Substation Protection

Question 1

Types of 132/11 kV S/S communication

Answer 1

RTU
BCU
BCPU
BMP

Question 2

What is IBT Protection

Answer 2

OC RELAY
EF RELAY
REF
BUCHHOLZ
SBEF
PRV
OIL TEMP.
WINDING TEMP.
DIFFERENTIAL

Question 3

33kV feeder Protection

Answer 3

PWP/Line Differential
Guard relay
Backup: OC and EF
Guard OC and EF

Question 4

33 kV busbar protection

Answer 4

Discriminating Zone
Check Zone
OC
EF

Question 5

33kV Capacitor protection

Answer 5

Over voltage
Under voltage
EF
OC
Out of balance

Question 6

Earthing Transformer Protection

Answer 6

OC
EF
REF
Buchholz
PRV
Oil Temp.
Winding Temp.

Question 7

IDT Protection (Old)

Answer 7

OC
EF
REF
BUCHHOLZ
SBEF
PRV
OIL TEMP.
WINDING TEMP.
DIFFERENTIAL

Question 8

11 kV Feeder protection (Old)

Answer 8

OC
EF
SEF

Question 9

11 kV capacitor protection (Old)

Answer 9

OV
UV
EF
OC
Out of balance

Question 10

11 kV busbar protection (old)

Answer 10

Discriminating zone
Check zone
OC
EF

Question 11

11 kV feeder main protection (New/BMP)

Answer 11

OC
EF
BF
UFLS
BB PROTECTION

Question 12

11 kV feeder back up protection (New/BMP)

Answer 12

OC
EF
BF
Negative sequence

Question 13

IDT Main 1 Protection (New/BMP)

Answer 13

Differential
HV: REF, BEF, SBEF
LV REF, BEF, SBEF
BUCHHOLZ(IDT/ET)
Oil Temp. (IDT/ET)
Mechanical Alarm (IDT/ET)

Question 14

IDT Main 2 Protection (New/BMP)

Answer 14

Differential
HV: REF, CBF, SBEF, OC
LV: CBF, SBEF
PRV (IDT/ET)
Winding temp. (IDT/ET)
Mechanical alarm (IDT/ET)
C&I DC fail

Question 15

11 kV protection (new/BMP)

Answer 15

Main:
- OC/EF stage 1 & 2 trip
- BB protection trip
- BF trip
Back up:
- OC
- EF

Question 16

11 kV capacitor protection (BMP)

Answer 16

OC, EF, UFLS, BB protection
CPB relay: Unbalance, overload, fire protection

Question 17

11 kV busbar protection (New/BMP)

Answer 17

• High impedance Discriminating zone
• Low Impedance check zone

Question 18

33/11-6.6 DT protection

Answer 18

Primary & Secondary side: OC, REF
Secondary only: EF
PRV
BUCHHOLZ
OIL TEMP
WINDING TEMP

Question 19

33 kV feeder protection (Cable circuit)

Answer 19

PWP
Guard relay
OC
EF

Question 20

33 kV feeder protection (OHL)

Answer 20

OC
EF

Question 21

33 kV BB protection

Answer 21

ARC protection (MG, Tamco, GEC, Alsthom, Energoinvest, ABB, Konkar, Siemens)
OC & EF (Bus section)

Question 22

11-6.6 kV feeder protection

Answer 22

OC
EF

Question 23

11-6.6 kV OHL

Answer 23

OC
EF
SEF

Question 24

11 kV busbar protection

Answer 24

OC
Mechanical protection (VEM)

Question 25

11-6.6/0.4 kV

Answer 25

HRC (for OC)
TLF (OC trip coil, EF trip coil)
CB with relay (OC & EF)