Reactive power management is needed due to high seasonal loads causing generators to draw high reactive power, overloading transformers, and low voltages affecting loads. A case study identified areas and radial feeders with reactive power issues. Modifications to 0.6 MVAR capacitors improved compensation. This reduced overloads, improved voltages from 105V to 190V on LT and 7.6kV to 9.8kV on 11kV, and decreased energy consumption by 43.24% on a feeder from 1998-2001 after capacitor additions. Non-switched capacitors provided economical reactive compensation when complemented by switching.

1. Reactive Power Management
- Case study
-- Nandan Pathak (AE)

2. ICT -1 ICT -2 G-3 G-4 G-5
200 MW
160 MVAR
160 MW
135
MVAR
200 MW
160 MVAR
160 MW
135
MVAR
160 MW
140
MVAR
LOAD LOAD
220 kV
Girwali Bus
220 kV
Parli Bus

3. ~
GENERATION
870 MW
730 MVAR
LOAD:
A ) GENERATORS:
a) High MVAR drawl
b) High excitation current
B) ICT:
a) Overloading due to MVAR
b) Low voltage on 220 kV bus ( 200 kV)

4. C) LOAD:
11 kV side:
a) Overload tripping
b) Very low voltages
c) Conductor snapping
d) Local load shedding
440 V side:
a) Failure of transformers
b) Conductor snapping

5. A)High seasonal load especially agriculture
during October to March
B) Failure of reactive compensation

6. A)Identification of areas
a) Beed district
b) Solapur district
c) Nanded district
d) Pabhani district
e) Latur district

7. A)Identification of radial feeders
220 kV
Girwali Bus
220 kV Nanded
160 MW 100 MVAR
220 kV Parbhani
100 MW 80 MVAR 132 kV
Parli Bus
132kV Beed
80 MW 60 MVAR
~ ~
132 kV Latur -1
90 MW 75 MVAR
132 kV Latur -2
60 MW 45 MVAR
132 kV
Girwali Bus
On similar lines loaded 11 & 33 feeders were identified.

8. I) Reactive power compensation available :
i. Substation ----- 164 MVAR
ii. Switched capacitors on 11kV – 240 MVAR (0.6 X405)
II) Focus Area – 11 kV , 0.6 MVAR capacitors
a. Repairs in a central laboratory
b. On site replacement, checking, modification, training

9. Modifications adopted for
optimum compensation
 1. Cell rating 0.66 Mvar at 12 kV
 2. De-rating at Low Voltage2. De-rating at Low Voltage
 3.3. ModificationModification
 A. Fixed capacitorsA. Fixed capacitors
 B. Addition to basic schemeB. Addition to basic scheme

12.  4. On site demonstrations
 5. Team visit – Nasik , Pune (R ),
Kolhapur, Sangli,Parbhani

13.  1. Reduction in overload tripping of 11 kV &
33 kV feeders.
 2. Reduction in blowing of HG fuses at 33/11
kV transformers.
 3. Reduction in conductor snapping.
 4. Improvement in voltage profiles
 LTLT 105 Volts to 190 volts105 Volts to 190 volts
 11kV11kV 7.6 kV to 9.8 kV7.6 kV to 9.8 kV

14. ICT -1 ICT -2 G-3 G-4 G-5
250 MW (200)
100 MVAR(160)
200 MW(160)
60 MVAR(135)250 MW(200)
100MVAR(160
)
200 MW
60 MVAR
195 MW(150)
80 MVAR(140)
LOAD LOAD
220 kV
Girwali Bus
220 kV
Parli Bus

15. ~
GENERATION
1095 MW (870)
400 MVAR (730)
LOAD:
Voltage changes:
220 kV 215 kV (200 kV)
132 kV 125 kV (106 kV)
33 kV 31 kV (27 kV)

16. Radial load changes
132 kV
Parli Bus
132kV Beed
95 MW 30 MVAR
(80 MW 60 MVAR)
~ ~
132 kV Latur –1
105 MW 40 MVAR
(90 MW 75 MVAR)
132 kV Latur –2
70 MW 30 MVAR
(60 MW 45 MVAR)
132 kV
Girwali
Bus

17. MONTH KWH 1998 KWH 1999 KWH 2000 KWH 2001
January 791500 1101100 1014800 401700
February 545000 938100 699100 239400
March 667900 819800 663300* 262200
April 539400 790900 87400* 183400
May 512000 473200 -* 275400
June 164400* 459800 167700* 43800**
July 313900 1170300♣ 442100
August 310400 948000♣ 490900
September 330600 630400 342700
October 500300 706100 350100
November 530400 854700 626000
December 307300* 1104100 542000
•---Load shifted to another feeder ♣--- Load of other feeder taken on this feeder
•** --- kWh meter stopped due to leading PF
Note:
0.6 MVAR capacitor bank recommissioned at village Pandharee on Dt.28.11.2000
0.6 MVAR capacitor bank added at same location on Dt.4.12.2000
New 0.6 MVAR capacitor bank commissioned at Pokharni Phata on Dt.8.12.2000
KWH recorded on 11kV Matkuli feeder from 132 / 11 kV T/F at 132 kV Ashti
substation

18. 0
200000
400000
600000
800000
1000000
1200000
JanuaryFebruary
March
April
May
June
July
August
Septem
berOctoberNovem
berDecem
ber
1998
1999
2000
2001

19. Month Forecasted Energy sent
out (kWH)
Actual Energy sent out
(kWH)
Savings
(kWH)
Remark
Dec 2000 689997 542000 147997 21.45 %
Jan 2001 624172 401700 222472 35.60 %
Feb 2001 520905 239400 281505 54.00 %
Mar 2001 562029 265200 296829 52.00 %
Apr 2001 511766 183400 328366 64.10 %
May 2001 451451 275400 176051 39.00 %
Total 3360320 1907100 1453220 43.24 %
Energy savings on 11 kV Matkuli feeder

20. 1.System requires high order reactive compensation.
2.Use of fixed value non switched/seasonal manual switched
capacitors is economical.
3. Complementary switching for optimum compensation.
4. Dedicated setup for overall line loss reduction.