Sravanthi Relay Setting Chart
Short Description
SIPL...
Description
Greenesol Power Systems Pvt. Ltd., Revision Rev 0
Descriptions R0-Issued for approval
Date 11.07.11
PROJECT
225 MW KASHIPUR GAS COMBINED CYCLE POWER PROJECT AT KASHIPUR. KASHIPUR.
OWNER
M/s. SRAVA NTHI ENERGY ENERGY PVT LTD.
OWNER CONSULTANT
M/S.TATA CONSULTING ENGINEERS LIMITED, BANGALORE.
EPC CONTRACTOR
M/s. SRAVANTHI INFRATECH PVT LTD (EPC DEVISION)
EPC CONSULTANT
M/s. TOSHIBA TERMAL AND HYDRO POWER SYSTEM SYSTEM COMPANY TOSHIBA INDIA PVT LTD.
Prepared by
11.07.11
SRIRANGAN Checked by
11.07.11
STG RELAY SETTINGS GREENESOL POWER SYSTEMS PVT. LTD., # 995, SERVICE ROAD, RPC LAYOUT, VIJAYANAGAR, BENGALURU – 560 040.
ARK Approved by
Approved
11.07.11
DJY CAD File Date:
Size
Office: GPSPL
Scale
Drawing No: P-1113-G60-1-RS
NA
Job Number: P-1113
Doc No: P-1113-G60-1-RS Rev:00
Page 1 of 24
Greenesol Power Systems Pvt. Ltd., Input Details Generator data: Rated Generator output: 100 MVA (80 MW) Rated voltage between phases: 11.5 kV Power Factor: 0.8 Rated speed: 3000 rpm Frequency: 50 Hz 6 3 Current at full load = 100 x 10 / √3 x 11.5 x 10 = 5020.58 A I2 Capability : 10% I22t Constant: = 15 Direct axis synchronous reactance X d(UNSAT) : 2.077 p.u Direct axis synchronous reactance X d(UNSAT) :2.7468 Ohms Direct axis transient reactance X’d(SAT) : 0.163 p.u Direct axis transient reactance X’d(SAT) :0.2155 Ohms [(kV 2 / MVA) * p.u)] Direct axis sub transient reactance X”d(SAT) : 0.103 p.u Direct axis sub transient reactance X”d(SAT) :0.1362 ohms [(kV 2 / MVA) * p.u)] Fault current: 80KA Line-1 length: 18km ACSR DRAKE conductor (To be confirmed by consultant) Line-2 length: 4km ACSR DRAKE conductor (To be confirmed by consultant)
Neutral grounding Transformer (NGT) Ratio: 11KV/220V
CT / PT Details Generator 11.5 kV side, CT ratio: 5500/1 A GROUND CT RATIO: 50/1 A Generator PT ratio: 11.5kV/ √ 3/ 3/ 110√ 3 V
Doc No: P-1113-G60-1-RS Rev:00
Page 2 of 24
Greenesol Power Systems Pvt. Ltd.,
Generator Protection Protection functions Generator Protection system GPR-1 G60 are: Note: Similar protection functions are enabled in GPR-2 relay a lso. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
Generator Differential Protection - 87 Generator Unbalance Protection – 46 Loss of Excitation Protection – 40 Under Frequency – 81U Over Frequency – 81O Over Voltage – 59 Under Voltage – 27 Over Excitation / Over Fluxing Protection – 24 Phase Instantaneous O/C Protection – 50P Phase IDMT O/C Protection – 51P Neutral IDMT O/C Protection – 51N Directional Power Protection - 37 100% Stator Ground Fault Protection – 64TN Dead Machine Protection – 50/27 System Back-up O/C Protection - 51V Back-up Impedance protection – 21G Pole Slipping Protection (78G) Reverse active power protection (32P) Reverse reactive power protection(32Q)
Protection functions for CDG 11 relay 1. Stand-by Earth fault Protection (51S) Protection functions for RXNB-4 relay 1. Rotor Earthfault Protection (64F)
Doc No: P-1113-G60-1-RS Rev:00
Page 3 of 24
Greenesol Power Systems Pvt. Ltd., Generator Differential Protection (87) Relay Type Make
-
G60 GE MULTILIN
Calculation The differential current pickup setting can be set as low as 5% of rated generator current, to provide protection for as much of the winding as possible. Thus, to obtain maximum sensitivity, the differential pickup current is chosen as 0.05 P.U. The percentage differential element has a dual slope characteristic. The “through current” is adjusted to compensate for CT ratio error mismatch and CT response via a dual slope characteristic typically as shown below. Slope 1, set at 15% starting from 0.04 (Restrain Current) as shown below. The STATOR DIFF BREAK 1 setting should greater than the maximum overload expected for the machine, so it is set at 1.25 PU Slope 2, set at 80 %. The STATOR DIFF BREAK 2 setting is set at 3 PU.
6.0
5.0
) 4.0 T C f o s e 3.0 l p i t l u M ( e t a r e p O I
Operating Region
Slope 2 80 %
2. 0
1.0
Restraint Region
Slope 1 15 % Minimum Pickup = 0.5
0.5 0.5
1.0
1.5
2.0
2.5
3.0
I Restraint (Multiples of CT)
Fig-1
Doc No: P-1113-G60-1-RS Rev:00
Page 4 of 24
Greenesol Power Systems Pvt. Ltd., Protection Setting Sl No 1
Protection Function Stator Differential Pickup Slope 1 Break 1 Slope 2
Setting Available in the Relay
Recommended Setting
0.05 to 1 p.u in 0.001 p.u steps. 1 - 100% in 1% steps. 1 to 1.5 p.u in 0.01 p.u steps.
0.05 15% 1.25
1 - 100% IN 1% STEPS
80%
1.5 to 30 p.u 0.01 p.u steps
3.00 p.u
Remarks
Break 2
Generator Unbalance Protection (46) Calculation System Details: Asymmetrical short circuit performance is given by I 22 t Continuous negative sequence capability CT Ratio
= 10 = 8% = 5500/1
The generator nominal current Inom (p.u)
= (Inom primary) / CT Primary = 5020.4/5500
= 0.912 P.U Recommended settings: Stage 1 Pickup
The minimum operate time of Stage 1 The maximum operating time
= 100% x I 2 capability = 1.0 x 8% = 8 % of FLC = 8% = 0.2seconds = 600 seconds
Stage 2 is typically set lower than Stage 1 with a time delay to prevent nuisance alarms for external faults that are normally cleared by system protection. Stage 2 pickup = 5.6% (70% of I 2 capability) with time delay of 10 sec.
Doc No: P-1113-G60-1-RS Rev:00
Page 5 of 24
Greenesol Power Systems Pvt. Ltd.,
Protection Setting Sl No 1
Protection Function
Setting Available in the Relay
GEN UNBAL INOM Stage 1 Pickup Stage 1 K-Value Stage 1 Tmin Stage 1 Tmax Stage 1 K-Reset Stage 2 Pickup Stage 2 Pickup Delay
0.000 to 1.250 p.u in steps of 0.001 0.00 to 100.00% in steps of 0.01 0.00 to 100.00 in steps of 0.01 0.000 to 50.000 s in steps of 0.001 0.0 to 1000.0 s in steps of 0.1 0.0 to 1000.0 s in steps of 0.1 0.05 to 30.00 p.u in steps of 0.01 0.0 to 1000.0 s in steps of 0.1
Recommended Setting 0.912 8% 10 0.2 s 600.0 s 240.0 s 5.6% 10 s
Remarks
Stage 1 for 86BTrip Stage 2 for 86C Trip
Loss of Excitation Protection (40) This protection is applicable when the unit is running in Generator Mode. Calculation Xd X’d
= 2.077 pu = 0.163 pu
MVA
= 100
CTR/PTR Zbase (sec)
= (5500 / 1) x (110/11500) = 52.6 = (base kV2 / base MVA) x (CT ratio / VT ratio) = (11.5 kV 2 / 100 MVA) x (5500/ 104.5) = 69.63
X’d (sec)
=X’d x Zb = 0.163 ×69.63 = 11.34Ω
Xd (sec)
= Xd x Zb = 2.077 ×69.63 =144.62 Ω
CENTER 1 RADIUS 1 PICKUP DELAY 1 The stage 1 element (50mS) CENTER 2 RADIUS 2
Ω
= (Z base (sec) + X’d (sec) ) / 2 = (69.63 Ω + 11.34 Ω) /2 = 40.48Ω = Zbase (sec)/2 = (69.63 Ω) /2 = 34.81 Ω = 0.06 seconds should be time delayed to allow for blocking by the VT fuse failure element
= (Xd (sec)+ X’d (sec)) / 2 = (144.62 Ω+11.34 = X d (sec)/ 2= (144.62)/2 = 72.31 Ω
Doc No: P-1113-G60-1-RS Rev:00
Ω)
/2= 77.98Ω
Page 6 of 24
Greenesol Power Systems Pvt. Ltd.,
During stable Power swing conditions the positive-sequence impedance may momentarily enter the stage 2 characteristics. For security of the function under such conditions, it is recommended to delay stage2 by a minimum of 0.5 seconds
FIG-2 Protection Setting Sl No
Protection Function
Setting Available in the Relay
Center 1 Radius 1 UV Supervision Pickup Delay 1
0.10 to 300.00 Ω in steps of 0.01 0.10 to 300.00 Ω in steps of 0.01 Disabled, Enabled 0.000 to 65.535 s in steps of 0.01
Recommended Setting 40.48 34.81 Enabled 0.06
Center 2 Radius 2 UV Supervision
0.10 to 300.00 Ω in steps of 0.01 0.10 to 300.00 Ω in steps of 0.01 Disabled, Enabled
77.98 72.31 Disabled
Pickup Delay 2 UV Supervision
0.000 to 65.535 s in steps of 0.01 0.000 to 1.250 p.u in steps of 0.001
0.5 0.7
BLOCK
Flex logic
VT FUSE FAIL
Remarks
Under Frequency Protection (81U) Rated frequency is 50 Hz
UNDERFREQUENCY 1 Sl Protection Function No 1 Min Volt/Amp
Setting Available in the Relay 0.10 to 1.25 p.u in steps of 0.01
Doc No: P-1113-G60-1-RS Rev:00
Recommended Setting 0.5
Remarks To Trip 86C
Page 7 of 24
Greenesol Power Systems Pvt. Ltd., Pickup
20.00 to 65.00 Hz in steps of 0.01
47.5
Pickup Delay
0.000 to 65.535 s in steps of 0.001
0.5 sec
Reset Delay
0.000 to 65.535 s in steps of 0.001
0 sec
Setting Available in the Relay 0.10 to 1.25 p.u in steps of 0.01 20.00 to 65.00 Hz in steps of 0.01
Recommended Setting 0.5
Pickup Delay
0.000 to 65.535 s in steps of 0.001
3 sec
Reset Delay
0.000 to 65.535 s in steps of 0.001
0 sec
UNDERFREQUENCY 2 Sl Protection Function No 1 Min Volt/Amp Pickup
Remarks To Trip 86B
47.5
Over Frequency Protection (81O) Stage -1 Sl No 1
Protection Function
Setting Available in the Relay 0.10 to 1.25 p.u in steps of 0.01 20.00 to 65.00 Hz in steps of 0.01
Recommended Setting 0.5
Pickup Delay
0.000 to 65.535 s in steps of 0.001
0.5 sec
Reset Delay
0.000 to 65.535 s in steps of 0.001
0 sec
BLOCK
Flex logic
Min Volt/Amp Pickup
Doc No: P-1113-G60-1-RS Rev:00
Remarks To Trip 86C
52.5
Page 8 of 24
Greenesol Power Systems Pvt. Ltd., Stage-2 Sl No 1
Protection Function
Setting Available in the Relay 0.10 to 1.25 p.u in steps of 0.01 20.00 to 65.00 Hz in steps of 0.01
Recommended Setting 0.5
Pickup Delay
0.000 to 65.535 s in steps of 0.001
3 sec
Reset Delay
0.000 to 65.535 s in steps of 0.001
0 sec
BLOCK
Flex logic
Min Volt/Amp Pickup
Remarks To Trip 86B
52.5
Over Voltage Protection (59) These settings are used as backup for failure of AVR or other regulators. The time settings should also be depended on the withstand levels of the machine Calculations: Trip stage-1 & 2 110 % of the rated Voltage Protection Setting – Stage-1 Sl Protection Setting Available in the Relay No Function Pickup 0.000 to 3.000 p.u in steps of 0.001 Delay 0.00 to 600.00 s in steps of 0.01 Reset Delay 0.00 to 600.00 s in steps of 0.01
Recommended Setting 1.1 p.u 0.5 s 1.00 s
Stage-2 (Flex Elements-1, 2 & 3) Sl Protection Setting Available in the Relay No Function Pickup -90 to 90 p.u in steps of 0.001 Delay 0.00 to 65.50 s in steps of 0.001
Recommended Setting 1.1 p.u 3.00 s
Remarks To TRIP 86C
Remarks To TRIP 86B
Under Voltage Protection (27) Calculations: Trip stage-1 & 2 90 % of the rated Voltage Under Voltage stage 1 Sl No
Protection Function
Setting Available in the Relay
Doc No: P-1113-G60-1-RS Rev:00
Recommended Setting
Remarks
Page 9 of 24
Greenesol Power Systems Pvt. Ltd., 1
Mode
Phase to Ground, Phase to Phase
Phase to Phase
Pickup
0.000 to 3.000 p.u in steps of 0.001
0.90 p.u
Curve
Definite Time, Inverse Time
Definite Time
Delay
0.00 to 600.00 s in steps of 0.01
0.50 s
Min Volt
0.000 to 3.000 p.u in steps of 0.001
0.100 p.u
Setting Available in the Relay
To Trip 86C
Under Voltage stage 2 Sl No 1
Protection Function Mode
Phase to Ground, Phase to Phase
Recommended Setting Phase to Phase
Pickup
0.000 to 3.000 p.u in steps of 0.001
0.90 p.u
Curve
Definite Time, Inverse Time
Definite Time
Delay
0.00 to 600.00 s in steps of 0.01
3.00 s
Min Volt
0.000 to 3.000 p.u in steps of 0.001
0.100 p.u
Remarks To Trip 86B
Over Excitation Protection (24) Calculations: Rated Generator Voltage: 11.5 kV, 50 Hz Ratio of the voltage transformer: 11500/ √ 3/110/ √ 3 Rated generator secondary voltage: 63.5 Rated generator V/Hz on secondary side: 63.5/50 = 1.27 V/Hz. With max. Permissible continuous over excitation 105% (assumed) Definite Time Element (ALARM SETTING): Minimum Pickup Level = 1.06 x 1.27 = 1.3462 PU (106 %) Independent Time Delay= 3 s
Inverse Time Element (TRIP SETTING): Select setting 110 % of rated generator V/Hz. Minimum Pickup Level = 1.1 x 1.27 V/Hz = 1.397 PU Protection Setting VOLTS PER HERTZ 1 (Stage-1) Sl Protection Function No 1 Pickup
Setting Available in the Relay 0.80 to 4.00 p.u in steps of 0.01
Doc No: P-1113-G60-1-RS Rev:00
Recommended Setting 1.35
Remarks ALARM
Page 10 of 24
Greenesol Power Systems Pvt. Ltd., 2
3 4
CURVES
TD MULTIPLIER T Reset
VOLTS PER HERTZ 2 (Stage-2) Sl Protection Function No 1 Pickup
Definite Time, Inverse A, Inverse B, Inverse C, Flex Curve A, Flex Curve B
Definite time 3 seconds
0.05 to 600.00 in steps of 0.01 0.0 to 1000.0 s in steps of 0.1
1 second
Setting Available in the Relay
Recommended Setting 1.4
0.80 to 4.00 p.u in steps of 0.01
2
Curves
Definite Time, Inverse A, Inverse B, Inverse C, Flex Curve A, Flex Curve B
Inverse B
3
TD Multiplier
0.05 to 600.00 in steps of 0.01
3 sec
4
T Reset
0.0 to 1000.0 s in steps of 0.1
0.1sec
Remarks To TRIP 86B
Generator Phase Instantaneous O/C (IOC) Protection (50P) The phase instantaneous overcurrent element is used as an instantaneous element with no intentional delay or as a Definite Time element. The input current is the fundamental phasor magnitude. The setting is selected to protect for fault at or near generator terminals. Calculation Phase Instantaneous Over Current Max. Fault current of Generator = 48741.74A (i.e 5020.4 / 0.103)
Therefore we have chosen the trip setting as 30% of the total fault value for protecting the generator windings. i.e 48741x0.3 = 14622.52A. When it is converted into secondary we get 14622.52 / 5020.4 = 2.91 p.u PROTECTION SETTING Sl No
Protection Function
Setting Available in the Relay
Pickup
0.000 to 30.000 p.u in steps of 0.001 0.00 to 600.00 s in steps of 0.01
Delay
Doc No: P-1113-G60-1-RS Rev:00
Recommended Setting 2.91 p.u
Remarks
0
Page 11 of 24
Greenesol Power Systems Pvt. Ltd., Reset Delay
0.00 to 600.00 s in steps of 0.01
0
Generator Phase time O/C (TOC) Protection (51P)
This protection is implemented using a Phase TOC element. The pickup of this element is set at a safe margin above the maximum load expected on the machine. Pickup
= 1.1 x Generator Nominal Current CT Primary
= 1.1 x 5020.4 5500 = 1.004P.U The equation for IEC Curve-A is as follows: T = TDM x
K I I Pick up
E -1
Where, I= Input current, I Pickup =Relay Setting current, K = 0.14(constant), E = 0.020 (constant) and Considered operating time for a three phase fault on the HV side of transformer as 0.50s (to be confirmed by customer). 0.50 TDM = 0.14 8.86 0.02 1.004 - 1
TDM = 0.16
Protection setting
Doc No: P-1113-G60-1-RS Rev:00
Page 12 of 24
Greenesol Power Systems Pvt. Ltd., Function Input Pickup Curve TD Multiplier Reset Voltage Restraint Target Events
Available Setting Enabled, Disable Phasor, RMS 0.00 to 30.00pu in steps of 0.001
0.00 to 600.00 in steps of 0.01 Instantaneous, Timed Disabled, Enabled Self-reset, Latched, Disabled Disabled, Enabled
Recommended Setting Enabled Phasor 1.004 P.U IEC Curve-A 0.16 Instantaneous Disabled Latched Enabled
Directional Power Low Forward Power (37) Assuming 10% as the minimum power below which the generator should trip on turbine faults, we get: 10% of 80MW = 0.1 X 80 = 8 MW
Smin
=
Minimum operating Power (PW) 3 X Phase CT Primary X Phase VT Ratio X Phase VT Sec
=
8MW 3 X 5500 X 104 X 63.5
=
0.073 P.U
Smin = - 0.0734 P.U (For Low forward power S MIN < 0. Refer ‘b’ diagram below) Delay = 3 seconds RCA = 180 ˚
Doc No: P-1113-G60-1-RS Rev:00
Page 13 of 24
Greenesol Power Systems Pvt. Ltd.,
Sensitive Directional Power RCA Stage 1 SMIN Stage 1 Delay Stage 2 SMIN Stage 2 Delay
Available setting 0 to 359° in steps of 1
–1.200 to 1.200 pu in steps of 0.001 0.00 to 600.00 s in steps of 0.01 –1.200 to 1.200 pu in steps of 0.001 0.00 to 600.00 s in steps of 0.01
Block
Sensitive Power 1 180 ˚
Sensitive Power 2 270 ˚
- 0.0734 p.u
0.0743 p.u
3 seconds
2 seconds
0.0743 p.u
NA
2 seconds
NA
VT FUSE FAIL OP
VT FUSE FAIL OP
100% Stator Ground Fault Protection (64TN) This element has two stages, stage 1 to Trip the machine & stage 2 for Alarm. Set the pickup to 0.15 for both stages to provide adequate overlap with the Auxiliary voltage element. Set stage 1 to 0.375V secondary (this value may be increased fo r security in particularly noisy environments). Stage 2 is typically set at 0.3 V secondary. The supervision settings are expressed in per unit of the Nominal phase VT secondary setting. The time delay settings are 5 seconds for stage 1 and 1 second for stage 2 elements respectively This protection will be set after measurement of third harmonic voltage generated by the machine at various loads.
Calculation Stage-1 supervision = 0.375/63.5V = 0.0059 p.u Stage-2 supervision = 0.300/63.5V = 0.0047 p.u
Doc No: P-1113-G60-1-RS Rev:00
Page 14 of 24
Greenesol Power Systems Pvt. Ltd., Protection Setting
Stage 1 Pickup Stage 1 Pickup delay Stage 1 supv Stage 2 Pickup Stage 2 Pickup delay Stage 2 supv
Available setting 0.000 to 0.250 p.u in steps of 0.001 0.00 to 600.00 s in steps of 0.01 s 0.0010 to 0.1000 p.u in steps of 0.0001 p.u 0.000 to 0.250 p.u in steps of 0.001 0.00 to 600.00 s in steps of 0.01 s 0.0010 to 0.1000 p.u in steps of 0.0001 p.u
Recommended setting 0.15 p.u 5 seconds 0.0059 p.u 0.15 p.u 1 seconds 0.0047 p.u
Dead Machine Protection (50/27) PROTECTION SETTING Sl No
Protection Function
Setting Available in the Relay
Accdnt Enrg Arming Mode Accdnt Enrg OC pickup
UV or Offline / UV & Offline
Accdnt Enrg UV pickup Accdnt Enrg Offline
0.00 to 3.00 p.u in steps of 0.01 0.00 to 3.00 p.u in steps of 0.01 OFF, ON
Recommended Setting UV & Offline
Remarks
1.0 0.7 OFF
Back-up Impedance protection (21G) Generator Trafo. Impedance @ 11.5 kV base
= 11.52 x 0.125 95 = 0.174 Ohm
Generator Transformer Impedance x 0.8
Secondary Impedance
= 0.174 x 0.8 = 0.1392
= 0.1392 x CT ratio PT ratio
= 0.1392 x 52.60
Doc No: P-1113-G60-1-RS Rev:00
Page 15 of 24
Greenesol Power Systems Pvt. Ltd., = 7.3231 Ohm Line Backup impedance protection setting
Line Positive sequence impedance / km = 0.3Ohm (Assumed. Exact to be given by customer). Line Voltage = 230kV Line-1 Length = 18km Line-2 Length = 4km Total Line-1 Impedance (Z L1) = 0.3 x 18 = 5.4 Ohm Total Line-2 Impedance (Z L2) = 0.3 x 4= 1.2 Ohm Total Impedance on 230kV Base = Z L1*ZL2 / ZL1 + ZL2 = 0.981 Ohm Impedance on 11.5 kV base = Impedance on 230kV base x = 0.9818 x
11.5 2 2302
11.52 2302
= 0.002450 Ohm Total Impedance = (Line Impedance + Transformer Impedance) x 1.1 = 0.00245 + 0.0.174 x 1.1 = 0.1940 Ohm Total Secondary Impedance
= 0.1940 x CT ratio PT ratio
= 0.1940 x 52.60 = 10.20 Ohm Generator Impedance
= Xd x VL2 MVA
= j2.077 x 11.52 100 = j 2.746 Ohm Zone 3 = (1.2 x Generator Impedance x CTR) / PTR = (1.2 x j3.02 x 5500) / 110
Doc No: P-1113-G60-1-RS Rev:00
Page 16 of 24
Greenesol Power Systems Pvt. Ltd., = j164.80 Ohm
Available Setting
Function Function Xfmr Vol connection Xfmr Cur connection Reach Delay
Enabled, Disabled Forward, Reverse, NonDirectional Dy1, Dy3, Dy5, Dy7, Dy9, Dy11, Yd1, Yd3, Yd5, Yd7, Yd9, Yd11 Dy1, Dy3, Dy5, Dy7, Dy9, Dy11, Yd1, Yd3, Yd5, Yd7, Yd9, Yd11 0.02 to 500.00 Ohm in steps of 0.01 0.000 to 65.535s in steps of 0.001
Recommended Setting for Zone-1 Enabled Forward
Recommended Setting for Zone-3 Enabled Reverse
Dy1
None
Dy1
None
10.20 Ohm
164.80 Ohm
5.00s
100ms (considering Backup protection for Gen. Diff)
Back-up Impedance should have time delay marginally higher than the longest time delay employed in any of the protection system which is tripping the Generator CB.
Pole Slipping protection / Power Swing Blocking (78G)
The out of step protection is used to detect a loss of synchronism of the generator. The impedance locus is measured as compared with blinders and MHO circle.
SGnom = 100 MVA UGnom = 11.5 KV IGnom = SGnom √3. UGnom
= 5020.6A
Generator nominal impedance in Primary value XGnom = UGnom2
= 1.3225Ω
SGnom
Secondary impedance calculated from primary impedance, CT generator neutral end ratio and VT output ratio.
Doc No: P-1113-G60-1-RS Rev:00
Page 17 of 24
Greenesol Power Systems Pvt. Ltd., XGsec = XGpri . CTRatio VTRatio
= 69.53Ω
Generator synchronous reactance in p.u. value Xd = 2.077
Primary impedance calculated from nominal (generator) voltage and nominal apparent power Xdprim = Xd . UGnom2
= 2.745Ω
SGnom
Secondary impedance calculated from primary impedance, CT generator neutral end ratio and VT output ratio. Xdsec = Xdprim . CTratio PTratio
= 144.42Ω
Generator transient reactance in P.U. value Xd’ = 0.187
Primary impedance from nominal (generator) voltage and nominal apparent power Xd’prim = Xd’ . UGnom2
= 0.247Ω
SGnom
Secondary impedance calculated from primary impedance, CT generator neutral end ratio and VT output ratio. Xd’sec = Xd’prim . CTratio PTratio
=13.008Ω
Transformer impedance in p.u. value Uk = 12.5% = 0.125 p.u
Primary impedance calculated from nominal (generator) voltage and nominal apparent power
Doc No: P-1113-G60-1-RS Rev:00
Page 18 of 24
Greenesol Power Systems Pvt. Ltd., ZTprim = Uk
.
U2LVnom STnom
= 0.181Ω
Secondary impedance calculated from primary impedance and CT generator output ratio. ZTsec =ZTprim . CTratio PTratio
= 9.872Ω
The protective function operates if the impedance locus crosses first the right blinder and within a time delay the left blinder.
Generator Impedance The generator impedance is equal to the transient reactance: Zg = j.Xd’sec
= 16.418iΩ
Transformer Impedance The transformer impedance is equal to the short circuit impedance: Zt = j.ZTsec
= 9.872iΩ
Doc No: P-1113-G60-1-RS Rev:00
Page 19 of 24
Greenesol Power Systems Pvt. Ltd., External system Impedance Zsext = 3.97Ω. exp (j.86 deg) (Assumed. Customer to give the exact value)
The impedance is based on 220KV and has to be adapted to the generator voltage, Zs = Zsext
.
U2Gnom . CTR (220KV)2 PTR
= 0.541Ω
System Impedance: Z = Zg + Zt + Zs
= 0.0135 + 26.829iΩ
MHO Characteristic s The forward reach is calculated with the transformer impedance as following: Reach =150% Fwdreach = |Reach.Zt| = 14.805Ω
The forward angle is equal to the angle of the system impedance as following: Fwdrca = arg(Z)
= 89.97
˚
The reverse reach is calculated with the generator impedance as following: Reach=200% Revreach = |Reach.Zg| = 32.836Ω
The reverse angle is equal to the angle of the generator impedance Revrca = arg(Zg)
= 90
˚
Blinder Calculation
Doc No: P-1113-G60-1-RS Rev:00
Page 20 of 24
Greenesol Power Systems Pvt. Ltd.,
Outer Blinder The outer blinder is calculated with the system angle as following: Θout =
60
˚
The offset between the right and left blinder is calculated according the picture above as following:
180 - Θout 2 ˚
tan Offsetout =
= 46.46 Ω
. |Z| sin (arg(Z))
With this offset the position of the right and left blinder is as following:
180 - Θout 2 ˚
tan Blinder outright =
|Z| .
sin (arg(Z))
|Zg| = 23.24 Ω
+ 2
tan(arg(Z))
Blinder outleft = Offsetout - Blinder outright = 23.22 Ω
Doc No: P-1113-G60-1-RS Rev:00
Page 21 of 24
Greenesol Power Systems Pvt. Ltd., Inner Blinder The inner Blinder is calculated with the system angle as following: Θin =
120
˚
The offset between the right and left blinder is calculated according the picture above as following:
180 - Θin 2 ˚
tan Offsetin =
= 15.50 Ω
. |Z| sin (arg(Z))
With this offset the position of the right and left blinder is as following:
180 - Θin 2 ˚
tan
|Z|
Blinder intright =
. sin (arg(Z))
Blinder inleft =
|Zg| = 7.75 Ω
+ 2
tan(arg(Z))
Offsetin – Blinder inright = 7.75 Ω
PROTECTION SETTING Sl No
Protection Function
Setting Available in the Relay
Power Swing Shape Power Swing Mode
Mho, Quad Two step, Three step
Power Swing Supv
0.050 to 30.00 p.u in steps of 0.001 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 40 to 90Deg. in steps of 1 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 40 to 90Deg. in steps of 1
Power Swing Fwd Rch Power Swing Quad Fwd Rch Power Swing Quad Fwd Rch Mid Power Swing Quad Fwd Rch Out Power Swing Fwd RCA Power Swing Rev Reach Power Swing Quad Rev Rch Mid Power Swing Quad Rev Rch Out Power Swing Rev RCA
Doc No: P-1113-G60-1-RS Rev:00
Recommended Setting Mho
Remarks
TWO STEP 0.6 14.8 89.97 32.8 90
Page 22 of 24
Greenesol Power Systems Pvt. Ltd., Power Swing Outer Limit Angle Power Swing Middle Limit Angle Power Swing Inner Limit Angle Power Swing Outer Rgt Bld Power Swing Outer Lft Bld Power Swing Middle Rgt Bld Power Swing Middle Lft Bld Power Swing Inner Rgt Bld Power Swing Inner Lft Bld Power Swing Pickup Delay 1 Power Swing Reset Delay 1 Power Swing Pickup Delay 2 Power Swing Pickup Delay 3 Power Swing Pickup Delay 4 Power Swing Seal-in Delay Power Swing Trip mode Power Swing Blk Power Swing target
40 to 140Deg. in steps of 1
60
40 to 140Deg. in steps of 1
90
40 to 140Deg. in steps of 1
120
0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.1 to 500.00 Ohm in steps of 0.01 0.000 to 65.535 s in steps of 0.001 0.000 to 65.535 s in steps of 0.001 0.000 to 65.535 s in steps of 0.001 0.000 to 65.535 s in steps of 0.001 0.000 to 65.535 s in steps of 0.001 0.000 to 65.535 s in steps of 0.001 Early, Delayed Flex logic operand Self reset, latched, disabled
23.24 23.22 7.75 7.75 0.03 0.05 0.017 0.009 0.017 0.4 Early off Self-reset
Stand-by Earth fault relay (51S) Relay Type Make
Pickup Curve TDM
-
Electromagnetic relay GE MULTILIN Available setting 0.1 to 2.4 x In 0.05 to 2.00
Recommended setting 0.10 x In Standard Inverse 0.1
Rotor Earthfault relay (64F)
Doc No: P-1113-G60-1-RS Rev:00
Page 23 of 24
Greenesol Power Systems Pvt. Ltd., Relay Type Make
-
RXNB4 ABB Available setting
Stage-1 Delay Stage-2 Delay
Recommended setting **5000 Ohm 3 secs. **2000 Ohm 2 secs.
Note: **-To be checked and decided at site.
Doc No: P-1113-G60-1-RS Rev:00
Page 24 of 24
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