2. 1.0 PURPOSE:
This document is intended to show Protection Relay Calculations settings for
132KV Station Tr 16MVA, 132 KV BB Differetial & 132KV BC at PL Sw. Yd.
2.0 DESIGN INPUT :
i) Relay Catalogues
ii) Protection and Measuring diagram
3.0 ASSUMPTIONS:
i). If any change is noticed in the CT Ratio from the value considered in the relay setting
document, then settings would need to be modified suitably.
ii). This document is issued for protection functions and related settings only.
The configuration of BO, BI,LEDs,CFC logic and settings such as CT star points,
Breaker residual currents, etc, shall be as prepared at site as per actual approved wiring
3. Sr. No. Description
1 Calculations 132KV BB Differntial at SS
2 Settings 132KV BB Differential
3 Calculations 132KV BC at SS
4 Settings 132KV BC at SS
5 Calculations 132KV_6.6KV Station Tr 16MVA
6 Settings 132/6.6KV Station Tr 16MVA
7 Grading Curves
i) OC Curve
ii) EF Curve
Table of Contents
132KV Relay Setting:
4. 87BB 132KV Sw. Yd. Relay 7SR2303
Main Zone.
Busbar Rating 1250 A
40% of the Bus Bar rating is selected as Pri Op. Current POC = 500 A
Selected CTR 800 /1
Voltage Knee Point (VK) 650 V
Magnetising Current (Imag) @ VK/2 30 mA
CT secondary resistance (RCT) 10.5
CT lead loop resistance (RL) Max 0.5
Required Stability Voltage Vs = Vk/2 325 V
Calculation of Stabilising Resistor Value
No of Fdr Bays 4
The required relay setting (87/50-1) Is can be calculated from:
POC = ( IMAG TOTAL + Is ) / Turns ratio = 4(IMAG) + Is ) / T
Is = POC x T – IMAG TOTAL = 500/800 – IMAG TOTAL = 0.505 A
87/50-1 Setting (Say) 0.5 In
Rstab = 325/0.5 = 650 say 650
CT Supervision Settings
Generally a current setting of 2 - 10% of the full load rating of the busbar is acceptable.
Typically a setting of 2 to 10 seconds is applied.
CT50 Setting is 4% of 1250A = 50 A 0.06
say 0.06 In
CT50 Delay 3 s
Check Zone
Busbar Rating 1250 A
40% of the Bus Bar rating is selected as Pri Op. Current POC = 500 A
Selected CTR 800 /1
Voltage Knee Point (VK) 650 V
Magnetising Current (Imag) @ VK/2 30 mA
CT secondary resistance (RCT) 10.5
CT lead loop resistance (RL) Max 0.5
Required Stability Voltage Vs = Vk/2 325 V
Calculation of Stabilising Resistor Value
No of Fdr Bays 6 (B/C bay excluded)
The required relay setting (87/50-1) Is can be calculated from:
POC = ( IMAG TOTAL + Is ) / Turns ratio = 3(IMAG) + Is ) / T
Is = POC x T – IMAG TOTAL = 500/800 – IMAG TOTAL = 0.445 A
87/50-1 Setting (Say) 0.44 In
Rstab = 325/0.53 = 738.64 say 730
CT Supervision Settings
Generally a current setting of 2 - 10% of the full load rating of the busbar is acceptable.
Typically a setting of 2 to 10 seconds is applied.
CT50 Setting is 4% of 1250A = 50 A 0.06 In
say 0.06 In
CT50 Delay 3 s
Note: Calculations are based on setting Guide lines of 7SR23 Manual.
5. Fdr Detail Relay CTR PTR Functions: Address ANSI
Gn Differential Enabled
Gn CT Supervision Enabled
Gn 87/50-1 Element Enabled
Gn 87/50-1 Setting 0.5 In
Gn 87/50-1 Delay 0 s
Gn CT50 Element Enabled
CT50 Setting 0.06 In
Gn CT50 Delay 3 s
Stab Resistance (SR) 650
Gn Differential Enabled
Gn CT Supervision Enabled
Gn 87/50-1 Element Enabled
Gn 87/50-1 Setting 0.44 In
Gn 87/50-1 Delay 0 s
Gn CT50 Element Enabled
CT50 Setting 0.06 In
Gn CT50 Delay 3 s
Stab Resistance (SR) 730
Settings:
132KV
CT
800/1
7SR
2302
132KV
BB
differential
Sw.
Yd.
Main
Zone
Check
Zone
87
7. Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Gn Phase O/C Enabled 50/51
Gn Measured E/F Enabled 50N/51N
Gn Phase U/O Voltage Enabled 27/59
Gn CB Fail Enabled 50LBB
Gn 51-1 Element Enabled
Gn 51-1 Dir. Control Non Dir
Gn 51-1 Setting 0.50 In
Gn 51-1 Char IEC NI
Gn 51-1 Time Mult 0.45
Gn 50-1 Element Enabled
Gn 50-1 Dir. Control Non Dir
Gn 50-1 Setting - In
Gn 50-1 Delay - s
Gn 51G-1 Element Enabled
Gn 51G-1 Dir. Control Non Dir
Gn 51G-1 Setting 0.25 In
Gn 51G-1 Char IEC NI
Gn 51G-1 Time Mult 0.53
Gn 50-1 Element Enabled
Gn 50-1 Dir. Control Non Dir
Gn 50-1 Setting - In
Gn 50-1 Delay - s
Gn 27/59-1 Element Enabled
Gn 27/59-1 Operation Under
Gn 27/59-1 Setting 88 V
Gn 27/ 59-1 Hysteresis 3%
Gn 27/ 59-1 Delay 3 sec
Gn 27/ 59-1 U/V Guarded No
Gn 27/ 59-1 VTS Inhibit No
Gn 27/ 59-1 O/P Phases All
Gn 27/59-2 Element Enabled
Gn 27/59-2 Operation Over
Gn 27/59-2 Setting 126.5 V
Gn 27/ 59-2 Hysteresis 3%
Gn 27/ 59-2 Delay 2 sec
Gn 27/ 59-2 U/V Guarded No
Gn 27/ 59-2 VTS Inhibit No
Gn 27/ 59-2 O/P Phases All
Gn 50BF Element Enabled
Gn 50BF Setting 0.1 In
Gn 50BF1 Delay 0.25 s
Gn 50BF2 Delay 0.5 s
50
51N
50N
132KV/
3
110V/
3
7SR22
(51/51N)
132KV
BC
S/S
27-1
59-1
50BF
800-400-200/1
51
8. 132KV SS 132/6.9KV, 16MVA Station Tr. make Voltamp Setting Calculations:
Differential Relay 7UT 612 Settings:
Pri KV MVA Tap @ Sec KV HV CTP LV CTP %z @16
132 16 ± 10% 1.250% 6.9 200 2000 10.00%
VG 132KV A 6.9KV A HV N CTP
YNyn0 69.98 1338.78 800
Inrush Current 559.85 A
Tr HV side 87T, 51G 7UT6121-5EB90-1AA0+L0S
Prot Fcns & relays 50/51/50N, 51N, 50LBB, 27, 59 7SR2202-2AA87-0CA0
64REF HV 7SR2102-1BA87-0CA0
PROT. OBJECT (address 105): 3 phase transf.
The rated voltage UN in kV (phase-to-phase) under address 0311 UN-PRI SIDE 1.
The starpoint condition under address 0313 STARPNT SIDE 1: Solid Earthed
Umax (Tap 1) = 145.2 KV
Umin (Tap 21) = 118.8 KV
UN = 2/(I/Umax + 1/Umin) = 130.68 say 130 130 KV
Usc transf = 10.00%
Sntransf = 16 MVA
I 3polemax = (1/Usc transf) x INtransf = (1/Usc transf)x(SNtransf/((3^0.5)*UN) 706.89 A
Assume an asymmetrical m.f. 1.2 848.26 A
Instantaneous Differential:
So I>> 4.00 say 4.00 4.0
Limits (I-DIFF>>) < 132KV Fault level
(I-DIFF>>) >Through fault 0.815173 KA say 800 A
Set I-DIFF>> (address 1231) 4.0 A
T I-DIFF>> 1236A 0 s
2nd
Harmonic Restraint:
The ratio of the 2nd harmonic to the fundamental frequency 2. HARMONIC (address
1271) is preset to I2fN/IfN = 15% and can, as a rule, be retained without change.
2nd
Harmonic containt in Idifferential (address1271) 15%
5th
. Harmonic Restraint:
Steady-state overexcitation of transformers is characterized by odd harmonic content.
The 5th harmonic is suitable to detect overexcitation & to avoid trip.
nth.
Harmonic containt in Idifferential (address1276) 30%
Differential & % Slope setting (16 MVA):
Object rated current of the regulated side IN1 = MVA/(3^0.5)*UN 70.69 A
Corresponding HV side current (referred to S1) = (70.69 / HV CT P) = 0.35 INobj
Object rated current of the unregulated side = MVA/(3^0.5)*UNLV 1338.78 A
Corresponding LV side current (referred to S2) = 1338.78 / LV CT P = 0.67 INobj
Calculations of the differential/restraint currents in the tap changer extreme positions:
Tap position = +10%
Object current in max volts tap position = IN1(+10%) = MVA/((3^0.5)*Umax) 63.62 A
corresponds on the CT1 secondary side to IN1(+10%) = 63.62/HV CT P 0.32 ·INobj
Differential current in max volts tap position Idiff = IN1(+10%) - INobj 0.04 ·INobj
Restraint current in max voltage tap position IRestraint = IN1(+10%) + INobj 0.67 ·INobj
Tap position = -10%
Object current in min volts tap position = IN1(-10%) = MVA/((3^0.5)*Umin) 77.76 A
Corresponding HV side current (referred to S1) = (77.76 / HV CT P) = 0.3888 INobj
Differential current in minimum volt tap position Idiff = IN1(-10%) - INobj 0.04 ·INobj
Restraint current in minimum volt tap position = IN1(-10%) + INobj 0.74 ·INobj
9. I-DIFF> (address 1221) is the pickup value of the differential current.
The pickup value is referred to the rated current of the protected object.
Transformer: IDiff> 0.2 + 0.5xktcr [I/InO] ktcr is Tap changer range
ktcr = (10% + -10% )/2 = 10% = 0.1 I/InO 10.0%
IDiff> = 0.2 +0.5* 0.10 0.250 I/InO
IDiff> = say 0.25 (address 1221) 0.25 I/INobj
"Setting of the slope of the 1st branch to 25%
and 2nd to 50% is appropriate for normal applications" - " Tr. Diff Prot - Zeigler Book"
At maximum voltage tap position + 10 % it follows that
Idiff / Irestraint = 5.26%
At minimum voltage tap position - 10 % it follows that
Idiff / Irestraint = 4.76%
%SLOPE 1 of tripping characteristics (address1241A) 25%
Add-on stabilization:
In systems with very high traversing currents a dynamic add-on stabilization is being
enabled for external faults
Setting Add-on stabilization: (address:1261A) 4 I/Inobj
The maximum duration of the add-on stabilization:
T ADD ON-STAB (address 1262A ) 15 Cycle
Tripping characteristic of differential Protection:
Base Point 1 (address 1242A) 0
Slope 1 (address 1241A) 25%
Slope 2 (address 1243A) 0.5
Base Point 2 (address 1244A) 2.5 I/Inobj
Start Factor (address 1252A) 1
Add-on stabilisa (address 1261A) 4 I/Inobj
Tr HV side REF:
Tr FLC on 132KV side 69.98 A
CTR 800 /1
EATS 48-3 recommends that the primary fault setting should be in the range of 10% to 60% of the
rated current of the protected winding (when the protected winding is connected to a solidly earthed
power system). Application Guide - Restricted Earth Fault - Reyrolle'
REF Setting range 0.008748 > Is < 0.052486
REF element has a setting range from 0.005 to 0.95A
An initial setting 0.017495 say 0.018 A
Thus, actual setting = 0.018 - 3Imag
Knee point voltage 650 V
Stability voltage within the range Vk/4 to Vk/2 is normal
Minimum stability voltage to ensure stability during maximum through fault is 9.77 V
since the CT Vk is more than 650V, a setting of 20 V is proposed.
The value of magnetising current, Imag, at Vs is 0.002 A.
Setting, in secondary amps 0.012 A
Stabilizing Resistor Rs = 833.3333 say 830
10. Fault Level System Voltage 132 KV
3Ph Fault Currentat 132KV 23.18 KA
3Ph Fault Level 5300 MVA
Base MVA 100 MVA
Source Imp 0.0189
Tr. Imp on 16 MVA base 0.100
Tr Imp on 100 MVA base 0.63
Total Imp 0.644
3Ph Fault MVA at 6.9KV 155.31 MVA
3Ph Fault Current at 6.6KV 13.59 KA
132KV through 3Ph Fault Current 0.68 KA
Stn Tr Capacity 16 MVA Load PF 0.80
Load envisaged 70%
MVA 11.2 Current I= 979.75
CWP (SB) 0.6 MW I Cos phi = 783.80 I Sin phi = 587.85
Start Current (DOL) 6 FLC
FLC 68.00 A I Cos phi = 61.20 I Sin phi = 403.38
Start PF 0.15 Total Current = 1302.52
Start Time 3 s MVA 15.57
Sec Crusher 700 KW
Start Current (DOL) 444 A I Cos phi = 53.28 I Sin phi = 440.79
Start Time 3.3 s Total Current = 1326.20
Start PF 0.12 MVA 15.85
6.6KV Side ST. O/C Curve Data 3I> 1399.637 Ip = 0.70 say 0.65
MVA If CTP 3I> Eff I/Ip tp top REF615H
16.35 1430 2000 0.65 1300 1.1 0.25 18.34 Curve
17.83 1560 2000 0.65 1300 1.20 0.25 9.58 IEC NI
19.32 1690 2000 0.65 1300 1.3 0.25 6.65 3I>
22.29 1950 2000 0.65 1300 1.5 0.25 4.30 0.65
26.01 2275 2000 0.65 1300 1.75 0.25 3.11 tp
29.72 2600 2000 0.65 1300 2 0.25 2.51 0.25
44.58 3900 2000 0.65 1300 3 0.25 1.58 3I>>
59.44 5200 2000 0.65 1300 4 0.25 1.24 -
89.17 7800 2000 0.65 1300 6 0.25 0.96 tI>>
118.89 10400 2000 0.65 1300 8.00 0.25 0.82 -
155.31 13586.22 2000 0.65 1300 10.45 0.25 0.73
EF Setting for 6.6KV Inc from Stn Tr. 51N Relay REF615H Def Time Io>
MVA Ief CTP Io> Eff CTP Ief/Ie> tIe> top 0.07
1.76 154 2000 0.07 140 1.1 0.75 0.75 tIe>
3.43 300 2000 0.07 140 2.142857 0.75 0.75 0.75
EF Setting for 6.6KV Inc from Stn Tr. 51G Relay VIPS98P Def Time Ie>
MVA Ief CTP Ie> Eff CTP Ief/Ie> tIe> top 0.5
1.89 165 300 0.5 150 1.1 1 1.00 tIe>
3.43 300 300 0.5 150 2 1 1.00 1.00
12. Detail Relay CTR PTR Functions: Settings: Address ANSI Remarks
PROT. OBJECT 3 phase transf. 0115
DIFF. PROT. Enabled 0112 87
DMT/IDMT Earth TOC IEC 0124 51G
- UN-PRI SIDE 1 130.00 KV 0311
SN SIDE 1 16 MVA 0312
STARPNT SIDE 1 Earthed 0313
CONNECTION S1 Y 0314
UN-PRI SIDE 2 6.9 KV 0321
SN SIDE 2 16 MVA 0322
STARPNT SIDE 2 Earthed 0323
CONNECTION S2 Y 0324
VECTOR GRP S2 0 0325
I-DIFF> 0.25 I/InO 1221
tIdiff > 0 sec 1226A
Idiff >> 4 I/InO 1231
tIdiff >> 0 sec 1236A
2
nd
Harmonic 15% 1271
CROSSB. 2. HARM 3 Cycle 1272A
5th
Harmonic 30% 1276
%Slope 1 25% 1241A
BASE POINT 1 0.00 I/InO 1242A
SLOPE 2 0.50 1243A
BASE POINT 2 2.5 I/InO 1244A
START-FACTOR 1 1252A
Add on Stabili 4 I/InO 1261A
T ADD ON-STAB. 15 Cycle 1262A
CROSSB. ADD ON 15 Cycle 1263A
EARTH O/C ON 2401
InRushRestEarth ON 2402
IE> Pickup - A 2413
T IE> Time Delay - s 2414
IEp Pickup 0.10 A 2421
T IEp Time Dial 0.66 2422
IEC CURVE NI 2425
2.HARM. Earth 15% 2441
I Max InRr. E 4 A 2442
Gn Restricted E/F Enabled
Gn 64H Element Enabled
Gn 64H Setting 0.012 In
Gn 64H Delay 0 s
Stab Resistance (SR) 830
7SR2102
132KV
Ph
&
132KV
NCT
800/1,
PS
cl.
64R
(HV)
132
/
6.9
KV,
VG:
YNyn0,
16MVA
Stn
Tr
7UT
612
132KV
CT:
200/1
6.9KV
CT
:
2000/1
(PS
Cl.)
132KV
NCT:
800/1(5P20)
51G
(SBEF)
87
13. Detail Relay CTR PTR Functions: Settings: Address ANSI Remarks
Gn Phase O/C Enabled 50/51
Gn Measured E/F Enabled 50N/51N
Gn Phase U/O Voltage Enabled 27/59
Gn CB Fail Enabled 50LBB
Gn 51-1 Element Enabled
Gn 51-1 Dir. Control Non Dir
Gn 51-1 Setting 0.33 In
Gn 51-1 Char IEC NI
Gn 51-1 Time Mult 0.35
Gn 50-1 Element Enabled
Gn 50-1 Dir. Control Non Dir
Gn 50-1 Setting 4.00 In
Gn 50-1 Delay 0.01 s
Gn 51G-1 Element Enabled
Gn 51G-1 Dir. Control Non Dir
Gn 51G-1 Setting 0.40 In
Gn 51G-1 Char IEC NI
Gn 51G-1 Time Mult 0.55
Gn 50-1 Element Enabled
Gn 50-1 Dir. Control Non Dir
Gn 50-1 Setting - In
Gn 50-1 Delay - s
Gn 27/59-1 Element Enabled
Gn 27/59-1 Operation Under
Gn 27/59-1 Setting 88 V
Gn 27/ 59-1 Hysteresis 3%
Gn 27/ 59-1 Delay 3 sec
Gn 27/ 59-1 U/V Guarded No
Gn 27/ 59-1 VTS Inhibit No
Gn 27/ 59-1 O/P Phases All
Gn 27/59-2 Element Enabled
Gn 27/59-2 Operation Over
Gn 27/59-2 Setting 126.5 V
Gn 27/ 59-2 Hysteresis 3%
Gn 27/ 59-2 Delay 2 sec
Gn 27/ 59-2 U/V Guarded No
Gn 27/ 59-2 VTS Inhibit No
Gn 27/ 59-2 O/P Phases All
Gn 50BF Element Enabled
Gn 50BF Setting 0.1 In
Gn 50BF1 Delay 0.25 s
Gn 50BF2 Delay 0.5 s
132/6.9KV,
VG:
Ynyno,
16MVA
Stn
Tr
51N
132KV/
3
110V/
3
132KV
CT:
200/1
7SR2202
50N
51
50
27-1
59-1
50BF
14. Detail Relay CTR PTR Functions: Settings: Address ANSI Remarks
FCT 50/51 Enabled 50/51
FCT 50N/51N Enabled 50N/51N
FCT 27 (3U<) Enabled 27
FCT 25 Enabled 25
51, 3I> Start Value 0.65 A
Time Multiplier 0.25
Operating Curve Type IEC NI
3I>> -
Delay 3I>> -
Characteristics -
51N-1 PU (Start Value) 0.07 In
51N-1 DELAY 0.75 sec
Operating Curve Type IEC Def. Time
FCT 27 ON
Start value of stage U< 0.80 Un
Operate time of stage U< 3 s
Op. Mode setting for U< Def. Time
Live Dead Mode Live Line Dead Bus
Difference voltage 0.05 Un
Difference frequency 0.001 Fn
Difference angle 10 °
Operation ON
Synchro check mode Asynchronous
Dead line value 0.2 Un
Live line value 0.9 Un
Dead bus value 0.2 Un
Live bus value 0.9 Un
Max energizing V 1.05 Un
Control mode Continuous
Close pulse 200 m.s.
Phase shift 0 °
Minimum Syn time 0 m.s.
Maximum Syn time 2000 m.s.
Energizing time 100 m.s.
Closing time of CB 60 m.s.
Current Setting 0.5 A
Delay 1.00 s
REF
615H
300/1
6.6KV
Inc
from
16
MVA
Stn
Tr
50-1
VIPS
98P
2000/1
27
6.6KV/
3
110V/
3/110V/3
25
LV
SBEF
Stn
Sw.
Gr.
Tr
Inc
6.6KV
LPT
USW
BPT
51NS
50N/51N
51
LPT
15. Detail Relay CTR PTR Functions: Settings: Address ANSI Remarks
Start value of stage U< 0.80 Un
Operate time of stage U< 2.5 s
Op. Mode setting for U< 0 = Def. Time
Voltage Setting 33 V
Def. Time (Delay) 0.1 s
27
6.6KV
Bus
PT
Station
Sw.
Gr.
REU
610
JRV
922
6.6KV/
3
110V/
3/110V/3
Bus
Under
Voltage
27N
No
Volt
Relay
19. Relay Setting of 132 kV Switchyard
(132KV O/H Line Feeder at both ends )
20. 132KV & OPTCL Sw. Yd.
1.0 PURPOSE:
This document is intended to show Protection Relay Calculations settings for
132KV OG Line (O/H Twin ACSR Zebra Conductor) Feeder at both ends of
132KV Switch Yd & that at 132KV OPTCL Sw. Yd.
2.0 DESIGN INPUT :
i) Relay Catalogues
ii) Protection and Measuring diagram
3.0 ASSUMPTIONS:
i). If any change is noticed in the CT Ratio from the value considered in the relay setting
document, then settings would need to be modified suitably.
ii). This document is issued for protection functions and related settings only.
The configuration of BO, BI,LEDs,CFC logic and settings such as CT star points,
Breaker residual currents, etc, shall be as prepared at site as per actual approved wiring
21. Sr. No. Description
1 7SD Line Differntial at & OPTCL SS Calculations
2 Calculations of Back up protections _OPTCL
3 Relay Settings at Substation - OPTCL Line
4 Relay Settings at 132KV OPTCL - Plant Fdr
5 Grading Curves
i) OC Curve
ii) EF Curve
Table of Contents
22. 800/1 800/1
PL OPTCL
132KV OH Conductor Twin Zebra 20 M length
132KV Line Charging Current Negligible Very short Line length
The Pickup Value is set at 2.5 times the charging current or 15% of the rated current of the line
whichever is greater.
Pickup value I DIFF >= (2.5*Ic) Ngligible
For I Diff > = Min setting value available 0.1 A
which corresponds to 80 A & > 15% rated current 120 A
So, set Idiff > pick up: 0.15 1210
I-DIF>SWITCH ON (address 1213) - A setting to three to four times the steady-state charging current
ensures usually the stability of the protection during switch-on of the line. 0.15 A
So, I-DIF>SWITCH ON (address 1213) 0.15 A 1213
1233 I>> Setting near the operational nominal current is adequate in most cases
PL Interconnecting Line to OPTCL Substation Power Flow – 101.25 MW
Line Amps 553.57 A say 560 A
Operational Current Assumed = 560 A
I>> Setting = 0.7 A Min Setting Av = 0.8 A 1233
7SD 610 at OPTCL
Addr. Parameter Remarks
0112 DIFF.PROTECTION Enabled Enabled 87 L
0126 Back-Up O/C TOC IEC TOC IEC 51,51N
0205 CT PRIMARY 800 A 800 A
0206 CT SECONDARY 1 A 1 A
1201 STATE OF DIFF. ON ON
1210 I-DIFF>: Pickup value 0.1 A 0.1 A
1213 I-DIF>SWITCH ON 0.15 A 0.15 A
1217A T-DELAY I-DIFF> 0 s 0 s
Line diff (7SD610) 87L for 132KV Lines:
7SD 610 at PL
Setting Options
1217A T-DELAY I-DIFF> 0 s 0 s
1233 I-DIFF>> 0.8 A 0.8 A
1235 I-DIF>>SWITCHON 0.8 A 0.8 A
2301 INRUSH REST. OFF OFF
2302 2nd HARMONIC 15% 15%
2303 CROSS BLOCK NO NO
2305 MAX INRUSH PEAK 15.00 A 15.0 A
2310 CROSSB 2HM 00 s 00 s
2601 Operating Mode Only Emer. prot Only Emer. prot
2610 Iph>> Pickup - A - A
2611 T Iph>> Time delay - s - s
2620 Iph> Pickup - A - A
2621 T Iph> Time delay - s - s
2640 Ip> 0.70 A 0.70 A
2642 T Ip Time Dial 0.33 0.33
2646 T Ip Add 0 s 0 s
2660 IEC Curve NI NI
2650 3I0p PICKUP 0.20 A 0.20 A
2652 T 3I0p Time Dial 0.33 0.33
2656 T 3I0p Add 0.00 s 0.00 s
Emergency
function
in
case
of
a
Transmission
Failure
26. Fdr Detail Relay CTR PTR Functions: Address ANSI
67/67-TOC TOC IEC 0115 67
67N/67N-TOC TOC IEC 0116 67N
27, 59 Under/Overvoltage Enabled 0150 27/59
50BF Enabled 0170 50BF
Flexible Function Function 01 df/dt
VT Connect. 3ph Van, Vbn, Vcn 0213
FCT 67/67-TOC ON 1501
67 Direction Forward 1516
FCT 67N/67N-TOC ON 1601
67N Direction Forward 1616
67N POLARIZAT with VN and IN 1617
67-2 PICKUP - A 1502
67-2 DELAY - s 1503
67-1 PICKUP - A 1504
67-1 DELAY - s 1505
67-TOC PICKUP 0.70 A 1507
67 TIME DIAL 0.33 1508
67- IEC CURVE NI 1511
67N-2 PICKUP - A 1602
67N-2 DELAY - s 1603
67N-1 PICKUP - A 1604
67N-1 DELAY - s 1605
67N-TOC PICKUP 0.20 A 1607
67N-TOC T-DIAL 0.33 1608
IEC Curve NI 1611
FCT 27 ON 5101
FCT 59 ON 5001
27-1 PICKUP 88 V 5102
27-1 DELAY 2 s 5106
27-2 PICKUP 77 V 5110
27-2 DELAY 1 s 5112
CURRENT SUPERV ON 5120A
59-1 PICKUP 121 V 5002
59-1 DELAY 2 s 5004
59-2 PICKUP 132 V 5005
59-2 DELAY 1 s 5007
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.25 s 7005
50BF PICKUP 0.1 A 7006
Flexible Function ON
Mode of Operation w/o Ph Ref
Select of Measured quantity df/dt falling
Pick up threshold 1 Hz/s
Time delay 0.5 s
OPTCL S/S
OPTCL S/S
50BF
67
67N
81R
df/dt
27
59
132KV/
3
110V/
3
132KV
CT
800/1
7SJ803
(F67
/
67N)
132KV
Line
PL
-
OPTCL
Settings
at
PL
Settings:
27. Detail Relay CTP CTS Functions: Address ANSI Remarks
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
7SD610
(F87L)
800
1
Settings:
DIFF. PROTECTION Enabled 0112 87L
Back-Up O/C Only Emer. prot 0126 51/51N
STATE OF DIFF ON 1201
I-DIFF> 0.1 A 1210
I-DIF>SWITCH ON 0.15 A 1213
T-DELAY I-DIFF> 0 s 1217A
I-DIFF>> 0.8 A 1233
I-DIF>>SWITCHON 0.8 A 1235
INRUSH REST OFF 2301
2nd HARMONIC 15% 2302
CROSS BLOCK NO 2303
MAX INRUSH PEAK 15.0 A 2305
CROSSB 2HM 00 s 2310
Operating Mode Only Emer. prot 2601
Ip> 0.70 A 2640
T Ip Time Dial 0.33 2642
T Ip Add 0 s 2646
IEC Curve NI 2660
3I0p PICKUP 0.20 A 2650
T 3I0p Time Dial 0.33 2652
T 3I0p Add 0 s 2656
51/ 51N
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
1
1
3
3
2
2
K
K
V
V
B
B
P
P
L
L
_
_
O
O
P
P
T
T
C
C
L
L
S
S
/
/
S
S
S
S
e
e
t
t
t
t
i
i
n
n
g
g
s
s
a
a
t
t
B
B
PL
L
7SD610
(F87L)
800
1
87L
28. Fdr Detail Relay CTR PTR Functions: Address ANSI
Charac. Phase TOC IEC 0112 51
Charac. Ground TOC IEC 0113 51N
67/67-TOC TOC IEC 0115 67
67N/67N-TOC TOC IEC 0116 67N
27, 59 Under/Overvoltage Enabled 0150 27/59
50BF Enabled 0170 50BF
Flexible Function Function 01 df/dt
VT Connect. 3ph Van, Vbn, Vcn 0213
FCT 50/51 ON 1201
50-2 PICKUP - A 1202
50-2 DELAY - s 1203
50-1 PICKUP - A 1204
50-1 DELAY - s 1205
51 PICKUP 0.7 A 1207
51 TIME DIAL 0.33 1208
51 IEC CURVE NI 1211
FCT 50N/51N ON 1301
50N-2 PICKUP - A 1302
50N-2 DELAY - s 1303
50N-1 PICKUP - A 1304
50N-1 DELAY - s 1305
51N PICKUP 0.2 A 1307
51N TIME DIAL 0.33 1308
51N IEC CURVE NI 1311
FCT 67/67-TOC ON 1501
67-2 Direction Forward 1523
67-1 Direction Forward 1524
67-TOC Direction Forward 1525
FCT 67N/67N-TOC ON 1601
67N-2 Direction Forward 1623
67N-1 Direction Forward 1624
67N-TOC Direct. Forward 1625
67N POLARIZAT with VN and IN 1617
67-2 PICKUP - A 1502
67-2 DELAY - s 1503
67-1 PICKUP - A 1504
67-1 DELAY - s 1505
67-TOC PICKUP 0.70 A 1507
67 TIME DIAL 0.33 1508
67- IEC CURVE NI 1511
67N-2 PICKUP - A 1602
67N-2 DELAY - s 1603
67N-1 PICKUP - A 1604
67N-1 DELAY - s 1605
67N-TOC PICKUP 0.20 A 1607
67N-TOC T-DIAL 0.33 1608
IEC Curve NI 1611
132KV
CT
800/1
7SJ622
(F67
/
67N)
132KV
Line
OPTCL
SS
-
PL
Sw.
Yd.
Settings
at
OPTCL
SS
Settings:
67
67N
PL Sw.
Yd.
PL Sw.
Yd
132KV/
3
110V/
3
50/51
50N /
51N
29. Fdr Detail Relay CTR PTR Functions: Address ANSI
FCT 27 ON 5101
FCT 59 ON 5001
27-1 PICKUP 88 V 5102
27-1 DELAY 2 s 5106
27-2 PICKUP 77 V 5110
27-2 DELAY 1 s 5112
CURRENT SUPERV ON 5120A
59-1 PICKUP 121 V 5002
59-1 DELAY 2 s 5004
59-2 PICKUP 132 V 5005
59-2 DELAY 1 s 5007
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.25 s 7005
50BF PICKUP 0.1 A 7006
50BF-2 Delay 0.5 s 7008
Flexible Function ON
Mode of Operation w/o Ph Ref
Select of Measured quantity df/dt falling
Pick up threshold 1 Hz/s
Time delay 0.5 s
Detail Relay CTP CTS Functions: Address ANSI Remarks
132KV
CT
800/1
7SJ622
(F67/67N)
132KV
Line
OPTCL
SS
-
PL
Sw.
Yd.
Settings
at
OPTCL
SS
Settings:
81R
df/dt
27
59
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
7SD610
(F87L)
800
1
50BF
Settings:
132KV/
3
110V/
3
DIFF. PROTECTION Enabled 0112 87L
Back-Up O/C TOC IEC 0126 51/51N
STATE OF DIFF ON 1201
I-DIFF> 0.1 A 1210
I-DIF>SWITCH ON 0.15 A 1213
T-DELAY I-DIFF> 0 s 1217A
I-DIFF>> 0.8 A 1233
I-DIF>>SWITCHON 0.8 A 1235
INRUSH REST OFF 2301
2nd HARMONIC 15% 2302
CROSS BLOCK NO 2303
MAX INRUSH PEAK 15.0 A 2305
CROSSB 2HM 00 s 2310
Operating Mode Only Emer. prot 2601
Ip> 0.70 A 2640
T Ip Time Dial 0.33 2642
T Ip Add 0 s 2646
IEC Curve NI 2660
3I0p PICKUP 0.20 A 2650
T 3I0p Time Dial 0.33 2652
T 3I0p Add 0 s 2656
87L
51/ 51N
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
1
1
3
3
2
2
K
K
V
V
L
L
i
i
n
n
e
e
P
P
P
P
T
T
C
C
L
L
S
S
S
S
_
_
B
B
P
P
L
L
S
S
w
w
.
.
Y
Y
d
d
.
.
S
S
e
e
t
t
t
t
i
i
n
n
g
g
s
s
a
a
t
t
O
O
P
P
T
T
C
C
L
L
S
S
S
S
7SD610
(F87L)
800
1
34. PL_ TS Alloy 132KV Relay Setting
(132KV OG Line - Bay 106_ EHV Cable Feeder)
35. 1.0 PURPOSE:
This document is intended to show Protection Relay Calculations settings for
132KV OG Line (Cable) Feeder (Bay 106) at both ends of 132KV PL Switch Yd &
that at 132KV TS Alloy Sw. Yd.
2.0 DESIGN INPUT :
i) Relay Catalogues
ii) Protection and Measuring diagram
3.0 ASSUMPTIONS:
i). If any change is noticed in the CT Ratio from the value considered in the relay setting
document, then settings would need to be modified suitably.
ii). This document is issued for protection functions and related settings only.
The configuration of BO, BI,LEDs,CFC logic and settings such as CT star points,
Breaker residual currents, etc, shall be as prepared at site as per actual approved wiring
4.0 Attachment:
Related pages of manual for Setting Calculation purpose have been provided separately
in the attachment.
36. PL_ TS Alloy 132KV Relay Setting
Sr. No. Description
1 7SD Line Differntial at PL & TS Alloy Calculations
2 Calculations of Back up protections
3 Relay Settings at PL (Bay 106) - TS Alloy
4 Relay Settings at TS Alloy 132KV for PL Fdr (Bay 106)
5 Grading Curves
i) OC Curve
ii) EF Curve
Table of Contents
37. 800/1 800/1 132KV Cable 1C, 800mm2, 850 M
PL TS Alloy
Cable length: 850 M
Capacitance at 50Hz per 1000 meters 0.205 µF As per cable data sheet
Capacitance at 50Hz per 1000 meters 205 nF
Cable Length 0.85 Km
132KV Cable Charging Current IC = 3.63 · 10^-6 · UN · fN · CB' · s
Size Runs CB' (nF/Km) s(km) UN Fr IC =
800mm2
1 205.00 0.85 132 50 4.174682
The Pickup Value is set at 2.5 times the charging current or 15% of the rated current of the line
whichever is greater.
Pickup value I DIFF >= (2.5*Ic) 10.44 A
So I Diff > = 0.01 Min setting value available 0.1 A
which corresponds to 80 A & > 15% rated current 60 A
So, set Idiff > pick up: 0.1 1210
I-DIF>SWITCH ON (address 1213) - A setting to three to four times the steady-state charging current
ensures usually the stability of the protection during switch-on of the line. 16.70 A
So, I-DIF>SWITCH ON (address 1213) 0.1 A is ok 1213
1233 I>> Setting near the operational nominal current is adequate in most cases
Operational Current Assumed = 400 A
I>> Setting = 0.5 A 1233
PL Interconnecting Line to TS Alloy Substation – 67.5 MW
Line Amps 369.04 A say 400 A
7SD 610 at TS Alloy
Addr. Parameter Remarks
0112 DIFF.PROTECTION Enabled Enabled 87 L
0126 Back-Up O/C TOC IEC TOC IEC 51,51N
0205 CT PRIMARY 800 A 800 A
0206 CT SECONDARY 1 A 1 A
Line diff (7SD610) 87L for 132KV Lines:
7SD 610 at PL
Setting Options
0206 CT SECONDARY 1 A 1 A
1201 STATE OF DIFF. ON ON
1210 I-DIFF>: Pickup value 0.1 A 0.1 A
1213 I-DIF>SWITCH ON 0.1 A 0.1 A
1217A T-DELAY I-DIFF> 0 s 0 s
1233 I-DIFF>> 0.5 A 0.5 A
1235 I-DIF>>SWITCHON 0.5 A 0.5 A
2301 INRUSH REST. OFF OFF
2302 2nd HARMONIC 15% 15%
2303 CROSS BLOCK NO NO
2305 MAX INRUSH PEAK 15.00 A 15.0 A
2310 CROSSB 2HM 00 s 00 s
2601 Operating Mode ON OFF
2610 Iph>> Pickup - A - A
2611 T Iph>> Time delay - s - s
2620 Iph> Pickup - A - A
2621 T Iph> Time delay - s - s
2640 Ip> 0.40 A 0.40 A
2642 T Ip Time Dial 0.33 0.33
2646 T Ip Add 0 s 0 s
2660 IEC Curve NI NI
2650 3I0p PICKUP 0.20 A 0.20 A
2652 T 3I0p Time Dial 0.33 0.33
2656 T 3I0p Add 0.00 s 0.00 s
Prot.
Functions
51/51N
at
TS
Alloy
end
through
7SJ
803
41. Fdr Detail Relay CTR PTR Functions: Address ANSI
67/67-TOC TOC IEC 0115 67
67N/67N-TOC TOC IEC 0116 67N
27, 59 Under/Overvoltage Enabled 0150 27/59
50BF Enabled 0170 50BF
Flexible Function Function 01 df/dt
VT Connect. 3ph Van, Vbn, Vcn 0213
FCT 67/67-TOC ON 1501
67 Direction Forward 1516
FCT 67N/67N-TOC ON 1601
67N Direction Forward 1616
67N POLARIZAT with VN and IN 1617
67-2 PICKUP - A 1502
67-2 DELAY - s 1503
67-1 PICKUP 1.25 A 1504
67-1 DELAY 0.05 s 1505
67-TOC PICKUP 0.40 A 1507
67 TIME DIAL 0.25 1508
67- IEC CURVE NI 1511
67N-2 PICKUP - A 1602
67N-2 DELAY - s 1603
67N-1 PICKUP 0.18 A 1604
67N-1 DELAY 0.05 s 1605
67N-TOC PICKUP 0.05 A 1607
67N-TOC T-DIAL 0.05 1608
IEC Curve NI 1611
FCT 27 ON 5101
FCT 59 ON 5001
27-1 PICKUP 88 V 5102
27-1 DELAY 2 s 5106
27-2 PICKUP 77 V 5110
27-2 DELAY 1 s 5112
CURRENT SUPERV ON 5120A
59-1 PICKUP 121 V 5002
59-1 DELAY 2 s 5004
59-2 PICKUP 132 V 5005
59-2 DELAY 1 s 5007
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.25 s 7005
50BF PICKUP 0.1 A 7006
Flexible Function ON
Mode of Operation w/o Ph Ref
Select of Measured quantity df/dt falling
Pick up threshold 1 Hz/s
Time delay 0.5 s
132KV/
3
110V/
3
132KV
CT
800/1
7SJ803
(F67
/
67N)
132KV
Line
PL
-
TS
Alloy
S/S
Settings
at
PL
Settings:
67
67N
81R
df/dt
27
59
TS Alloy
S/S
TS Alloy
S/S
50BF
42. Detail Relay CTP CTS Functions: Address ANSI Remarks
Settings:
7SD610
(F87L)
800
1
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
DIFF. PROTECTION Enabled 0112 87L
Back-Up O/C TOC IEC 0126 51/51N
STATE OF DIFF ON 1201
I-DIFF> 0.1 A 1210
I-DIF>SWITCH ON 0.1 A 1213
T-DELAY I-DIFF> 0 s 1217A
I-DIFF>> 0.5 A 1233
I-DIF>>SWITCHON 0.5 A 1235
INRUSH REST OFF 2301
2nd HARMONIC 15% 2302
CROSS BLOCK NO 2303
MAX INRUSH PEAK 15.0 A 2305
CROSSB 2HM 00 s 2310
Operating Mode ON 2601
Ip> 0.40 A 2640
T Ip Time Dial 0.33 2642
T Ip Add 0 s 2646
IEC Curve NI 2660
3I0p PICKUP 0.20 A 2650
T 3I0p Time Dial 0.33 2652
T 3I0p Add 0 s 2656
1
1
3
3
2
2
K
K
V
V
B
B
P
P
L
L
_
_
T
T
S
S
A
A
l
l
l
l
o
o
y
y
S
S
/
/
S
S
S
S
e
e
t
t
t
t
i
i
n
n
g
g
s
s
a
a
t
t
B
B
P
P
L
L
7SD610
(F87L)
800
1
87L
51/ 51N
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
43. Fdr Detail Relay CTR PTR Functions: Address ANSI
Charac. Phase TOC IEC 0112 51
Charac. Ground TOC IEC 0113 51N
67/67-TOC TOC IEC 0115 67
67N/67N-TOC TOC IEC 0116 67N
27, 59 Under/Overvoltage Enabled 0150 27/59
50BF Enabled 0170 50BF
Flexible Function Function 01 df/dt
VT Connect. 3ph Van, Vbn, Vcn 0213
FCT 50/51 ON 1201
50-2 PICKUP - A 1202
50-2 DELAY - s 1203
50-1 PICKUP - A 1204
50-1 DELAY - s 1205
51 PICKUP 0.4 A 1207
51 TIME DIAL 0.33 1208
51 IEC CURVE NI 1211
FCT 50N/51N ON 1301
50N-2 PICKUP - A 1302
50N-2 DELAY - s 1303
50N-1 PICKUP - A 1304
50N-1 DELAY - s 1305
51N PICKUP 0.2 A 1307
51N TIME DIAL 0.33 1308
51N IEC CURVE NI 1311
FCT 67/67-TOC ON 1501
67 Direction Forward 1516
FCT 67N/67N-TOC ON 1601
67N Direction Forward 1616
67N POLARIZAT with VN and IN 1617
67-2 PICKUP - A 1502
67-2 DELAY - s 1503
67-1 PICKUP - A 1504
67-1 DELAY - s 1505
67-TOC PICKUP 0.40 A 1507
67 TIME DIAL 0.33 1508
67- IEC CURVE NI 1511
67N-2 PICKUP - A 1602
67N-2 DELAY - s 1603
67N-1 PICKUP - A 1604
67N-1 DELAY - s 1605
67N-TOC PICKUP 0.20 A 1607
67N-TOC T-DIAL 0.33 1608
IEC Curve NI 1611
PL Sw.
Yd.
PL Sw.
Yd
132KV/
3
110V/
3
50/51
50N /
51N
Settings:
67
67N
132KV
CT
800/1
7SJ803
(F67
/
67N)
132KV
Line
TS
Alloy
SS
-
PL
Sw.
Yd.
Settings
at
TS
Alloy
SS
44. Fdr Detail Relay CTR PTR Functions: Address ANSI
FCT 27 ON 5101
FCT 59 ON 5001
27-1 PICKUP 88 V 5102
27-1 DELAY 2 s 5106
27-2 PICKUP 77 V 5110
27-2 DELAY 1 s 5112
CURRENT SUPERV ON 5120A
59-1 PICKUP 121 V 5002
59-1 DELAY 2 s 5004
59-2 PICKUP 132 V 5005
59-2 DELAY 1 s 5007
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.25 s 7005
50BF PICKUP 0.1 A 7006
Flexible Function ON
Mode of Operation w/o Ph Ref
Select of Measured quantity df/dt falling
Pick up threshold 1 Hz/s
Time delay 0.5 s
Detail Relay CTP CTS Functions: Address ANSI Remarks
50BF
Settings:
132KV/
3
110V/
3
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
7SD610
(F87L)
800
1
Settings:
81R
df/dt
27
59
132KV
CT
800/1
7SJ803
(F67/67N)
132KV
Line
TS
Alloy
SS
-
PL
Sw.
Yd.
Settings
at
TS
Alloy
SS
DIFF. PROTECTION Enabled 0112 87L
Back-Up O/C TOC IEC 0126 51/51N
STATE OF DIFF ON 1201
I-DIFF> 0.1 A 1210
I-DIF>SWITCH ON 0.1 A 1213
T-DELAY I-DIFF> 0 s 1217A
I-DIFF>> 0.5 A 1233
I-DIF>>SWITCHON 0.5 A 1235
INRUSH REST OFF 2301
2nd HARMONIC 15% 2302
CROSS BLOCK NO 2303
MAX INRUSH PEAK 15.0 A 2305
CROSSB 2HM 00 s 2310
Operating Mode OFF 2601
Ip> 0.40 A 2640
T Ip Time Dial 0.33 2642
T Ip Add 0 s 2646
IEC Curve NI 2660
3I0p PICKUP 0.20 A 2650
T 3I0p Time Dial 0.33 2652
T 3I0p Add 0 s 2656
87L
51/ 51N
Identical
Differential
Settings
(CTR
800/1)
to
be
implemented
at
both
ends
1
1
3
3
2
2
K
K
V
V
T
T
S
S
A
A
l
l
l
l
o
o
y
y
S
S
/
/
S
S
_
_
B
P
P
L
L
S
S
w
w
.
.
Y
Y
d
d
.
.
S
S
e
e
t
t
t
t
i
i
n
n
g
g
s
s
a
a
t
t
T
T
S
S
A
A
l
l
l
l
o
o
y
y
S
S
S
S
7SD610
(F87L)
800
1
49. 2.3 Differential Protection
71
7SD610 Manual
C53000-G1176-C145-4
Pickup Value of the
Differential Current
The current sensitivity is set with address 1210 I-DIFF>. It is determined by the
entire current flowing into a protected zone in case of a fault. This is the total fault
current regardless of how it is distributed between the ends of the protected object.
This pickup value must be set to a value that is higher than the total steady-state shunt
current of the protected object. For cables and long overhead lines, the charging
current is to be considered in particular. It is calculated from the operational capaci-
tance:
IC = 3.63 · 10–6
· UN · fN · CB' · s
with
IC Charging current to be calculated in A primary
UNom Nominal voltage of the network in kV primary
fN Nominal frequency of the network in Hz
CB' Per unit line length service capacitance of the line in nF/km or nF/mile
s Length of the line in km or miles
Considering the variations of voltage and frequency, the value set should be at least
2 to 3 times higher than the calculated charging current. Moreover, the pickup value
should not be less than 15 % of the operating rated current. The operating rated
current either derives from the rated apparent power of a transformer in the protected
area (as described in 2.1.4.1 under margin heading „topological data for transformers
is described in the protection zone (optional)“, or from the addresses 1104
FullScaleCurr. according to Section 2.1.4.1 under margin heading „Rated Values
of Protected Lines“. It must be equal at all ends of the protected object.
If setting is performed from a personal computer using DIGSI, the parameters can be
set either as primary or as secondary quantities. If secondary quantities are set, all
currents must be converted to the secondary side of the current transformers.
Calculation Example:
110 kV single-conductor oil-filled cable
Cross section = 240 mm2
Rated frequency fN = 50 Hz
Length s = 16 km
Service capacitance CB' = 310 nF/km
Current transformer, transformer ratio 600 A/5 A
From that the steady-state charging current is calculated:
IC = 3.63 · 10–6
· UN · fN · CB' · s = 3.63 · 10–6
· 110 · 50 · 310 · 16 = 99 A
For the setting with primary values at least the double value is to be set, i.e.:
Setting value I-DIFF> = 200
For the setting with secondary values this value has to be converted to secondary
quantity:
If a power transformer with voltage regulation is installed within the protected zone
consider that a differential current may be present even during normal operation, de-
pendent on the position of the tap changer. Please also refer to the notes in chapter
REFERENCES
50. 2 Functions
72 7SD610 Manual
C53000-G1176-C145-4
2.1.2.1 Setting information, Margin heading „Power Transformer with Voltage Regula-
tion“.
Pickup value
during switch-on
When switching on long, unloaded cables, overhead lines and arc-compensated lines,
pronounced higher-frequency transient reactions may take place. These peaks are
considerably damped by means of a digital filter in the differential protection. A pickup
value I-DIF>SWITCH ON (address 1213) can be set to reliably prevent single-sided
pickup of the protection. This pickup value is always active when a device has recog-
nized the connection of a dead line at its end. For the duration of the seal-in time SI
Time all Cl. which was set in the general protection data at address 1132 (Section
2.1.4.1) all devices are then switched over to this particular pickup value. A setting to
three to four times the steady-state charging current ensures usually the stability of the
protection during switch-on of the line. For switch-on of a transformer or shunt reactor,
an inrush restraint is incorporated (see below under margin heading „Inrush Re-
straint“).
Final checks will be carried out during commissioning. Further information can be
found in chapter Installation and Commissioning.
Delays In special cases of application it may be useful to delay the tripping of the differential
protection with an additional timer, e.g. in case of reverse interlocking. The delay time
T-DELAY I-DIFF> (address 1217) is only started upon detection of an internal fault.
This parameter can only be altered with DIGSI under Additional Settings.
If the differential protection is applied to an isolated or resonant-earthed network, it
must be ensured that tripping is avoided during the transient oscillations of a single
earth fault. With address 1218 T3I0 1PHAS the pickup to a single fault is therefore
delayed for 0.04 s (presetting). For large resonant-earthed systems the time delay
should be increased. By setting the address to the single-phase tripping is totally
suppressed.
In an earthed system, T3I0 1PHAS shall be set to 0.00 s. This parameter can only be
altered in DIGSI at Additional Settings.
If it is desired that a TRIP command is generated in the event of an internal fault only
if simultaneously the current of the local line end has exceeded a specific quantity,
then this current threshold can be set for enabling the differential protection TRIP at
address 1219 I> RELEASE DIFF. This parameter can only be altered in DIGSI at
Additional Settings.
Pickup value
charge comparison
stage
The pickup threshold of the charge comparison stage is set in address 1233 I-
DIFF>>. The RMS value of the current is decisive. The conversion into charge value
is carried out by the device itself.
Setting near the operational nominal current is adequate in most cases. Please also
remember that the setting is related to the operational nominal values that must be
equal (primary) at all ends of the protected object.
Since this stage reacts very fast, a pickup of capacitive charging currents (for lines)
and inductive magnetising currents (for transformers or shunt reactors) — also for
switch-on condition — must be excluded.
In resonant-earthed systems also the value of the non-compensated system earth
fault current may not be undershot. It derives from the total capacitive earth fault
current without considering the Petersen coil. As the Petersen coil serves to compen-
sate nearly the total earth fault current, its rated current can be taken as a base.
For transformers set the value IN Trafo/uk Trafo.
51. OPTCL Switchyard Relay Setting
(132KV Lines Chandaka, Bidanasi and B/C at OPTCL Switchyard)
52. 132KV OPTCL Sw. Yd.
1.0 PURPOSE:
This document is intended to show Protection Relay Calculations settings for
132KV OG Line Feeders from 132KV OPTCL Switch Yd and that of 132KV B/C.
2.0 DESIGN INPUT :
i) Relay Catalogues
ii) Protection and Measuring diagram
3.0 ASSUMPTIONS:
i). If any change is noticed in the CT Ratio from the value considered in the relay setting
document, then settings would need to be modified suitably.
ii). This document is issued for protection functions and related settings only.
The configuration of BO, BI,LEDs,CFC logic and settings such as CT star points,
Breaker residual currents, etc, shall be as prepared at site as per actual approved wiring
4.0 Attachment:
Reference pages related to Setting Calculation have been provided separately
in the attachment.
53. Sr. No. Description
OPTCL_132KV Provisional Setting Calculation Documet:
1 Distance & Dir Protection 7SA522, 7SJ62 Calculations - Chandaka Line
2 Chandaka Line Settings
3 Distance & Dir Protection 7SA522, 7SJ62 Calculations - Bidanasi Line
4 Bidanasi Line Settings
5 132KV BC 7SJ 62 Setting Calculations
6 132KV BC Setting
Table of Contents
54. 132KV Line OPTCL - Chandaka
132KV Line OPTCL - Chandaka . Dis.PICKUP = Z< (quadrilat.)
OPTCL
20 KM 14.5 KM
Panther Panther
Chandaka
Bidanasi
18 KM
Panther
Choudar
3Ph Fault Level at OPTCL 132KV Bus 4200 MVA
Line data for OPTCL - Chandaka Panther 14.5 KM
R1/s = 0.16743 / Km
X1/s = 0.4141 / Km
Positive Seq. Imp Z1= 0.1674 + J 0.4141 / Km 0.447 67.99 °
Line Angle = 67.99 ° 1105
R1 = 14.5 X 0.16743 For 14.5Km 2.428
X1 = 14.5 X 0.4141 For 14.5Km 6.00
Line CT CTP 800 CTS 1
PT PTP 132KV/ 3 PTS 110V/ 3
CTR/PTR = 0.67
X1/s 0.4141 As seen by Relay = (X1/s)x(CTR/PTR) 0.2760733 / Km 1110
Ro Zero seq resistance / Km Ro/s = 0.41392 / Km
Ro Zero seq resistance for 14.5 Km 6.00184
Xo/s 1.39764 / Km
Act zero seq reactance for 14.5 KM 20.266
Zero seq Imp Z0 = 0.41392+1.139764 /Km 1.4576 73.50 °
Zo for 14.5 Km 21.136
Earth impedance ratios,
0.491 Formula reference - attached 1116
SIPROTEC, 7SA522, page
0.792 1117
Distance between OPTCL & Chandaka (Line Length) s = 14.5 KM. 1111
Distance between OPTCL & Bidanasi (Reverse looking) 20 KM.
There is no other outgoing line at Chandaka.
Pri Sec
PT Rating 76210.236 63.51
CT Rating 800 1
In 1 CTR/PTR=
A 1 0.67
Line data for:
Ra = For 14.5 KM 2.428
Xa = For 14.5 KM 6.005
SETTING CALCULATION FOR : 7SA 522
Entire Line
OPTCL - Chandaka
Distance Relay
55. 132KV Line OPTCL - Chandaka
Reactance Setting 1st
. Zone :
The following Zone limits arise:
X1 Primary (80% of the line reactance Xa) = 4.804
X1 Secondary (X1 Pri*(CTR/PTR)) = 3.202 X(Z1) 1303
Reactance Setting 2nd
. Zone :
Zone 2 Primary + 50% upto next Shortest line.
X2 Pri = Xa+0.5Xb = Reactance of entire Line (No OG Line at Chandaka) 6.005
X2 Secondary (X2 Pri*(CTR/PTR)) = 4.003 X(Z2) 1313
Reactance Setting 3rd
. Zone :
Zone 3 14.5 Km
X 3 Pri = Same value kept as that for 2nd Zone 6.005
X 3 Secondary (X 3 Pri*(CTR/PTR)) = 4.003 X(Z3) 1323
Resistance Setting 1
st.
Zone:
Minimum fault current: Assumed 1 kA
Uarc = 2500 V larc whereby larc is the length of the arc 2500 V x Arc length
Arc Length (Assumed) 3 m
Arc Resistance (R arc) = Uarc/Iarc 7.5
R(Z1) Pri =1.2x1/2 Rarc =1.2x(0.5Rarc) (1.2 safety margin) 4.5
R(Z1) Sec = R1 Pri X (CTR/PTR) 3.00 R(Z1) 1302
"The resistance RL of the line itself can be ignored with SIPROTEC 4 devices. It is taken into account by the
shape of the polygon, provided that the inclination angle of the polygon Distance Angle (address 1211) is
not set greater than the line angle Line Angle (address 1105)" - refer 7SA Manual
Resistance Setting 2
nd.
Zone:
R(Z2) Sec = (R(Z1) +R(L1))x(CTR/PTR) 3.61849 R(Z2) 1312
Resistance Setting 3r
d.
Zone:
(Since there is no OG Line at Chandaka 2nd & 3rd Zone settings kept same excepting for Time grading.
R(Z3) Sec = R3 Pri X (CTR/PTR) 3.61849 R(Z3) 1322
For Earth Fault:
Rre: Earth Fault Resistance measured by distance protection
Ref: 7SA manual
Page attached
R1E Setting in the distance protection RE(Z1) Ø-E, address 1304
I2/I1 Approx value of can be assumed. 3
RTF value of can be assumed for overhead lines with earth wire 3
Arc length: (Assumed) 3 m
Minimum fault current: 1 kA
Std value for the arc voltage UArc approx.per meter of arc length 2.5 kV
Arc Resistance (R arc) = (As per formula given below:) 1.875
Tower footing Resistance (R tower) = 3
Distance Relay
56. 132KV Line OPTCL - Chandaka
The following recommended setting applies for the resistance tolerance of distance zone Z1:
Ref: 7SA manual
Page attached
RE(Z1) Pri 15.697
RE(Z1) Sec = (CTR/PTR)*(R1E Pri) 10.465 RE(Z1) 1304
Resistance tolerance of distance zone Z2:
RE(Z2) Ø-E, address 1314 setting:
RE(Z2) Pri = RE(Z1)+RL1 18.125
RE(Z2) Sec = RE(Z2)x(CTR/PTR) 12.083 RE(Z2) 1314
Resistance tolerance of distance zone Z3:
RE(Z3) Ø-E, address 1324 setting:
RE(Z3) Sec = R3E Pri X (CTR/PTR) 12.083 RE(Z3) 1324
Zone 4 = Reverse (25% of Bidanasi line as per mail information) 25% 1331
R(Z4) Ø-Ø (sec) = (CTR/PTR)x(0.5*Arc R)*1.2 3.000 R(Z4) Ø-Ø 1332
X(Z4) (sec)= (CTR/PTR)x0.25x20x0.41411 1.380 X(Z4) 1333
RE(Z4) Ø-E (sec) 10.46 RE(Z4) Ø-E 1334
1
st.
Zone Time Zone Timings as per mail information. 0 m.s. 1305/1306
2nd.
Zone Time 0.5 sec 1315/1316
3rd.
Zone Time 1.5 sec 1325
4th.
Zone Time 1.5 sec 1335
O/C Pick Up Iph>: Emergency O/C (Loss of VT)
CTP 800 A
Max. A At 65°C Panther capacity 395A say 400 A doc encl.
Iph> 0.50 A 1507/2640
T Iph> 0.66 1508/2642
T Ip Add 0 s 2646
Curve NI 1511/2660
3Iop PICKUP 0.25 A 1607/2650
T 3Iop TimeDial 0.66 1608/2652
T 3Iop Add 0 s 2656
Maximum transmittable power 91.45 MVA 400 A
Minimum operating voltage 7SA ref attached 118.800 KV
The resulting minimum load impedance 171.473
RL sec 114.315
R load (Ø-Ø) = Security margin of 10% 102.884
Secondary: R load (Ø-Ø) = 102.884 1241/1243
cos min = 0.8
max = 36.87 °
Setting value load (Ø-Ø) = max = 36.87 ° 1242/1244
R1/X1 = 0.9367826 “Alpha Angle” setting is 20.00 ° doc encl. 1307
Source Imp Zs1=Zs2= KV^2/MVA = 4.15
Line Imp = 6.477 End Fault Current = 4.64 KA
SOTF prot I>>> 5.80 SF 0.5 2.90 say 2.90 A 2404
Distance Relay
57. 132KV Line OPTCL - Chandaka
Max Volt.Diff Synchronism and voltage check 10 V 3531
Max Freq.Diff 0.1 Hz 3532
Max Angle Diff 10 ° 3533
Voltage threshold dead line / bus 22 V 3502
Voltage threshold live line / bus 88 V 3503
Umax 121 V 3504
T-SYN. DURATION 1 s 3507
Time of operation 3rd Zone clearance = Back up time 1.5 s
T Ip Add 0 s 2646/2656
Back up time setting 0.66 0.66 2642
EF back up Time 1.5 s
EF Back up time setting NI 0.66 0.66 s 2652
EF Back up P.U. 200 A 0.25 A 1607
Trip Time (O/C) 1.50 s
Trip Time (E/F) 1.50 s
Distance Relay
58. OPTCL _Chandaka 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Phase Distance Quadrilateral 0112
Earth Distance Quadrilateral 0113
P. S. detection Enabled 0120 68
DTT Direct Trip Enabled 0122
SOTF Overcurr Enabled 0124
Back-Up O/C TOC IEC 0126 50/51
Syn. and Voltage Check Enabled 0135 25
U/O VOLTAGE Enabled 0137 27/59
Primary Voltage 132 KV 0203
Sec. Volt (Ph-Ph) 110 V 0204
CT Primary Curr 800 A 0205
CT Sec Current 1 A 0206
System Star point Solid Earthed 0207
Rated Frequency 50 Hz 0230
Phase Sequence L1 L2 L3 0235
Dist measure unit km 0236
Format Z0/Z1 RE/RL, XE/XL 0237
Full ScaleVolt. 132 kV 1103
Full Scale Curr. 800 A 1104
Line Angle 68 ° 1105
Distance Angle 68 ° 1211
x' - Line React / km 0.2761 /Km 1110
Line Length km 14.5 km 1111
RE/RL(Z1) 0.49 1116
XE/XL(Z1) 0.79 1117
RE/RL(> Z1) 0.49 1118
XE/XL(> Z1) 0.79 1119
FCT Distance ON 1201
Minimum Iph> 0.1 A 1202
Distance Angle 68 ° 1211
SER-COMP. NO 1208
SOTF zone PICKUP 1232
R load (Ø-E) 102.88 1241
load (Ø-E) 37 ° 1242
R load (Ø-Ø) 102.88 1243
load (Ø-Ø) 37 ° 1244
1st AR -> Z1B NO 1357
3I0> Threshold 0.1 A 1203
3U0> Threshold 5 V 1204
Start Timers on Dis. Pickup 1210
T1 delay sec 0 sec 1305/1306
T2 delay sec 0.5 sec 1315/1316
T3 delay sec 1.5 sec 1325
T4 delay sec 1.5 sec 1335
Operating mode Z1 Forward 1301
R(Z1), R ph-ph-faults 3.000 1302
X(Z1), Reactance 3.202 1303
RE(Z1) Ø-E 10.465 1304
Zone Reduction 20 ° 1307
132KV/
3
110V/
3
21
800-400-200/1
7SA
522
(21)
132KV
Line
OPTCL
-
Chandaka
59. OPTCL _Chandaka 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Z1B (overrreach zone) Inactive 1351
Operating mode Z2 Forward 1311
R(Z2), R ph-ph-faults 3.618 1312
X(Z2), Reactance 4.003 1313
RE(Z2) Ø-E 12.083 1314
Operating mode Z3 Forward 1321
R(Z3), R ph-ph-faults 3.618 1322
X(Z3), Reactance 4.003 1323
RE(Z3) Ø-E 12.083 1324
Operating mode Z4 Reverse 1331
R(Z4), R ph-ph-faults 3.000 1332
X(Z4), Reactance 1.380 1333
RE(Z4) Ø-E 10.465 1334
Op. mode Z5 Inactive 1341
P. S. Operating mode All zones block 2002
PowerSwing trip NO 2006
Trip delay after P. S. Block 0.08 sec 2007
FCT Direct Trip ON 2201
Trip Time DELAY 0.01 sec 2202
FCT SOTF-O/C ON 2401
I>>> 2.90 A 2404
O/C - Operating Mode ON:with VT loss 2601
Ip> 0.50 A 2640
SOTF Time DELAY 0.00 sec 2680
T Ip Time Dial 0.66 sec 2642
T Ip Add 0 sec 2646
IEC Curve NI 2660
3Iop PICKUP 0.25 A 2650
T 3Iop TimeDial 0.66 sec 2652
T 3Iop Add 0 sec 2656
FCT Synchronism ON 3501
Dead Volt. Thr. 22 V 3502
Live Volt. Thr. 88 V 3503
Umax 121 V 3504
MC maxVolt.Diff 10 V 3531
MC maxFreq.Diff 0.1 Hz 3532
MC maxAngleDiff 10 ° 3533
Uph-ph>(>) ON 3711
Uph-ph> 132 V 3712
T Uph-ph> 2 sec 3713
Uph-ph>> 143 V 3714
T Uph-ph>> 0.5 sec 3715
Uph-ph<(<) ON 3761
Uph-ph< 82.5 V 3762
T Uph-ph< 2 sec 3763
Uph-ph<< 77 V 3764
T Uphph<< 1.5 sec 3765
CURR.SUP.Uphph< ON 3768
One side
Source at
OPTCL end
Only
Fcn 25 may
be kept OFF
at OPTCL
end if no
source is
available at
Chandaka.
132KV/
3
110V/
3
132KV
Line
OPTCL
-
Chandaka
7SA
522
(21)
800-400-200/1
60. OPTCL _Chandaka 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
67- IEC CURVE TOC IEC 0115 67
67N-TOC PICKUP TOC IEC 0116 67N
Breaker Failure Protection enabled w/ 3I0> 0170 50BF
VT Connect. 3ph Van, Vbn, Vcn 213
FCT 67/67-TOC ON 1501
I>> Direction Forward 1523
I> Direction Forward 1524
Ip> Direction Forward 1525
67-2 PICKUP A 1502
67-2 DELAY sec 1503
67-1 PICKUP A 1504
67-1 DELAY sec 1505
67-TOC PICKUP 0.50 A 1507
67 TIME DIAL 0.66 1508
67- IEC CURVE NI 1511
FCT 67N/67N-TOC ON 1601
IE>> Direction Forward 1623
IE> Direction Forward 1624
IEp> Direction Forward 1625
Ground Polarisation With UE & IE 1617
67N-2 PICKUP A 1602
67N-2 DELAY sec 1603
67N-1 PICKUP 1604
67N-1 DELAY 1605
67N-TOC PICKUP 0.25 A 1607
67N-TOC T-DIAL 0.66 1608
67N-TOC IEC NI 1611
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.2 sec 7005
50BF PICKUP 0.1 A 7006
50BF PICKUP IE> 0.1 A 7007
TRIP-Timer 2 0.5 sec 7008
Ref attached
Trip Timer 2
Setting to be
decided as
required
67 Towards
Chandaka
67N Towards
Chandaka
132KV/
3
110V/
3
132KV
Line
OPTCL
-
Chandaka
800-400-200/1
7SJ
622
(F67/67N)
61. 132KV Line OPTCL - Bidanasi
132KV Line OPTCL - Bidanasi . Dis.PICKUP = Z< (quadrilat.)
OPTCL
14.5 KM 20 KM
Panther Panther
Chandaka Bidanasi
18 Km
Panther
Choudhar Line
3Ph Fault Level at OPTCL 132KV Bus 4200 MVA
Line data for OPTCL - Bidanasi Panther 20 KM
R1/s = 0.16743 / Km
X1/s 0.4141 / Km
Positive Seq. Imp Z1= 0.16743 + J 0.4141 / Km 0.447 67.99 °
Line Angle = 67.99 ° 1105
R1 = 20 X 0.16743 For 20Km 3.349
X1 = 20 X 0.4141 For 20Km 8.28
Line CT CTP 800 CTS 1
PT PTP 132KV/ 3 PTS 110V/ 3
CTR/PTR = 0.67
X1/s 0.4141 As seen by Relay = (X1/s)x(CTR/PTR) 0.2760733 / Km 1110
Ro Zero seq resistance / Km Ro/s = 0.41392 / Km
Ro Zero seq resistance for 20 Km 8.2784
Xo/s 1.39764 / Km
Act zero seq reactance for 20 KM 27.953
Zero seq Imp Z0 = 0.41392+1.139764 /Km 1.4576 73.50 °
Zo for 20 Km 29.153
Earth impedance ratios,
0.491 Formula reference - attached 1116
SIPROTEC, 7SA522, page
0.792 1117
Line data for Bidanasi - Choudhar s = 18 KM Panther
R2/s = 0.16743 / Km
X2/s 0.41411 / Km
Positive Seq. Imp Z1= 0.16743 + J 0.4141 / Km 0.447 67.99 °
Positive Seq. Imp Z for 18 km = 8.040 67.99 °
R2 = 3.01374 for 18 km
X2 = 7.45398 for 18 km
Line Angle = 67.99 °
Ro/s = 0.4139 / Km
Ro Zero seq resistance for 18 Km 7.451
Xo/s 1.39764 / Km
Zero seq Xo reactance for 18 Km 25.158
Zero seq Imp Z0 = 0.41392+1.139764 /Km 1.458 73.50 °
Zero seq Imp Z0 for km = 18 26.2376 73.50 °
SETTING CALCULATION FOR : 7SA 522
Distance Relay
62. 132KV Line OPTCL - Bidanasi
Distance between OPTCL & Bidanasi (Line Length) s = 20 KM. 1111
Distance between next adjacent Stations 18 KM.
Distance between next adjacent Stations (other longest line) - KM.
Distance between OPTCL & Chandaka (Reverse looking) 14.5 KM.
Line data for:
1 st section Ra = For 20 KM 3.349
Xa = For 20 KM 8.282
2nd Section Rb = For 18 KM 3.014
Xb = For 18 KM 7.454
3rd Zone Rc = for entire 38 KM 6.362
Xc = for entire 38 KM 15.736
Reactance Setting 1st
. Zone :
The following Zone limits arise:
X1 Primary (80% of the line reactance Xa) = 6.626
X1 Secondary (X1 Pri*(CTR/PTR)) = 4.417 X(Z1) 1303
Reactance Setting 2nd
. Zone :
Zone 2 Primary + 50% upto next Shortest line.
X2 Pri = Xa+0.5Xb = 12.009
X2 Secondary (X2 Pri*(CTR/PTR)) = 8.006 X(Z2) 1313
Reactance Setting 3rd
. Zone :
Zone 3 38 Km
X 3 Pri = 15.736
X 3 Secondary (X 3 Pri*(CTR/PTR)) = 10.491 X(Z3) 1323
Resistance Setting 1st.
Zone:
Minimum fault current: 1 kA
Uarc = 2500 V larc whereby larc is the length of the arc 2500 V x Arc length
Arc length: (Assumed) 3 m
Arc Resistance (R arc) = Uarc/Iarc 7.5
R(Z1) Pri =1.2x1/2 Rarc =1.2x(0.5Rarc) (1.2 safety margin) 4.5
R(Z1) Sec = R1 Pri X (CTR/PTR) 3.00 R(Z1) 1302
"The resistance RL of the line itself can be ignored with SIPROTEC 4 devices. It is taken into account by the
shape of the polygon, provided that the inclination angle of the polygon Distance Angle (address 1211) is
not set greater than the line angle Line Angle (address 1105)" - refer 7SA Manual
Resistance Setting 2nd.
Zone:
R2 Pri =Ra Line +0.5Rb+1/2 Rarc 8.605
R(Z2) Sec = (Ra Line +0.5Rb+1/2 Rac)x(CTR/PTR) 5.737 R(Z2) 1312
Resistance Setting 3rd.
Zone:
R3 Pri =Rc+1/2 Rarc 10.112
R3 Sec = R3 Pri X (CTR/PTR) 6.742 R(Z3) 1322
For Earth Fault:
Rre: Earth Fault Resistance measured by distance protection
Ref: 7SA manual
Page attached
Distance Relay
63. 132KV Line OPTCL - Bidanasi
R1E Setting in the distance protection RE(Z1) Ø-E, address 1304
I2/I1 Approx value of can be assumed. 3 Ref: 7SA manual
RTF value of can be assumed for overhead lines with earth wire 3 Page attached
Arc length: (Assumed) 3 m
Minimum fault current: 1 kA
Std value for the arc voltage UArc approx.per meter of arc length 2.5 kV
Arc Resistance (R arc) = 1.875
Tower footing Resistance (R tower) = 3
RE(Z1) Pri 15.697
RE(Z1) Sec = (CTR/PTR)*(R1E Pri) 10.465 RE(Z1) 1304
Resistance tolerance of distance zone Z2:
RE(Z2) Ø-E, address 1314 setting:
RE(Z2) Pri = RE(Z1)+Ra+0.5Rb 20.552
RE(Z2) Sec = RE(Z2)x(CTR/PTR) 13.702 RE(Z2) 1314
Resistance tolerance of distance zone Z3:
RE(Z3) Ø-E, address 1324 setting:
R3E Pri = RE(Z1)+Ra+Rb 22.059
R3E Sec = R3E Pri X (CTR/PTR) 14.706 RE(Z3) 1324
Zone 4 = Reverse (25% of Chandaka line as per mail information) 25% 1331
R(Z4) Ø-Ø (sec) = (CTR/PTR)x(0.5*Arc R)*1.2 3.000 R(Z4) Ø-Ø 1332
X(Z4) (sec) = (CTR/PTR)x0.25x14.5x0.41411 1.001 X(Z4) 1333
RE(Z4) Ø-E (sec) 10.46 RE(Z4) Ø-E 1334
1st.
Zone Time Zone Timings as per mail information. 0 m.s. 1305/1306
2nd.
Zone Time 0.5 sec 1315/1316
3rd.
Zone Time 1.5 sec 1325
4
th.
Zone Time 1.5 sec 1335
O/C Pick Up Iph>: Emergency O/C (Loss of VT)
CTP 800 A
Max. A At 65°C Panther capacity 395A say 400 A doc encl.
Iph> 0.50 A 2640
T Iph> 0.66 2642
T Ip Add 0 s 2646
Curve NI 2660
3Iop PICKUP 0.25 A 2650
T 3Iop TimeDial 0.66 2652
T 3Iop Add 0 s 2656
SOTF prot:
I>>> 2.50 A 2404
Distance Relay
64. 132KV Line OPTCL - Bidanasi
Maximum transmittable power 91.45 MVA 400 A
Minimum operating voltage 7SA ref attached 118.800 KV
The resulting minimum load impedance 171.473
RL sec 114.315
R load (Ø-Ø) = Security margin of 10% 102.884
Secondary: R load (Ø-Ø) = 102.884 1241/1243
cos min = 0.8
max = 36.87 °
Setting value load (Ø-Ø) = max = 36.87 ° 1242/1244
R1/X1 = 0.679167 “Alpha Angle” setting is 15.00 ° doc encl. 1307
Source Imp Zs1=Zs2= KV^2/MVA 4.15
Line Imp = 8.934 End Fault Current = 3.98 KA
I>>> 4.98 S.F. 0.5 2.49 Say 2.50 A
Max Volt.Diff Synchronism and voltage check 10 V 3531
Max Freq.Diff 0.1 Hz 3532
Max Angle Diff 10 ° 3533
Voltage threshold dead line / bus 22 V 3502
Voltage threshold live line / bus 88 V 3503
Umax 121 V 3504
T-SYN. DURATION 1 s 3507
Time of operation 3rd Zone clearance = Back up time 1.5 s
T Ip Add 0 s 2646/2656
Back up time setting 0.66 0.66 2642
EF back up Time 1.5 s
EF Back up time setting NI 0.66 0.66 s 2652
EF Back up P.U. 200 A 0.25 A
Trip Time (O/C) 1.50 s
Trip Time (E/F) 1.50 s
Distance Relay
65. OPTCL _Bidanasi 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Phase Distance Quadrilateral 0112
Earth Distance Quadrilateral 0113
P. S. detection Enabled 0120 68
DTT Direct Trip Enabled 0122
SOTF Overcurr Enabled 0124
Back-Up O/C TOC IEC 0126 50/51
Syn. and Voltage Check Enabled 0135 25
U/O VOLTAGE Enabled 0137 27/59
Primary Voltage 132 KV 0203
Sec. Volt (Ph-Ph) 110 V 0204
CT Primary Curr 800 A 0205
CT Sec Current 1 A 0206
System Star point Solid Earthed 0207
Rated Frequency 50 Hz 0230
Phase Sequence L1 L2 L3 0235
Dist measure unit km 0236
Format Z0/Z1 RE/RL, XE/XL 0237
Full ScaleVolt. 132 kV 1103
Full Scale Curr. 800 A 1104
Line Angle 68 ° 1105
Distance Angle 68 ° 1211
x' - Line React / km 0.2761 /Km 1110
Line Length km 20.0 km 1111
RE/RL(Z1) 0.49 1116
XE/XL(Z1) 0.79 1117
RE/RL(> Z1) 0.49 1118
XE/XL(> Z1) 0.79 1119
FCT Distance ON 1201
Minimum Iph> 0.1 A 1202
Distance Angle 68 ° 1211
SER-COMP. NO 1208
SOTF zone PICKUP 1232
R load (Ø-E) 102.88 1241
load (Ø-E) 37 ° 1242
R load (Ø-Ø) 102.88 1243
load (Ø-Ø) 37 ° 1244
1st AR -> Z1B NO 1357
3I0> Threshold 0.1 A 1203
3U0> Threshold 5 V 1204
Start Timers on Dis. Pickup 1210
T1 delay sec 0 sec 1305/1306
T2 delay sec 0.5 sec 1315/1316
T3 delay sec 1.50 sec 1325
T4 delay sec 1.5 sec 1335
Operating mode Z1 Forward 1301
R(Z1), R ph-ph-faults 3.000 1302
X(Z1), Reactance 4.417 1303
RE(Z1) Ø-E 10.465 1304
800-400-200/1
7SA
522
(21)
132KV
Line
OPTCL
-
Bidanasi
21
132KV/
3
110V/
3
66. OPTCL _Bidanasi 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Zone Reduction 15 ° 1307
Z1B (overrreach zone) Inactive 1351
Operating mode Z2 Forward 1311
R(Z2), R ph-ph-faults 5.737 1312
X(Z2), Reactance 8.006 1313
RE(Z2) Ø-E 13.702 1314
Operating mode Z3 Forward 1321
R(Z3), R ph-ph-faults 6.742 1322
X(Z3), Reactance 10.491 1323
RE(Z3) Ø-E 14.706 1324
Operating mode Z4 Reverse 1331
R(Z4), R ph-ph-faults 3.000 1332
X(Z4), Reactance 1.001 1333
RE(Z4) Ø-E 10.465 1334
Op. mode Z5 Inactive 1341
P. S. Operating mode All zones block 2002
PowerSwing trip NO 2006
Trip delay after P. S. Block 0.08 sec 2007
FCT Direct Trip ON 2201
Trip Time DELAY 0.01 sec 2202
FCT SOTF-O/C ON 2401
I>>> 2.50 A 2404
O/C - Operating Mode ON:with VT loss 2601
Ip> 0.50 A 2640
SOTF Time DELAY 0.00 sec 2680
T Ip Time Dial 0.66 sec 2642
T Ip Add 0 sec 2646
IEC Curve NI 2660
3Iop PICKUP 0.25 A 2650
T 3Iop TimeDial 0.66 sec 2652
T 3Iop Add 0 sec 2656
FCT Synchronism ON 3501
Dead Volt. Thr. 22 V 3502
Live Volt. Thr. 88 V 3503
Umax 121 V 3504
MC maxVolt.Diff 10 V 3531
MC maxFreq.Diff 0.1 Hz 3532
MC maxAngleDiff 10 ° 3533
Uph-ph>(>) ON 3711
Uph-ph> 132 V 3712
T Uph-ph> 2 sec 3713
Uph-ph>> 143 V 3714
T Uph-ph>> 0.5 sec 3715
Uph-ph<(<) ON 3761
Uph-ph< 82.5 V 3762
T Uph-ph< 2 sec 3763
Uph-ph<< 77 V 3764
T Uphph<< 1.5 sec 3765
CURR.SUP.Uphph< ON 3768
132KV
Line
OPTCL
-
Bidanasi
132KV/
3
110V/
3
800-400-200/1
7SA
522
(21)
One side
Source at
OPTCL end
Only
Fcn 25 may
be kept OFF
at OPTCL
end if no
source is
available at
Bidanasi.
67. OPTCL _Bidanasi 132KV Line
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
67- IEC CURVE TOC IEC 0115 67
67N-TOC PICKUP TOC IEC 0116 67N
Breaker Failure Protection enabled w/ 3I0> 0170 50BF
VT Connect. 3ph Van, Vbn, Vcn 213
FCT 67/67-TOC ON 1501
I>> Direction Forward 1523
I> Direction Forward 1524
Ip> Direction Forward 1525
67-2 PICKUP A 1502
67-2 DELAY sec 1503
67-1 PICKUP A 1504
67-1 DELAY sec 1505
67-TOC PICKUP 0.50 A 1507
67 TIME DIAL 0.66 1508
67- IEC CURVE NI 1511
FCT 67N/67N-TOC ON 1601
IE>> Direction Forward 1623
IE> Direction Forward 1624
IEp> Direction Forward 1625
Ground Polarisation With UE & IE 1617
67N-2 PICKUP A 1602
67N-2 DELAY sec 1603
67N-1 PICKUP 1604
67N-1 DELAY 1605
67N-TOC PICKUP 0.25 A 1607
67N-TOC T-DIAL 0.66 1608
67N-TOC IEC NI 1611
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.2 sec 7005
50BF PICKUP 0.1 A 7006
50BF PICKUP IE> 0.1 A 7007
TRIP-Timer 2 0.5 sec 7008
67 Towards
Bidanasi
67N Towards
Bidanasi
132KV/
3
110V/
3
7SJ
622
(F67/67N)
Ref attached
Trip Timer 2
Setting to be
decided as
required
132KV
Line
OPTCL
-
Bidanasi
800-400-200/1
68. 132KV BC
132KV B/C Setting Calculations in OPTCL 132KV Bus.
3Ph Fault Level 4200 MVA
System Voltage 132 KV
3Ph Fault Current 18.37 KA
3Ph Fault Level 4200.00 MVA
Source Imp = Zs1 = Zs2 = 4.15
As per available Trip Transfer Scheme, Protections of the particular Line / Fdr is effective for B/C CB
when diverted. Still another relay 7SJ 62 is available in the B/C bay and as per Trip Logic the functions
selected are 50/51 & 50BF (Ref drg No: (4)-G719EA-EG9016-W101-BSHT 02
Preliminary Charging setting selected are the same as that of Outgoing 132KV Lines.
132KV BC O/C Curve Data 132KV CTP 800 Relay 7SJ62 Curve NI
MVA If CTP P.S Eff I/Ip tp top Ip
100.60 440 800 0.50 400 1.1 0.44 32.28 0.50
109.74 480 800 0.5 400 1.2 0.44 16.86 tp
137.18 600 800 0.5 400 1.5 0.44 7.57 0.44
182.90 800 800 0.5 400 2 0.44 4.41 I>
274.36 1200 800 0.5 400 3 0.44 2.77 -
365.81 1600 800 0.5 400 4 0.44 2.19 tI>
548.71 2400 800 0.5 400 6 0.44 1.69 -
731.62 3200 800 0.5 400 8 0.44 1.45 I>>
914.52 4000 800 0.5 400 10 0.44 1.31 -
1097.43 4800 800 0.5 400 12 0.44 1.21 tI>>
1463.24 6400 800 0.5 400 16 0.44 1.08 -
1829.05 8000 800 0.5 400 20 0.44 1.00
132KV Side BC EF Curve Data Relay 7SJ62
132KV CTP 800 PS 0.25 Curve NI
MVA If CTP P.S Eff I/Ip tp top Iep
50.30 220 800 0.25 200 1.1 0.44 32.28 0.25
59.44 260 800 0.25 200 1.3 0.44 11.71 tep
68.59 300 800 0.25 200 1.5 0.44 7.57 0.44
91.45 400 800 0.25 200 2 0.44 4.41 Ie>
182.90 800 800 0.25 200 4 0.44 2.19 -
274.36 1200 800 0.25 200 6 0.44 1.69 tIe>
365.81 1600 800 0.25 200 8 0.44 1.45 -
457.26 2000 800 0.25 200 10 0.44 1.31 Ie>>
548.71 2400 800 0.25 200 12 0.44 1.21 -
731.62 3200 800 0.25 200 16 0.44 1.08 tIe>>
914.52 4000 800 0.25 200 20 0.44 1.00 -
OPTCL 132KV SS
69. OPTCL SS Bus Coupler
Fdr Detail Relay CTR PTR Functions: Settings: Address Remarks
Charac. Phase 50/51 TOC IEC 0112 50/51
Charac. Ground 50N/51N TOC IEC 0113 50N/51N
Breaker Failure Protection enabled w/ 3I0> 0170 50BF
FCT 50/51 ON 1201
I>>> pickup A 1217
TI>>> Time Delay s 1218
50-2 PICKUP A 1202
50-2 DELAY s 1203
50-1 PICKUP - A 1204
50-1 DELAY - s 1205
51 PICKUP 0.50 A 1207
51 TIME DIAL 0.44 s 1208
51 IEC CURVE NI 1211
VOLT. INFLUENCE NO 1223
FCT 50N/51N ON 1301
50N-3 PICKUP A 1317
50N-3 DELAY s 1318
50N-2 PICKUP A 1302
50N-2 DELAY s 1303
50N-1 PICKUP - A 1304
50N-1 DELAY - s 1305
51N PICKUP 0.25 A 1307
51N TIME DIAL 0.44 s 1308
51N IEC CURVE NI 1311
FCT 50BF ON 7001
Chk BRK CONTACT ON 7004
TRIP-Timer 0.2 sec 7005
50BF PICKUP 0.1 A 7006
50BF PICKUP IE> 0.1 A 7007
TRIP-Timer 2 0.5 sec 7008
Protection
of
Feeders
being
diverted
through
B/C
retains
its
normal
protection
through
Trip
Transfer
Scheme.
Ref attached
Trip Timer 2
Setting to be
decided as
required
132KV
BC
OPTCL
S/S
800-400-200/1
132KV/
3
110V/
3
7SJ
622
(50/51)
B/C Relay
70. Functions
2.2 Distance Protection
SIPROTEC, 7SA522, Manual
C53000-G1176-C155-7, Release date 02.2011
73
is set, the zone Z1 is relevant, however, it acts in both directions, regardless of the operating direction set in
address 1301 Op. mode Z1. The setting PICKUP implies that the non-delayed tripping following line energi-
zation is activated for all recognized faults in any zone (i.e. with general fault detection of the distance protec-
tion).
Load Range
On long heavily loaded lines, the risk of encroachment of the load impedance into the tripping characteristics
of the distance protection may exist. To exclude the risk of unwanted fault detection by the distance protection
during heavy load flow, a load trapezoid characteristic may be set for tripping characteristics with large R-reach-
es, which excludes such unwanted fault detection by overload. This load area is considered in the description
of the tripping characteristics (see also Section 2.2.2 and Section 2.2.3).
The R value R load (Ø-E) (address 1241) refers to the phase-to-earth loops, R load (Ø-Ø) (address
1243) to the phase-to-phase loops. The values are set somewhat (approx. 10 %) below the minimum expected
load impedance. The minimum load impedance appears when the maximum load current and minimum oper-
ating voltage exist.
For a 1-pole tripping, the setting of the load trapezoid characteristic for earth loops must consider the load
current in the earth path. This is very critical for double circuit lines (on a tower with significant coupling between
both lines). Due to the zero sequence mutual coupling, a significant amount of load current will flow in the „zero
sequence“ path when the parallel line has a single pole open condition. The R setting for the ground loops (or
load encroachment setting) must take into account the ground current that flows when the parallel line has a
single pole open condition.
Calculation Example 1:
110 kV-overhead line 150 mm2, 3-pole tripping, with the following data:
maximum transmittable power
Pmax = 100 MVA corresponds to
Imax = 525 A
minimum operating voltage
Umin = 0.9 UN
Current Transformer 600 A / 5 A
Voltage Transformer 110 kV / 0.1 kV
The resultant minimum load impedance is therefore:
This value can be entered as a primary value when parameterizing with a PC and DIGSI. The conversion to
secondary values is
when applying a security margin of 10% the following is set:
R load (Ø-Ø) = 97.98 primary = 10.69 secondary
R load (Ø-E) = 97.98 primary = 10.69 secondary
The spread angle of the load trapezoid characteristic load (Ø-E) (address 1242) and load (Ø-Ø)
(address 1244) must be greater (approx. 5°) than the maximum arising load angle (corresponding to the
minimum power factor cos ).
REFERENCES
71. Functions
2.2 Distance Protection
SIPROTEC, 7SA522, Manual
C53000-G1176-C155-7, Release date 02.2011
87
Resistance tolerance
The resistance setting R allows a reserve for fault resistance which appears as an additional resistance at the
fault location and is added to the impedance of the line conductors. It comprises, for example, the resistance
in arcs, the earth distribution resistance of earth points and others. The setting must consider these fault resis-
tances, but should at the same time not be larger than necessary. On long heavily loaded lines, the setting may
extend into the load impedance range. Fault detection due to overload conditions is then prevented with the
load impedance range. Refer to margin heading „Load range“ in Section 2.2.1. The resistance tolerance may
be separately set for the phase-phase faults on the one hand and the phase-earth faults on the other hand. It
is therefore possible to allow for a larger fault resistance for earth faults for example.
Most important for this setting on overhead lines, is the resistance of the fault arc. In cables on the other hand,
an appreciable arc can not exist. On very short cables, care must however be taken that an arc fault on the
local cable termination is inside the set resistance of the first zone.
The standard value for the arc voltage UArc is approx. 2.5 kV per meter of arc length.
Example:
A maximum arc voltage of 8 kV is assumed for phase-to-phase faults (line data as above). If the minimum
primary short-circuit current is assumed to be 1000 A this corresponds to 8 primary. The resistance setting
for the first zone, including a safety margin of 20%, would be
primary:
R1prim = 0.5 · Rarc · 1.2 = 0.5 · 8 · 1.2 = 4.8
or secondary:
Only half the arc resistance was applied in the equation, as it is added to the loop impedance and therefore
only half the arc resistance appears in the per phase impedance. Since an arc resistance is assumed to be
present in this case, infeed from the opposite end need not be considered.
The resistance RL of the line itself can be ignored with SIPROTEC 4 devices. It is taken into account by the
shape of the polygon, provided that the inclination angle of the polygon Distance Angle (address 1211) is
not set greater than the line angle Line Angle (address 1105).
A separate resistance tolerance can be set for earth faults. Figure 2-27 illustrates the relationships.
Figure 2-27 Resistance measurement of the distance protection in the presence of arc faults
The maximum arc resistance RArc must be determined for setting the distance zone in R direction. The
maximum arc fault resistance is attained when the smallest fault current at which an arc is still present flows
during an earth fault.
72. Functions
2.2 Distance Protection
SIPROTEC, 7SA522, Manual
C53000-G1176-C155-7, Release date 02.2011
88
The earth fault resistance measured by the distance protection then results from the formula below (it is
assumed that I1 and IE are in phase opposition):
with
RRE Resistance measured by the SIPROTEC distance protection
RL1 Line resistance up to the fault location
RArc Arc resistance
RE/RL Setting in the distance protection (address 1116 and 1118)
I2/I1 Ratio between earth fault currents at the opposite end and the local end. For a correct R
setting of the distance zone, the most unfavourable case must be considered. This most un-
favourable case would be a maximum earth fault current at the opposite end and a minimum
earth fault current at the local end. Moreover, the currents considered are the r.m.s. values
without phase displacement. Where no information is available on the current ratio, a value
of approx. „3“ can be assumed. On radial feeders with negligible infeed from the opposite
end, this ratio is „0“.
RTF Effective tower footing resistance of the overhead line system. Where no information is avail-
able on the amount of tower footing resistance, a value of 3 can be assumed for overhead
lines with earth wire (see also /5/).
The following recommended setting applies for the resistance tolerance of distance zone Z1:
with
R1E Setting in the distance protection RE(Z1) Ø-E, address 1304
1.2 Safety margin 20%
The resistance RL of the line itself can be ignored with SIPROTEC 4 devices. It is taken into account by the
shape of the polygon, provided that the inclination angle of the polygon Distance Angle (address 1211) is
not set greater than the line angle Line Angle (address 1105).
Example:
Arc length: 2 m
Minimum fault current: 1.0 kA
Effective tower footing resistance of the overhead line system: 3
with
I2/I1 = 3
RE/RL = 0,6
Voltage transformer 110 kV / 0.1 kV
Current transformer 600 A / 5 A
73. Functions
2.2 Distance Protection
SIPROTEC, 7SA522, Manual
C53000-G1176-C155-7, Release date 02.2011
91
Figure 2-29 Recommended setting for 1307 Zone Reduction (this graphic applies for overhead lines with a line angle
of more than 60°. A smaller setting may be chosen for cables or protected objects with a smaller angle)
The first step to determine the setting for 1307 Zone Reduction is to determine the maximum load angle for
normal operation (by computer simulation). If this information is not available, a value of about 20° can be
assumed for Western Europe. For other regions with less closely meshed systems, larger angles may have to
be chosen. The next step is to select from Figure 2-29 the curve that matches the load angle. With the set ratio
R1/X1 (zone Z1 polygon) the appropriate setting for 1307 Zone Reduction is then determined.
Example:
With a load angle of 20° and a setting R/X = 2.5 (R1 = 25 , X1 = 10 ), a setting of 10° is adequate for 1307
Zone Reduction.
Different delay times can be set for single- and multiple-phase faults in the first zone: T1-1phase (Address
1305) and T1-multi-phase (address 1306). The first zone is normally set to operate without additional time
delay.
For the remaining zones the following correspondingly applies:
X(Z2) (address 1313), R(Z2) Ø-Ø (address 1312), RE(Z2) Ø-E (address 1314);
X(Z3) (address 1323), R(Z3) Ø-Ø (address 1322), RE(Z3) Ø-E (address 1324);
X(Z4) (address 1333), R(Z4) Ø-Ø (address 1332), RE(Z4) Ø-E (address 1334);
X(Z5)+ (address 1343) for forward direction, X(Z5)- (address 1346) for reverse direction, R(Z5) Ø-Ø (ad-
dress 1342), RE(Z5) Ø-E (address 1344);
X(Z6)+ (address 1363) for forward direction, X(Z6)- (address 1366) for reverse direction, R(Z6) Ø-Ø (ad-
dress 1362), RE(Z6) Ø-E (address 1364).
For the second zone, it is also possible to set separate delay times for single-phase and multi-phase faults. In
general, the delay times are set the same. If stability problems are expected during multi-phase faults, a shorter
delay time could be considered for T2-multi-phase (address 1316) while tolerating a longer delay time for
single-phase faults with T2-1phase (address 1315).
The zone timers for the remaining zones are set with the parameters T3 DELAY (address 1325), T4 DELAY
(address 1335), T5 DELAY (address 1345), and T6 DELAY (address 1365).
74. Two-Element Breaker Failure Protection
In two-element breaker failure protection, the trip command is output again to the local feeder circuit breaker, normally to a separate set of trip coils of the feeder breaker,
after the time delay TRIP-Timer (address 7005) has elapsed.
If the circuit breaker does not respond to the repeated trip, the adjacent circuit breakers, i.e. the breakers of the busbar or the busbar section affected, and where
applicable also the breaker at the remote end, are tripped after the time delay 50BF-2 Delay (Adresse 7008) has elapsed and the fault still exists.
The time delays to be set should be based on the maximum circuit breaker operating time plus the dropout time of the current flow monitoring element plus a safety
margin which takes into consideration the tolerance of the time delay. Figure Time sequence example for normal clearance of a fault, and for circuit breaker failure with
two-element breaker failure protection illustrates the time sequences in an example.
Time sequence example for normal clearance of a fault, and for circuit breaker failure with two-element breaker failure protection
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Two-Element Breaker Failure Protection
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75. Settings
The table indicates region-specific default settings. Column C (configuration) indicates the corresponding
secondary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
7001 FCT 50BF OFF
ON
OFF 50BF Breaker Failure Protection
7004 Chk BRK CONTACT OFF
ON
OFF Check Breaker contacts
7005 TRIP-Timer 0.06 .. 60.00 sec; ∞ 0.25 sec TRIP-Timer
7006 50BF PICKUP 1A 0.03 .. 20.00 A 0.10 A 50BF Pickup current threshold
5A 0.15 .. 100.00 A 0.50 A
7007 50BF PICKUP IE> 0.03 .. 20.00 A 0.10 A 50BF Pickup earth current threshold
7008 50BF-2 Delay 0.06 .. 60.00 sec; ∞ 0.50 sec Delay of 2nd stage for busbar trip
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Settings
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76.
77. Functions
2.1 General
SIPROTEC, 7SA522, Manual
C53000-G1176-C155-7, Release date 02.2011
48
Calculation Example:
110 kV overhead line 150 mm2
as above
R'1 = 0.19 /km
X'1 = 0.42 /km
C' = 0.008 µF/km
Current Transformer 600 A / 1 A
Voltage transformer 110 kV / 0.1 kV
The secondary per distance unit reactance is therefore:
In address 1110 the setting x' = 0.229 /km is entered.
The secondary per distance unit capacitance is therefore:
In address 1114 the setting c' = 0.015 µF/km is entered.
Earth impedance ratio
Setting of the earth to line impedance ratio is an essential prerequisite for the accurate measurement of the
fault distance (distance protection, fault locator) during earth faults. This compensation is either achieved by
entering the resistance ratio RE/RL and the reactance ratio XE/XL or by entry of the complex earth (residual)
compensation factor K0. Which of these two entry options applies, was determined by the setting in address
237 Format Z0/Z1 (refer to Section 2.1.2.1). Only the addresses applicable for this setting will be displayed.
Earth Impedance (Residual) Compensation with Scalar Factors RE/RL and XE/XL
When entering the resistance ratio RE/RL and the reactance ratio XE/XL the addresses 1116 to 1119 apply.
They are calculated separately, and do not correspond to the real and imaginary components of ZE/ZL. A com-
putation with complex numbers is therefore not necessary! The ratios are obtained from system data using the
following formulas:
Where
R0 = Zero sequence resistance of the line
X0 = Zero sequence reactance of the line
R1 = Positive sequence resistance of the line
X1 = Positive sequence reactance of the line
These values can be applied either to the entire line or as per unit of length values since the quotients are in-
dependent of length. Furthermore, it makes no difference whether the quotients are calculated with primary, or
secondary values.
Resistance ratio: Reactance ratio:
