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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
Universal Relay FamilyUniversal Relay Family
Configurable Configurable SourcesSources
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
Sources: Sources: Typical ApplicationsTypical Applications
• Breaker-and-a-half schemes
• Multi-winding (multi-restraint) Transformers
• Busbars
• Multiple Feeder applications
• Multiple Meter
• Synchrocheck
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
VT1
CT1
CT2
CT3
Sources Example 1: Sources Example 1: Inputs into the Universal RelayInputs into the Universal Relay
Power Management The The Universal RelayUniversal 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
Physical 3-phaseI &V Inputs
CT1
CT2
CT1
CT2
Con
figur
e So
urce
s(d
one
via
setti
ngs)
VT1
CT3
Universal RelayUniversal Relay
Sources Example 1: Sources Example 1: Universal Relay solution using SourcesUniversal Relay solution using Sources
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
VT1
CT1
CT2
CT3
CT4
Sources Example 2: Sources Example 2: Inputs into the Universal RelayInputs into the Universal Relay
Power Management The The Universal RelayUniversal 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
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
Physical 3-phaseI &V Inputs
CT1
CT2
CT1
CT2
Con
figur
e So
urce
s(d
one
via
setti
ngs)
VT1
CT3CT4
VI
II
V
CT4 Source #5
Universal RelayUniversal Relay
Sources Example 2: Sources Example 2: Universal Relay solution using SourcesUniversal Relay solution using Sources
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
VT1
CT1
CT2
CT3
CT4
CT5
Sources Example 3: Sources Example 3: Inputs into the Universal RelayInputs into the Universal Relay
Power Management The The Universal RelayUniversal Relay
VT1
VV
II
I
VI
II
V
CT1
CT2
VI
II
V
CT3
50/51 81
VI
II
V
Source #1
Physical 3-phaseI &V Inputs
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
Physical 3-phaseI &V Inputs
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
Sources Example 3: Sources Example 3: Universal Relay solution using SourcesUniversal Relay solution using Sources
Universal Relay FamilyUniversal Relay Family
FlexLogicFlexLogicTMTM
&&Distributed FlexLogicDistributed FlexLogicTMTM
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
AND
AND
AND
OR
Remote Input: Trip Relay 2
Remote Input: Trip Relay 2
Remote Input: Trip Relay 3
Remote Input: Trip Relay 3
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
Power Management The The Universal RelayUniversal Relay
Distributed FlexLogic Example 1:Distributed FlexLogic Example 1: Implementation of 2 out of 3 Voting SchemeImplementation of 2 out of 3 Voting Scheme
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Universal Relay FamilyUniversal Relay Family
L90L90Line Differential RelayLine Differential Relay
Power Management The The Universal RelayUniversal 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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
L90 Current Differential Relay: L90 Current Differential Relay: DigitalDigital Phasor MeasurementPhasor Measurement
Sliding Data WindowSliding Data Window
waveformwaveform magnitudemagnitude
window
timetime
presenttime
presenttime
Power Management The The Universal RelayUniversal Relay
L90 Current Differential Relay: L90 Current Differential Relay: DigitalDigital Phasor MeasurementPhasor Measurement
Sliding Data WindowSliding Data Window
waveformwaveform magnitudemagnitude
window
timetime
windowwindowwindowwindowwindowwindowwindow
Power Management The The Universal RelayUniversal Relay
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)
Power Management The The Universal RelayUniversal Relay
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)
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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)
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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]
L90 Current Differential Relay: L90 Current Differential Relay: Effect of CompensationEffect of Compensation
Current, ACurrent, A
time, sectime, sec
Traditional and compensated differentialcurrents (waveforms)
Power Management The The Universal RelayUniversal Relay
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]
L90 Current Differential Relay: L90 Current Differential Relay: Effect of CompensationEffect of Compensation
Current, ACurrent, A
time, sectime, sec
Traditional and compensated differentialcurrents (magnitudes)
Power Management The The Universal RelayUniversal Relay
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”
Power Management The The Universal RelayUniversal Relay
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
Store T1i-1=8.33Capture T2i=18.96
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°
Power Management The The Universal RelayUniversal Relay
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-1=49.93Capture T1i=54.03
Store T2i-2=35.62
Store T1i-1=50.00Capture T2i=53.16
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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)
Universal Relay FamilyUniversal Relay Family
D60D60Line Distance RelayLine Distance Relay
Power Management The The Universal RelayUniversal 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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: FeaturesFeatures
• Protection (continued):Protection (continued):– Phase under- and overvoltage– Power swing blocking– Out of step tripping
• Control:Control:– Breaker Failure (phase/neutral amps)– Synchrocheck– Autoreclosure
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: FeaturesFeatures
• Metering:Metering:– Fault Locator– Oscillography– Event Recorder– Data Logger– Phasors / true RMS / active, reactive and
apparent power, power factor
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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)
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
• 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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
-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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
• Transient overreach due to CVTs - solutions:– apply delay (fixed or adaptable)– reduce the reach– adaptive techniques and better filtering
algorithms
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
• 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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
• 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
Power Management The The Universal RelayUniversal Relay
No TripNo Trip
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
DelayedTrip
DelayedTrip
InstantaneousTrip
InstantaneousTrip
Set reachSet reach
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
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
Power Management The The Universal RelayUniversal Relay
D60 Line Distance Relay: D60 Line Distance Relay: Zone 1 andZone 1 and CVT transientsCVT transients
• Performance:Performance:– excellent transient overreach control (5% up to
a SIR of 30)– no unnecessary decrease in speed
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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)
Universal Relay FamilyUniversal Relay Family
T60T60Transformer Management RelayTransformer Management Relay
Power Management The The Universal RelayUniversal 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
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: FeaturesFeatures
• Metering:Metering:– Oscillography– Event Recorder– Data Logger– Phasors / true RMS / active, reactive and
apparent power, power factor
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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...
Power Management The The Universal RelayUniversal Relay
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:
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
Inrush PatternInrush Pattern
3D View
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
Internal Fault PatternInternal Fault Pattern
3D View
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
• 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
Power Management The The Universal RelayUniversal Relay
0
30
60
90
120
150
180
210
240
270
300
330
0.4
0.3
0.2
0
0.1
0OPERATE
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
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
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
-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
Power Management The The Universal RelayUniversal Relay
T60 Transformer Management Relay: T60 Transformer Management Relay: New Inrush RestraintNew Inrush Restraint
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
Power Management The The Universal RelayUniversal Relay
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)
Universal Relay FamilyUniversal Relay Family
B30B30Bus Differential RelayBus Differential Relay
Power Management The The Universal RelayUniversal 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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: FeaturesFeatures
• 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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: FeaturesFeatures
• Metering:Metering:– Oscillography– Event Recorder– Data Logger– Phasors / true RMS – active, reactive and apparent power, power
factor (if voltage available)
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory
External fault: ratio mismatch
diffe
rent
ial
restrainingA
B 1
K 2
K 1
B 2
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory
External fault: CT saturation
diffe
rent
ial
restrainingA
B 1
K 2
K 1
B 2
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory
Internal fault: high current
diffe
rent
ial
restrainingA
B 1
K 2
K 1
B 2
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory
Internal fault: low current
diffe
rent
ial
restrainingA
B 1
K 2
K 1
B 2
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: DIF-RES trajectoryDIF-RES trajectory
External fault: extreme CT saturation
diffe
rent
ial
restrainingA
B 1
K 2
K 1
B 2
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: LogicLogic
DIF1
DIR
SAT
DIF2
OR
AN
D
OR TRIP
AN
D
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: LogicLogic
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)
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: LogicLogic
DIF1
DIR
SAT
DIF2
OR
AN
D
OR TRIP
AN
D
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
• Internal faultsInternal faults - all currents approximately in phase
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
• External faultsExternal faults - one current approximately out of phase
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
• 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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
"contributor"(phasor)
differential less"contributor"(phasor)
BLOCK
TRIP
TRIP
BLOCK
BLOCK
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Directional principleDirectional principle
BLOCK
BLOCK
BLOCK
pD
p
II
Ireal
pD
p
II
Iimag
Ip
ID - I p
Internal Fault Conditions
OPERATE
OPERATE
BLOCK
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: LogicLogic
DIF1
DIR
SAT
DIF2
OR
AN
D
OR TRIP
AN
D
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
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)
Power Management The The Universal RelayUniversal Relay
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)
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
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
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
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
Power Management The The Universal RelayUniversal Relay
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)
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
dI/dt principle enables the B30 to detect CT saturation
dI/dt principle enables the B30 to detect CT saturation
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
NORMAL
SAT := 0
EXTERNALFAULT
SAT := 1
EXTERNALFAULT / CT SAT
SAT := 1
DIF=1DIF=0for 100msec
IDIF < K 1*I RESfor 200msec
"saturation"condition
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Saturation DetectorSaturation Detector
• 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
Power Management The The Universal RelayUniversal Relay
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)
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: ExtensionsExtensions
6 feeders6 feeders
6 feeders6 feeders
6 feeders6 feeders
fastcommunication
Universal Relay FamilyUniversal Relay Family
F60F60Feeder Management RelayFeeder Management Relay
Power Management The The Universal RelayUniversal 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)
Power Management The The Universal RelayUniversal Relay
F60 Feeder RelayF60 Feeder Relay: : FeaturesFeatures
• Control:Control:– Manually Control up to Two Breakers– Autoreclosure & Synchrocheck– FlexLogic
• Metering:Metering:– Fault Locator– Oscillography– Event Recorder– Data Logger– Phasors / true RMS / active, reactive and
apparent power, power factor, frequency
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
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
Power Management The The Universal RelayUniversal Relay
-10 -5 0 5 10
-10
-5
0
5
10
Real
Imag
inar
y
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
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)
Power Management The The Universal RelayUniversal Relay
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]
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
Sample three-phase currents (symmetrical components)
Sample three-phase currents (symmetrical components)
Positive Sequence
Negative Sequence
Zero Sequence
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
• 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
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
• 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
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
• 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
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
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
Power Management The The Universal RelayUniversal Relay
F60 Feeder Relay: F60 Feeder Relay: Ground Directional ElementsGround Directional Elements
• 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
Power Management The The Universal RelayUniversal Relay
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
Power Management The The Universal RelayUniversal Relay
Power Management The The Universal RelayUniversal Relay