Transcript No Slide Title

Universal Relay Family
Protection Overview
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
Power Management
The Universal Relay
Universal Relay Family
Configurable 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
Source

I
Metering
A
W
Protection
51P
V I
Universal Relay
Power Management
The Universal Relay
Sources: Typical Applications
• Breaker-and-a-half schemes
• Multi-winding (multi-restraint)
Transformers
• Busbars
• Multiple Feeder applications
• Multiple Meter
• Synchrocheck
Power Management
The Universal Relay
Sources Example 1: Breaker-and-a-Half Scheme
50BF
50BF
VT1
CT1
CT2
50P
W
87T
Transf ormer
CT3
Power Management
The Universal Relay
Sources Example 1: Traditional Relay Application
50BF
50BF
VT1
CT1
CT2
50P
50BF
RELAY
W
87T
50BF
RELAY
Transf ormer
External
Summation
VOLT
AMPS
50P
W
CT3
87T
AMPS
Transformer Differential
Relay
Power Management
The Universal Relay
Sources Example 1: Inputs into the Universal Relay
Power Management
CT2
VT1
CT3
CT1
The Universal Relay
Sources Example 1: Universal Relay solution using Sources
II
Source #1
CT1
Physical 3-phase
I &V Inputs
CT1
CT2
CT3
Configure Sources
(done via settings)
VT1
I
V
V
II
CT2
I
V
50BF
Source #2
50BF
V
CT1
CT2
II
Source #3
VT1
V
50P
W
I
87T
II
Source #4
CT3
I
V
Power Management
V
Universal Relay
The Universal Relay
Sources Example 2: Breaker-and-a-Half Scheme with 3-Winding Transformer
50BF
50BF
VT1
CT1
CT2
50P
W
87T
T1
CT3
CT4
Power Management
The Universal Relay
Sources Example 2: Inputs into the Universal Relay
CT4
Power Management
CT2
VT1
CT3
CT1
The Universal Relay
Sources Example 2: Universal Relay solution using Sources
I I
CT1
Physical 3-phase
I &V Inputs
CT1
CT2
CT3
Configure Sources
(done via settings)
VT1
Source #1
50BF
I V
V
I I
CT2
Source #2
50BF
I V
V
CT1
CT2
VT1
I I
V I
I I
CT4
Source #3
Source #4
50P
W
87T
CT3
I V
V
CT4
I I
I V
V
Power Management
Source #5
Universal Relay
The Universal Relay
Sources
Multiple
Example
Feeder
3: Busbar
+ Busbar
with 5 feeders
W
51
27P
VT1
CT1
50/
51
50/
51
50/
51
50/
51
50/
51
W
W
W
W
W
81
81
81
81
81
CT2
Power Management
CT3
CT4
CT5
The Universal Relay
Sources Example 3: Inputs into the Universal Relay
Power Management
CT4
CT2
VT1
CT5
CT3
CT1
The Universal Relay
Sources Example 3: Universal Relay solution using Sources
Physical 3-phase
I &V Inputs
CT1
CT2
CT3
I I
VT1
I V
V
CT2
VT1
Configure Sources
(done via settings)
VT1
CT1
CT3
VT1
CT4
VT1
CT4
CT5
Universal
Relay
Power Management
CT5
VT1
I I
Source #2
50/51
81
W
50/51
81
W
50/51
81
W
50/51
81
W
50/51
81
W
51
27P
W
I V
V
I I
Source #3
V I
I I
Source #4
I V
V
I I
Source #5
I V
V
I I
CT1..CT5
VT1
Source #1
Source #6
I V
V
The Universal Relay
Universal Relay Family
FlexLogicTM
&
Distributed FlexLogicTM
Universal Relay: Functional Architecture
Analog
Inputs
A/D
DSP
Digital
Inputs
Virtual
Inputs
Computed
Parameters
Metering
Protection & Control
Elements
Programmable
Logic
(FlexLogic™)
Remote
Inputs
Remote
Outputs
Virtual
Outputs
Digital
Outputs
Hardware
Software
Ethernet (Fiber)
Ethernet LAN (Dual Redundant Fiber)
Power Management
The Universal Relay
Distributed FlexLogic Example 1: 2 out of 3 Trip Logic Voting Scheme
Local: Trip
Remote Input: Trip Relay 2
LOCAL RELAY
AND
Digital
Output
ENABLE
Local: Trip
Remote Input: Trip Relay 3
AND
OR
0ms
0ms
ENABLE
Remote
Output
Remote Input: Trip Relay 2
Remote Input: Trip Relay 3
AND
ENABLE
Substation LAN
RELAY 2
Power Management
Local
RELAY
RELAY 3
The Universal Relay
Distributed FlexLogic Example 1: Implementation of 2 out of 3 Voting Scheme
Power Management
The Universal Relay
Distributed FlexLogic Example 2: Transformer Overcurrent Acceleration
TIME
Animation
UR-T60
Transformer IED
Transformer
TOC Curve
Coordination
Time
Accelerated
Transformer
TOC Curve
Feeder TOC Curve
Current Pick-Up Level
UR-F60
Feeder IED
UR-F60
Feeder IED
UR-F60
Feeder IED
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.
Power Management
The Universal Relay
FlexLogic: Benefits
• FlexLogic™
– Tailor your scheme logic to suit the application
– Avoid custom software modifications
• 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
Power Management
The Universal Relay
Universal Relay Family
L90
Line Differential Relay
L90 Current Differential Relay: Features
• 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 Universal Relay
L90 Current Differential Relay: Features
• Control:
– Breaker Failure (phase/neutral amps)
– Synchrocheck & Autoreclosure
– Direct messaging (8 extra inter-relay DTT bits
exchanged)
• Metering:
–
–
–
–
–
Fault Locator
Oscillography
Event Recorder
Data Logger
Phasors / true RMS / active, reactive and
apparent power, power factor
Power Management
The Universal Relay
L90 Current Differential Relay: Overview
Direct point-to-point Fiber
(up to 70Km)
(64Kbps)
- G.703
- RS422
OR
- G.703
- RS422
Via SONET system telecom multiplexer
(GE’s FSC)
(155Mbps)
FSC
(SONET)
Power Management
FSC
(SONET)
The Universal Relay
L90 Current Differential Relay: Line Current Differential
• Improved operation of the line current
differential (87L) element:
– dynamic restraint increasing security without
jeopardizing sensitivity
– line charge current compensation to increase
sensitivity
– self-synchronization
Power Management
The Universal Relay
Operate Current
L90 Current Differential Relay: Traditional Restraint Method
K2
K1
Restraint Current
– Traditional method is STATIC
– Compromise between Sensitivity and Security
Power Management
The Universal Relay
L90 Current Differential Relay: Dynamic 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 Universal Relay
L90 Current Differential Relay: Digital Phasor Measurement
• The L90 measures the current phasors
(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 Universal Relay
L90 Current Differential Relay: Digital Phasor Measurement
Sliding Data Window
present
time
window
time
waveform
Power Management
time
magnitude
The Universal Relay
L90 Current Differential Relay: Digital Phasor Measurement
Sliding Data Window
window
window
window
window
window
window
window
window
time
waveform
Power Management
time
magnitude
The Universal Relay
L90 Current Differential Relay: Goodness of Fit
• 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)
window
time
Power Management
The Universal Relay
L90 Current Differential Relay: Phasor 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 Universal Relay
L90 Current Differential Relay: Operate-Restraint Regions
ILOC – local current
IREM – remote end current
Imaginary (ILOC/IREM)
OPERATE
OPERATE
RESTRAINT
Real (ILOC/IREM)
OPERATE
OPERATE
Power Management
The Universal Relay
L90 Current Differential Relay: Dynamic Restraint
Dynamic restraint signal =
Traditional restraint signal + Error factor
Imaginary (ILOC/IREM)
OPERATE
Error factor is high
Real (ILOC/IREM)
REST.
Error factor is low
Power Management
The Universal Relay
L90 Current Differential Relay: Charge 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 Universal Relay
L90 Current Differential Relay: Charge 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 Universal Relay
L90 Current Differential Relay: Effect of Compensation
Local and remote voltages
Voltage, V
200
150
Voltages: v1(r), v2(b)
100
50
0
-50
-100
-150
-200
0.04
0.06
0.08
0.1
0.12
time [sec]
0.14
0.16
0.18
time, sec
Power Management
The Universal Relay
L90 Current Differential Relay: Effect of Compensation
Traditional and compensated differential
currents (waveforms)
Current, A
0.3
0.25
id: raw (r), compensated (b)
0.2
0.15
0.1
0.05
0
-0.05
-0.1
-0.15
-0.2
0.04
0.06
0.08
0.1
0.12
time [sec]
0.14
0.16
0.18
time, sec
Power Management
The Universal Relay
L90 Current Differential Relay: Effect of Compensation
Traditional and compensated differential
currents (magnitudes)
Current, A
0.08
Id: raw (r), compensated (b)
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
0.04
0.06
0.08
0.1
0.12
time [sec]
0.14
0.16
0.18
time, sec
Power Management
The Universal Relay
L90 Current Differential Relay: Self-Synchronization
RELAY 1
Forward
travel
time
Return
travel
time
t0
RELAY 2
tf
“ping-pong”
tr
t1 Relay
turn-around
t2 time
t3
t3  t0  t2  t1 
t f  tr 
2
Power Management
The Universal Relay
L90 Current Differential Relay: Ping-Pong (example)
Relay 1
Send start bit
Store T1i-3=0
Relay 2
0
Initial clocks mismatch=1.4ms or 30°
Communication path
Send start bit
Store T2i-3=0
0
8.33 ms
Capture T2i-2=2.3
5.1
Capture T1i-2=5.1
2.3
8.33 ms
Send T1i-2=5.1
8.33
8.33
Store T1i-2=5.1
8.33 ms
13.43
Store T2i-2=2.3
Send T2i-2=2.3
10.53
8.33 ms
Send T1i-1=16.66
16.66
16.66
Send T2i-1=16.66
8.33 ms
21.76
Store T2i-1=8.33
Capture T1i=21.76
T1i-3=0
T2i-2=2.3
T2i-1=16.66
T1i=21.76
Store T1i-1=8.33
Capture T2i=18.96
18.96
T2i-3=0
T1i-2=5.1
T1i-1=16.66
T2i=18.96
a1=2.3-0=2.3
b1=21.76-16.66=5.1
1=(2.3-5.1)/2=
= -1.4ms (ahead)
a2=5.1-0=5.1
b2=18.96-16.66=2.3
2=(5.1-2.3)/2=
= +1.4ms (behind)
Speed up
Slow down
30°
0°
t1
Power Management
t2
The Universal Relay
L90 Current Differential Relay: Ping-Pong (example cnt.)
Relay 1
Relay 2
33.32
Store T1i-3=33.32
33.32
Store T2i-3=33.32
8.52 ms
38.28
Capture T1i-2=38.28
Capture T2i-2=35.62
35.62
8.14 ms
41.55
Send T1i-2=38.28
41.55
8.52 ms
Send T2i-2=35.62
Store T1i-2=38.28
Store T2i-2=35.62
8.14 ms
Send T1i-1=50.00
50.00
8.52 ms
54.03
49.93
Send T2i-1=49.93
53.16
Store T1i-1=50.00
Capture T2i=53.16
Store T2i-1=49.93
Capture T1i=54.03
8.14 ms
T1i-3=33.32
T2i-2=35.62
T2i-1=49.93
T1i=54.03
T2i-3=33.32
T1i-2=38.28
T1i-1=50.00
T2i=53.16
a1=35.62-33.32=2.3
b1=54.03-49.93=4.1
1=(2.3-4.1)/2=
= -0.9ms (ahead)
a2=38.28-33.32=4.96
b2=53.16-50.00=3.16
2=(4.96-3.16)/2=
= +0.9ms (behind)
Speed up
Slow down
0°
19.5°
30°
t1
Power Management
t2
The Universal Relay
L90 Current Differential Relay: Digital “Flywheel”


“Virtual Shaft”
clock 1
clock 2
• If communications is lost, sample clocks
continue to “free wheel”
• Long term accuracy is only a function of the
base crystal stability
Power Management
The Universal Relay
L90 Current Differential Relay: Peer-to-Peer Operation
– Each relay has sufficient information to make
an independent decision
– Communication redundancy
L90-2
L90-1
L90-3
Power Management
The Universal Relay
L90 Current Differential Relay: Master-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
L90-2
L90-1
L90-3
Data (currents)
Transfer Trip
Power Management
The Universal Relay
L90 Current Differential Relay: Benefits
• Increased Sensitivity without sacrificing
Security:
–
–
–
–
Fast operation (11.5 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 Universal Relay
L90 Current Differential Relay: Benefits
• 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 platform (back-up
protection, autoreclosure, breaker failure,
metering and oscillography, event recorder,
data logger, FlexLogicTM, fast peer-to-peer
communications)
Power Management
The Universal Relay
Universal Relay Family
D60
Line Distance Relay
D60 Line Distance Relay: Features
• 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 Universal Relay
D60 Line Distance Relay: Features
• Protection (continued):
– Phase under- and overvoltage
– Power swing blocking
– Out of step tripping
• Control:
– Breaker Failure (phase/neutral amps)
– Synchrocheck
– Autoreclosure
Power Management
The Universal Relay
D60 Line Distance Relay: Features
• Metering:
–
–
–
–
–
Fault Locator
Oscillography
Event Recorder
Data Logger
Phasors / true RMS / active, reactive and
apparent power, power factor
Power Management
The Universal Relay
D60 Line Distance Relay: 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 Universal Relay
D60 Line Distance Relay: Zone 1 and CVT 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 3040%) 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 Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
Sample CVT output voltages
(the primary voltage drops
to zero)
1
0.8
0.6
"High-C CVT" (CVT-1)
Voltage [pu]
0.4
0.2
"Extra-High-C CVT" (CVT-2)
0
-0.2
-0.4
0.3
-0.6
0.25
-0.8
0.2
0.05
0.06
0.07
0.08
time [sec]
0.09
0.1
0.11
Voltage [pu]
-1
NOISE COMPONENT 2
0.15
0.12
NOISE COMPONENT 1
0.1
60Hz SIGNAL
0.05
0
-0.05
Illustration of the
signal-to-noise ratio
-0.1
Power Management
0
0.01
0.02
0.03
0.04
0.05
time [sec]
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT 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 Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
5
x 10
Estimated voltage magnitude
does not (a)
seem to be underestimated
5
4
3
estimated
amplitude
Voltage [V]
2
1
0
-1
voltage
waveform
-2
x 10
-3
4
-4
3
0.04
0.06
0.08
0.1
0.12
time [sec]
2
0.14
Voltage [V]
-5
0.02
2.2% of the nominal =
70% of the actual(b)value
estimated
4
0.16
0.18
0.2
amplitude
actual
value
1
0
-1
-2
2.2% of the nominal =
70% of the actual value
-3
-4
0.04
Power Management
0.05
0.06
0.07
0.08 0.09
time [sec]
0.1
0.11
0.12
0.13
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
15
34
42
Actual Fault
Location
44
Reactance [ohm]
10
30
dynamic mho
zone extended
for high SIRs
Line
Impedance
5
18
22
Trajectory
(msec)
0
26
-5
-10
Power Management
-5
0
Resistance [ohm]
Impedance locus may pass
below
the origin
of the Z-plane 5
10
this would call for a time delay
to obtain stability
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
• Transient overreach due to CVTs solutions:
– apply delay (fixed or adaptable)
– reduce the reach
– adaptive techniques and better filtering
algorithms
Power Management
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
Actual maximum reach curves
D60
100
90
Relay D
80
Maximum Rach [%]
70
60
50
40
Relay S
30
20
Relay A
10
0
0
Power Management
5
10
15
SIR
20
25
30
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
• 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 Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
• The outer zone 1:
– is fixed at the actual reach
– applies certain security delay to cope with CVT
transients
• The inner zone 1:
– has its reach
dynamically
controlled by the
voltage magnitude
– is instantaneous
X
Delay ed
Trip
Instantaneous
Trip
R
Power Management
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
Set reach
No Trip
Delayed
Trip
Instantaneous
Trip
Power Management
The Universal Relay
1
0.95
Secure Reach
Multiplier for the inner zone 1 reach, pu
D60 Line Distance Relay: Zone 1 and CVT transients
0.9
0.85
0.8
0.75
0
0.2
0.4
0.6
0.8
1
Voltage
Element’s Voltage, pu
Power Management
The Universal Relay
D60 Line Distance Relay: Zone 1 and CVT transients
• Performance:
– excellent transient overreach control (5% up to
a SIR of 30)
– no unnecessary decrease in speed
Power Management
The Universal Relay
D60 Line Distance Relay: Zone 1 Speed
Phase Element
30
Operating Time [ms]
25
20
SIR =
SIR =
SIR =
SIR =
SIR =
15
0.1
1
10
20
30
10
5
0
0%
10%
20%
30%
40%
50%
60%
70%
80%
Fault Location [%]
Power Management
The Universal Relay
D60 Line Distance Relay: Zone 1 Speed
Ground Element
35
Operating Time [ms]
30
25
SIR =
SIR =
SIR =
SIR =
SIR =
20
15
0.1
1
10
20
30
10
5
0
0%
10%
20%
30%
40%
50%
60%
70%
80%
Fault Location [%]
Power Management
The Universal Relay
D60 Line Distance Relay: Pilot Schemes
• 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 Universal Relay
D60 Line Distance Relay: Pilot Schemes
• 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 Universal Relay
D60 Line Distance Relay: Benefits
• 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)
Power Management
The Universal Relay
Universal Relay Family
T60
Transformer Management Relay
T60 Transformer Management Relay: Features
• 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 Universal Relay
T60 Transformer Management Relay: Features
• Metering:
–
–
–
–
Oscillography
Event Recorder
Data Logger
Phasors / true RMS / active, reactive and
apparent power, power factor
Power Management
The Universal Relay
T60 Transformer Management Relay: Restrained 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 Universal Relay
T60 Transformer Management Relay: Differential 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 Universal Relay
T60 Transformer Management Relay: Restraining 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 Universal Relay
T60 Transformer Management Relay: Operating Characteristic
• Two slopes used to cope with:
differential
– small errors during linear operation of the CTs
(K1) and
– large CT errors (saturation) for high through
currents (K2)
K2
K1
A
B1 B2
Power Management
restraining
The Universal Relay
T60 Transformer Management Relay: Operating Characteristic
• Two breakpoints used to specify:
differential
– 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)
K2
K1
A
B1 B2
Power Management
restraining
The Universal Relay
T60 Transformer Management Relay: Magnetizing Inrush
Sample (a)
magnetizing
inrush current
i [A]
1500
1000
500
0
-400
I2 / I1
0
1
2
4
3
5
6
8
7
9
10
11
Time (cycles)
(b)
Second harmonic
ratio
1
0.8
0.6
0.4
0.2
0
0
1
2
3
4
Power Management
5
6
7
8
9
10
Time (cy cles)
The Universal Relay
T60 Transformer Management Relay: Magnetizing Inrush
• New second harmonic restraint:
– uses both the magnitude and phase relation
between the second harmonic and the
fundamental frequency (60Hz) component
• 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 Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
Fundamental
phasor
2nd harmonic
phasor
Solution:
I 21 
Power Management
I2
I1 e
jt
I2

arg I 2   2  arg I 1 
I1
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
3D View
Inrush Pattern
Power Management
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
3D View
Internal Fault Pattern
Power Management
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
• 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 Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
New restraint
characteristic
90
0 .4
120
150
60
0 .3
30
0 .2
0 .1
OPERATE
180
90
0 .4
120
00
60
0
0 .3
150
210
30
0 .2
330
0 .1
0
180
240
0
300
270
210
330
The characteristic is
dynamic
240
300
270
Power Management
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
Power Management
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
Effective
Isochrone contours,
cyclesrestraint
characteristic:
time (cycles) the restraint is kept
vs. complex second harmonic ratio
0.25
0.2
3
54
32
1
0.1
0.1
1
4
5
-0.05
2
1
0.1215 4
0
4
2 3 0.1
0.05
1
3
I2 / I1 (imaginary)
0.1
3
1
0.1
4.1
50
2
0.15
5
2
-0.1
3
3
0.
1
1
-0.15
02.1
54
-0.2
13
2
45
-0.25
-0.2
Power Management
-0.1
0
I2 / I1 (real)
0.1
0.2
0.3
The Universal Relay
T60 Transformer Management Relay: New Inrush Restraint
Effective restraint characteristic:
time for which the restraint is kept
vs. complex second harmonic ratio
3D View
Power Management
The Universal Relay
T60 Transformer Management Relay: Benefits
• 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)
Power Management
The Universal Relay
Universal Relay Family
B30
Bus Differential Relay
B30 Bus Differential Relay: Features
• Configuration:
– up to 5 feeders with bus voltage
– up to 6 feeders without bus voltage
Power Management
The Universal Relay
B30 Bus Differential Relay: Features
• 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 Universal Relay
B30 Bus Differential Relay: Features
• Metering:
–
–
–
–
–
Oscillography
Event Recorder
Data Logger
Phasors / true RMS
active, reactive and apparent power, power
factor (if voltage available)
Power Management
The Universal Relay
B30 Bus Differential Relay: CT 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 Universal Relay
B30 Bus Differential Relay: DIF-RES trajectory
differential
DIF
RES
K2
– differential
– restraining
External
fault: ideal
CTs
K1
A
B1 B2
Power Management
restraining
The Universal Relay
differential
B30 Bus Differential Relay: DIF-RES trajectory
K2
External
fault: ratio
mismatch
K1
A
B1 B2
Power Management
restraining
The Universal Relay
differential
B30 Bus Differential Relay: DIF-RES trajectory
K2
External
fault: CT
saturation
K1
A
B1 B2
Power Management
restraining
The Universal Relay
differential
B30 Bus Differential Relay: DIF-RES trajectory
K2
Internal
fault: high
current
K1
A
B1 B2
Power Management
restraining
The Universal Relay
differential
B30 Bus Differential Relay: DIF-RES trajectory
K2
Internal
fault: low
current
K1
A
B1 B2
Power Management
restraining
The Universal Relay
differential
B30 Bus Differential Relay: DIF-RES trajectory
K2
K1
External
fault:
extreme CT
saturation
A
B1 B2
Power Management
restraining
The Universal Relay
B30 Bus Differential Relay: Operating principles
• Combination of
– Low-impedance biased differential
– Directional (phase comparison)
• Adaptively switched between
– 1-out-of-2 operating mode
– 2-out-of-2 operating mode
• by
– Saturation Detector
Power Management
The Universal Relay
• low currents
• saturation possible
due to dc offset
• saturation very
difficult to detect
• more security
required
differential
B30 Bus Differential Relay: Two operating zones
K2
DIF 1
K1
A
B1 B2
Power Management
restraining
The Universal Relay
• large currents
• quick saturation
possible due to
large magnitude
• saturation easier
to detect
• security required
only if saturation
detected
Power Management
differential
B30 Bus Differential Relay: Two operating zones
DIF 2
K2
K1
A
B1 B2
restraining
The Universal Relay
B30 Bus Differential Relay: Logic
AND
DIF1
OR
OR
DIR
AND
SAT
TRIP
DIF2
Power Management
The Universal Relay
differential
B30 Bus Differential Relay: Logic
1-out-of-2 (DIF) if no saturation
2-out-of-2 (DIF+DIR) if saturation
detected
K2
2-out-of-2
(DIF+DIR)
K1
A
B1 B2
Power Management
restraining
The Universal Relay
B30 Bus Differential Relay: Logic
AND
DIF1
OR
OR
DIR
AND
SAT
TRIP
DIF2
Power Management
The Universal Relay
B30 Bus Differential Relay: Directional principle
• Internal faults - all currents approximately
in phase
Power Management
The Universal Relay
B30 Bus Differential Relay: Directional principle
• External faults - one current approximately
out of phase
Power Management
The Universal Relay
B30 Bus Differential Relay: Directional 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 Universal Relay
B30 Bus Differential Relay: Directional principle
dif f erential less
"contributor"
(phasor)
BLOCK
TRIP
BLOCK
TRIP "contributor"
(phasor)
BLOCK
Power Management
The Universal Relay
B30 Bus Differential Relay: Directional principle
External Fault Conditions
 Ip 

imag 
 ID  I p 


BLOCK
BLOCK
ID - Ip
OPERATE
ALIM
Ip
 Ip 

real 
 ID  I p 


-ALIM
BLOCK
OPERATE
BLOCK
Power Management
The Universal Relay
B30 Bus Differential Relay: Directional principle
Inte rnal Fault Conditions
 Ip 

imag 
 ID  I p 


BLOCK
OPERATE
BLOCK
ID - Ip
 Ip 

real 
 ID  I p 


Ip
BLOCK
OPERATE
BLOCK
Power Management
The Universal Relay
B30 Bus Differential Relay: Logic
AND
DIF1
OR
OR
DIR
AND
SAT
TRIP
DIF2
Power Management
The Universal Relay
B30 Bus Differential Relay: Saturation Detector
differential
• differential-restraining trajectory
• dI/dt
K2
K1
A
B1 B2
Power Management
restraining
The Universal Relay
Feeder 1
40
20
0
-20
-40
Feeder 2
40
20
0
-20
-40
Feeder 3
40
20
0
-20
-40
Feeder 4
40
20
0
-20
-40
Feeder 5
B30 Bus Differential Relay: Saturation Detector
40
20
0
-20
-40
Sample External
Fault (Feeder 1)
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
Time, sec
0.3
0.35
0.4
0.45
Power Management
The Universal Relay
B30 Bus Differential Relay: Saturation Detector
Analysis of the DIFRES trajectory enables
the B30 to detect CT
saturation
35
Phase A (Infms)
30
Differential [A]
25
20
15
16
17
18
19
10
22
23
24
25
26
27
21
28
32
31
29
30
33
13
15
14
12 11
10
20
9
8
7
5
0
2 3
1
0
5
Power Management
4
10
6
5
15
20
Restraining [A]
25
30
35
The Universal Relay
Feeder 1
B30 Bus Differential Relay: Saturation Detector
20
0
Feeder 2
-20
Sample External
Fault (Feeder 4) severe CT saturation
after 1.5msec
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.05
0.1
0.15
0.2
0.25
0.3
Time, sec
0.35
0.4
0.45
20
0
Feeder 3
-20
20
0
Feeder 4
-20
20
0
Feeder 5
-20
20
0
-20
Power Management
The Universal Relay
B30 Bus Differential Relay: Saturation Detector
dI/dt principle enables
the B30 to detect CT
saturation
Phase A (Infms)
15
20
14
10
9
11
12
13
16
17
18
19
8
Differential [A]
15
20
22 21
7
23
24
27
25
26
29 28
30
31
3233
4
10
5
6
5
3
0
2
1
0
5
10
15
20
Restraining [A]
Power Management
The Universal Relay
B30 Bus Differential Relay: Saturation Detector
NORM AL
SAT := 0
IDIF < K1*IRES
for 200m s e c
"s aturation"
condition
EXTERNAL
FAULT
SAT := 1
DIF=1
DIF=0
for 100m s e c
EXTERNAL
FAULT / CT SAT
SAT := 1
Power Management
The Universal Relay
B30 Bus Differential Relay: Saturation Detector
• 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 Universal Relay
B30 Bus Differential Relay: Benefits
•
•
•
•
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 Universal Relay
B30 Bus Differential Relay: Extensions
6 feeders
6 feeders
fast
communication
6 feeders
Power Management
The Universal Relay
Universal Relay Family
F60
Feeder Management Relay
F60 Feeder Relay: Features
• 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 Universal Relay
F60 Feeder Relay: Features
• Control:
– Manually Control up to Two Breakers
– Autoreclosure & Synchrocheck
– FlexLogic
• Metering:
–
–
–
–
–
Fault Locator
Oscillography
Event Recorder
Data Logger
Phasors / true RMS / active, reactive and
apparent power, power factor, frequency
Power Management
The Universal Relay
F60 Feeder Relay: Phase Directional Element
• Directional element
controls the RUN
command of the
overcurrent element
(emulation of
“torque control”)
• Memory voltage
polarization held for
1 second
-90o
VAG(Unfaulted)
BLOCK
Fault angle
set @ 60o Lag
VPol
VAG(Faulted)
IA
ECA
set @ 30o
VBC
VBC
VCG
VBG
+90o
Phasors for Phase A Polarization:
VPol = VBC* (1/_ECA) = polarizing voltage
IA = operating current
o
ECA = Element Characteristic Angle @ 30
Power Management
The Universal Relay
F60 Feeder Relay: Neutral 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 Universal Relay
F60 Feeder Relay: Ground Directional Elements
• Limitations of Fast Ground Directional
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 Universal Relay
F60 Feeder Relay: Ground Directional Elements
Sample three-phase
fault currents
25
20
15
10
5
0
-5
-10
-15
-20
-25
0.05
Power Management
0.1
0.15
time [sec]
0.2
0.25
The Universal Relay
F60 Feeder Relay: Ground Directional Elements
Sample three-phase
fault currents (phasors)
10
Fault phasors
(symmetrical)
Imaginary
5
0
Pre-fault phasors
(symmetrical)
-5
Transient phasors
-10
(slightly asymmetrical)
Transient phasors
(slightly asymmetrical)
-10
-5
Power Management
0
Real
5
10
The Universal Relay
F60 Feeder Relay: Ground Directional Elements
Sample three-phase
currents (symmetrical
components)
14
12
Positive Sequence
10
8
6
Zero Sequence
4
Negative Sequence
2
0
0.05
Power Management
0.1
0.15
time [sec]
0.2
0.25
The Universal Relay
F60 Feeder Relay: Ground Directional Elements
• Solutions to the problem of spurious zero
and negative sequence quantities:
– do not allow too sensitive settings
– apply delay
– new approach:
• energy based comparator
• positive sequence restraint
Power Management
The Universal Relay
F60 Feeder Relay: Ground 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 Universal Relay
F60 Feeder Relay: Ground Directional Elements
• The “powers” are averaged over certain
short period of time creating the operating
and restraining “energies”
• The element operates when
Operating Energy  K  Restraining Energy
• Both “forward” and “reverse” operating
energies are calculated
• The factor K is lower for the reverse
looking element to ensure faster operation
Power Management
The Universal Relay
F60 Feeder Relay: Ground Directional Elements
Forward looking
element
50
Restraining Energy
40
30
20
10
0
Reverse looking
element
-10
-20
0.05
Operating Energy
0.1
0.15
time [sec]
0.2
0.25
20
15
Despite spurious
negative sequence
neither the forward nor
the reverse looking
element maloperate
Operating Energy
10
5
0
-5
-10
-15
Power Management
0.05
Restraining Energy
0.1
0.15
time [sec]
0.2
0.25
The Universal Relay
F60 Feeder Relay: Ground Directional Elements
• Positive Sequence Restraint:
– Classical Negative Sequence IOC:
I 2  PICKUP
– Positive Sequence Restrained Negative
Sequence IOC:
I 2  K1  I1  PICKUP
– K1 = 1/8 for negative sequence IOC
– K1 = 1/16 for zero sequence IOC
Power Management
The Universal Relay
F60 Feeder Relay: Negative 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 Universal Relay
Power Management
The Universal Relay
Power Management
The Universal Relay