3 570 087a

O & M Manual Generator Control Panel

Dwg.No.: 3 570 087 Rev.A

Edition: 23.05.2006 3570087A_OperationMaintenanceManual.doc Page 1 /66

Excitation SystemforGenerator Control Panel

Operation andMaintenance Manual


Dwg.No.: 3 570 087 Rev.A


CAUTION

Installing, commissioning and operating of this product may be performed by thoroughly trained and

specialized personnel *

only. We explicitly will not take any responsibility for any damage on our products caused by im-proper installation, configuration and handling. Internal modifications must solely be carried out by specialized personnel authorized by VA TECH SAT GmbH & Co / Department EXC.

* Definition: Specialized personnel, when authorized and properly instructed, may perform fol-lowing tasks.

• Installing, mounting, commissioning and operating of the apparatus and the system when fa-miliar with,

• Switching operations according to the relevant Safety Standards for medium and high voltage switchgear, i.e. plant energizing and de-energizing, preventive isolation, safety earthing and securing, when instructed,

• Maintenance and application of safety gear according to Standard Rules and Regulations,• First Aid after extensive training.

CAUTION

Insulation resistance- and high voltage tests must never be applied and may only be carried out on the power circuits. Improper use of such tests could damage the system's solid state compo-nents.


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TABLE OF CONTENTS1. INTRODUCTION 6

2. PRODUCT DECLARATION AND CE-IDENTIFICATION 6

3. BASIC PRINCIPLE OF EXCITATION SYSTEMS 7

4. BASICS OF THE THYNE4 SYSTEM 8

5. SUBSTANTIAL FEATURES 9

6. EXCITATION SYSTEM THYNE4 SPECIFICATION 10

6.1. POWER SUPPLY 106.1.1. With Excitation Transformer in Generator Shunt Field Connection 106.1.2. External- and Test Supply from the Station Auxiliary System 11

6.2. POWER CIRCUIT DESIGN 126.2.1. Rectifier Unit and Overvoltage Protection 126.2.2. DC Overvoltage Limiter 126.2.3. Field Flashing 126.2.4. Current forcing 13

6.3. AUTOMATIC VOLTAGE REGULATOR AND GATE CONTROL GMR3 146.3.1. Overview 146.3.2. Description of Hardware 176.3.3. Description of Software 23

7. INTERFACE OF EXCITATION SYSTEM 35

7.1. EXCITATION POWER CIRCUIT 357.1.1. Connection of the Field Winding of the Exciter Machine 357.1.2. Excitation AC Supply 357.1.3. Current Forcing 357.1.4. CT / PT and Actual Measured Value Connections 35

8. LOCAL OPERATION 36

8.1. Introduction 36

8.2. Description of Functions 368.2.1. Basic Screen - Main Menu 36

9. REMOTE CONTROL 37

9.1. INTERFACE 379.1.1. Digital Inputs 379.1.2. Digital Outputs 38

9.2. OPERATING MODES 389.2.1. Voltage Regulator (Automatic Mode) 389.2.2. Field Current Regulator (Manual Control) 389.2.3. Change Over Between the Automatic and Manual and Power factor /

Reactive Power Regulation Mode 39

9.3. DE-EXCITATION 39

10. MAINTENANCE AND TROUBLE SHOOTING 40

10.1. ALARM ANNUNCIATION 40


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10.1.1. General and Accepting/resetting 4010.1.2. List of Possible Alarm Annunciation 4110.1.3. Detailed Specification 42

10.2. FAULTFINDING 47

10.3. FAULTY PRINTED CIRCUIT CARDS 52

10.4. PERIODIC MAINTENANCE 52

11. INSTALLATION 53

12. PRE-SETTINGS FOR COMMISSIONING 54

12.1. SWITCHES ON MRB3 MODULE 54

12.2. LIST OF THE CONFIGURATION PARAMETERS 54

12.3. CALIBRATION OF LC-DISPLAY 54

13. COMMISSIONING 57

13.1. PREPARATION FOR COMMISSIONING 57

13.2. MEASURING POINTS 57

13.3. CONSIDERATIONS 5813.3.1. Calibration Principle 5813.3.2. Principle for Optimizing the Regulator 6013.3.3. Recommended Settings 61

13.4. CARRYING OUT COMMISSIONING 6113.4.1. Tests at Standstill 6213.4.2. Short Circuit Tests – If Applicable 6213.4.3. Open Circuit Voltage Tests 6213.4.4. On Load Tests 6313.4.5. Remaining Activities 64

14. TECHNICAL DATA 65

14.1. DIMENSIONS 65

14.2. ELEKTRICAL DATA 6514.2.1. Rectifier capability 65

14.3. ELEKTRICAL DATA OF ROTOR SUPPLY 6514.3.1. Rectifier capability 65

14.4. EMC COMPATIBILITY 65

15. PLEASE NOTE! 66


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LEGEND AND ABBREVIATIONS

S Apparent powerP Active powerQ Reactive powerV, U VoltageI CurrentUG Generator voltageIG Generator currentIw Generator active currentIb Generator reactive currentIF Field currentfg Generator frequency3ph Three phaseDC Direct currentC CommandA AnnunciationB Command (Befehl) refers to digital signalsNB No command refers to digital signalsM Annunciation (Meldung) refers to digital signalsNM No annunciation refers to digital signals

Note: Index “n”, “N” means nominal, e.g. UGN is generator nominal voltage.


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1. INTRODUCTION

The THYNE4 is an excitation system comprising the complete power circuit part as well as the digital regulating and control functions. This operating manual shall assist to be able to use all features contained in the system and also supply the necessary information required for mount-ing, installing, commissioning and maintenance.

However, should there be any questions at all regarding this excitation system please contact our Head Office in Vienna.

2. PRODUCT DECLARATION AND CE-IDENTIFICATION

The excitation system THYNE4 is designed and manufactured in accordance with the CE-identification Standard (93/68/EWG) with consideration of the EU-Standards for low voltage switch gear (73/23/EWG) as well as the EU-Standard for electromagnetic compatibility (89/336/EWG).

Standards considered:

VDE 160,EN 50178

Ausrüstung von Starkstromanlagen mit elektronischen Betriebsmitteln

Electronic equipment for use in power installations

IEC 60146 Halbleiter-Stromrichter Semiconductor converters

IEC 60726 Leistungs-transformatoren Dry-type power transformers

IEEE 421 B High Potential Test Requirements for Excitation Systems for Synchronous Machines

IEC 61000-4 Elektromagnetische Verträglichkeit Electromagnetic Compatibility


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3. BASIC PRINCIPLE OF EXCITATION SYSTEMS

For the operation of a synchronous generator a magnetic rotor field is required which a DC cur-rent flowing in the rotor windings produces. This DC current is generated by the excitation system.

There are several kinds of excitation systems which are employing either rotating machinery or static elements. A static excitation system is connected via an excitation transformer to a power source. Should the source be the generator winding itself we are referring to a shunt field excita-tion system. When the excitation transformer is connected to an external power source, e.g. an AC generator on the rotor shaft or to the auxiliary supply of the plant, it is denominated as excita-tion system with an external supply. The voltage output of the excitation transformer is rectified and regulated and is transmitted to the field winding via the rotor brushes.

A further possibility is the use of a pilot exciter machine which can either be a brushless AC ex-citer with flywheel diodes or, especially in older plants, a DC exciter machine. The pilot exciter is acting as an amplifier of the field current. The flywheel diodes are mounted on the common shaft of the generator rotor and pilot exciter and are supplying the necessary DC current for the rotor. The regulation of the pilot exciter field is performed via a voltage regulator with a fully controlled thyristor unit.

The excitation performs either• production and regulation of the generator voltage when not connected to the power grid or

when operating as an isolated system• production and regulation of the reactive power when operating in parallel with other units to

the power system. Maintaining the voltage level is caused by the grid system itself provided that it is able to do so. When during on-line operation the rotor current is reduced too muchthen the stability of the generator set is also decreasing. This can lead to loss of synchronism with subsequent damage to the generator within a relatively short period due to additional cur-rents circulating in the generator windings. Generator speed and active power output is solely determined by the turbine drive

The figure below shows the permissible load range for stable operation of the generator set.

Max. permissible stator current

Min. Permissible rotor current

P (pu), active power

-0,5-1

Stabiliy limit

0.5

1

Q (pu), reactive power0,5 1

Max. permissible rotor current

Operating range


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4. BASICS OF THE THYNE4 SYSTEM

The THYNE4 system is an integrated compact static and numeric excitation system for excitation and regulation of small and medium sized synchronous alternators having either AC or DC exciter machines. The central component is the THYNE4 device, which is containing the complete power circuit with a single or three-phase fully controlled thyristor bridge as well as the integrated micro-processor system of the GMR3 family for all control and regulating operations.

The exciter cubicle contains all power circuits (except excitation transformer), the automatic volt-age regulator and the complete sequencer, which is necessary to control the individual compo-nents. The system also comprises a local operating panel with alarm indication, which enables local operation and quick trouble-shooting in case of excitation failures.

The excitation system THYNE4 supports all standard excitation systems, such as generator shunt field excitation, systems employing an excitation transformer supplied by auxiliary power and exci-tation via a permanent magnet generator PMG.

The local control and alarm annunciation facilities enable the operating staff to locally control the excitation system, read the actual measured values and also provide swift and precise diagnosis and repair in case of component failure.

The complete THYNE4 System is consisting of:

• Fully controlled thyristor bridge• DC overvoltage limiter• AC overvoltage limiter• Field flashing (not provided in case of a foreign supply)• Current forcing• Voltage regulator with limiters• Additional regulators: reactive power regulator, power factor regulator• Field current regulator• Automatic follow-up and transfer between voltage regulator and field current regulator• Integrated digital sequencer for internal control sequences• Facilities for local control indication and alarm annunciation• Excitation supply with fuses• Voltage actual value provided by a set of PT's (3 phase or single phase)• Generator current provided by a set of CT's (3 phase or single phase)


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5. SUBSTANTIAL FEATURES

• Supply via external excitation transformer in shunt field connection or an auxiliary supply source coming from MCC

• Nominal frequency range between 50 Hz and 400 HzOperating range from 10 Hz to 440 Hz

• Integrated µP-system of the GMR3 type for digital sequencer and regulation• Voltage regulation in automatic mode with inner loop current regulating• Field current regulation in manual mode• Adjustable active and reactive load compensation• Following limiters are provided in the standard design:

− Maximum field current limiter with an instantaneous and delayed response− Overfluxing limiter (V / Hz)− Stator voltage limiter− Under excitation limiter

• Diode fault monitoring on AC exciter machines with flywheel diodes for open circuit or short circuit

• Soft-Start feature, i.e. start the initial raising of the generator voltage with a defined rate of rise without hunting

• Manual and automatic smooth transfer from automatic to manual operating mode• Additional regulators: p.f. regulator or reactive power regulator selectable on the excitation unit• All set value potentiometers are part of the software having no contacts and therefore require

no maintenance.• Three phase fully controlled bridge rectifier• Overvoltage protection of the excitation machine's field circuit• Initial excitation effective for generator shunt field excitation• Current forcing, which is enabled during a changeover of the excitation supply from one source

to another one.• Manually operated links to change over to the external test supply for the test purposes, in

case of shunt field excitation• Operation and indication unit for local operation at the device or excitation cubicle with the cor-

responding feedback, i.e. excitation ON and OFF, set value RAISE and LOWER, operating mode selection and resetting the alarm annunciation

• Above control unit comprises a keypad for the operating commands and a four line LC display for annunciation and measured values

• Display of following measured values via the LC display of the control unit:− Generator voltage− Generator current− Field current− Generator active power− Generator reactive power− Generator power factor

• Alarm display in correct time sequence• Redundant supplies for regulator from the existing station battery and from the excitation sup-

ply• Defined communication interface ports with voltage-free inputs and outputs for remote control

and annunciation


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6. EXCITATION SYSTEM THYNE4 SPECIFICATION

The THYNE4 system is distinguished by a uniform hard- and software for two different power circuit supplies for the excitation system. Besides the power circuit it contains the voltage regula-tor, the field current regulator, additional regulators as well as the complete sub-automatic system necessary for the control of the individual components.

6.1. POWER SUPPLY

6.1.1. With Excitation Transformer in Generator Shunt Field Connection

The excitation power is provided by a single-phase or a three-phase supply from the generator terminals in shunt field connection via the excitation transformer or from a station auxiliary supply. The rectified field voltage from the thyristor is connected to the field.

The internal regulating matching transformer is connected to the ac supply of the excitation sys-tem and provides with its first secondary output the synchronizing voltage of the regulator for thy-ristor commutation. The second transformer output is producing via rectifiers the buffered 24 VDC for the regulation system. The transformer is of dry type.

The system supports AC exciter of machine arrangement.

The field and rotor magnitudes can be operating within the following ranges:

• Field voltage: positive and negative• Field current: positive• Rotor voltage and rotor current: positive


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THYNE4

AC-exciter machine

Machine arrangement

Actualvaluesensing

Gen.∼

Excitation

transformer

Fig. 1: Power circuit THYNE4 with shunt field excitation

6.1.2. External- and Test Supply from the Station Auxiliary System

During first commissioning, i.e. short circuit- and open circuit tests, heat run, protection and exci-tation setting and for subsequent periodic checks an external test supply not depending on the generator voltage output is necessary.

For this purpose an external supply from the auxiliary system can be taken whereby for this pur-pose the manually operated links should be prepared for the excitation test supply. The field cur-rent can now be adjusted in manual control with the field regulator from zero up to nominal cur-rent.

In case of a safe AC supply, it can be utilized for the excitation during normal on-line operation via the low voltage excitation transformer.

The external supply, when designed accordingly, provides the same power and dynamic charac-teristics of the excitation system as generator being on-line in shunt field operation.


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6.2. POWER CIRCUIT DESIGN

6.2.1. Rectifier Unit and Overvoltage Protection

The input to the excitation system from the power circuit for the supply of the rectifier unit is pro-tected with semiconductor fuses in each phase and further equipped with an overvoltage protec-tion an AC RC-assembly.

The rectifier unit is a fully controlled thyristor bridge whereby each thyristor is provided with itsown snubber circuit. Positive and negative field voltages are permitted with a resulting high speed regulator response.

The thyristor bridge is provided with a cooling element based on natural cooling.

With the back-feed information of the regulator's microprocessors the ignition of the thyristor con-trol pulses are calculated. These pulses are amplified and sent via the impulse transfer circuit, being galvanic isolated from the thyristors.

6.2.2. DC Overvoltage Limiter

A voltage-dependent semiconductor is parallel connected to the field of exciter. The transient voltages caused by short circuits at the synchronous machine are limited.

To spare the contacts of the de-excitation contactor during normal shut down of the unit the thy-ristor bridge is regulated fully into converter mode thus decaying the field current and the contac-tor is opened after a time delay. During a protection trip this contactor is opened instantaneously.

6.2.3. Field Flashing

Initial excitation during start up of a synchronous generator equipped with a shunt field excitation system can only be secured with additional measures since the residual voltage is not sufficient to provide the energy required.

The necessary energy is delivered by the station battery via diodes a limiting resistor and a start up contactor to the filed circuit. During initial excitation this contactor is closed and as soon as the thyristor unit has taken over the filed current opened again. Now the thyristor unit is regulating to the adjusted set value.

For excitation systems deriving the energy from an excitation transformer connected to the station auxiliaries or from a permanent magnet pole generator an initial excitation is not necessary.


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6.2.4. Current forcing

In case of external supply for the excitation system, the supply is given by the MCC AC circuit. If for any reason this voltage is no more available, an undervoltage relay connected to this bus has to switch over from normal supply to a separate supply independent from the common supply. During this change-over, a single phase thyristor connected to the 125 Vdc battery receives a firing impulse to keep the field current at 2/3 of its nominal value. The detection of the voltage drop for the firing of the thyristor is realized in the voltage regulator.

Forcing circuit is only active during online operation of the generator, which means that a contac-tor closes after synchronization of the generator to the grid and connects the battery voltage to the forcing thyristor, with opening of this contactor the thyristor gets nonconductive.


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6.3. AUTOMATIC VOLTAGE REGULATOR AND GATE CONTROL GMR3

6.3.1. Overview

The regulator and gate-control unit GMR3 is a multi-processor voltage regulator for synchronous single-phase and three-phase machines with a broad frequency range. It comprises a complete voltage regulator, the firing circuitry for single-phase or three-phase operation and the control logic that is necessary for the proper operation of an excitation system.

6.3.1.1 Operating Principle

In its basic embodiment, the system comprises a main processor (MRB), 3 sub-processors (card PGS, Pr.A,B,C), digital and analogue inputs and outputs in variable numbers, and a measured-value processing board (PGS) for the electrical quantities of the machine and the gate pulses. The regulator is structured as voltage regulator with one master (voltage) control loop and one slave (exciter current) control loop.

Matching transformers provide isolation for the actual values (stator voltage UG, stator current IG,exciter current IP, thyristor voltage USYN). They are transformed into low voltages, which a cable feeds to board PGS. On the PGS board, the measured values are processed for the sub-processors.

MRB (µP)

RS

IWN

LCOM

RS

DPR C

DPR B

DPR A

µP C

µP B

µP A

A/D

MIC1703(µP)

USYN

UG

IG

IF

GMR3

LG6

UG=12198398IG=198217

ELTERM

PGS

TCP

Fig. 2: Block diagram GMR3

Sub-processor C calculates the parameters required to regulate a synchronous machine. Via a dual-port RAM (DPR C), the results are transmitted to the main processor MRB. (A dual-port RAM is a memory device, which gives access to two processors, independent of each other.)

MCPARTTI

Note

IWK - Actual Value board -provides isolation

MCPARTTI

Note

Cable from IWK to PGS board

MCPARTTI

Note

Dual Port Ram, Memory that is used by two processors, independent of each other

MCPARTTI

Note

Contains AVR Limiters, control cicuits, the output goes to DPR B where microprocessor C can have access. (ie grabs the AVR output to use as the MAnual reg input. Additional values are fed to the MRB via the ethernet bus link.

MCPARTTI

Note

Manual Regulator

MCPARTTI

Note

Calculates firing signals

MCPARTTI

Note

Makes the calculation from the feedback signals ie Takes the generator feedback voltage in counts, scales it then stores it in a memory address in DPR C that allows MRB to grab it. It probably does other calculations like watts, pf etc, like the TCCB board


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The main processor contains the software for the voltage loop (automatic operating mode), the limiters, the additional regulators, and the entire control logic that is necessary for a proper opera-tion. All digital I/Os and all additional system-specific analogue I/Os are connected to the main processor unit via Ethernet-bus link. The output value of the voltage loop is transferred to sub-processor B on board PGS via dual-port RAM DPR B.

Sub-processor B contains the exciter-current loop (manual operating mode). On the basis of the actual field current and the information provided by the main processor, this loop calculates the firing angle for the thyristor pulses. The firing angle is transferred to sub-processor A via DPR A.

Sub-processor A calculates the firing pulses. Transistors on module PGS amplify the pulses, which a cable feeds to the firing transformers (one for every thyristor). A switch on the front panel of the PGS facilitates the manual testing of the firing pulses.

Digital in- and outputs on board IWN are provided for supervision of the regulator. All analogue inputs and outputs required for regulating are available on board PGS. Other in- and outputs serve to control and process commands, feedbacks, and alarms. They are connected to the regu-lator via an Ethernet link with SAT-bus modules.

6.3.1.2 Regulator Assembly

The different regulator boards are built into a 19" rack. At the rear, they are connected by means of a wiring print. The voltage supply and all external inputs and outputs are connected via front-panel connectors.

In standard configuration below boards are mounted in one regulator unit:

1 main processor board MRB3 (position -A13)with memory for program and setting parameters, 1 serial service adapter at the front

1 communication board COM4 (position -A17)1 RS485 serial adapter for Modbus communication1 RS232 serial adapter for Modbus communication1 serial service adapter at the front

1 sub-processor and signal processing board PGS (position -A29)to couple the measured values and to uncouple the gate pulseswith 3 signal processors (A, B, C) and attached program memory

1 voltage supply IWN_B (position -A37)with each 8 digital inputs and outputs for internal use

1 communication board LCOM (position -A45)1 RJ45 adapter at the front for the Ethernet LAN2 serial service adapters at the front

1 actual value pick-up IWK2includes isolating and matching PTs and CTs

MCPARTTI

Highlight

MCPARTTI

Highlight


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6.3.1.3 Scope of Program

The software comprises the operating system and the regulator programs with the setting pa-rameters for the main processor board (MRB) and the different programs for the sub-processorboard (PGS) and the communication cards (LCOM and COM4). All programs are stored in EPROMs; all adjustable parameters are stored in EEPROMs.

The operating system provides input and output conversion, co-ordinates the sequence of the regulator program, the data exchange to the sub-processors, and facilitates communication with the regulator via a serial interface. Different monitoring functions permit selective error detection. In addition, the operating system comprises an editor, which serves to work on the regulator pro-grams.

For operating, an operation terminal or compatible PC may be attached via an RS232-C interface on the main processor board or communication card.

The programs on the sub-processor board contain the compiling of the measured values and the calculation of the actual values (processor C), one exciter-current regulator (processor B), and the gate pulse generation (processor A).The programs on the communication card include the Ethernet IEC 104 protocol and the data exchange with the main processor.

The regulator programs offer the following features:

• Voltage regulation to an adjustable voltage set value, using sub-processor B as secondary current loop (automatic operation).

• Active and reactive load compensation.• Exciter current regulation to an adjustable manual set value (manual operation).• Since both regulating modes (automatic, manual) are balanced continuously, a bumpless

changeover is possible at all times.• Maximum exciter current limiter (undelayed), to limit the maximum possible short-term ceiling

current.• Maximum exciter current limiter, with delay depending on the overcurrent (inverse time charac-

teristic), to limit the continuously admissible current.• Minimum exciter current limiter (undelayed), to prevent any operation below the admissible

minimum current.

The following functions are optional features:

• Stator current limiter, with delay depending on the overcurrent (inverse time characteristic), for operation with over- and under-excitation.

• Load angle limiter undelayed (under-excitation limiter).• Voltage limiter, with delay for minimum and maximum values.• Flux (Volts/Hertz) limiter with delay.• Power system stabilizer.• Since the regulators are balanced continuously, a bumpless changeover between the different

operating modes is possible at all times.• Site-specific functions.

Different control tasks, which are required for a proper functioning of the system (e.g. initial exci-tation, monitoring functions ...) are integrated into the regulator software in a separate program section.

MCPARTTI

Highlight

MCPARTTI

Highlight

MCPARTTI

Highlight

MCPARTTI

Note

The communication card refers to the LCOM board that communicates to the PLC via the Ethernet cable

MCPARTTI

Underline

MCPARTTI

Note

LCOM board connect to TM1703


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6.3.2. Description of Hardware

The regulator consists of a 19" rack (6HE, 84TE) fitted with the printed circuit boards necessary to satisfy the system specifications. On the rear of the regulator, all units are connected via a wiring print. Additional connections for some modules are made via the respective application plug with plug-on wiring prints. The voltage supply and all inputs and outputs are connected by cable via connectors on the front panel.

The following is an overview of the functions of the cards. For details see the respective descrip-tions of the printed circuit boards.

6.3.2.1 Power Supply IWN_B

The module IWN_B provides the supply voltages for all GMR3 circuit boards. Digital in- and out-puts are mounted for internal use.

Voltage SupplyThe regulator requires a 24Vdc supply. The supply is provided redundant, on the one hand from the thyristor voltage via a matching transformer and a diode rectifier, and on the other hand from the station battery.

Supply to Regulator Electronics

The supply voltage from the redundant supply (nominal value 24Vdc, range 18-32 Vdc) is fed to the DC/DC converters of module IWN_B in the regulator via a front-panel connector. It supplies the voltages needed by the regulator electronics:

5V: supply for all functional groups processing digital signals.±15V: supply for all functional groups processing analogue signals.±15V: supply for Hall type transformer mounted externally or on the IWK unit.

On the rear of the rack, these voltages are connected to the individual boards via a wiring print. The regulator ground is connected to the regulator casing.

Supply to Pulse Amplifiers

The pulse amplifiers, fitted near the thyristors, need a supply of 24Vdc. The redundant regulator supply is therefore fed to the pulse amplifiers via card PGS. The 24Vdc ground is connected to the regulator ground and the regulator casing.

Digital InputsThe print has 8 digital inputs. Each of the inputs is passed over optocouplers. Four inputs each use a common potential. All connections are wired by cable to the terminal strip via a front-panelconnector. 24Vdc is used as coupling voltage. The software reads the inputs via variables E00 to E07.

Digital OutputsThe print has 8 digital outputs. Each of the outputs is passed over a printed-board relay. Four outputs each have use common potential. All connections are wired by cable to the terminal strip via a front-panel connector. 24Vdc is used as query voltage. The software actuates the outputs via the variables A00 to A07.


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6.3.2.2 Main Processor Board MRB

The operating system with the main regulator program is on this board. The board has an INTEL processor and EPROMs for programs, in addition to the working memory, as well as an EEPROM to store site dependent parameters. The board can only be used in plug-in position A13 of the regulator. An RS232-C serial interface adapter is located on the front panel, in order to connect an operation terminal or a compatible PC for maintenance purposes.

8 DIP switches are accessible from the front panel. During normal operation, all switches except switch 4 (numbered consecutively from top to bottom) must be on the right (in position "NORM"). Switch 4 must be on the left. LED’s indicate the different system statuses.

6.3.2.3 Pulse Generation and Signal Processing Board PGS

The board contains 3 independent signal processors (A, B, C) with corresponding periphery. Each of the processors serves a precisely defined task which is in line with the corresponding software. Dual-port RAMs are used for data exchange with the main processor. They are memo-ries that 2 processors can use for writing and reading. Consequently, the processors are uncou-pled. The sub-processors can work independent of the main processor, which means that the sub-processors can continue to operate, also in case of a main processor board failure.Up to 4 sub-processor boards (PGS, LCOM, COM4 …) with DP-RAM data exchange can be used in one regulator unit (in positions A4 to A9, as required). The boards are numbered consecutively, starting at 0, and the number must be set with the jumpers on the board.

The system signals are connected via 2 front-panel connectors.Signal processing serves for the below tasks:

- to read in actual values- to read in 6 free analogue values- to output gate pulses- to enable manual setting operation

Caution: All analogue signals and gate pulses are electrically connected to the regulator ground! Analogue signals may only be connected via isolating transducers or transformers.

Actual ValuesA maximum of 8 measured values, required for regulating and gate-control, are read in via isolat-ing transformers:- synchronizing (thyristor) voltage US1 (L1-L3)- synchronizing (thyristor) voltage US2 (L2-L3)- stator voltage UG1 (L1-L3)- stator voltage UG2 (L2-L3)- stator current IG1 (L1)- stator current IG2 (L2)- exciter current IP1- exciter current IP2 (can be used for exciter voltage)

The measured physical values are filtered and converted into digital signals. In addition, different input-signal levels can be matched by setting jumpers.

Single-phase or three-phase signals can be processed. The three-phase signals are recorded via two measuring channels against ground. When measuring single-phase signals, the second channel for the respective measured quantity is not used. The exciter current is always trans-ferred as direct-voltage value via one channel.


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Dependent on site conditions the following combinations are possible:

Three-phase rectifier bridgeUS1: thyristor voltage L1-L3US2: thyristor voltage L2-L3

Single-phase rectifier bridgeUS1: thyristor voltage L-NUS2: no used

Three-phase machine with three-phase measurementUG1: stator voltage L1-L3UG2: stator voltage L2-L3IG1: stator current L1IG2: stator current L2

Three-phase machine with single-phase measurementUG1: stator voltage L1-L3UG2: no usedIG1: no usedIG2: stator current L2

Single-phase machineUG1: stator voltage L-NUG2: no usedIG1: stator current LIG2: no used

Free Analogue InputsBoard PGS has 6 analogue inputs (ANA1 to ANA6) for site applications, which can be used to implement user-specific tasks. DC or AC signals can be processed, which must be connected via external isolating transmitters. Via input circuitry, voltage divider, rectifier with add-on offset and low pass, they are passed to A/D-converters. Jumpers facilitate an adjustment to different inputsignal levels. The analogue inputs ANA1 to.ANA4 have a resolution of 12 bits, inputs ANA5 and ANA6 have a resolution of 10 bits.

The software uses the 6 analogue signals via variables V511 (ANA1) to V516 (ANA6).

Pulse OutputsThe gate pulses, required to control the thyristors of the power rectifier, are amplified on the PGS board and supplied to the upper front-panel connector, together with the 24Vdc auxiliary voltage for the pulse amplifiers. A maximum of 6 pulses is available.

Selectable by jumpers on the printed board, either pulse amplifiers (transformers with amplifiers connected in series) or pulse transformers (without amplifiers) can be connected. Thyristor bridges can only be connected in parallel when pulse amplifiers are used. Triggering gate pulses can be prevented by software or the optional gate pulse blocking relay on the board.


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Front-Panel SwitchesSwitches on the front panel enable manual setting operation. When switch "HST" is moved to position "1", the control angle of the thyristor bridge can be adjusted manually via control key "±". The set firing angle can be measured at measuring sleeve "A_PWM" (0...5V correspond to 0...180°).

During manual setting operation, the optionally mounted gate blocking relay is ineffective, and gate pulses are triggered independent of the position of the gate blocking relay.

6.3.2.4 Actual Value Pick-Up IWK2

This board is mounted behind a protection cover on the back of the regulator unit. It contains the necessary devices to match and isolate at maximum 9 measured actual values. The external sig-nals are connected to a terminal strip on the IWK. The internal signals are connected to the PGS by a cable for further processing. The main components on the IWK board are:

2 PT’s for the synchronizing (thyristor) voltages US1, US22 PT’s for the stator voltage UG1, UG22 CT’s for the stator current IG1, IG21 circuit for the supply of a hall-sensor type transformer to measure the exciter current IP1 in

the field circuit, or alternatively 2 CT’s and a rectifier for the exciter current IP1, measured at AC-side of the thyristor bridge

1 circuit for the supply of a hall-sensor type transformer to measure the exciter current IP2 or exciter voltage UP in the field circuit

1 PT for the net voltage UN

4 of the 6 free analogue values (ANA1, ANA4, ANA5, and ANA6) are passed through the IWKunit without further processing. 1 input (ANA2) is reserved for the connection of the net voltage and 1 input (ANA3) is reserved for the field voltage (to be measured by a hall-sensor type trans-former).The regulator consists of a 19" rack (6HE, 84TE), which is fitted with the printed circuit boards necessary to satisfy the system specifications. On the rear of the regulator, all units are con-nected via a wiring print. Additional connections for some modules are made via the respective application plug with plug-on wiring prints. The voltage supply and all inputs and outputs are con-nected by cable via connectors on the front panel.

The following is an overview of the functions of the cards. For details see the respective descrip-tions of the printed circuit boards.

6.3.2.5 Communication with Periphery via LAN

The network interface according to IEC 60870-5-104 of type Ethernet TCP/IP provides the com-munication with the periphery.

The regulator printed circuit board LCOM acts as controller via the Ethernet interface for the TM1703 mic terminal modules. TM1703 mic (Terminal Module for microcontrol) provides modular compact telecontrol system consisting of a master control unit element and various I/O modules.

The master control unit element serves for the interfacing and supplying of the I/O modules and provides a telecommunication interface in accordance with IEC 60870-5-104 for LAN/WAN com-munication based on Ethernet TCP/IP.

The master control unit element has an integrated web server for configuration, diagnostics and testing which allows operation with standard web browser. Simple application programs are cre-

MCPARTTI

Note

A_PWM is one of the test jack points, see PGS manual

MCPARTTI

Note

Master Control Unit means the CPU of the PLC


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ated in form of an instruction list (following IEC 61131-3), using any text editor. The program and the parameters are stored in a SIM card put in master control element.Following modules are used in dependence of the site specific configuration, whereas each mod-ule assembly consisting of maximum 8 I/O modules has to be connected to a power supply and a master control module:

Master Control Module ET10TX/V.28 / Modules

• 6 binary inputs− galvanically insulated by optocouplers− signal voltage 24-60VDC− the states of the inputs are indicated by LED’s

• 1 binary relay output (command)− galvanically insulated− the state of the output is indicated by LED

• 1 binary relay output (command, watchdog, error)− galvanically insulated− can be used either as command output, watchdog indication or failure indication− if used as command output, the state of the output is indicated by LED

• connects additional I/O modules via the internal TM (terminal modules) bus− up to 8 I/O modules

• 1 Ethernet LAN/WAN interface• indication of function and errors via LED’s• power to be supplied by power supply module PS-6620

Binary Input Module DI-6100 2x8, 24-60VDC

• 16 binary inputs• galvanically insulated by optocouplers• signal voltage 24-60VDC• removable screw terminals• the states of the inputs are indicated via LED’s

Binary Input Module DI-6101 2x 8, 110/220VDC

• 16 binary inputs• galvanically insulated by optocouplers• signal voltage 110/220VDC• removable screw terminals• the states of the inputs are indicated via LED’s

Binary Output Module DO-6212 8x 24-220VDC/230VAC

• 8 relay outputs• galvanically insulated• switching voltage 24-220VDC/230VAC• outputs can switch DC and AC voltages• removable screw terminals• the indication of function and states of the outputs via LED’s

Analog Input Module AI-6300 4x 0-20mA

• 4 analog inputs• galvanically insulated by optocouplers• acquisition of currents ±20 mA• removable screw terminals


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• function indication via LED

Analog Input Module AI-6310 4x PT100

• 4 analog inputs• galvanically insulated by optocouplers• acquisition of temperatures via PT100 resistance measurement in two-, three-, or four wire

technology• one current source is assigned to each resistance measurement• removable screw terminals• function indication via LED

Analog Output Module AO-6380 4x 0-20 mA

• 4 analog outputs• galvanically insulated by optocouplers• output of currents ±20 mA• removable screw terminals• function indication via LED


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6.3.3. Description of Software

The software comprises the program elements:• operating system with editor and monitoring functions• regulator program with site-specific setting values• sub-programs for the sub-processors used

The operating system and the regulator program run on the main processor board MRB. The sub-programs for the sub-processors of board PGS and LCOM are separate functional units. They handle certain time-critical tasks, which the main processor cannot handle (e.g. gate pulse gen-eration, actual value calculation, Ethernet communication ...).

All programs are stored on EPROMs. The site-specific parameters are saved to EEPROMs and can be changed at any time.

6.3.3.1 Operating System ECS

The operating system ECS runs on main processor board MRB. It provides the input and output conversion, co-ordinates the execution of the regulator program, as well as the data exchange to the sub-processors and it facilitates communication with the regulator via the serial service adapter on the main processor board MRB. Different monitoring functions permit selective error detection. In addition, the operating system comprises an editor, which helps to generate, change and list user programs.

Basically, the regulator is therefore a freely programmable control and regulating system, which can be programmed in a language using functional blocks. With this language, pre-defined soft-ware modules (functional blocks) are connected via a linking list to a user program. The operating system comprises a module library with a large number of analogue and digital modules, with optimized running times. The modules facilitate the implementation of regulating and control tasks.

Program Execution Control

A micro-processor can implement the individual functions only consecutively (serially). The time required to run one program one time is called "execution time". Once the end of a program is reached, the whole process is started again. Since the system is used for regulating tasks, it is necessary to run certain programs at precisely defined time intervals (program cycle time). This is achieved by starting them every 10 msec, for example. The entire execution time of a program must, of course, be shorter than the program cycle time.

Outline of program execution:

•••••••••••••••••••• •••••••••••••••••••• •···•1•2• 3 • •1•2• 3 • •1

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••···•••••••••TL••••••••••••••TW•••••••••••••••••••••TA••••••••••••••••

TL...program execution timeTW...waiting timeTA...program cycle time

Sequence:1 scan inputs2 set outputs (according to results of previous program cycle)3 execute program (the resulting new output statuses are set during the subsequent program

cycle)


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The maximum possible program size is limited by the program cycle time. In order to be able to use also comprehensive programs when cycle times are short, a user program may be divided into maximal 8 components (tasks) with different requirements on execution speed. An individual constant cycle time Ta (1 to 65535 ms) may be selected for every task.

The tasks are numbered 1 to 8, with the lower-numbered tasks having a higher priority and shorter cycle times than the higher-numbered tasks. Tasks with higher priority may interrupt tasks with lower priority. As a result, several tasks may be operated in a "quasi parallel" mode. During breaks between tasks, the service interface, and alike, are operated. While running the user pro-gram, the parameters may be set.

Example:

0 10 20 30 40 50 60 70 ms | | | | | | | |

••••• ••••• ••••• ••••• ••••• ••••• ••••• ••••T1•• ••••••• •••••••• ••••••• ••••••• ••••••• ••••••• •••••••

••••••• ••• ••••••• •••T2•••••• ••••• •••••••••••••••••••••••••••••••••••••••• ••••• ••••••••

•••••• ••••••• ••••••T3•••••••••••••••••• ••••• ••••• •••••••••••••••••••••••••••••••••••

•• •••••••HG••••••••••••••••••••••••••••••••••••••••••••••• ••••••••••••••••••••••••

T1 (Task1): TA = 10 ms, exec. time = 4 ms HG: backgroundT2 (Task2): TA = 50 ms, exec. time = 8 ms During these phases, the serviceT3 (Task3): TA = 200 ms, exec. time = 16 ms interface, for example, is served.

In the above example, Task 3 is never interrupted by Task 2 while running, but twice by Task 1.

Classes of Variables and their Formats for Display

The user program on the main processor board is programmed in a language that has been as-similated to conventional regulating and control technologies, i.e. individual elements (modules) are connected to create a global structure. Discreet circuit engineering uses wires for the connec-tions, here memory locations are used. In the system, different connecting elements ("variables") are available for the individual applications. They are distinguished according to "classes of vari-ables". In line with their area of application, the different classes of variables have different ranges of values and formats for display.

The software uses 9 classes of variables in 3 formats for display.

Classes of Variables

Digital Variables:

E: digital input variables (from the inputs of board IWN)A: digital output variables (to the outputs of board IWN)I: digital internal variables (connecting variables)C: digital internal constants


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Analogue Variables:

X: analogue input variables (from analogue input AE8, not used in the standard version)Y: analogue output variables (to analogue output AA8, not used in the standard version)V: analogue internal variables (connecting variables)P: analogue internal constants

Time Constants:

T: internal time constants

The variables of a class are distinguished by numbers behind the letters (starting at 0, e.g. C0, V251 ...).

Formats for Display

The values for the individual variables are shown on the user screen (PC, operation terminal) as follows:

Digital Variables/Constants (E,A,I,C): L, H (0, 1 on operation terminal)

The range of values comprises only the two values L (low, log. 0) and H (high, log. 1). If, for a digital parameter, the value U (undefined) appears on the screen, this is most likely due to a hard-ware fault.

Analogue Variables/Parameters (X,Y,V,P): -16.0000 to +15.9995 (p.u. format)

The following conversion applies to analogue inputs and outputs from the CAN bus modules:

-16.0000 is the negative limit of the range (-10V)0.0000 is 0V, 0(4) mA

+15.9995 is the positive limit of the range (e.g. +10V, +20mA)

The range of the analogue signals is set on the module by means of bridges (see description of respective module above)

Time Constants (T): 0 to 65535 (decimal format)

With this parameter class, all internal logic masks of the system, all communication addresses with sub-processors and the unchangeable time constants are determined. When using them as time parameters, the set value should be understood to be a factor of the cycle time.

Example: A parameter T20 is assumed for Task 1. The cycle time for Task 1 is assumed to be 2 msec, 140 was entered as the value for T20. The set time is therefore 140 x 2 msec = 0.24 sec.


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Representation of Variables within the Operating System

Within the system, the digital variables E, A, I and C are represented by "bytes" (of 8 bits). Byte value 0 corresponds to logical value L, byte value 255 corresponds to logical value H. All other values are displayed as U (undefined).

The analogue variables X, Y, V, P and T are represented by "words" (of 16 bits). On a service device, parameters X, Y, V and P are displayed in the "p.u." (per unit) format (e.g. +01.0000),parameter T in decimal format (e.g. 30100). The values have the following meaning:

internal system representation decimal format p.u.-format (two's-complement) (T) (X,Y,V,P)

32767 = 32767 = +15.9995 1 = 1 = +00.0005 0 = 0 = +00.0000

-1 = 65535 = -00.0005-32768 = 32768 = -16.0000

The computer does not make any difference between the classes of analogue variables. This distinction only serves for a clearer display.

Memory AreasThe operating system, the regulator program and site-specific values are stored on EEPROMs. The site-specific setting values can be changed at all times and saved again.

At every re-start of the system (reset, voltage failure) the system checks whether a regulator pro-gram EEPROM with an executable program is available. If this is the case, the regulator program and the setting values (from the parameter EEPROM) are loaded into the respective areas of the working memory. If this is not the case, an error message is displayed, which can be processed on an operation terminal or a PC.

Distribution of the Parameters among the Non-volatile Memories

P, T and C constants are stored on one EPROM, together with the program. They are used for basic settings and should not be changed.

The variables beyond V1800 and beyond I2000 are reserved for setting parameters and stored on EEPROMs.

MCPARTTI

Note

P- Analog Internal Constant T - Internal Time Constant C- Digital Internal constant


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6.3.3.2 Main Regulator Program

The regulator allows automatic and manual regulation. The regulator structure is embodied as voltage regulator with two control loops (master - slave) and regulates the generator or motor volt-age to an adjustable voltage set value.

The master (for voltage regulation) consists of a PI(D) regulator with integrator feedback and con-trols the slave (for exciter current regulation) with P(I) characteristics. The above structure pro-vides for a high control speed, as well as a high stability at all load points. A large number of limit-ing and additional regulators, some of which are optional features, permits a high degree of ad-justment to all requirements.

The main regulator program is executed by the main processor MRB. It was programmed, using the modules that are contained in the module library of the operating system ECS. The regulator program contains the voltage control loop, all limiting and additional regulators, as well as the logic control sequences and their monitoring functions, which are necessary for a faultless opera-tion of the complete excitation unit. The secondary exciter current loop is a component of the sub-program on sub-processor board PGS. The different functions are activated in keeping with site specifications, depending on the task in hand.

The total scope of the program depends upon the configuration of the system and is therefore variable. Chapter 1.3 gives an overview of a major part of the available regulator functions. A de-scription of the individual regulator parameters can be taken from the drawings and descriptions which are supplied with the system documentation.

The main program is divided into 8 tasks, and the variables into groups of numbers.

Division of Tasks

The below table gives an overview of the division of the regulator program into the individual tasks and the corresponding cycle times.

Task CycleNo. Time Program Component

1 2ms voltage regulator2 4ms undelayed field current limiter3 20ms load angle limiter4 50ms other limiting regulators5 50ms I/O data exchange to LCOM card6 50ms logic control7 100ms set value generation

reactive load regulationanalogue value monitoringregulator operation messageserror messages

8 300ms parameter exchangetime base conversion

Groups of Numbers for Variables

The variable numbers are split up into different groups, depending on their purpose of use.

e.g.: V0 - V199 analogue variables for regulatingI0 - I199 digital variables for regulating


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The variable numbers beyond V1800 and beyond I2000 are reserved for setting parameters and are stored on an EEPROM.

V1800 - V1899 analogue parameters

V1900 - V1949 time parameters 1.0000 = 1 secV1950 - V1999 time parameters 1.0000 = 100 sec

I2000-I2015 variables used to connect limiters and regulator add-ons

Normalizing Measuring Values

The regulator software uses normalized values for calculating. In general, every physical measur-ing value is related to its rated value and represented as p.u. (per unit) value.

Example: The machine voltage is represented by variable V501. In case of a rated voltage at the machine terminals, V501 has the value 1.0000.

6.3.3.3 Regulator Sub-Programs

Various functions, which the main processor cannot handle, are implemented by sub-processorson the PGS board. The regulator has a minimum of one PGS board with 3 sub-processors. These processors serve to calculate the actual value, to regulate the exciter current and to generate the gate pulses.

The data exchange with the main processor on board MRB is by means of DP-RAMs. A series of parameters and variables serves to complete the configuration of the individual sub-programs, as well as to monitor them.

Gate Pulse Generation, Manual Setting Operation

A gate-control unit serves to generate firing pulses for thyristors, in order to produce a variable direct voltage from an alternating voltage (thyristor voltage). The thyristor voltage can be single-phase or three-phase, and the frequency can also be variable within a broad range (e.g. in case of a permanent magnet generator). The direct current, generated at load (field, rotor), is smoothed sufficiently on account of the inductivity of the load.

Control angle α is the control input of the gate-control unit. The control angle (firing angle) is de-fined as the position in time of the firing pulse to the phase position of the phase voltage. De-pending upon the thyristor bridge, which is attached to the firing circuitry, the output voltage is generated via a certain control law, in accordance with the given firing angle.

In general, a control angle α = 0° is the rectifier end position (maximum possible positive output voltage). A control angle α = 90° results in an output voltage with a value 0, and the maximum possible control angle must be less than 180° (inverter end position, negative output voltage).

The control angle is measured from the natural firing point. This means that the gate-control must know the current phase relation of the phase voltages. In addition, it must be possible to calculate in advance at what instant a certain phase relation is reached. It is therefore necessary to know the frequency of the phase voltage. (Synchronizing the firing pulses to the thyristor voltage).

The gate-control consists of processor A, with the corresponding circuits on sub-processor board PGS and its input and output circuits. It is suited for applications in three-phase systems (6 thyris-tors) and in single-phase systems (4 thyristors). Processor A calculates the firing pulses for the thyristor bridges.


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Gate Pulse Generation

For processor A, the phase to phase synchronizing voltages US1 (L1-L3) and US2 (L2-L3) are available as measuring values and to synchronize the firing pulses (in case of single-phase sys-tems only US1 is used). Each of these voltages is filtered on board PGS and transformed by A/D converters to digital values.

The software simulates the vector of the synchronizing voltage (thyristor voltage). It serves as reference for the natural firing point, as well as for the frequency. The actual firing point of every thyristor is derived from firing angle α, which the field current regulator (processor B) computes. It can be calculated from the sum of firing angle α and the natural firing point that is assigned to the thyristor.

The rectifier limit defines the lower limit of the working range of firing angle α (rectifier operation), while the inverter limit defines the upper limit (inverter operation).

For every thyristor branch of a fully controlled bridge, a firing pulse is generated at the corre-sponding HSO (high speed output) of processor A, at the actual firing instant. The length of the firing pulse depends upon the frequency of the synchronizing voltage.

The computation method works independent of sense of phase sequence and frequency, so that the capacity of processor A is the only limiting factor. The pulse calculating program runs syn-chronously to the thyristor voltage, at a multiple (synchronizing coefficient m) of the thyristor fre-quency, i.e. the measurements and calculations are made m times in every period. The synchro-nizing coefficient satisfies the following condition:

The calculations require a certain time, which limits the synchronizing coefficient m; yet, the calcu-lations should be repeated as often as possible. This results in changing the synchronizing coeffi-cients within the operating range of the gate-control set of the thyristor bridge.

On the basis of the calculating capacity, the maximum admissible frequency of the thyristor volt-age is 540 Hz when m = 1. Together with the possible synchronizing coefficients, the program cycle time is in a range of approximately 0.3 to 1.3 msec, depending on the thyristor frequency.

Different operating modes can be configured via software input parameters:

- thyristor converter operation, 3-phase system with automatic detection of phase sequence- thyristor converter operation, 1-phase system- free-wheeling diode operation (a chain of pulses will be generated simultaneously for the

thyristors L1+ and L1-)- diode rectifier operation (a chain of pulses will be generated simultaneously for all thyristors)- gate pulse blocking (no gate pulses will be generated)


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Three-Phase Rectifier Bridge

It consists of 6 thyristors; accordingly, 6 firing pulses must be generated. The distance between the pulses is 60°.

The phase to phase voltages US1 (L1-L3) and US2 (L2-L3) are measured. The natural firing point is at 30° after zero passage of the corresponding phase voltage. Double pulses at a distance of 60° are generated during rectifier operation (firing angle α = 0...90°), i.e. for a commutation, these two thyristors which shall conduct the current always receive a firing pulse at the same time. Dur-ing inverter operation (firing angle α = 90...180°), only single pulses are generated, for reasons of safety.

The below figure shows the sequence in time of pulses in a system with positive phase se-quence: (L1+ refers to the thyristor of phase L1 in the positive semi-bridge.)

••• ••• •••L1+ (R+) •• ••••• ••••••••••••••••••••••••••••• ••

••• •••L3- (T-) •••••••• ••••• ••••••••••••••••••••••••••

••• •••L2+ (S+) •••••••••••••• ••••• ••••••••••••••••••••

••• •••L1- (R-) •••••••••••••••••••• ••••• ••••••••••••••

••• •••L3+ (T+) •••••••••••••••••••••••••• ••••• ••••••••

••• ••• ••• L2- (S-) •• ••••••••••••••••••••••••••••• ••••• ••

• • • • • • • 0 60 120 180 240 300 360 °

Pulse sequence of a three-phase bridge with positive phase sequence, and rectifier operation(related to phase L1)

Single-Phase Rectifier Bridge

It consists of 4 thyristors. 4 firing pulses are generated; of which 2 pulses must always be set at the same time (i.e. 2 pulse pairs are generated, with a distance of 180°). The alternating voltage US1 (L-N) is measured. The natural firing point occurs at zero passage of the phase voltage.

Pulse sequence:

••• ••• L+ (R+) •• ••••••••••••••••••••••••••••••••••• ••

••• ••• N- (T-) •• ••••••••••••••••••••••••••••••••••• ••

•••L- (R-) •••••••••••••••••••• ••••••••••••••••••••

•••N+ (T+) •••••••••••••••••••• ••••••••••••••••••••

• • • 0 180 360 °

Pulse sequence for a single-phase bridge (related to phase L+)


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Manual Setting Operation

The firing angle may be set manually for testing purposes. The switches for manual operation on board PGS act on the digital inputs of processor A. The instantaneous value of the firing angle is output as a signal with modulated pulse-width at an HSO (high speed output) of the processor, and can be measured at measuring jacks. Exciter Current Regulator, Free Analogue Values

Exciter Current Regulator

The regulating algorithm of voltage regulator GMR contains a secondary exciter current loop, which can also be used for manual-operation purposes. This loop with P(I) characteristic is im-plemented in sub-processor B. The P and I behavior can be configured individually or switched off.

The set value for the exciter current is supplied by the main processor. The measured value of the exciter current is filtered on board PGS and transformed into a digital value by an A/D-converter. This exciter current value is filtered in the software by a symmetrical 3rd- order low pass with adjustable time constant and supplied to the regulating algorithm as actual value.

The regulator output is the firing angle, which is transferred to the gate-control in processor A. The regulating algorithm in processor B runs synchronously to processor A and has therefore the same cycle time as the former.

Different operating modes can be configured via software input parameters:

• PI regulation, the P and I shares can be set individually.• P regulation, the P share can be set (I share = 0).• Loading the integrator with a pre-set value.• Setting the firing angle directly by main processor.

Free Analogue Values

Six analogue inputs are available via board PGS. They are used for system-specific tasks. Four inputs (ANA1 to ANA4) are converted by A/D-converters with a resolution of 12 bits. Two ana-logue values (ANA5, ANA6) are transformed into 0...+5V signals. Sub-processor B reads these values via its analogue inputs, with a resolution of 10 bits. In addition, they are filtered by the software (1st-order low passes, PT1) and supplied to the main processor via the DP-RAM. The filter-time constants can be set individually.

Analogue value 1 (V511 ANA1) is available in the main processor with a time resolution of 4 msec, all others (V512 - V516) with a resolution of 100 msec.


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Actual Value Measurement and Computation

Processor C calculates the values required for regulating and optional power system stabilizing (voltage, current, frequency, rotor angle, power, stabilizing signal ...), from the measured genera-tor or motor quantities. The calculation method is equally suited, both for single-phase or three-phase machines (turning left or right) and covers a broad frequency range. The program has a cycle time of 1 msec. The following configurations are possible.

• 3-phase systems with 3-phase measurement:• stator voltages UG1 (L1-L3), UG2 (L2-L3), stator currents IG1 (L1), IG2 (L2) • 3-phase systems with 1-phase measurement:• stator voltage UG1 (L1-L3), stator current IG2 (L2) • 1-phase systems:• stator voltage UG1, stator current IG1

These measured values are filtered on board PGS and transformed into digital values by A/D-converters with a resolution of 12 bits.

Tolerances of electrical parts in the measured-value processing may cause minor differences in amplification and zero points of the signals. They result in an asymmetry of the internal vectors. In case of a zero shift, an asymmetry occurs at basic frequency, in case of amplification differences, an asymmetry occurs at double frequency of the measured voltage. These component-dependentasymmetries have no impact on the overall functioning. They only cause a minor ripple in the thy-ristor output voltage and may be compensated, if necessary, by means of parameters V1810 to V1812 for the stator voltage, or V1814 to V1816 for the stator current (see also chapter 5 "Opera-tion and Maintenance").

Determining Active Current, Reactive Current and Active Power

The x- and y-components of the voltage vector u and of the current vector i are calculated from the measured values.

Components of the voltage vector:

)t(tru32(t)stu

31(t)xu ∗−∗−= real part of u(t)

(t)stu3

1(t)yu ∗−= imaginary part of u(t)

Components of the current vector:

)t(ri(t)xi = real part of i(t)

))t(si2(t)ri(31(t)yi ∗+∗−= imaginary part of i(t)

(The inferior characters r, s, t refer to the phases L1, L2, L3.)

All other dimensions are calculated on the basis of the above x- and y-components. The vectors are shown in the below figure.


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Vector diagram for machine voltage and current

Active current iw corresponds to the value projected for current vector i on voltage vector u,while the reactive current ib corresponds to the component that is in an orthogonal relation to it.

In a three-phase system, the instantaneous value for the normalized active power is determined as product of the voltage vector with that part of the current vector that is in phase therewith. This part corresponds to the active current.

(t)wi)t(up(t) ∗= active power

Determining the Load Angle

When referring to the load angle of synchronous machines, one must distinguish between an internal and an external angle. As can be seen from the below vector diagram, the internal load angle δi is the angle between the vector of the fictitious rotor EMK e p (which is identical to the quadrature axis of the rotor) and stator voltage u. The external load angle δa is found between e p and line voltage u n. Angle δa is decisive for the stability of the machine. This value is calcu-lated and provided for the limiters.

For the calculation, e p is replaced by the vector with the same phase relation e. Internal voltagee and line voltage u n can thus be obtained.

qxji(t)u(t)e(t) ∗∗= internal voltage

nxji(t)u(t)(t)nu ∗−= line voltage

The angle between these two vectors determines the external load angle δa.


Dwg.No.: 3 570 087 Rev.A


Vector diagram to calculate the load angle of a synchronous machine

xd ..... synchronous direct axis reactance of the machinexq ..... synchronous quadrature axis reactance of the machinexn ..... net reactance


Dwg.No.: 3 570 087 Rev.A


7. INTERFACE OF EXCITATION SYSTEM

7.1. EXCITATION POWER CIRCUIT

7.1.1. Connection of the Field Winding of the Exciter Machine

Signal name EXCITREXCIT:The output of the excitation system for the supply of the field winding is carried out via terminals-X01/3 (positive current) and -X01/4 (negative current).

7.1.2. Excitation AC Supply

Signal name EXCIT PWRSPLY:The three phase AC power supply of the excitation system is connected to terminals –X01/6, 9 and 12.

7.1.3. Current Forcing

Signal name FORCE PWRSPLY:For the current forcing circuit the battery supply 125 Vdc (2) has to be connected to the termi-nals–X01/1 (plus) and –X01/2 (minus).

7.1.4. CT / PT and Actual Measured Value Connections

Signal name AVR VOLTMEAS1:The actual measured values of the generator voltage and current is applied as three phase. The actual measured values connection can be with either a clockwise or anticlockwise phase rotation whereby the former is preferred.

CAUTION

The correct allocation of the current vectors and voltage vectors has to be strictly observed!

The three phase actual value of the stator voltage L1, L2, L3 has to be connected to the terminals –X10/34, 36, 38.Signal name AVR VOLTMEAS2:In case of optional dual channel regulator, for redundancy the actual value has to be connected to the terminals –X10/06, 07, 08.Signal name MEAS CURRMEAS:The phase currents from CT's L1 and L2 are allocated to terminals –X10/02 (→) and –X10/01 (←)for L1 and terminals –X10/04 (→) and –X10/03 (←) for L2.For the optional energy meter or transducers with analogues output signals for active and reactive power, stator current and power factor also the third phase form CT is needed, this will be con-nected to terminals –X10/06 (→) and –X10/01 (←).

Note: -X10/02 (→) means, the current is entering terminal –X10/02 of the excitation system-X10/01 (←) means, the current is leaving terminal –X01/02 of the excitation system


Dwg.No.: 3 570 087 Rev.A


8. LOCAL OPERATION

8.1. Introduction

Touch Panel user interface is integrated in the digital voltage regulator GMR3 and provides easy local operation along with indication of all generator quantities and last alarm indication facilities.Reference values can be changed with the Touch Panel.

The main features of the Touch Panel are:• On-line display of the system status in plain language• Keys provide all direct local operation commands necessary• Menu guided service and maintenance functions• The most important actual values are displayed in physical quantities.• All actual values are displayed in per unit values.• Reference values for generator voltage and field current are displayed in per unit values.• Alarm messages provide precise trouble shooting information.• Automatic display of self-supervision functions in case of an AVR failure, indicating the defec-

tive hard- or software component.

The easy, menu guided operation and the status display in plain language result in a significant improvement compared to conventional user interfaces. All necessary operation procedures can be carried out with the Touch Panel. Hence no additional terminal or a PC is necessary for oper-ating the excitation system equipped with GMR3 digital regulator.

CAUTION

Any regulator-manipulation with the Touch Panel or a PC constitutes an operating risk for the generator in operation! The staff responsible for the operation of the generator must be contactedprior to any such intervention!

The manufacturer of the terminal does not assume any liability for any possible damage or oper-ating stoppage!

8.2. Description of Functions

8.2.1. Basic Screen - Main Menu

A nine-pole cable connects the Touch Panel to the third RS 232 C interface of the COM4 card of the GMR3 regulator via Modbus communication.After connecting the Touch Panel to the COM4-board the communication starts which can be seen by the blinking LED’s. The basic screen shows a menu with a short description how to oper-ate with Touch Panel.The operation with pressing the buttons is as follows.F1 to go to main menuF2 to go to alarm pageF3 to go to next screenF4 to go to previous screenF5 to reset the alarms and stop the buzzerF6 to enable the AVT operation


Dwg.No.: 3 570 087 Rev.A


9. REMOTE CONTROL

Following signals coming from periphery are connected to the digital input module.

9.1. INTERFACE

9.1.1. Digital Inputs

B Excitation On L41FXAutomatic closing orderB Excitation Off L83SRXSpeedtronic field breaker permissive to closeM Unit Circuit Breaker Off UNITBRK POS1Generator circuit breaker position M Line Circuit Breaker Off LINEBRK POS1Line circuit breaker positionB Excitation Raise AVRINC CMDExcitation increasing order 83RVB Excitation Lower AVRDEC CMDExcitation decreasing order 83LVB Remote 43R L43RLocal/remote selectionB Turbine Normal Stop L94X194X1=1 in case of 32L and 94X1=0 in case of 32RB Dead Bus Automatic Order L52GCXDead bus automatic order to close 52GB Remote Channel Selection AUTOAVR SELRemote channel selection auto 1 / auto 2B PSS Off PWRSTABAYS INHInhibition of power system stabilizerSFC Starting Order EXCIT START CMDOn command for the excitation for the rotor supplyDeadbus synchro permissive to close DEADGRIDSYNCEN


Dwg.No.: 3 570 087 Rev.A


9.1.2. Digital Outputs

M Excitation Manual MANU AVR ONManual feedback positionM Excitation Automatic AUTO AVR ONAutomatic feedback positionM LocalM Synchronization Automatic L43S AUTOAuto/manu selection synchronization modeM PSS On PWRSTABSYS ONPower system stabilizer is activeM Generator Alarms GENTR ALARMGrouped alarm of GCPM Excitation Trip

9.2. OPERATING MODES

9.2.1. Voltage Regulator (Automatic Mode)

For shunt field excitation systems the initial excitation is switched on with the beginning of the excitation sequence and deactivated when a minimum thyristor voltage is reached.

In this operating mode the generator voltage is regulated to the adjusted set value. The setting range for the set value is adjusted to the permissible limits of the generator and can be viewed and changed with the User terminal in the menu Regulator Settings as "Max. Reference Value UG" or "Min. Reference Value UG"

The regulator is locally brought to this operating mode with the AUTO/MANUAL key.

When the ON command is given an internal automatic sequence is executed which is first closing the field breaker. When all commands are accomplished an all feedback signals available then the "EXCITATION ON" indication is set and displayed locally and also the "M Excitation On" out-put activated. After completing the start-up sequence the machine is always regulating to the set "Start Reference Value UG".After the ON indication the voltage can be controlled either from remote or locally with the keys. Thus in on-load operation the voltage and therefore also the reactive power is regulated.

9.2.2. Field Current Regulator (Manual Control)

The starting sequence is terminated when a minimum value of thyristor voltage or othyristor cur-rent is attained and the field current is then regulated to a starting value (factory setting 0,45 pu).This operating mode is applied for test purposes as well as case of actual value loss of the volt-age regulator. During on-load operation in this mode the generator values have to be perma-nently checked and when necessary in case of power system fluctuations or generator load changes the generator voltage respectively the reactive power controlled accordingly. Further, no limiters are active and also the additional regulator cannot be selected and activated.

The regulator is pre-selected for this operating mode via the AUTO/MANUAL key. After start-upthe current regulator is regulating to the starting set value "Start Reference Value IF", the genera-tor is excited to a value corresponding to this field current and can be brought from there on to nominal voltage with the key.


Dwg.No.: 3 570 087 Rev.A


When the excitation is changed to test operation the starting set value is equal to the negative limit of the field current regulator, which is less then 0 to have a secure condition after starting of the excitation in manual mode.

The control sequence and the start conditions are analogous to the automatic mode of operation.The setting range for the set value can be viewed and modified under option "Max. Reference Value IF" and " Min. Reference Value IF".

9.2.3. Change Over Between the Automatic and Manual and Power factor / Reac-tive Power Regulation Mode

The operating modes can be changed locally:

• During operation whereby an automatic follow-up feature will ensure matching between the active and not active channel whereby at any time a smooth transfer is taking place.

• By failure of the automatic operating mode an automatic change over to manual mode is per-formed. This transfer is initiated upon loss of the generator voltage actual value. A transfer from manual- to automatic mode can be performed locally or with a remote signal.

• When the "AUTO" mode is pre-selected the additional regulator can be selected locally via the "p.f. / VAR" keys. The optional additional regulator must be activated in regulator software and this is done if the reactive load regulator are provided.

• In case the power factor- or reactive power regulator is active and it is transferred to "MANUAL" then the previous operating mode is not stored and when it is changed back to "AUTO" the power factor- or reactive power regulator has to be activated again.

• If the regulator is in manual mode during the switching on of the generator circuit breaker the regulator makes an automatically change over to the automatic mode.

When during operation the operating mode is transferred to manual then it will also remain in this state during shut down, standstill and re-start as long as the AUTO/MANUAL key of the excitation is operated.

Note: In case a transfer from manual- to automatic operating mode is blocked then possibly the generator voltage is outside the automatic regulating range.

9.3. DE-EXCITATION

De-excitation can be performed during normal operation or due to a protection trip. The "EXCITATION OFF" command can be given from remote or locally.

During an operational shut down first of all the thyristor will internally change into converter opera-tion. Thus the energy stored in the field is dissipated and the field breaker opened with a time delay and therefore for it's main contacts under no-load conditions.

During an external protection trip as well as an internal forced shut down the de-excitation contac-tor is directly and immediately operated and a follow-up of the control circuits is carried out.


Dwg.No.: 3 570 087 Rev.A


10. MAINTENANCE AND TROUBLE SHOOTING

10.1. ALARM ANNUNCIATION

10.1.1. General and Accepting/resetting

CAUTION

Opening the GCP cubicle and working in the excitation system under voltage is dangerous and therefore strictly prohibited until all supplies have been switched off.

The more important components which are catering for correct operation and provisions for safety are partly supervised by electrical contacts or monitored via the software.

Each abnormal condition in the excitation system is indicated on the LC display and depending on it's cause and importance will produce an alarm annunciation, a trip or a transfer of operating mode. A common external annunciation for alarm and trip is included in the system.

The alarm menu is accessed by either pressing MENU/ENTER or by operating any of the number keys.

Each alarm annunciation is displayed by a text line, yet a fault can also initiate several annuncia-tion thus providing additional information of the occurring fault condition (e.g. "voltage actual value failure" and "mcb trip alarm").

A flashing * asterisk on the left of the annunciation indicates an alarm status which can only be reset once the fault has disappeared. It could also happen that a fault is cancelled by a shutdown and reoccurs when starting up again (e.g. a missing actual value, an excessive operating se-quence runtime, etc.).

The order of the annunciation corresponds to the time sequence of the faults occurring and is independent from the alarm being either steady-on or gone. The uppermost line represents the most recent alarm.

Example:

Last (most recent) alarm

Flashing asterisk: steady-on alarm

By operating the scroll down key the earlier alarms occurred are displayed.

It is recommended that at each fault displayed to refer to the following fault check list, to find and rectify the cause to exchange a possibly faulty component.Have all LED's on the MRB3 module gone out then the power supply has failed and also the User operating unit cannot provide information anymore. In this case the watchdog facility will initiate an external alarm.

start overtime trip thyr. current fail∗thyristor fuse fail∗m.c.b. tripped


Dwg.No.: 3 570 087 Rev.A


10.1.2. List of Possible Alarm Annunciation

01 start overtime trip I901 V791.00 49 invalid parameter I949 V794.0002 stop overtime trip I902 V791.01 50 exc.overcurr. trip I950 V794.0103 volt.sensing fail I903 V791.02 51 I951 V794.0204 field breaker fail I904 V791.03 52 PIM0 man.gate contr I520 V794.0305 field flashing fail I905 V791.04 53 PIM0-A program stop I521 V794.0406 AC supply fail I906 V791.05 54 PIM0-A synchr. fail I522 V794.0507 DC supply fail I907 V791.06 55 PIM0-B program stop I523 V794.0608 I908 V791.07 56 PIM0-C program stop I524 V794.0709 standby chann. fail I909 V791.08 57 PIM0 communic.error I525 V794.0810 I910 V791.09 58 PIM0 proc. A,B fail I526 V794.0911 I911 V791.10 59 PIM0 proc. C fail I527 V794.1012 m.c.b. tripped I912 V791.11 60 LCOM DPR comm. fail I528 V794.1113 AC-overvolt.pr.fail I913 V791.12 61 LCOM bus conn. fail I529 V794.1214 I914 V791.13 62 COM4 DPR comm. fail I500 V794.1315 I915 V791.14 63 I501 V794.1416 exc.overcurr. warn I916 V791.15 64 I502 V794.1517 I917 V792.00 65 I503 V795.0018 rotating diode fail I918 V792.01 66 I504 V795.0119 thyristor volt.fail I919 V792.02 67 I505 V795.0220 thyr.current fail I920 V792.03 68 I506 V795.0321 I921 V792.04 69 I507 V795.0422 thyr.fuse failure I922 V792.05 70 I508 V795.0523 I923 V792.06 71 I509 V795.0624 fbr.open gcbr.close I924 V792.07 72 I511 V795.0725 I925 V792.08 73 I512 V795.0826 I926 V792.09 74 I513 V795.0927 I927 V792.10 75 I514 V795.1028 thyristor temp.high I928 V792.11 76 I515 V795.1129 gate pulse fail I929 V792.12 77 I516 V795.1230 pulse relay fail I930 V792.13 78 I517 V795.1331 I931 V792.14 79 I518 V795.1432 remote setval. fail I932 V792.15 80 I519 V795.1533 I933 V793.00 81 I952 V796.0034 exc.trans.temp.warn I934 V793.01 82 I953 V796.0135 exc.trans.temp.trip I935 V793.02 83 I954 V796.0236 exc.trans. fail I936 V793.03 84 I955 V796.0337 I937 V793.04 85 I956 V796.0438 max.exc.lim. active I938 V793.05 86 SFC summary trip I957 V796.0539 gen.curr.lim.active I939 V793.06 87 I958 V796.0640 load angle lim.act. I940 V793.07 88 I959 V796.0741 over flux lim.act. I941 V793.08 89 I960 V796.0842 min.volt. lim.act. I942 V793.09 90 I961 V796.0943 boosting trip I943 V793.10 91 I962 V796.1044 gen.short circuited I944 V793.11 92 I963 V796.1145 I945 V793.12 93 I964 V796.1246 I946 V793.13 94 I965 V796.1347 forcing trip I947 V793.14 95 protection watchdog I966 V796.1448 TP communic. error I948 V793.15 96 I967 V796.15


Dwg.No.: 3 570 087 Rev.A


10.1.3. Detailed Specification

901 Start overtime trip Result: TripSupervised:Runtime supervision (internal software logic).Cause: Excessive starting time during start-up se-

quence;Initial excitation voltage missing;Malfunctioning of a relay or contactor;Malfunction of input output modules;Malfunction of de-excitation contactor;Missing feedback signal.

Measures: Check all voltage supplies;Check inputs and outputs of interface relays;Check contactors and feedback signals.

902 Stop overtime trip Result: TripSupervised:Runtime supervision (internal software logic).Cause: Excessive starting time during shut down se-

quence;Malfunctioning of a relay or contactor;Malfunction of module DE inputs or DA outputsMissing feedback signal.

Measures: Check all voltage supplies;Check inputs and outputs of interface relays;Check contactors and feedback signals.

903 Voltage sensing fail Result: Transfer to MANUAL when AUTO mode;Alarm when in MANUAL mode;Channel change-over in case of dual channel regulator.

Supervised: Internal software logic;Cause: Loss of PT voltage during operation;

PT mcb trip;Generator PT or interposing PT fault;Disruption of actual value circuit.

Measures: Check PT and PT-wiring; switch on PT mcb; slowly raise voltage in manual mode and meas-ure generator voltage(also internal variable UGK V501);Change back to AUTO mode.

904 Field breaker fail Result: TripSupervised:Position indication circuit of field breaker;

Additional information to runtime supervision.Cause: Fault in the field breaker ON control circuit;

Malfunction of field breaker;Start overtime or stop overtime time trip;Field breaker switched off during operation;Fault in position indication circuit;Missing feedback signal.

Measures: Check all voltage supplies;Check field breaker and ON circuit;Test trip circuits.


Dwg.No.: 3 570 087 Rev.A


906 AC supply fail Result: Alarm dual channel regulator;Trip single channel regulator.

Supervised: Internal software logic or thyristor fuses or mcb -F09 trip.

Cause: Gate control set cannot synchronize impulses;Lack of thyristor voltage during operation;Thyristor fuses trip;Regulator mcb -F09 (-F19 dual channel regula-tor) trip (regulator supply);Excitation transformer HV fuse blown;Short circuit or overload of excitation supply cir-cuits.

Measures: Switch on mcb or replace fuse;Check excitation transformer or regulator trans-former;Check thyristor fuse;Check power supply cables.

909 Stand-by channel fail Result: AlarmSupervised: Internal software logic.Cause: Change-over to stand-by channel is not allowed.Measures Check the stand-by channel according its fail-

ures.912 mcb tripped Result: Alarm

Supervised:Auxiliary contacts of mcb’s .Cause: Short circuit;

Overload.Measures: Switch on the mcb’s;

Check the respective current.916 Excitation overcurrent

alarmResult: AlarmSupervised:Overcurrent protection relay.Cause: Overcurrent in field circuit.Measures: Check the field circuit;

Check the actual value of field current.918 Rotating diode fail Result: Trip

Supervised:Software monitoring (evaluation of field current higher harmonics).

Cause: Short- or open circuit of rotating diode.Measures: Check flywheel diodes rectifier in rotor circuit;

Replace defective parts.Note: When fault occurs during normal operation with-

out any diode fault then the trigger value for di-ode failure supervision has to be increased.


Dwg.No.: 3 570 087 Rev.A


919 Thyristor voltage fail Result: TripSupervised: Internal software logic – additional information to

runtime supervision.Cause: Start-up overtime;

After starting AC thyristor voltage is not estab-lished;Thyristor fuse blown;Station supply too low or not available (at test supply);Initial excitation voltage too low or not available.

Measures: Measure station supply voltage;Check supply fuses;Check thyristor fuses;Check initial excitation circuit;Check matching transformer;Check power supply cable.

920 Thyristor current fail Result: TripSupervised: Internal software logic - additional information to

run-time supervision.Cause: Start-up overtime;

After starting thyristor current is not established;Thyristor fuse blown;Initial excitation voltage too low or not available.

Measures: Check initial excitation voltage and supply fuses;Check thyristor fuses;Check initial excitation circuit;Check matching transformer;Check power supply cable.

923 Thyristor fuse trip Result: Alarm dual channel regulator;Trip single channel regulator.

Supervised:Micro switches mounted on the fuses of the thy-ristor bridge.

Cause: Short circuit on;Defective thyristor;Defective AC overvoltage protection circuit;Excessive overload due to fault.

Measures: Check thyristors;Check AC overvoltage protection circuit;Replace the defective fuse(s).


Dwg.No.: 3 570 087 Rev.A


929 Gate pulse failure Result: Trip single channel regulator;Alarm dual channel regulator.

Supervised: Internal software logic.Cause: Thyristor current less then 0.1 p.u., caused by

missing or incorrect firing pulses;Fault in a pulse cable;Gate pulse transducer board LG6;Gate pulse output board PGS;Change over board ZUP (cold stand-by rectifier).

Measures: Check firing pulses on all p.c.b.’s;Check the wiring of the firing pulses to the thyris-tors.

930 Pulse relay fault Result: Trip single channel regulator;Alarm dual channel regulator.

Supervised: Internal software logic.Cause: Defective gate pulse blocking relay;

Wiring fault.Measures: Check the relay on board LG6;

Check the wiring and voltages to board IWK.932 Excitation overcurrent trip Result: Trip

Supervised:Overcurrent protection relay.Cause: Field current regulator failure.Measures: Check the actual value of field current;

Check the circuit for the actual value of field cur-rent;Check the overprotection relay.

934 Excitation transformer tem-perature warning

Result: AlarmSupervised:Signal to the regulator coming from transformer

temperature detection.Cause: Overload;

Insufficient cooling.Measures: Decrease reactive load;

Wait cooling, clean air inlets.935 Excitation transformer tem-

perature tripResult: TripSupervised:Signal to the regulator coming from transformer

temperature detection.Cause: Overload;

Insufficient cooling.Measures: Decrease reactive load;

Wait cooling, clean air inlets.937 HV fuse fail Result: Alarm

Supervised:Signal to the regulator coming from HV fuses.Cause:Measures:


Dwg.No.: 3 570 087 Rev.A


944 Generator short circuited Result: TripSupervised: Internal software logic.Cause: Stator current rising during initial excitation;

Generator terminals are short circuited.Measures: Check generator busbar.

947 Current boosting trip Result: TripSupervised: Internal software logic.Cause: Defective current boosting circuit;

Defective contactor;Measures: Check the current boosting circuit;

Check the contactor.948 Touch Panel Communica-

tion failResult: AlarmSupervised: Internal software logic.Cause: Defective modbus communication board COM4;

Defective Touch PanelBad connection of the modbus link.

Measures: Check the communication card;Check Touch Panel;Check the modbus link.

949 Invalid parameter Result: TripSupervised:Software monitoring.Cause: No valid parameter set in EEPROM processors.Measures: Load and save BIN-file or change MRB3 mod-

ule.520 PIM0 manual gate control Result: Alarm

Supervised: Internal software logic.Cause: Switch HST on PGS module set to 1. Gate con-

trol is switched to manual operation, regulator is disabled!

Measures: After finalizing tests change switch back again.522 PIM0-A synchronization fail Result: Trip

Supervised:Software monitoring;Cause: Grid regulator unable to synchronize impulses.Measures: Check and measure voltages on regulator sup-

plytransformer T05;Check plug-in connector PGS-IWK.

521 PIM0-A program stop523 PIM0-B program stop524 PIM0-C program stop525 PIM0 communication error526 PIM0 processor A,B fail527 PIM0 processor C fail

Result: Alarm or trip, depending on type of failureSupervised: Internal software logicCause: Defective circuit on board PIM, or communica-

tion with the main processor board MRB3 failed.Measures: Replace board PIM.

NO LOCAL ANNUNCIATION, HOWEVER A PERMANENT TRIP

Result: Trip; external annunciationSupervised:Regulator watchdog.Cause: Regulating supply failure; Microprocessor

stopped, therefore no alarm indication.Measures: Check regulator supply


Dwg.No.: 3 570 087 Rev.A


10.2. FAULTFINDING

SYMPTOMS POSSIBLE CAUSE SOLUTION

Generator voltage not being established

Voltage supply for initial excita-tion not connected

Connect voltage supply for initial exci-tation to the terminals FLASH/BOOSTPWRSPLY

Regulator selected to "MANUAL" operating mode

Change regulator to "AUTO" mode

Field breaker is in open position Check control circuits

No voltage on terminals EXCITPWRSPLY

Check fuses, wiring and rating of power transformers

No connection between excita-tion system and field of exciter machine

Check wiring

Thyristor fuses not inserted or blown

Check nominal value and insert fuse

Generator voltage only 2...3 % of UGN

Exciter machine or rotating diode wheel faulty, open circuit in rotor

Shut down unit and measure diodes of exciter machine

Regulator selected to "MANUAL" operating mode

Change regulator mode to "AUTO"


Dwg.No.: 3 570 087 Rev.A



Terminal voltage is rising to approx. 80 % UGN and falls back again

After initial excitation the thyris-tors do not take over the field current because of:

Thyristors faulty Check thyristors:G-C circuit:R=5...100RC-A circuit: R>100K (+) and (-)

Thyristor fuses not inserted or defect

Check fuse rating and insert fuses

No firing impulse on thyristors Regulator board PGS does not pro-duce impulses, therefore replace board

Terminal voltage toohigh and uncontrolla-ble

No actual value on terminals AVRVOLTMEAS

Check wiring

Actual value mcb open position Close actual value mcb

Actual value circuit connected to wrong voltage

Check PT rating and wiring

Voltage set value not calibratedcorrectly

Re-calibrate voltage set value properly (NormUg V1813)

Thyristors faulty, continuous fir-ing

Check thyristors

Terminal voltage is not exactly rising to nominal voltage

Parameter for start-up set value incorrectly adjusted

Set parameter for start-up set value SWAU V1827 to 1,0

Terminal voltage too high or too low but controllable

Actual value circuit connected to wrong voltage

Check PT rating and wiring

Voltage set value calibrated not correctly

Adjust voltage set value properly (Nor-mUg V1813)

Regulator selected to "MANUAL" mode

Change regulator to "AUTO" mode of operation


Dwg.No.: 3 570 087 Rev.A



Inaccurate or slow regulation

According to the machine data required excitation voltage at full load is larger than the maximum excitation system output voltage; Field section connected in series

Check design and/or contact VA TECH SAT / dept. PE

Regulator not optimised Optimise regulator

Fault in generator, excitation machine or the rotating diode wheel, increased field current

Shut down unit and check diodes; replace if necessary

Reactive power static (BSTAT V1831) not in 0 position (only recognised in isolated operation, is all right for system on-loadoperation)

Does not represent a fault since for stability when operating in parallel to the grid a reactive static is required (either natural transformer static and or static of voltage regulator). Accu-racy can be enhanced by varying static into 0 direction (caution! A ma-chine with a too low static will be un-stable in on-load operation).

Generator unit not on nominal speed

Adjust to nominal speed

Thyristor fault in power circuit Measure thyristors as outlined before

Terminal voltage ex-cessive overshoot during start-up

Soft-Start parameter not properly adjusted

Set parameter for Soft-Start properly

Terminal voltage os-cillates

Frequency unstable Optimize turbine regulator, fault not within excitation system


Dwg.No.: 3 570 087 Rev.A



Terminal voltage os-cillates (continued)

System voltage oscillation due to loading or unloading high con-sumers

Represents no fault since the con-sumers are causing voltage dips or raise when connected or discon-nected which only can subsequently be compensated by the voltage regu-lator. Oscillations can possibly be re-duced by raising the reactive static from 0 further to negative direction (BSTAT V1831) or varying VPU V1872

Intermittent fault in generator, in exciter machine or in diode wheel

Shut down unit and check diodes of the exciter machine

When connected in parallel to the grid system no reactive load static can be attained (reactive cur-rent is running off) or the voltage regulator is responding too vio-lently on small system changes or when op-erating in parallel with other units the reac-tive power distribution is oscillating

Reactive power static (BSTAT V1831) set too low or to 0

Static CT or PT actual value not connected to the correct phases or wrong polarity

Increase reactive power static from 0 into negative direction (BSTAT V1831)Check wiring and correct if necessary. With single phase measuring the CT has to be located in the phase which is not used for voltage measuring

Static CT polarity not correctly connected or even still short cir-cuited

Check wiring and CT terminal stripsCheck an calibrate active- and reac-tive power to a value and polarity


Dwg.No.: 3 570 087 Rev.A



Reactive power shar-ing not equal but sta-ble

Reactive power static (BSTAT V1831) not equally set on units operating in parallel

Check setting and equally adjust reac-tive power static(BSTAT V1831)

Unable to control the excitation system

System is selected to "REMOTE" Change operating mode to "LOCAL"

Some control func-tions cannot be exe-cuted

Some inputs or outputs faulty Replace the input and output modules

User terminal defect Replace User terminal

Diode failure supervi-sion is activated dur-ing normal system operation

Fault in rotating diode wheel Shut down unit and check diodes of excitation machine

If diodes are in order: Increase trip setting (V2003)


Dwg.No.: 3 570 087 Rev.A


10.3. FAULTY PRINTED CIRCUIT CARDS

When the digital system is running, on the board MRB3 following LED's must be active:

RUN, HWOK, POWER

If one of the LED's is not active, then each of the cards can be the reason for this. By change of the individual cards the defective card can be fixed.

If spare cards are delivered, then these spare cards are identical with the cards in operation. That means, they have installed the same software, parameters and jumpers. Nevertheless before changing a card an optical check should be performed:• Is there a visual mechanical of electrical damage?• Do all jumpers match with the original card?• Do all switch positions (f.e. DIP switches) match with the original card?• Can you conclude from different EPROM labels to different program versions?• Do the IC equipment match with the original card (especially EPROM's)?

Each pcb is fixed by screws on the front plate (top and bottom screws). To pull out and to plug ina card the voltage supply must be switched off (the best is to switch off the DC voltage supply of the regulator GMR3).

CAUTION

Switching off the mcb -F91 (in dual channel design -F92) results in every case in a trip of the exci-tation!

After change of the card and restoration of the operation conditions (fix all plugs and screws) the voltage can be switched on again by operation the mcb.

If all card are ready, then after switching on the voltage supply the LED "POWER" on the MRB3 card must be active. After an initialization time of the MRB3 card of approx. 8 sec. the LED's RUN and HWOK must become active. Then the GMR3 and so the excitation system is ready for opera-tion again. The user terminal needs (approx.) 8 sec. more for readiness of indication and com-mands.

If not so, then the replaced card was not the reason for the failure and faultfinding responding changing of cards must be continued.

After replacement of a card we recommend to perform a complete start/stop procedure of the excitation until reaching nominal voltage of the generator. During this sequences the function of the excitation shall be observed.

10.4. PERIODIC MAINTENANCE

With the exception of relays, contactors and ventilator there are no other moving parts in the exci-tation and therefore the system can be referred to as being almost maintenance-free. The equip-ment should be cleaned at regular intervals, the terminal connection checked and tightened if necessary.


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11. INSTALLATION

CAUTION

1) Insulation- and high voltage tests can internally be done only by the power circuits. Improper application can severely damage semiconductors or solid state modules of the excitation sys-tem!

2) Assembling of the excitation system must be carried out very careful with due consideration of the technical data of the synchronous generator and the CT's and PT's. Even short operation with incorrect connections may destroy the excitation equipment.

All devices are naturally cooled except the rectifier cooling of the SFC start and should not be mounted in the vicinity of heat producing equipment or installed in such enclosed places where the ambient temperature is exceeding the maximum permissible operational temperature.


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12. PRE-SETTINGS FOR COMMISSIONING

12.1. SWITCHES ON MRB3 MODULE

The DIP switches on the front plate of the MRB3 module have always to following positions (for parameter setting as well as for operation). Merely for loading a modified parameter into the EEPROM the parameter I419 should be set high, during the updating of EEPROM the UPD-LEDblinks shortly.

OUT EN 1 outputs activeAUTRES 2 auto reset activeAUTSTA 3 N auto start activeNOQUIT 4 O program stop enabledBATT 5 R battery supervision lockedHW EN 6 M hardware activeAP ROM 7 after reset EEPROM -> user programROM PR 8 write protected

12.2. LIST OF THE CONFIGURATION PARAMETERS

The parameters listed in Settings and Scalings are required for configuration and have to be veri-fied and if necessary corrected before commissioning.

Testing and setting is carried out via the User terminal in terminal operation mode.

NOTE

After parameter modification these data have to be stored in EEPOROM.

12.3. CALIBRATION OF LC-DISPLAY

In order that the measured value shown on the LC display correspond with the actual physical ranges have to be calibrated. Calibration is carried out in a way that the entered value according to the instructions below is corresponding to the 1 p.u. value of the variable.

The representation of the calibration parameter is based on a diminished floating point format whereby the last digit of the parameter is interpreted as exponent and the first four as mantissa.

The corresponding variable is computed with the computing format, a 5-digit integer number. For the input into the User terminal it has to be converted to the entry format (decimal point in format +00.0000).

Format: XXXXE

e.g.: V1005 = 01006 (computing format): 100*10E6 = 100 MWV1005 = 00103 (computing format): 10*10E3 = 10 kV

Largest value of mantissa: 6553Largest value of exponent: 6 (above values are not considered).

Mantissa

Exponent


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Following calibration parameters and actual values are used:

Actualvalue

Calibration parameter

Generator voltage V501 V2102Generator current V503 V2103Active power V574 V2104Reactive power V65 V2104Field current V500 V2101

Converting the computing format (CF) into entry format (EF):

0 ≤ V (CF) ≤ 32767: V (EF) = V (CF) / 2048 (V with positive sign)32768 ≤ V (CF) ≤ 65535: V (EF) = V (CF) / 2048 - 32 (V with negative sign)

Example: V (RF) = 1006 ⇒ V (EF) = 0.4912V (RF) = 40004 ⇒ V (EF) = -12.4668

Note: After the decimal point there must be 4 digits whereby the last digit is rounded (from 0, i.e. with negative integers rounded to negative: -12.46679 ⇒ -12.4668)

Output Format:

The terminal is operating with 2 output formats, which are specified in the terminal text file.

Format 1: 4 digits, including decimal point: only negative sign is issued.Format 2: 4 digits, including decimal point: correct sign is always issued.

The choice of the exponents influences the number of digits after the decimal point. The number of digits before the decimal point is fixed. There are always 4 digits produced including zeroes before the point. In case of an overflow the output will exceed 4 digits.

Entering kVA Ratings:

Machine nominal rating V1005 (CF) Output format<2 kVA XXXX0 +yyyy VA2...20 kVA XXXX1 +yy.yy kVA20...80 kVA XXXX2 +yyy.y kVA80 kVA...2 MVA XXXX3 +yyyy kVA2...20 MVA XXXX4 +yy.yy MVA20...80 MVA XXXX5 +yyy.y MVA80...6553 MVA XXXX6 +yyy MVA

Example: Snom=40 MVA: V2005 (RF) = 40004 Output at Pnom: +40.00 MWV2005 (RF) = 04005 Output at Pnom: +040.0 MWV2005 (RF) = 00406 Output at Pnom: +040 MW

Example: Snom=100 VA: V2005 (RF) = 01000 Output at Pnom: 100 WV2005 (EF) = 0.4883


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Entering Voltages:

Machine nominal voltage V2007 (RF) Output format<6553 V XXXX0 Yyyy V<8 kV XXXX1 (y)y.yy kV>8 kV XXXX2 yy.y kV

Example: Vnom =8 kV: V2007 (RF) = 08001 Output at Vnom: 8.00 kVV2007 (RF) = 00802 Output at Vnom: 08.0 kV

Example: Vnom=100 V: V2007 (RF) = 01000 Output at Vnom: 100 VV2007 (EF) = 0.4883

Entering Currents:

Stator-/ Field nominal current V2004, V2006 (RF) Output formatI ≤ 10 A XXX8 y.yy AI ≤ 25 A XXX9 yy.y AI ≤ 300 A XXXX0 (y)yyy A (I > 50 A)

(y)yy.y A (I < 50 A)I >300 A XXXX0 Yyyy AI >1000 A XXXX1 y.yy kA

Example: Inom=1000 A: V2006 (RF) = 01001 Output at Inom: 1.00 kAV2006 (RF) = 10000 Output at Inom: 1000 AV2006 (RF) = 10000 Output at Inom: 1000 A

Example: Inom=25 A: V2004 (RF) = 00250 Output at Inom: 25.0 AV2004 (EF) = 0.1221

Inom=13,5 A: V2004 (RF) = 01359 Output at Inom: 13.5 AV2004 (EF) = 0. 6636

Inom=8,5 A: V2004 (RF) = 08508 Output at Inom: 8.5 AV2004 (EF) = 4.1543

Note: For currents < 50 A a digit after the decimal point is produced.(y)..... 'Overflow', can also be applied intentionally.For values >1000 A optionally XXXX1 or XXXX0 can be used.


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13. COMMISSIONING

13.1. PREPARATION FOR COMMISSIONING

Before commissioning it has to be checked whether the ordered and delivered excitation system parameters are identical to plant requirements – especially the voltage range.

CAUTION

Following items have strictly to be verified to ensure perfect operation of the excitation system:

1) Check design and external components2) Correct installation of all components3) All mcb's switched OFF4) Check interface to plant, station control and protection5) CT/PT wiring check6) All voltage circuits to be checked7) Preliminary setting of all configuration parameters8) Preliminary setting calibration values for LC display

Note: For items 7) and 8) the GMR3 has to be energized.

13.2. MEASURING POINTS

During the commissioning most important regulator internal variables should be displayed on os-cilloscope, for this the transformation of the internal variables are made by the analogues output board AA8. The commissioning personal has to insert this board for the duration of the commis-sioning.Following signals are available on the AA8 for test purposes.

Designation Name Variable Calibration⊥ Common GroundY3 DEIW

Calculated value of load angleV38 1 V = 20°el.

Y7 UGKActual value of stator voltage

V501 5 V = 100% UGN

Y6 UGSW-UGKDifference between set and actual value of stator voltage

V79 10 V = 100% UGN

Y2 IPIWActual value of field current

V500 5 V = IFN

Y5 ALPHIWActual value of firing angle

V509 1 V = 20° el.

Tolerance for all measuring signals: ±10 %


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13.3. CONSIDERATIONS

13.3.1. Calibration Principle

Within the regulator several calibrations have to be performed in order that the regulating quanti-ties correspond with the actual values of the plant equipment. For example: so that the generator current actual value (IGIW) is really equal to 1 p.u. (100 %) in the regulator at an actual 100 % generator current flow. The calibration sequence should be applied according to this protocol in order that by adjusting the calibration setting value there is no influence on the momentarily regu-lation. For example the IGIW calibration should be carried out at rated generator current which is possible during primary short circuit tests where the excitation is in field current regulating mode and the generator current does not represent any regulating quantity in that operating mode.

For calibration the terminal mode has to be selected on the User terminal. After calibration the new parameter setting have to be stored permanently.

The calibration values of the excitation system are pre-set according to the generator data during the workshop test, but these parameters should be checked with the actual technical data of the generator.

The following values have to calibrated or the calibration must be checked according to the gen-erator data.• Thyristor voltage• Field current• Generator stator current• Generator terminal voltage

Calibration of thyristor voltage (supply voltage):

1.) Set V1803 to 12.) Read V37 and substitute it in the following formula3.) Measure the incoming supply voltage4.) Calculation:

USynNUSyn

V371V1803 ∗=

V1803.........…. Calibration factor for the thyristor voltage NormUsynUSyn.............. Incoming supply voltageUSynN……….. Nominal supply voltage

5.) Enter the calculated value of the variable V8036.) Afterwards the variable should be: USYNIW V37 = 1,0


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Calibration of the field current:

1.) Set V1805 to 12.) Read V500 and substitute it in the following formula3.) Measure the field current (on shunt 150 A / 150 mV)4.) Calculation:

FNIFI

V5001V1805 ∗=

V1805..........… Calibration factor for the field current NormIfIF..............…. Actual value of the current, measured on ShuntIFN.............… Nominal field current

5.) Enter the calculated value of the variable V18056.) Afterwards the variable should be at nominal current: IPIW V500 = 1,0

Calibration of the generator stator current:

1.) Set V1817 to 12.) Read V503 and substitute it in the following formula3.) Measure the generator stator current (secondary side of the CT)4.) Calculation:

GNIGI

V5031V1817 ∗=

V1817..........… Calibration factor for generator stator current NormIgIG..............…. Actual value of the current, measured at the CTIGN.............… CT secondary current at generator nominal current

7.) Enter the calculated value of the variable V8178.) Afterwards the variable should be at nominal current: IGIW V503 = 1,0

Calibration of the generator terminal voltage:

1.) Set V1813 to 12.) Read V501 and substitute it in the following formula3.) Measure the generator terminal voltage (secondary side of the PT)4.) Calculation:

GNUGU

V5011V1813 ∗=

V1813.........…. Calibration factor for generator voltage NormUgUG.................. Actual value of the voltage, measured at the PTUGN................ PT secondary voltage at generator nominal voltage

5.) Enter the calculated value of the variable V18136.) Afterwards the variable should be at nominal voltage: UGK V501 = 1,0


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13.3.2. Principle for Optimizing the Regulator

The purpose of optimization is that the regulating value (field current or generator voltage) is re-acting as rapidly as possible to sudden changes without oscillation (to be recognized on the firing angle α). Therefore the firing angle α has to be displayed on oscilloscope.

Procedures:1. First of all optimize the regulator with small step signals (step functions with 3 - 5 %)2. only then later with large jumps (step functions with 10 %)3. and then excitation raising from zero

At optimizing with small value signals always optimize from the inner loop to the outer loop, that means:1. Field current regulator (PI)2. Voltage regulator (PID)3. Limiters and additional regulator (reactive power or p.f. regulator)

ad 1) + 2) Field current regulator and Voltage regulator

Optimizing is carried out by increasing the P-gain until the respective regulator starts oscillation (firing angle α). Then decrease the gain slightly again until oscillation stops. Afterwards adjust the integration time with step functions (in that way, that actual value reaches the new setpoint with small or without overshooting). At excitation systems with exciter machines optimize the differen-tial part (D-part) with the same procedure (increase the D-gain until overshooting at step functions or until oscillation of the firing angle α, afterwards adjust the differential damping).

When during on-load operation the control voltage is starting to oscillate then the P-gain has still to be reduced.

NOTE

General statement: At a high gain the regulator tends to oscillate, but has a fast regulation. A low gain increases the stability, but results in poor regulation

Note: Generally pre-setting of the D-part is sufficient without any further modifications.

ad 3) p.f. and reactive power regulator

At the p.f. and reactive power regulator the regulation part with the gain is integrated in the feed-back. Therefore the considerations regarding the stability and oscillation is exactly reverse. That means, a low gain results in high oscillation tendency, at a higher gain the regulator tends to sta-bility. Generally the presetting can be left unchanged.


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13.3.3. Recommended Settings

Normally with the settings from the workshop test the excitation system can be operated without or with slightly parameter changes. If nevertheless parameters have to be changes due to poor regulation (oscillation, to much overshooting, slow regulation) we recommend the followingranges:

Recommendation for the field current regulator:

V1870 VPI Gain field current regulator 2.00 ... 5.00V1900 TNI Integration time field current regulator 0.0

Recommendation for the voltage regulator:

V1872 VPU Gain voltage regulator 5.00 ... 8.00V1902 TNU Integration time voltage regulator 0.20 ... 2.00 = 0.2 ... 2 sV1871 KDU Differential gain voltage regulator 0.50 ... 1.00V1901 TDU Differential damping voltage regulator 0.05.. 0.2 = 0.05 ... 0.2 s

Recommendation for the p.f. and reactive power regulator:

V1877 KPQRF Gain p.f. / reactive power regulator 8.0 ... 16.0V1957 TIQRF Integration time p.f. / reactive power regulator 0.02 ... 0.1 = 5 ... 10 s

13.4. CARRYING OUT COMMISSIONING

CAUTION

Before initial energizing of the excitation system the previously specified checklist according to chapter 13.1, "PREPARATION FOR COMMISSIONING" has to be gone through!

• The excitation system has to be connected with test supply, in case of external supply not needed.

• The battery supplies has to be connected.• After check of the polarity of the battery supply switch on the mcb's for the regulator voltage

supply.• Operating mode "MANUAL" has to be selected.

NOTE

• These items of the commissioning instructions must be completed.• We recommend that these items of the commissioning instructions are to be fulfilled in order to ensure that the

safety for correct functioning of the integration is guaranteed.


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13.4.1. Tests at Standstill

• Protection trip checks• Checking and measuring supply voltages in test mode• Check of thyristors voltage (=supply voltage) USYNIW (V37 = 0.9 ... 1.1). Only if V37 is out of

the range of 0.9 ... 1.1, this variable has to be calibrated as described in 13.3.1, “CalibrationPrinciple”

• Check of thyristors voltage frequency FSYNIW (V78 = +1.0)Positive sign: Clock wise phase rotationNegative sign: Anti-clock wise phase rotation

• During standstill operate the excitation ON key and slowly raise the field current until Ifn is reached (or as far up as possible)

• Check and calibration of the field current IPIWAt nominal field current has to be V500=1

After that store setting parameter

13.4.2. Short Circuit Tests – If Applicable

• Operating mode "MANUAL" has to be selected• Generator terminal short circuited• Generator brought to nominal speed• Check of integrity of CT circuits whether all are closed but not short circuited with residual cur-

rent or minimum current (0.1p.u.) • Life trip check from a protection relay• Calibration of generator current IGIW as described in 13.3.1 Calibration Principle


13.4.3. Open Circuit Voltage Tests

• Operating mode "MANUAL" has to be selected• Generator terminal short circuit is removed • Generator brought to rated speed • Check of residual voltages at actual value input• Check of residual voltages at excitation transformer input• Excitation ON and raising excitation up to nominal voltage• Check of thyristor voltage USYNIW (V37 = 0.95 ... 1.05)• Check of thyristor voltage frequency FSYNIW (V78 = +1.0)• Calibration of generator voltage as described in 13.3.1, “Calibration Principle”• Check of voltages at all transformers• Optimization of current regulator gain (preliminary VPI=2, final adjustment in shunt field opera-

tion mode)• Change over to voltage regulator mode (key "AUTO/MANUAL")• Change over to field current regulator mode (key "AUTO/MANUAL")• De-excitation• Change over from test- to shunt field supply• Operating mode "MANUAL" • Excitation ON, optimizing gain and integration time of current regulator• Change over to voltage "AUTO"• Optimizing gain and integration time of voltage regulator


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• De-excitation with voltage regulator• Check and optimizing of Soft-Start by excitation in voltage regulator mode to nominal voltage:

generator voltage must not swing over• Start-up and de-excitation with voltage regulator• Oscilloscopic record of a set value jump 95 % 105 % 95 % Ugn• Oscilloscopic record of an excitation process from 0 to nominal voltage• Oscilloscopic record of a de-excitation process (operational de-excitation)• Generator shut down, 1 diode in excitation machine shorted or disconnected (for diode fault

supervision), run up unit to rated speed again.− Parameter V1003 (max. amplitude for trip) set to 15.0 − Variable V518 (Supervision output signal) to be measured (should be 0.0)− Operating mode "MANUAL" has to be selected− Excitation ON, adjust field current to approximately ½ open circuit voltage value, but at

least 0,2 Ug− Variable V518 (Supervision output signal) to be measured (should be bigger as 1.0)− Variable V1003 (max. amplitude for trip) set just under value of V518 resulting in an exci-

tation trip− Generator shut down, remove diode short circuit or open circuit

• Check of remote operation control

• Prior to synchronizing: check CB intertrip


13.4.4. On Load Tests

NOTE

1) When after synchronizing the reactive current suddenly rises above 100 % Ign (generator overexcited and field current high) or drops to 40...80 % Ign (generator underexcited, field cur-rent zero) and the voltage regulator does not get any response then the generator has to be immediately disconnected from the power system and the external wiring is to be checked be-cause the CT polarity and/or CT allocation is incorrect.

2) When after synchronizing small changes of the setting value will result in considerable fluctua-tions of the reactive current then the reactive power static is to be increased in negative direc-tion. This is especially important when there is no generator-transformer and therefore no natu-ral static or when several generating units are connected in parallel.

After paralleling the generator to the grid system it can be observed that the response of reactive power output is without influence on the active power. When the CT's and PT's are connected correctly then after synchronizing the generator current will remain stable at a low level and can be adjusted with the voltage controller.

When the interrelation between set value changes and reactive power changes cannot be verified the external wiring has to be re-checked again.


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• Check current polarity (reactive current V504=IBIW, active current V505=IWIW)Positives sign: Current exportNegative sign:Current import

• Check actual value of active power (PWIW=V574) and reactive power (PBIW=V65)Positives sign: Power exportNegative sign:Power import

• Check actual value of power factor (CFR=V57)Calibrate generator current IGIW (if not performed as outlined in chapter 13.4.2, "Short CircuitTests – If Applicable" and described in 13.3.1, “Calibration Principle”

• Check of the regulator behavior by setpoint changes or setpoint steps (in on-load operation the regulator behavior is different to no-load operation). If the regulation is not satisfactory, it can be optimized by gain and integration time of the voltage regulator.

• Check reactive power static:1. Reactive power static V831 set to -0.02 (should already be 0.02)2. Select load position with reactive power export into grid.3. Increase reactive power static V831 step by step in negative direction (-0.03, -0.04),thereby the actual value of generator voltage and also the reactive current (reactive power) has to decrease (otherwise the CT connection is wrong).

• Measure the grid system static: XN = ............%Measuring procedures:Measuring of a load position (active current between 0...20 % Ign, p.f. approx.1): UG1, IB1 (in p.u.)Increase voltage (reactive power), thenmeasuring of a second load position: UG2, IB2 (in p.u.)

XN UG UGUG IB IB= −

∗ − ∗2 11 2 1 100( ) (result XN in %)

• Load rejections at various loads with oscilloscope recording of the load rejection.• Smooth transfer between automatic- and manual operating mode (in both directions).• Check following limiters by approaching the limit value with the raise and lower commands.

- Field current limiter (max., delayed)- Stator current limiterWhen the respective limiter shows no response the calibration is not correct

• Setting following additional regulators:- power factor regulator / reactive power regulator

• Heat runDuring heat run following temperature rises are to be checked:Excitation transformer, cable connections, cubicle heating, etc.


13.4.5. Remaining Activities

• Final parameter saving• Check spare parts (if applicable) and set parameters on spare p.c.b’s• Write and distribute the commissioning test sheets

⇒ 1 copy for reasons of Quality Control and Service Support has absolutely to be sent to SAT-EXC


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14. TECHNICAL DATA

14.1. DIMENSIONS

The equipment has following dimensionswidth x high x depth = 1200 x 2200 x 800 mm

14.2. ELEKTRICAL DATA

• Rated field current: 20 A• Ceiling current: 32 A• Ceiling time: 5 s

14.2.1. Rectifier capability

• Type: three phase, full wave controlled thyristor bridge• Rated current: 25 A• repetitive peak reverse voltage: 1600 V

14.3. ELEKTRICAL DATA OF ROTOR SUPPLY

• Rated rotor current: 400 A

14.3.1. Rectifier capability

• Type: three phase, half wave controlled thyristor bridge• Rated current: 400 A• repetitive peak reverse voltage: 1600 V

14.4. EMC COMPATIBILITY

The micro-processor system is manufactured according standard IEC 61000-4 and type tested by an international approved institute.

IEC 61000-4: EMC for industrial process automation• Part 1: General introduction• Part 2: ESD (Electrostatic discharge) class 4: 8 kV• Part 3: HF / Electromagnetic fields class 3: 10 V/m• Part 4: Fast transient / Burst class 4: 4 kV supply

2 kV input / output• Part 5: Surge immunity (1,2 / 50 µs) class 4: 4 kV


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15. PLEASE NOTE!

COPYRIGHT, REMARKS

This document is the sole property of VA TECH SAT GmbH & Co and may neither be copied nor distributed and used without our written consent. Violations will be prosecuted by Law according to DIN 34 Standard.

The data contained in this literature should be considered as product information only. We would like to advise that short term modifications of our production range are possible due to our aim to continuously improve the performance of our products for the benefit of our customers so there may be differences between the products supplied and the corresponding descriptive literature.

According to our experience following the instructions outlined in this document will provide the most satisfactory service performance.

In case of unusual troubles which cannot be resolved by referring to this literature please contact our nearest agent or our Head Office.

When commissioning the operating instructions and also the applicable Local Safety Standards have strictly to be observed.

This edition of the document has been carefully checked regarding up-to-date contents and cor-rectness. Should there be any discrepancies or contradictory information in this descriptive litera-ture could please inform us. In case of problems please do not try to solve them on your own but contact our nearest agent or our Head Office who will be glad to be of any assistance to you.

All agreements, legal rights, obligations, performance and scope of supply for VA TECH SAT GmbH & Co and also conditions governing the warranty are without expectation regulated ac-cording to the Contract Agreement and are not, in any way, influenced by the contents of the de-scriptive literature or operating instructions.

Urgent information will be conveyed by telephone or fax.

Our address:

VA TECH SAT GmbH & Co Phone: ++43 1 29 129 Ext. 4592Dept. EXC Fax: ++43 1 89 129 Ext. 4563Ruthnergasse 1A-1220 VIENNAAUSTRIA

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