GE Grid Solutions - Universal Relay Family · 2000. 10. 17. · Power Management The Universal...
Transcript of GE Grid Solutions - Universal Relay Family · 2000. 10. 17. · Power Management The Universal...
Universal Relay FamilyUniversal Relay Family
B30B30
Bus Differential RelayBus Differential Relay
Power Management The The Universal RelayUniversal Relay
Contents...Contents...
Features
CT Saturation Problem
Theory of Operation
Dynamic Bus Replica
Operation Examples (link)
Q&As (link)
Benefits
Power Management The The Universal RelayUniversal 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
FeaturesFeatures
•• Protection:Protection:
– Low-impedance biased differential protection
• CT saturation immunity
• sub-cycle tripping time
• dynamic 1-out-of-2 or 2-out-of-2 operation
– Unbiased differential protection
– Dynamic bus replica
– CT trouble monitoring
– Undervoltage (2 elements)
– Phase Overcurrent (2 elements)
Power Management The The Universal RelayUniversal Relay
FeaturesFeatures
•• Metering:Metering:
– Oscillography
– Event Recorder
– Phasors / true RMS
Power Management The The Universal RelayUniversal Relay
CT saturation problemCT saturation problem
• During an external fault
– 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
– a conventional restraining current may not be
sufficient to prevent maloperation
• CT saturation detection and a directional
principle enhance through-fault stability
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Externalfault: ideal
CTs
DIF – differential
RES – restraining
t0
– fault inception
t2
– fault conditions
t0
t2
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Externalfault: ratio
mismatch
DIF – differential
RES – restraining
t0
– fault inception
t2
– fault conditions
t0
t2
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Externalfault: CT
saturation
DIF – differential
RES – restraining
t0
– fault inception
t1
– CT starts to saturate
t2
– fault conditions
t0
t1
t2
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Internalfault: high
current
DIF – differential
RES – restraining
t0
– fault inception
t2
– fault conditions
t0
t2
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Internalfault: low
current
DIF – differential
RES – restraining
t0
– fault inception
t2
– fault conditions
t0
t2
Power Management The The Universal RelayUniversal Relay
differential
restraining
DIFFERENTIAL – RESTRAINT PointDIFFERENTIAL – RESTRAINT Point
Externalfault:
extreme CTsaturation
DIF – differential
RES – restraining
t0
– fault inception
t1
– CT starts to saturate
t2
– fault conditions
t0
t1
t2
Power Management The The Universal RelayUniversal Relay
Operating principlesOperating principles
•• Combination ofCombination of
–– low-impedance low-impedance biased differentialbiased differential
–– directionaldirectional (phase comparison)(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 DetectorSaturation Detector
Power Management The The Universal RelayUniversal Relay
Biased Characteristic: Biased Characteristic: Restraining CurrentRestraining Current
•• Restraining Current is a “maximum of”Restraining Current is a “maximum of”
the bus zone currents :the bus zone currents :
– better stability on external faults (as compared
to the “average of” definition)
– better sensitivity on internal faults (as compared
to the “sum of” definition)
Power Management The The Universal RelayUniversal Relay
Biased Characteristic: Biased Characteristic: ShapeShape
• Two breakpoints
• Two slopes
– both slopes provide TRUE percentage restraint,
i.e. they are represented by straight lines
crossing the origin of the differential-
restraining plane
– if the slopes are different, discontinuity of the
characteristic occurs
– the discontinuity issue is solved by a smooth
“gluing” function
Power Management The The Universal RelayUniversal Relay
Biased Characteristic: Biased Characteristic: ShapeShape
0 2 4 6 8 10 120
1
2
3
4
5
6
7
8
RESTRAINING, pu
DIF
FE
RE
NT
IAL
,pu
LOW BPNT HIGH BPNT
HIGH SLOPE
LOW SLOPE
PICKUP
Power Management The The Universal RelayUniversal Relay
Biased Characteristic: Biased Characteristic: Two distinctive regionsTwo distinctive regions
• low currents
• saturation possible
due to dc offset
• saturation very
difficult to detect
• more security
required
differential
restrainingA
B1
K2
K1
B2
DIF1
Power Management The The Universal RelayUniversal Relay
Biased Characteristic: Biased Characteristic: Two distinctive regionsTwo distinctive regions
• large currents
• quick saturation
possible due to
large magnitude
• saturation easier
to detect
• security required
only if saturation
detected
differential
restrainingA
B1
K2
K1
B2
DIF2
Power Management The The Universal RelayUniversal Relay
LogicLogic
DIF1
DIR
SAT
DIF2
OR
AND
OR
TRIP
AND
Power Management The The Universal RelayUniversal Relay
LogicLogic
differential
restrainingA
B1
K2
K1
B2
1-out-of-2 (DIF) if no saturation
2-out-of-2 (DIF+DIR) if saturation
detected
2-out-of-2
(DIF+DIR)
Power Management The The Universal RelayUniversal Relay
LogicLogic
DIF1
DIR
SAT
DIF2
OR
AND
OR
TRIP
AND
Power Management The The Universal RelayUniversal Relay
Directional principleDirectional principle
•• Internal faultsInternal faults - all currents approximately
in phase
Power Management The The Universal RelayUniversal Relay
Directional principleDirectional principle
•• External faultsExternal faults - one current approximately
out of phase
Power Management The The Universal RelayUniversal 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
Directional principleDirectional principle
"contributor"
(phasor)
differential less
"contributor"
(phasor)
BLOCK
TRIP
TRIP
BLOCK
BLOCK
Power Management The The Universal RelayUniversal Relay
Directional principleDirectional principle
BLOCK
OPERATE
BLOCK
− pD
p
II
Ireal
− pD
p
II
Iimag
Ip
ID - I
p
External Fault Conditions
OPERATE
Power Management The The Universal RelayUniversal Relay
Directional principleDirectional principle
BLOCK
BLOCK
− pD
p
II
Ireal
− pD
p
II
Iimag
Ip
ID - I
p
Internal Fault Conditions
OPERATE
OPERATE
Power Management The The Universal RelayUniversal Relay
LogicLogic
DIF1
DIR
SAT
DIF2
OR
AND
OR
TRIP
AND
Power Management The The Universal RelayUniversal Relay
Saturation DetectorSaturation Detector
• differential-restraining trajectory
• dI/dt
differential
restraining
External
fault: CTsaturation
t0
t1
t2
t0
– fault inception
t1
– CT starts to saturate
t2
– fault conditions
Power Management The The Universal RelayUniversal 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
eder
1
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fe
eder
2
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der3
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der4
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der5
Time, sec
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fe
eder
1
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fe
eder
2
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der3
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der4
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-40-20
02040
Fee
der5
Time, sec
Sample External
Fault on Feeder 1
(Case 1)
Sample External
Fault on Feeder 1
(Case 1)
Power Management The The Universal RelayUniversal Relay
0 5 10 15 20 25 30 350
5
10
15
20
25
30
35D
iffer
ent
ial[
A]
Restraining [A]
12 3 4 56
789
101112
13
1415
16171819
2021222324252627282930313233
Phase A (Infms)
0 5 10 15 20 25 30 350
5
10
15
20
25
30
35D
iffer
ent
ial[
A]
Restraining [A]
12 3 4 56
789
101112
13
1415
16171819
2021222324252627282930313233
Phase A (Infms)
Saturation DetectorSaturation Detector
Analysis of the DIF-
RES trajectory enables
the B30 to detect CT
saturation (Case 1)
Analysis of the DIF-
RES trajectory enables
the B30 to detect CT
saturation (Case 1)
Power Management The The Universal RelayUniversal 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
eede
r1
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fe
eder
2
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der
3
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der4
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der
5
Time, sec
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20F
eede
r1
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fe
eder
2
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der
3
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der4
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45-20
0
20
Fee
der
5
Time, sec
Sample External Fault
on Feeder 4 - severe
CT saturation after
1.5msec (Case 2)
Sample External Fault
on Feeder 4 - severe
CT saturation after
1.5msec (Case 2)
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)
Saturation DetectorSaturation Detector
dI/dt principle enables
the B30 to detect CT
saturation (Case 2)
dI/dt principle enables
the B30 to detect CT
saturation (Case 2)
Power Management The The Universal RelayUniversal Relay
Saturation Detector: Saturation Detector: State MachineState Machine
NORMAL
SAT := 0
EXTERNAL
FAULT
SAT := 1
EXTERNAL
FAULT & CT
SATURATION
SAT := 1
The differential
characteristic
entered
The differential-
restraining trajectory
out of the differential
characteristic for
certain period of time
saturation
condition
The differential
current below the
first slope for
certain period of
time
Power Management The The Universal RelayUniversal 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
ExamplesExamples
• The oscillograms on the next two slides
were captured from a B30 relay under test
on a real-time digital power system
simulator
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: External Fault ExampleExternal Fault Example
0.06 0.07 0.08 0.09 0.1 0.11 0.12-200
-150
-100
-50
0
50
100
150
200
~1 ms
The bus differential
protection element
picks up due to heavy
CT saturation
The CT saturation flag
is set safely before the
pickup flag
Despite heavy CTsaturation the
external fault currentis seen in theopposite direction
The
directional flag
is not set
The element
does not
maloperate
Power Management The The Universal RelayUniversal Relay
B30 Bus Differential Relay: B30 Bus Differential Relay: Internal Fault ExampleInternal Fault Example
The bus differential
protection element
picks upThe saturation
flag is not set - no
directional
decision required
The element
operates in
10ms
All the fault currents
are seen in one
direction
The
directional
flag is set
Power Management The The Universal RelayUniversal Relay
Dynamic Bus ReplicaDynamic Bus Replica
• The dynamic bus replica mechanism is
provided by associating a status signal with
each current of the differential zone
• The status signal is a FlexLogicTM operand
• The status signals are formed in
FlexLogicTM – including any filtering or
extra security checks – from the positions of
switches and/or breakers
Power Management The The Universal RelayUniversal Relay
Dynamic Bus ReplicaDynamic Bus Replica
BUS SECTION 2
F1
U7a
SOURCES
SRC 1
FLEXLOGICTM
Cont Ip 1 On BUS
Z1
BUS ZONE 1A STATUS
BUS ZONE 1A SOURCE
BUS SECTION 1
Power Management The The Universal RelayUniversal Relay
Dynamic Bus Replica: Dynamic Bus Replica: ExampleExample
NORTH BUS
SOUTH BUS
CT-8
B-5
B-6
CT-5
CT-6
S-5
S-6
B-4CT-4
S-3
S-4
B-3CT-3
S-1
S-2
B-2CT-2
CT-1
B-1
C-1 C-2 C-4
C-3 C-5
CT-7
B-7
Power Management The The Universal RelayUniversal Relay
Dynamic Bus Replica: Dynamic Bus Replica: ExampleExample
NORTH BUS
SOUTH BUS
CT-7
CT-8
B-7
B-5
B-6
CT-5
CT-6
S-5
S-6
B-4CT-4
S-3
S-4
B-3CT-3
S-1
S-2
B-2CT-2CT-1
B-1
C-1 C-2 C-4
C-3 C-5
B30 #1
Power Management The The Universal RelayUniversal Relay
Dynamic Bus Replica: Dynamic Bus Replica: ExampleExample
NORTH BUS
SOUTH BUS
CT-7
CT-8
B-7
B-5
B-6
CT-5
CT-6
S-5
S-6
B-4CT-4
S-3
S-4
B-3CT-3
S-1
S-2
B-2CT-2CT-1
B-1
C-1 C-2 C-4
C-3 C-5
B30 #2
Power Management The The Universal RelayUniversal Relay
Dynamic Bus Replica: Dynamic Bus Replica: ZoningZoning
NORTH BUS
SOUTH BUS
CT-8
B-5
B-6
CT-5
CT-6
S-5
S-6
B-4CT-4
S-3
S-4
B-3CT-3
S-1
S-2
B-2CT-2
CT-1
B-1
C-1 C-2 C-4
C-3 C-5
CT-7
B-7
B30 #2
B30 #1D60 #1
Power Management The The Universal RelayUniversal Relay
BenefitsBenefits
• Sensitive settings are possible
• Very good through-fault stability
• Fast operation:
– fast form-C contacts and FlexLogicTM
operands: typically 10-12ms
– form-A trip rated contacts: typically 13-15ms
• Benefits of the UR platform (metering and
oscillography, event recorder, FlexLogicTM,
fast peer-to-peer communication, etc.)