This document provides details about various high voltage equipment used in substations, including: 1) Single line diagrams showing 765kV and 400kV transmission lines and a one and a half breaker scheme. 2) Explanations of how protection systems like differential protection and line protection work using current transformers on breakers and isolators. 3) Descriptions of equipment like 400kV and 245kV circuit breakers, 800kV, 420kV, and 245kV current transformers, 765kV, 420kV, and 245kV isolators, and surge arrestors. 4) Technical specifications for the equipment such as voltage levels, current ratings, and

1. SINGLE TIME DIAGRAM OF 765 Kv Meerut

2. LINE LENGTH IN KM

3. SINGLE TIME DIAGRAM OF 400 Kv Meerut

4. One and Half Breaker scheme
21 3
1,2,3--.>Breaker Red –open ,Green-close

5. CT are provided on
both side of Breaker
so that differential
and line protection
provided
If all breaker are closed power is
feed from both bus and goes
through line 3 and 4Two
Line protection is done by out board
CT of Line breaker
Differential protection is by
outboard CT of bus breaker
ONE AND HALF BREAKER SCHEME
Two line and feed from
single Breaker so called
breaker and half

6. Separate differential protection
is provided for each bus
Mid bus section protected by
line protection

7. If breaker 4 to be on maintenance
open isolator of breaker 4 now
feeder1 and 2 are feed from bus 1
If a fault on bus A it is isolate from
system and now feed by bus b

8. SINGLE bay overview Moga line

9. 7 10 89 A E
BAY
Voltage
level
89-ISOLATOR
52-BREAKER
A,B For Similar Equopments
On same bay
Eqipment E-
Earth switch

10. TWO MAIN BUS & ONE TRANSFER BUS

11. End of grading capacitor
Nameplate of grading
400KV CIRCUIT BREAKER

13. 7
6
5
K
V
D
O
U
B
L
E
T
B
R
E
A
K
E
R
4
2
0
K
V
T
B
R
E
A
K
E
R
WITH
GRADING
CAPACITOR
2
4
5
K
V
T
B
R
E
A
K
E
R
WITH
GRADING
CAPACITOR

14. CAPICITOR VOLTAGE TRANSFORMER
SECONDARY CAPACITANCE GREATER THAN
PRIMARY (ALMOST 18 TIMES
D=DRAIN COLI
S=SURGE
ARRESTOR

15. 800KV CT DETAILS
THREE CORE FOR PROTECTION AND
TWO FOR METERING

16. 8
0
0
K
V
C
U
R
R
E
N
T
T
R
A
N
S
F
O
R
M
E
R
4
2
0
K
V
C
T
2
4
5
K
V
C
T

17.  800KV KNEE
TYPE ISOLATOR
 OPERATED
DEVICE
MOTOR
AC VOLTAGE 415
 CURRENT
3150AMPS

18. This
keen
moves
&
touch 2
2
7
6
5
K
V
K
N
E
E
T
Y
P
E
I
S
O
L
A
T
O
R

19. Double
break
rotating type
420KV ISOLATOR

20. 2
4
5
K
V
C
E
N
T
E
R
B
R
E
A
K
I
S
O

21. MORESTOR GAPLESS POLYMER SURGE ARRESTOR/ZnO
Gapless Lightning Arrester or Surge Arrester
TYPE:LASER (LPSC)
Max Continuous operating
voltage 66.75Kv
ELIEFCURRENT:63kamps rms
Nominal discharge
current:20kAmps

22. Spacer Arc horn

23. 220v dc (110*2) Two banks
48v(24*2) Two banks