

∆ω

D

Tespeed

Pmech

1. +

+

Σ+

_

_ω

n/dn Tm

d

Σ

Σ

Σ

Σ

Σ

Σ

ΣΣΣΣ

Σ

slip


CIM PSLF PSS/E DigSilent Eurostag Model Model Model Model Model loadMotor motorw CIM5xx,

CIMWxx ElmAsm

Notes: 1. PSS/E has several versions (xx) of the models for application to load at an individual bus (BL),

all loads with same owner (OW), all loads in a zone (ZN), all loads in an area (AR), or all loads in the system (AL). The CIMWxx models include a polynomial mechanical load model [Tl = To(Aw^2 + Bw + Co + Dw^E)] which should be represented by a separate mechanical load

Page 114

Mechanical Load Models A mechanical load model is used to represent the variation in a motor’s shaft torque or power as a function of shaft speed.

Model Interconnections Standard interconnection of mechanical load models with other models are shown in the following figure and table:

Synchronous or

AsynchronousMotor

PmechMechanical Load

speed

Mechanical Load Model Standard Interconnections

Mechanical Load Model Standard Interconnections Inputs:

Name Units Description Source speed p.u. Motor speed Motor Outputs:

Name Units Description Pmech p.u. Motor shaft mechanical power Initialization Inputs:

Name Units Description Source Pmech p.u. Motor shaft mechanical power Motor speed p.u. Motor speed Motor

Page 115

mechload1 - Mechanical Load Model 1 Model Name mechload1

Description Mechanical Load Model 1

Parameters:

Parameter Typical Name Units Value Description Bus Number Motor terminal bus number ID Generator or Load ID a Speed squared coefficient b Speed coefficient d Speed to the exponent coefficient e Exponent Notes: Equations:

( )

( )speedmotor initial

TmechtorqueinitialTo

dba01cwhere

TmechPmech

dcbaTTmech

o

o

1DMo

1DM

e20

=ωω

ω==

−−−=

ω=

ω++ω+ω=

−

−

.:


CIM PSLF PSS/E DigSilent Eurostag Model Type Model Model Model Model mechload1 apfl

spfl mdm1

mdm3 mdm5

Documents

Common Information Model Power System Dynamics Standard