Protection Overview Universal Relay Family. Power Management The Universal Relay Contents... Configurable Sources FlexLogic™ and Distributed FlexLogic™

Protection Overview

Universal Relay FamilyUniversal Relay Family

Power Management The The Universal RelayUniversal Relay

Contents...Contents...

Configurable Sources

FlexLogic™ and Distributed FlexLogic™

L90 – Line Differential Relay

D60 – Line Distance Relay

T60 – Transformer Management Relay

B30 – Bus Differential Relay

F60 – Feeder Management Relay


Configurable Configurable SourcesSources


AA WW 51P51P

VV

II

SourceSourceMeteringMetering ProtectionProtection

Universal RelayUniversal Relay

II

Concept of ‘Sources’Concept of ‘Sources’

• Configure multiple three phase current and voltage inputs from different points on the power system into Sources

• Sources are then inputs to Metering and Protection elements


Sources: Sources: Typical ApplicationsTypical Applications

• Breaker-and-a-half schemes

• Multi-winding (multi-restraint) Transformers

• Busbars

• Multiple Feeder applications

• Multiple Meter

• Synchrocheck


Transformer

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

Transformer

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

Sources Example 1: Sources Example 1: Breaker-and-a-Half SchemeBreaker-and-a-Half Scheme


Transformer

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

50BFRELAY

50BFRELAY

50P

87T

AMPS

Transformer DifferentialRelay

ExternalSummation

VOLT

W

AMPS

Transformer

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

50BFRELAY

50BFRELAY

50P

87T

AMPS

Transformer DifferentialRelay

ExternalSummation

VOLT

W

AMPS

Sources Example 1: Sources Example 1: Traditional Relay ApplicationTraditional Relay Application


VT1

CT1

CT2

CT3

Sources Example 1: Sources Example 1: Inputs into the Universal RelayInputs into the Universal Relay


VT1

VV

II

I

VI

II

VCT1

CT2

VI

II

V

CT3

50BF

50BF

VI

II

V

50P W

87T

Source #1

Source #2

Source #3

Source #4

Physical 3-phaseI &V Inputs

CT1

CT2

CT1

CT2

Con

figur

e So

urce

s(d

one

via

setti

ngs)

VT1

CT3

VT1

VV

II

I

VI

II

VCT1

CT2

VI

II

V

CT3

50BF

50BF

VI

II

V

50P W

87T

Source #1

Source #2

Source #3

Source #4


CT1

CT2

CT1

CT2

Con

figur

e So

urce

s(d

one

via

setti

ngs)

VT1

CT3


Sources Example 1: Sources Example 1: Universal Relay solution using SourcesUniversal Relay solution using Sources


T1

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

CT4

T1

CT1 CT2

CT3

VT1

87T

50BF50BF

W

50P

CT4

Sources Example 2:Sources Example 2: Breaker-and-a-Half Scheme with 3-Winding TransformerBreaker-and-a-Half Scheme with 3-Winding Transformer


VT1

CT1

CT2

CT3

CT4



VT1

VV

II

I

VI

II

VCT1

CT2

VI

II

V

CT3

50BF

50BF

VI

II

V

50P W

87T

Source #1

Source #2

Source #3

Source #4


CT1

CT2

CT1

CT2

Con

figur

e So

urce

s(d

one

via

setti

ngs)

VT1

CT3CT4

VI

II

V

CT4 Source #5

VT1

VV

II

I

VI

II

VCT1

CT2

VI

II

V

CT3

50BF

50BF

VI

II

V

50P W

87T

Source #1

Source #2

Source #3

Source #4


CT1

CT2

CT1

CT2

Con

figur

e So

urce

s(d

one

via

setti

ngs)

VT1

CT3CT4

VI

II

V

CT4 Source #5




VT1

27P

W

50/51

CT4

81

W

50/51

CT3

81

W

50/51

CT2

81

W

50/51

CT1

81

W

50/51

81

CT5

51WVT1

27P

W

50/51

CT4

81

W

50/51

CT3

81

W

50/51

CT2

81

W

50/51

CT1

81

W

50/51

81

CT5

51W

Multiple Feeder + BusbarSources Example 3: Sources Example 3: Busbar with 5 feedersBusbar with 5 feeders


VT1

CT1

CT2

CT3

CT4

CT5



VT1

VV

II

I

VI

II

V

CT1

CT2

VI

II

V

CT3

50/51 81

VI

II

V

Source #1


CT1

Conf

igur

e So

urce

s(d

one

via

setti

ngs)

CT4

VI

II

V

CT5

VT1

VI

II

V

CT2

VT1

CT3

VT1

CT4

VT1

CT5

VT1

W

CT1..CT5VT1

50/51 81Source #2

W

50/51 81Source #3

W

50/51 81Source #4

W

50/51 81Source #5

W

51 27PSource #6

W

VT1

VV

II

I

VI

II

V

CT1

CT2

VI

II

V

CT3

50/51 81

VI

II

V

Source #1


CT1

Conf

igur

e So

urce

s(d

one

via

setti

ngs)

CT4

VI

II

V

CT5

VT1

VI

II

V

CT2

VT1

CT3

VT1

CT4

VT1

CT5

VT1

W

CT1..CT5VT1

50/51 81Source #2

W

50/51 81Source #3

W

50/51 81Source #4

W

50/51 81Source #5

W

51 27PSource #6

WUniversal Universal RelayRelay



FlexLogicFlexLogicTMTM

&&Distributed FlexLogicDistributed FlexLogicTMTM


AnalogInputsAnalogInputs

ProgrammableLogic

(FlexLogic™)

ProgrammableLogic

(FlexLogic™)

VirtualOutputsVirtualOutputs

Ethernet (Fiber)Ethernet (Fiber)

DigitalInputsDigitalInputs

VirtualInputsVirtualInputs Remote

InputsRemoteInputs

DigitalOutputsDigital

Outputs

Computed ParametersComputed Parameters

MeteringMetering

Protection & Control Elements

Protection & Control Elements

RemoteOutputsRemoteOutputs

A/DA/D

DSPDSP

Hardware

Software

Ethernet LAN (Dual Redundant Fiber)

Universal Relay: Universal Relay: Functional ArchitectureFunctional Architecture


AND

AND

AND

OR

Remote Input: Trip Relay 2




Local: Trip

Local: Trip

ENABLE

ENABLE

ENABLE

0ms0ms

RemoteOutput

DigitalOutput

Substation LAN

LOCAL RELAY

RELAY 2 RELAY 3LocalRELAY

Distributed FlexLogic Example 1:Distributed FlexLogic Example 1: 2 out of 3 Trip Logic Voting Scheme2 out of 3 Trip Logic Voting Scheme


Distributed FlexLogic Example 1:Distributed FlexLogic Example 1: Implementation of 2 out of 3 Voting SchemeImplementation of 2 out of 3 Voting Scheme


Distributed FlexLogic Example 2Distributed FlexLogic Example 2:: Transformer Overcurrent Acceleration

UR-F60Feeder IED

UR-F60Feeder IED

UR-F60Feeder IED

UR-T60Transformer IED

TIME

Current Pick-Up Level

CoordinationTime

Feeder TOC Curve

Transformer TOC Curve

AcceleratedTransformer TOC Curve

Substation LAN: 10/100 Mbps Ethernet(Dual Redundant Fiber)

Transformer IED:IF Phase or Ground TOC pickup THEN send GOOSE message to ALL Feeder IEDs.

Feeder IEDs:Send “No Fault” GOOSE if no TOC pickup ELSE Send “Fault” GOOSE if TOC pickup.

Transformer IED:If “No Fault” GOOSE from any Feeder IED then switch to accelerated TOC curve.

Animation


FlexLogic: FlexLogic: BenefitsBenefits

• FlexLogic™FlexLogic™– Tailor your scheme logic to suit the application– Avoid custom software modifications

• Distributed FlexLogic™Distributed FlexLogic™ – Across the substation LAN (at 10/100Mpbs)

allows high-speed adaptive protection and coordination

– Across a power system WAN (at 155Mpbs using SONET system) allows high-speed control and automation


L90L90Line Differential RelayLine Differential Relay


L90 Current Differential RelayL90 Current Differential Relay: : FeaturesFeatures

• Protection:Protection:– Line current differential (87L)– Trip logic– Phase/Neutral/Ground TOCs– Phase/Neutral/Ground IOCs– Negative sequence TOC– Negative sequence IOC– Phase directional OCs– Neutral directional OC– Phase under- and overvoltage– Distance back-up


L90 Current Differential RelayL90 Current Differential Relay: : FeaturesFeatures

• Control:Control:– Breaker Failure (phase/neutral amps)– Synchrocheck & Autoreclosure– Direct messaging (8 extra inter-relay DTT bits

exchanged)

• Metering:Metering:– Fault Locator– Oscillography– Event Recorder– Data Logger– Phasors / true RMS / active, reactive and

apparent power, power factor


Direct point-to-point Fiber(up to 70Km)

ORVia SONET system telecom multiplexer

(GE’s FSC)

FSC(SONET)

FSC(SONET)

(64Kbps)

(155Mbps)

- G.703- RS422

- G.703- RS422

L90 Current Differential Relay: L90 Current Differential Relay: OverviewOverview


L90 Current Differential Relay: L90 Current Differential Relay: Line Current DifferentialLine Current Differential

• Improved operation of the line current Improved operation of the line current differential (87L) element:differential (87L) element:– dynamic restraint increasing security without

jeopardizing sensitivity– line charge current compensation to increase

sensitivity– self-synchronization


Restraint Current

Op

erat

e C

urr

ent

K1

K2

L90 Current Differential Relay: L90 Current Differential Relay: Traditional Restraint MethodTraditional Restraint Method

– Traditional method is STATIC– Compromise between Sensitivity and Security


L90 Current Differential Relay: L90 Current Differential Relay: Dynamic RestraintDynamic Restraint

• Dynamic restraint uses an estimate of a measurement error to dynamically increase the restraint

• On-line estimation of an error is possible owing to digital measuring techniques

• In digital relaying to measure means to calculate or to estimate a given signal feature such as magnitude from the raw samples of the signal waveform


L90 Current Differential Relay: L90 Current Differential Relay: DigitalDigital Phasor MeasurementPhasor Measurement

• The L90 measures the current phasors The L90 measures the current phasors (magnitude and phase angle) as follows:(magnitude and phase angle) as follows:– digital pre-filtering is applied to remove the

decaying dc component and a great deal of high frequency distortions

– the line charging current is estimated and used to compensate the differential signal

– full-cycle Fourier algorithm is used to estimate the magnitude and phase angle of the fundamental frequency (50 or 60Hz) signal



Sliding Data WindowSliding Data Window

waveformwaveform magnitudemagnitude

window

timetime

presenttime

presenttime



Sliding Data WindowSliding Data Window

waveformwaveform magnitudemagnitude

window

timetime

windowwindowwindowwindowwindowwindowwindow


L90 Current Differential Relay: L90 Current Differential Relay: Goodness of FitGoodness of Fit

window

time

• A sum of squared differences between the actual waveform and an ideal sinusoid over last window is a measure of a “goodness of fit” (a measurement error)


L90 Current Differential Relay: L90 Current Differential Relay: Phasor Goodness of FitPhasor Goodness of Fit

• The goodness of fit is an accuracy index for the digital measurement

• The goodness of fit reflects inaccuracy due to:– transients– CT saturation– inrush currents and other signal distortions

• The goodness of fit is used by the L90 to alter the traditional restraint signal (dynamic restraint)


L90 Current Differential Relay: L90 Current Differential Relay: Operate-Restraint RegionsOperate-Restraint Regions

ILOC – local currentIREM – remote end current

ILOC – local currentIREM – remote end current

Imaginary (ILOC/IREM)

Real (ILOC/IREM)

OPERATE

OPERATE

OPERATE

OPERATE

RESTRAINT


L90 Current Differential Relay: L90 Current Differential Relay: Dynamic RestraintDynamic Restraint

Dynamic restraint signal =

Traditional restraint signal + Error factorImaginary (ILOC/IREM)

Real (ILOC/IREM)

OPERATE

REST.

Error factor is high

Error factor is low


L90 Current Differential Relay: L90 Current Differential Relay: Charge Current CompensationCharge Current Compensation

• The L90 calculates the instantaneous values of the line charging current using the instantaneous values of the terminal voltage and shunt parameters of the line

• The calculated charging current is subtracted from the actually measured terminal current

• The compensation reduces the spurious differential current and allows for more sensitive settings


L90 Current Differential Relay: L90 Current Differential Relay: Charge Current CompensationCharge Current Compensation

• The compensating algorithm:– is accurate over wide range of frequencies – works with shunt reactors installed on the line– works in steady state and during transients– works with both wye- and delta-connected VTs

(for delta VTs the accuracy of compensation is limited)


L90 Current Differential Relay: L90 Current Differential Relay: Effect of CompensationEffect of Compensation

0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-200

-150

-100

-50

0

50

100

150

200V

olta

ge

s: v

1(r

), v

2(b

)

time [sec]

0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-200

-150

-100

-50

0

50

100

150

200V

olta

ge

s: v

1(r

), v

2(b

)

time [sec]

Voltage, VVoltage, V

time, sectime, sec

Local and remote voltages


0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3id

: ra

w (

r), c

om

pe

nsa

ted

(b

)

time [sec]

0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3id

: ra

w (

r), c

om

pe

nsa

ted

(b

)

time [sec]


Current, ACurrent, A

time, sectime, sec

Traditional and compensated differentialcurrents (waveforms)


0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.180

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08Id

: ra

w (

r), c

om

pe

nsa

ted

(b

)

time [sec]

0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.180

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08Id

: ra

w (

r), c

om

pe

nsa

ted

(b

)

time [sec]


Current, ACurrent, A

time, sectime, sec

Traditional and compensated differentialcurrents (magnitudes)


L90 Current Differential Relay: L90 Current Differential Relay: Self-SynchronizationSelf-Synchronization

t0

t1

t2

t3

tf

tr

Forwardtraveltime

Returntraveltime

Relayturn-aroundtime

RELAY 1 RELAY 2

2

1203 tttttt rf

2

1203 tttttt rf

“ping-pong”


L90 Current Differential Relay: L90 Current Differential Relay: Ping-Pong (example)Ping-Pong (example)

Communication path

Initial clocks mismatch=1.4ms or 30°

8.33 ms

8.33 ms

8.33 ms

Store T1i-2=5.1

8.33 ms

t1 t2

Slow down

Relay 10

5.1

0

2.3

8.33

8.33 Send T2i-2=2.3

Send T1i-2=5.1

Capture T1i-2=5.1

8.33 ms

Send start bitStore T1i-3=0

Send start bitStore T2i-3=0

13.4310.53

Send T1i-1=16.66

Capture T2i-2=2.3

16.66

21.76

16.66

18.96

Send T2i-1=16.66

Store T2i-1=8.33Capture T1i=21.76

Store T2i-2=2.3


T2i-3=0T1i-2=5.1T1i-1=16.66T2i=18.96

a2=5.1-0=5.1b2=18.96-16.66=2.32=(5.1-2.3)/2== +1.4ms (behind)

T1i-3=0T2i-2=2.3T2i-1=16.66T1i=21.76

a1=2.3-0=2.3b1=21.76-16.66=5.11=(2.3-5.1)/2== -1.4ms (ahead)

Speed up

Relay 2

30°0°


L90 Current Differential Relay: L90 Current Differential Relay: Ping-Pong (example cnt.)Ping-Pong (example cnt.)

8.52 ms

8.14 ms

8.14 ms

Store T1i-2=38.28

8.52 ms

t1 t2

Slow down

Relay 133.32

38.28

33.32

35.62

41.5541.55

Send T2i-2=35.62Send T1i-2=38.28

Capture T1i-2=38.28

8.52 ms

Store T1i-3=33.32

Store T2i-3=33.32

Send T1i-1=50.00

Capture T2i-

2=35.62

50.00

54.03

49.93

53.16

Send T2i-1=49.93


Store T2i-2=35.62


T2i-3=33.32T1i-2=38.28T1i-1=50.00T2i=53.16

a2=38.28-33.32=4.96b2=53.16-50.00=3.162=(4.96-3.16)/2== +0.9ms (behind)

T1i-3=33.32T2i-2=35.62T2i-1=49.93T1i=54.03

a1=35.62-33.32=2.3b1=54.03-49.93=4.11=(2.3-4.1)/2== -0.9ms (ahead)

Speed up

Relay 2

30°19.5°0°

8.14 ms


clock 1 clock 2

“Virtual Shaft”

L90 Current Differential Relay: L90 Current Differential Relay: Digital “Flywheel”Digital “Flywheel”

• If communications is lostIf communications is lost, sample clocks continue to “free wheel”

• Long term accuracy is only a function of the base crystal stability


L90 Current Differential Relay: L90 Current Differential Relay: Peer-to-Peer OperationPeer-to-Peer Operation

– Each relay has sufficient information to make an independent decision

– Communication redundancy

L90-1 L90-2

L90-3


L90 Current Differential Relay: L90 Current Differential Relay: Master-Slave OperationMaster-Slave Operation

– At least one relay has sufficient information to make an independent decision

– The deciding relay(s) sends a transfer-trip command to all other relays

L90-1 L90-2

L90-3 Data (currents)

Transfer Trip


L90 Current Differential Relay: L90 Current Differential Relay: BenefitsBenefits

• Increased Sensitivity without sacrificing Increased Sensitivity without sacrificing Security:Security:– Fast operation (11.5 cycles)– Lower restraint settings / higher sensitivity– Charging current compensation– Dynamic restraint ensures security during CT

saturation or transient conditions– Reduced CT requirements– Direct messaging– Increased redundancy due to master-master

configuration


L90 Current Differential Relay: L90 Current Differential Relay: BenefitsBenefits

• Self-Synchronization:Self-Synchronization:– No external synchronizing signal required– Two or three terminal applications– Communication path delay adjustment– Redundancy for loss of communications

• Benefits of the UR platformBenefits of the UR platform (back-up protection, autoreclosure, breaker failure, metering and oscillography, event recorder, data logger, FlexLogicTM, fast peer-to-peer communications)


D60D60Line Distance RelayLine Distance Relay


D60 Line Distance Relay: D60 Line Distance Relay: FeaturesFeatures

• Protection:Protection:– Four zones of distance protection– Pilot schemes– Phase/Neutral/Ground TOCs– Phase/Neutral/Ground IOCs– Negative sequence TOC– Negative sequence IOC– Phase directional OCs– Neutral directional OC– Negative sequence directional OC



• Protection (continued):Protection (continued):– Phase under- and overvoltage– Power swing blocking– Out of step tripping

• Control:Control:– Breaker Failure (phase/neutral amps)– Synchrocheck– Autoreclosure






D60 Line Distance Relay: D60 Line Distance Relay: Stepped DistanceStepped Distance

• Four zones of stepped distance:Four zones of stepped distance:– individual per-zone per-element characteristic:

• dynamic memory-polarized mho

• quadrilateral

– individual per-zone per-element current supervision

– multi-input phase comparator:• additional ground directional supervision

• dynamic reactance supervision

– all 4 zones reversible– excellent transient overreach control


D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients

• Capacitive Voltage Transformers (CVTs) create certain problems for fast distance relays in conjunction with high Source Impedance Ratios (SIRs):– the CVT induced transient voltage components

may assume large magnitudes (up to about 30-40%) and last for a comparatively long time (up to about 2 cycles)

– the 60Hz voltage for faults at the relay reach point may be as low as 3% for a SIR of 30

– the signal is buried under the noise


0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Volta

ge [p

u]

time [sec]

"High-C CVT" (CVT-1)

"Extra-High-C CVT" (CVT-2)


0 0.01 0.02 0.03 0.04 0.05-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

time [sec]

Vo

ltag

e [p

u]

NOISE COMPONENT 2

60Hz SIGNAL

NOISE COMPONENT 1

Sample CVT output voltages(the primary voltage dropsto zero)

Sample CVT output voltages(the primary voltage dropsto zero)

Illustration of thesignal-to-noise ratio

Illustration of thesignal-to-noise ratio



• CVTs cause distance relays to overreach

• Generally, transient overreach may be caused by: – overestimation of the current (the magnitude of

the current as measured is larger than its actual value, and consequently, the fault appears closer than it is actually located),

– underestimation of the voltage (the magnitude of the voltage as measured is lower than its actual value)

– combination of the above



0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-5

-4

-3

-2

-1

0

1

2

3

4

5x 10

5

Vo

ltag

e [V

]

time [sec]

voltagewaveform

estimatedamplitude

(a)

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-5

-4

-3

-2

-1

0

1

2

3

4

5x 10

5

Vo

ltag

e [V

]

time [sec]

voltagewaveform

estimatedamplitude

(a) Estimated voltage magnitude does not seem to be underestimated

Estimated voltage magnitude does not seem to be underestimated

0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13-4

-3

-2

-1

0

1

2

3

4

x 104

Vo

ltag

e [V

]

time [sec]

estimatedamplitude

(b)

actualvalue

2.2% of the nominal = 70% of the actual value

0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13-4

-3

-2

-1

0

1

2

3

4

x 104

Vo

ltag

e [V

]

time [sec]

estimatedamplitude

(b)

actualvalue

2.2% of the nominal = 70% of the actual value

2.2% of the nominal =70% of the actual value

2.2% of the nominal =70% of the actual value



-10 -5 0 5 10-5

0

5

10

15

Rea

ctan

ce [o

hm]

Resistance [ohm]

18

22

26

30

3442

44 Actual FaultLocation

LineImpedance

Trajectory(msec)

dynamic mhozone extendedfor high SIRs

-10 -5 0 5 10-5

0

5

10

15

Rea

ctan

ce [o

hm]

Resistance [ohm]

18

22

26

30

3442

44 Actual FaultLocation

LineImpedance

Trajectory(msec)

dynamic mhozone extendedfor high SIRs

Impedance locus may pass below the origin of the Z-plane - this would call for a time delayto obtain stability

Impedance locus may pass below the origin of the Z-plane - this would call for a time delayto obtain stability



• Transient overreach due to CVTs - solutions:– apply delay (fixed or adaptable)– reduce the reach– adaptive techniques and better filtering

algorithms



0 5 10 15 20 25 300

10

20

30

40

50

60

70

80

90

100M

axim

um R

ach

[%]

SIR

0 5 10 15 20 25 300

10

20

30

40

50

60

70

80

90

100M

axim

um R

ach

[%]

SIR

Actual maximum reach curvesActual maximum reach curves

Relay A

Relay D

Relay S

D60



• D60 Solution:D60 Solution:– Optimal signal filtering

• currents - max 3% error due to the dc component

• voltages - max 0.6% error due to CVT transients

– Adaptive double-reach approach• the filtering alone ensures maximum transient

overreach at the level of 1% (for SIRs up to 5) and 20% (for SIRs up to 30)

• to reduce the transient overreach even further an adaptive double-reach zone 1 has been implemented



• The outer zone 1:The outer zone 1:– is fixed at the actual reach– applies certain security delay to cope with CVT

transients

DelayedTrip

InstantaneousTrip

R

X

• The inner zone 1:The inner zone 1:– has its reach

dynamically controlled by the voltage magnitude

– is instantaneous


No TripNo Trip


DelayedTrip

DelayedTrip

InstantaneousTrip

InstantaneousTrip

Set reachSet reach



0 0.2 0.4 0.6 0.8 10.75

0.8

0.85

0.9

0.95

1

Se

cure

Re

ach

Voltage

0 0.2 0.4 0.6 0.8 10.75

0.8

0.85

0.9

0.95

1

Se

cure

Re

ach

Voltage

Element’s Voltage, puElement’s Voltage, pu

Mul

tiplie

r fo

r th

e in

ner

zone

1 r

each

, pu

Mul

tiplie

r fo

r th

e in

ner

zone

1 r

each

, pu



• Performance:Performance:– excellent transient overreach control (5% up to

a SIR of 30)– no unnecessary decrease in speed


D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 SpeedZone 1 Speed

Phase Element

0

5

10

15

20

25

30

0% 10% 20% 30% 40% 50% 60% 70% 80%

Fault Location [%]

Op

erat

ing

Tim

e [m

s]

SIR = 0.1

SIR = 1

SIR = 10

SIR = 20

SIR = 30

Phase Element

0

5

10

15

20

25

30

0% 10% 20% 30% 40% 50% 60% 70% 80%

Fault Location [%]

Op

erat

ing

Tim

e [m

s]

SIR = 0.1

SIR = 1

SIR = 10

SIR = 20

SIR = 30


D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 SpeedZone 1 Speed

Ground Element

0

5

10

15

20

25

30

35

0% 10% 20% 30% 40% 50% 60% 70% 80%

Fault Location [%]

Op

erat

ing

Tim

e [m

s]

SIR = 0.1

SIR = 1

SIR = 10

SIR = 20

SIR = 30

Ground Element

0

5

10

15

20

25

30

35

0% 10% 20% 30% 40% 50% 60% 70% 80%

Fault Location [%]

Op

erat

ing

Tim

e [m

s]

SIR = 0.1

SIR = 1

SIR = 10

SIR = 20

SIR = 30


D60 Line Distance Relay: D60 Line Distance Relay: Pilot SchemesPilot Schemes

• Pilot Schemes available:Pilot Schemes available:– Direct Underreaching Transfer Trip (DUTT)– Permissive Underreaching Transfer Trip (PUTT)– Permissive Overreaching Transfer Trip (POTT)– Hybrid Permissive Overreaching Transfer Trip

(HYB POTT)– Blocking Scheme


D60 Line Distance Relay: D60 Line Distance Relay: Pilot SchemesPilot Schemes

• Pilot Schemes - Features:Pilot Schemes - Features:– integrated functions :

• weak infeed

• echo

• line pick-up

– basic protection elements used to key the communication:

• distance elements

• fast and sensitive ground (zero- and negative sequence) directional IOCs with current/voltage/dual polarization


D60 Line Distance Relay: D60 Line Distance Relay: BenefitsBenefits

• Excellent CVT transient overreach control (without unnecessary decrease in speed)

• Fast, sensitive and accurate ground directional OCs

• Common pilot schemes

• Benefits of the UR platform (back-up protection, autoreclosure, breaker failure, metering and oscillography, event recorder, data logger, FlexLogicTM, fast peer-to-peer communications)


T60T60Transformer Management RelayTransformer Management Relay


T60 Transformer Management Relay: T60 Transformer Management Relay: FeaturesFeatures

• Protection:Protection:– Restrained differential– Instantaneous differential overcurrent– Restricted ground fault– Phase/Neutral/Ground TOCs– Phase/Neutral/Ground IOCs– Phase under- and overvoltage– Underfrequency


T60 Transformer Management Relay: T60 Transformer Management Relay: FeaturesFeatures

• Metering:Metering:– Oscillography– Event Recorder– Data Logger– Phasors / true RMS / active, reactive and



T60 Transformer Management Relay: T60 Transformer Management Relay: Restrained differentialRestrained differential

• Internal ratio and phase compensation

• Dual-slope dual-breakpoint operating characteristic

• Improved dynamic second harmonic restraint for magnetizing inrush conditions

• Fifth harmonic restraint for overexcitation conditions

• Up to six windings supported


T60 Transformer Management Relay: T60 Transformer Management Relay: Differential SignalDifferential Signal

• Removal of the zero sequence component from the differential signal:– optional for delta-connected windings– enables the T60 to cope with in-zone grounding

transformers and in-zone cables with significant zero-sequence charging currents

• Removal of the decaying dc component

• Full-cycle Fourier algorithm for measuring both the differential current phasor and the second and fifth harmonics


T60 Transformer Management Relay: T60 Transformer Management Relay: Restraining SignalRestraining Signal

• Removal of the decaying dc component

• Full-cycle Fourier algorithm for measuring the magnitude

• “Maximum of” principle used for deriving the restraining signal from the terminal currents:– the magnitude of the current flowing through a

CT that is more likely to saturate is used


T60 Transformer Management Relay: T60 Transformer Management Relay: Operating CharacteristicOperating Characteristic

• Two slopes used to cope with:Two slopes used to cope with:– small errors during linear operation of the CTs

(K1) and

– large CT errors (saturation) for high through currents (K2)

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2


T60 Transformer Management Relay: T60 Transformer Management Relay: Operating CharacteristicOperating Characteristic

• Two breakpoints used to specify:Two breakpoints used to specify:– the safe limit of linear CT operation (B1) and

– the minimum current level that may cause large spurious differential signals due to CT saturation (B2)

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2


T60 Transformer Management Relay: T60 Transformer Management Relay: Magnetizing InrushMagnetizing Inrush

0 1 2 3 4 5 6 7 8 9 10 11 Time (cycles)

0

500

1000

1500

-400

i [A] (a)

0 1 2 3 4 5 6 7 8 9 100

0.2

0.4

0.6

0.8

1

Time (cycles)

I2 / I 1(b)

Sample magnetizing inrush current

Sample magnetizing inrush current

Second harmonic ratio

Second harmonic ratio


T60 Transformer Management Relay: T60 Transformer Management Relay: Magnetizing InrushMagnetizing Inrush

• New second harmonic restraint:New second harmonic restraint:– uses both the magnitude and phase relation

between the second harmonic and the fundamental frequency (60Hz) component

• Implementation issues:Implementation issues:– the second harmonic rotates twice as fast as the

fundamental component (60Hz)– consequently the phase difference between the

second harmonic and the fundamental component changes in time...


T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint

Fundamentalphasor

2nd harmonicphasor

121

2

1

221 arg2arg II

I

I

eI

II

tj

121

2

1

221 arg2arg II

I

I

eI

II

tj

Solution:Solution:



Inrush PatternInrush Pattern

3D View



Internal Fault PatternInternal Fault Pattern

3D View



• Basic Operation:Basic Operation:– if the second harmonic drops magnitude-wise

below 20%, the phase angle of the complex second harmonic ratio is close to either +90 or -90 degrees during inrush conditions

– the phase angle may not display the 90-degree pattern if the second harmonic ratio is above some 20%

– if the second harmonic ratio is above 20% the restraint is in effect, if it is below - the restraint and its duration depend on the phase angle


0

30

60

90

120

150

180

210

240

270

300

330

0.4

0.3

0.2

0

0.1

0OPERATE


0

30

60

90

120

150

180

210

240

270

300

330

0.4

0.3

0.2

0.1

0

New restraintcharacteristic

New restraintcharacteristic

The characteristic is dynamic

The characteristic is dynamic





-0.2 -0.1 0 0.1 0.2 0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

I2 / I

1 (real)

I 2 / I 1 (

ima

gin

ary

)

Isochrone contours, cycles

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

1

11

1

1

1

11

2

2

22

2

2

2

23

3 3 3

3

33

34

4 4

4

44

4

5

55

5

5

5

5

-0.2 -0.1 0 0.1 0.2 0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

I2 / I

1 (real)

I 2 / I 1 (

ima

gin

ary

)

Isochrone contours, cycles

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

1

11

1

1

1

11

2

2

22

2

2

2

23

3 3 3

3

33

34

4 4

4

44

4

5

55

5

5

5

5

Effective restraint characteristic: time (cycles) the restraint is kept vs. complex second harmonic ratio

Effective restraint characteristic: time (cycles) the restraint is kept vs. complex second harmonic ratio



Effective restraint characteristic: time for which the restraint is kept vs. complex second harmonic ratio

Effective restraint characteristic: time for which the restraint is kept vs. complex second harmonic ratio

3D View


T60 Transformer Management Relay: T60 Transformer Management Relay: BenefitsBenefits

• Up to six windings supported

• Improved transformer auto-configuration

• Improved dual-slope differential characteristic

• Improved second harmonic restraint

• Benefits of the UR platform (back-up protection,metering and oscillography, event recorder, data logger, FlexLogicTM, fast peer-to-peer communications)


B30B30Bus Differential RelayBus Differential Relay


B30 Bus Differential Relay: B30 Bus Differential Relay: FeaturesFeatures

• Configuration:Configuration:– up to 5 feeders with bus voltage– up to 6 feeders without bus voltage



• Protection:Protection:– Biased differential protection

• CT saturation immunity

• typical trip time < 15 msec

• dynamic 1-out-of-2 or 2-out-of-2 operation

– Unbiased differential protection– CT trouble



• Metering:Metering:– Oscillography– Event Recorder– Data Logger– Phasors / true RMS – active, reactive and apparent power, power

factor (if voltage available)


B30 Bus Differential Relay: B30 Bus Differential Relay: CT saturation problemCT saturation problem

• During an external fault– the fault current may be supplied by a number

of sources– the CTs on the faulted circuit may saturate– Saturation of the CTs creates a current

unbalance and violates the differential principle– The conventional restraining current may not

be sufficient to prevent maloperation

• CT saturation detection and other operating principles enhance the through-fault stability


B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory

External fault: ideal CTs

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2

DIF – differentialRES – restraining



External fault: ratio mismatch

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2



External fault: CT saturation

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2



Internal fault: high current

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2



Internal fault: low current

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2



External fault: extreme CT saturation

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2


B30 Bus Differential Relay: B30 Bus Differential Relay: Operating principlesOperating principles

• Combination ofCombination of– Low-impedance Low-impedance biased differential– Directional (phase comparison)

• Adaptively switched betweenAdaptively switched between– 1-out-of-2 operating mode1-out-of-2 operating mode– 2-out-of-2 operating mode2-out-of-2 operating mode

• byby– Saturation Detector


B30 Bus Differential Relay: B30 Bus Differential Relay: Two operating zonesTwo operating zones

• low currents • saturation possible

due to dc offset• saturation very

difficult to detect• more security

required

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2

DIF 1


B30 Bus Differential Relay: B30 Bus Differential Relay: Two operating zonesTwo operating zones

• large currents • quick saturation

possible due to large magnitude

• saturation easier to detect

• security required only if saturation detected

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2

DIF 2


B30 Bus Differential Relay: B30 Bus Differential Relay: LogicLogic

DIF1

DIR

SAT

DIF2

OR

AN

D

OR TRIP

AN

D



diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2

1-out-of-2 (DIF) if no saturation2-out-of-2 (DIF+DIR) if saturationdetected

2-out-of-2(DIF+DIR)



DIF1

DIR

SAT

DIF2

OR

AN

D

OR TRIP

AN

D


B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle

• Internal faultsInternal faults - all currents approximately in phase



• External faultsExternal faults - one current approximately out of phase



• Check all the angles

• Select the maximum current contributor and check its position against the sum of all the remaining currents

• Select major current contributors and check their positions against the sum of all the remaining currents



"contributor"(phasor)

differential less"contributor"(phasor)

BLOCK

TRIP

TRIP

BLOCK

BLOCK



BLOCK OPERATE

BLOCK

BLOCK

pD

p

II

Ireal

pD

p

II

Iimag

Ip

ID - I p

External Fault Conditions

OPERATE

BLOCK

A LIM

-A LIM



BLOCK

BLOCK

BLOCK

pD

p

II

Ireal

pD

p

II

Iimag

Ip

ID - I p

Internal Fault Conditions

OPERATE

OPERATE

BLOCK



DIF1

DIR

SAT

DIF2

OR

AN

D

OR TRIP

AN

D


B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector

• differential-restraining trajectory

• dI/dt

diffe

rent

ial

restrainingA

B 1

K 2

K 1

B 2



0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

1

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

2

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

3

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

4

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

5

Time, sec

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

1

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

2

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

3

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

4

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20

02040

Fe

ed

er

5

Time, sec

Sample External Fault (Feeder 1)

Sample External Fault (Feeder 1)


0 5 10 15 20 25 30 350

5

10

15

20

25

30

35D

iffe

ren

tial [

A]

Restraining [A]

12 3 4 56

789

101112

13

1415

16

171819

2021222324252627282930313233

Phase A (Infms)

0 5 10 15 20 25 30 350

5

10

15

20

25

30

35D

iffe

ren

tial [

A]

Restraining [A]

12 3 4 56

789

101112

13

1415

16

171819

2021222324252627282930313233

Phase A (Infms)


Analysis of the DIF-RES trajectory enables the B30 to detect CT saturation

Analysis of the DIF-RES trajectory enables the B30 to detect CT saturation



0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20F

ee

de

r 1

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

2

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

3

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

4

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

5

Time, sec

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20F

ee

de

r 1

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

2

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

3

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

4

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20

0

20

Fe

ed

er

5

Time, sec

Sample External Fault (Feeder 4) - severe CT saturation after 1.5msec

Sample External Fault (Feeder 4) - severe CT saturation after 1.5msec


0 5 10 15 200

5

10

15

20

Diff

ere

ntia

l [A

]

Restraining [A]

12

3

4

5 6

7

8

91011121314

15

16

1718

19

20

2122

23

24252627282930

313233

Phase A (Infms)

0 5 10 15 200

5

10

15

20

Diff

ere

ntia

l [A

]

Restraining [A]

12

3

4

5 6

7

8

91011121314

15

16

1718

19

20

2122

23

24252627282930

313233

Phase A (Infms)


dI/dt principle enables the B30 to detect CT saturation

dI/dt principle enables the B30 to detect CT saturation



NORMAL

SAT := 0

EXTERNALFAULT

SAT := 1

EXTERNALFAULT / CT SAT

SAT := 1

DIF=1DIF=0for 100msec

IDIF < K 1*I RESfor 200msec

"saturation"condition



• Operation:Operation:– The SAT flag WILL NOT set during internal

faults whether or not the CT saturates– The SAT flag WILL SET during external faults

whether or not the CT saturates– The SAT flag is NOT used to block the relay

but to switch to 2-out-of-2 operating principle


B30 Bus Differential Relay: B30 Bus Differential Relay: BenefitsBenefits

• Sensitive settings possible

• Very good through-fault stability

• Fast operation (less than 3/4 of a cycle)

• Benefits of the UR platform (back-up protection,metering and oscillography, event recorder, data logger, FlexLogicTM, fast peer-to-peer communication)


B30 Bus Differential Relay: B30 Bus Differential Relay: ExtensionsExtensions

6 feeders6 feeders

6 feeders6 feeders

6 feeders6 feeders

fastcommunication


F60F60Feeder Management RelayFeeder Management Relay


F60 Feeder RelayF60 Feeder Relay: : FeaturesFeatures

• Protection:Protection:– Phase/Neutral/Ground IOC & TOC – Phase TOC with Voltage Restraint/Supervision– Negative sequence IOC & TOC– Phase directional supervision– Neutral directional overcurrent– Negative sequence directional overcurrent– Phase undervoltage & overvoltage– Underfrequency – Breaker Failure (phase/neutral supervision)


F60 Feeder RelayF60 Feeder Relay: : FeaturesFeatures

• Control:Control:– Manually Control up to Two Breakers– Autoreclosure & Synchrocheck– FlexLogic


apparent power, power factor, frequency


F60 Feeder Relay: F60 Feeder Relay: Phase Directional ElementPhase Directional Element

• Directional element controls the RUN command of the overcurrent element (emulation of “torque control”)

• Memory voltage polarization held for 1 second

V BGV C G

VA G (Fau lted ) IA

IA = o p erating cu rrent

P h aso rs fo r P h ase A P o lariza tio n:

E C Aset @ 30 o

V P o l = VB C * (1/_ E C A ) = po la rizing vo ltag e

B LO C K

E C A = E lem ent C h aracteris tic A ng le @ 30o

Fau lt an g leset @ 60 o Lag

VA G (U n fau lted )

V BC

V BC

V P o l

+90o

-90o


F60 Feeder Relay: F60 Feeder Relay: Neutral Directional ElementNeutral Directional Element

• Single protection element providing both forward and reverse looking IOC

• Independent settings for the forward and reverse elements

• Voltage, current or dual polarization

• Fast and secure operation due to the energy based comparator and positive sequence restraint


F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements

• Limitations of Fast Ground Directional Limitations of Fast Ground Directional IOCs:IOCs:– Spurious zero- and negative-sequence voltages

and currents may appear transiently due to the dynamics of digital measuring algorithms

– Magnitude of such spurious signals may reach up to 25% of the positive sequence quantities

– Phase angles of such spurious signals are random factors

– Combination of the above may cause maloperations



0.05 0.1 0.15 0.2 0.25-25

-20

-15

-10

-5

0

5

10

15

20

25

time [sec]

0.05 0.1 0.15 0.2 0.25-25

-20

-15

-10

-5

0

5

10

15

20

25

time [sec]

Sample three-phase fault currents

Sample three-phase fault currents


-10 -5 0 5 10

-10

-5

0

5

10

Real

Imag

inar

y


Sample three-phase fault currents (phasors)

Sample three-phase fault currents (phasors)

Pre-fault phasors(symmetrical)

Fault phasors(symmetrical)

Transient phasors(slightly asymmetrical)

Transient phasors(slightly asymmetrical)


0.05 0.1 0.15 0.2 0.250

2

4

6

8

10

12

14

time [sec]

0.05 0.1 0.15 0.2 0.250

2

4

6

8

10

12

14

time [sec]


Sample three-phase currents (symmetrical components)

Sample three-phase currents (symmetrical components)

Positive Sequence

Negative Sequence

Zero Sequence



• Solutions to the problem of spurious zero Solutions to the problem of spurious zero and negative sequence quantities:and negative sequence quantities:– do not allow too sensitive settings– apply delay– new approach:

• energy based comparatorenergy based comparator

• positive sequence restraintpositive sequence restraint



• Operating “power” is calculated as a function of:– magnitudes of the operating and polarizing

signals– the angle between the operating and polarizing

signals in conjunction with the characteristic and limit angles

• Restraining “power” is calculated as a product of magnitudes of the operating and restraining signals



• The “powers” are averaged over certain short period of time creating the operating and restraining “energies”

• The element operates when

• Both “forward” and “reverse” operating energies are calculated

• The factor K is lower for the reverse looking element to ensure faster operation

EnergygRestraininEnergyOperating K



0.05 0.1 0.15 0.2 0.25-20

-10

0

10

20

30

40

50

time [sec]

0.05 0.1 0.15 0.2 0.25-20

-10

0

10

20

30

40

50

time [sec]

0.05 0.1 0.15 0.2 0.25-15

-10

-5

0

5

10

15

20

time [sec]

0.05 0.1 0.15 0.2 0.25-15

-10

-5

0

5

10

15

20

time [sec]

Reverse looking element

Reverse looking element

Forward looking element

Forward looking elementRestraining Energy

Restraining Energy

Operating Energy

Operating Energy

Despite spurious negative sequence neither the forward nor the reverse looking element maloperate

Despite spurious negative sequence neither the forward nor the reverse looking element maloperate



• Positive Sequence Restraint:Positive Sequence Restraint:– Classical Negative Sequence IOC:

– Positive Sequence Restrained Negative Sequence IOC:

– K1 = 1/8 for negative sequence IOC

– K1 = 1/16 for zero sequence IOC

PICKUPI 2

PICKUPIKI 112


F60 Feeder Relay: F60 Feeder Relay: Negative Sequence Directional ElementNegative Sequence Directional Element

• Single protection element providing both forward and reverse looking IOC

• Independent settings for the forward and reverse elements

• Mixed operating mode available:– Negative Sequence IOC / Negative Sequence

Directional– Zero Sequence IOC / Negative Sequence Directional

• Energy based comparator and positive sequence restraint



Documents

Protection Overview Universal Relay Family. Power Management The Universal Relay Contents... Configurable Sources FlexLogic™ and Distributed FlexLogic™