impact of capacitor bank and oltc operation on energy ...cipech.org/papers16/109.pdfbeen studied on...

Impact of Capacitor Bank and OLTC Operation on Energy Savings

Supriya Awasthi Md. Imran Sarfaraz Nawaz Electrical Engineering Department Department of Electrical Engineering Department of Electrical Engineering Atharwa College of Engineering SKIT M&G, Jaipur, India SKIT M&G, Jaipur, India Mumbai, India email: [email protected]

Abstract— In this paper the impact of load side reactive power management in the power distribution system on energy saving and other technical parameters like Voltage profile and power transmission elements loading has been analyzed. MiPower system study package is used to carry out the analysis. In this paper, the impact of shunt capacitor bank has been studied on practical 132/33 kV Chambal GSS of Jaipur city. This paper presents how shunt capacitor banks which are already installed can work effectively without installing new devices for reactive power control.

Keywords— Mipower; Load flow study; OLTC; Grid substation (GSS); Low Tension (LT); High Tension (HT; Per Unit (PU); Rajasthan Rajya Vidyut Prasaran Nigam Limited (RRVPNL).

I. INTRODUCTION The electrical energy is normally generated at the

power stations delivered to the ultimate consumers through a network of transmission & distribution. In this paper controlling the transformation ratio of power transformers has been utilized to optimize system performance and to maintain the voltages acceptable at the service point [1]. The voltage at substation needs to be kept at high enough values as the power demand increases. This typically increases load consumption [2]. There are many control methods used to improve the performance of the system to obtain the optimal mode of operation of the electrical system. Voltage instability has long been categorized as a phenomenon that could be investigated using load flow methods [3˗8]. By undertaking installation of suitable capacity capacitor banks at required locations in transmission and distribution network and also understanding use of installed shunt capacitor banks and OLTC (on load tap changers), it is possible to bring down the technical losses in the transmission and distribution sector. The improvement of the power factor has a beneficial effect on the system voltage stability [9]. Shunt capacitor banks are widely used to achieve power and energy loss reductions as well as voltage & pf (power factor) correction [10] [11]. This paper contains case study

of benefits of capacitor banks on distribution system also the impacts of 220 kV & 132kV transformers OLTC on 132 kV Chambal distribution system of Jaipur city circle & technical impacts of operation of shunt capacitors and OLTC at different conditions.

II. CASE STUDY OF CHAMBAL GSS AT JAIPUR CITY CIRCLE

The Heerapura 220/132 kV CHAMBAL RRVPNL is ideally located at the HawaSadak, Sodala, Jaipur & was established in 1962, feeds to two ring feeder of 33/11 kV and one 33/11 kV radial feeder for supplying electricity to consumers.

Chitrakoot & Nirman-Nagar s/s are having 2*5 MVA transformers.

Mansarovar–II s/s is having 1*5 + 1*8 MVA transformer.

Shrigopalpura Nagar & Lalkothi s/s are having 2*8 MVA transformer.

Bias Godam s/s is having 1*8 MVA transformer.

Hatwara s/s having 2*5 MVA transformer.

2*5 MVA transformers are connected to radial feeder.

Some case studies of 132/33 kV Chambal GSS are analyzed.

1) Swing Bus Voltage: 125.40 kV with Transformer Tap:09 & Capacitor Bank position: Off

2) Swing Bus Voltage: 125.40 kV with Transformer Tap:09:& Capacitor Bank position: On

3) Swing Bus Voltage: 125.40 kV with Transformer Tap 03 & Capacitor Bank position: On

4) Swing Bus Voltage: 128.96 kV with Transformer Tap: 09 & Capacitor Bank position: On

System considered for study is shown in Mipower SimulationSheet“Fig.1”.

Impact of Capacitor Bank and OLTC Operationon Energy Savings

Supriya AwasthiElectrical Engineering DepartmentAtharwa College of Engineering

Mumbai, IndiaE-mail: [email protected]

Md. ImranDepartment of Electrical Engineering

SKIT M&G, Jaipur, India

Sarfaraz NawazDepartment of Electrical Engineering

SKIT M&G, Jaipur, India

978-1-4673-9080-4/16/$31.00 ©2016 IEEE

110 ♦ Innovative Applications of Computational Intelligence on Power, Energy and Controls with their Impact on Humanity (CIPECH-16)

Fig.1. (132/33 Kv Chambal Substation, Mipower Simulation Result)

Impact of Capacitor Bank and OLTC Operation on Energy Savings ♦ 111

TABLE I. IMPACT ON REACTIVE POWER FLOW OF RING FEEDER-1

TABLE II. IMPACT ON LOADING OF TRANSFORMERS AND TRANSMISSION LINES OF RING FEEDER-1

S. No.

Technical Parameters Case-1: (Without Compensation) Tap:09

Swing Bus Voltage: 125.40 kV

Case-2: (With Compensation)

Tap:09 Swing Bus Voltage: 125.40 kV





1 Load Reactive Power Demand

19.14 MVAR 19.14 MVAR 19.14 MVAR 19.14 MVAR

2 Reactive Power Fed By Capacitor Banks

0 MVAR 10.64 MVAR 11.87 MVAR 11.52 MVAR

3 Chitrakoot 33kV Incomer 10.17 MVAR 4.69 MVAR 4.01 MVAR 4.20 MVAR

4 Srigopalpuranagar 33kv outgoing


5 132/33kV Transformer Reactive Power Losses


6 33/11kV Transformer Reactive Power Losses


7 Transformer Primary side &

132 kV Incomer Feeder


8 132kV Transmission Line 0.29 MVAR 0.10 MVAR 0.08 MVAR 0.05 MVAR

9 132kV Transformer 39.27 MVAR 17.58 MVAR 15.06 MVAR 15.72 MVAR

10 33kV Transmission Lines 3.27 MVAR 2.01 MVAR 1.74 MVAR 1.8 MVAR

S. No

Power Distribution Equipment/ Line

Case-1: (Without Compensation)

Tap:09 Swing Bus

Voltage: 125.40 kV

Case-2: (With

Compensation) Tap:09

Swing Bus Voltage: 125.40 kV


Tap:03 Swing Bus Voltage:

125.40 kV


Tap:09 Swing Bus Voltage:

128.96 kV

MW MVAR MVA MW MVAR MVA MW MVAR MVA MW MVAR MVA

1 132 kV S/C Line Loading 48.75 42.36 64.59 47.31 19.54 51.18 47.03 16.76 49.93 47.07 17.49 50.21

2 132/33kV Transformers Loading

48.62

33.27 62.50 47.28 17.58 50.44 46.96 15.06 49.31 47.05 15.72 49.60

3 33/11kV Chitrakoot S/S Transformer Loading

4.50 3.38 5.63 4.51 1.44 4.74 4.50 1.24 4.67 4.51 1.29 4.69

4 33/11kV Nirmannagar S/S Transformer Loading

4.51 3.39 5.64 4.52 1.61 4.80 4.50 1.40 4.71 4.51 1.45 4.74

5 33/11kV Mansarovar S/S Transformer Loading

5.26 3.96 6.59 5.27 1.69 5.54 5.25 1.42 5.44 5.27 1.49 5.47

6 33/11kV Durgapura S/S Transformer loading

4.51 3.39 5.64 4.52 1.63 4.80 4.50 1.42 4.72 4.51 1.48 4.75

7 33/11kV Srigopalpura Nagar S/S Transformer Loading

6.76 5.08 8.46 6.77 2.15 7.10 6.75 1.81 6.99 6.77 1.90 7.03

112 ♦ Innovative Applications of Computational Intelligence on Power, Energy and Controls with their Impact on Humanity (CIPECH-16)

TABLE III. IMPACT OF VOLTAGE PROFILE ON RING FEDER-1

MW, MVAR losses are reduced after switching

capacitor bank

MVA loading of transformers and pf of generators, transformers and transmission line improve due to proper operation of OLTC and shunt capacitor bank

Total losses in case-1 (when capacitor bank position ‘OFF’) = 3.994423 MW

Total losses in case–2 (when capacitor bank position ‘ON’ = 2.473133 MW

Total losses in case–3 (after switching capacitor bank, OLTC tap position reduced to improve voltage profile) = 2.170599 MW

Total losses in case–4 (after switching capacitor bank swing bus voltage goes high) = 2.236595 MW

Energy saving of whole system of case-1 compare to case-2: = 1.52129 * 8760 * 1000 = 13,326,500.4 kwh and Energy saving in terms of rupees = 53,306,001.6 *@ 4.0 rupees / kwh

Energy saving of whole system of case-2 compare to case-3:= 0.302534 * 8760 * 1000 = 2,650,197.84

kwh and Energy saving in terms of rupees = 10,600,791.36 *@ 4.0 rupees / kwh

Energy saving of whole system of case-2 compare to case-4: = 0.236538 * 8760 * 1000 = 2,072,072.88 kwh and Energy saving in terms of rupees = 8,288,291.52 *@ 4.0 rupees / kwh

III. CONCLUSION In this paper, impact of shunt capacitor bank has been studied on practical 132/33 kV Chambal GSS of Jaipur city circle. From simulation studies, it is seen that reactive power losses and line loading are reduced in case-3 as compared to case-1 and case-2, there are overall cost savings after switching of capacitor banks and OLTC. If 132 kV swing bus voltage approaches to nominal value from 125 kV to 129 kV as seen in case-4, losses are reduced as compared to case-2, by already installed capacitors without change in their capacity. As we have seen in case-4 where conditions are same as in case-2, suddenly swing bus voltage goes high, we get low reactive power losses and improve voltages at all buses which results in overall saving in energy without change in

S.

No

Technical Parameters Case-1:

(Without

Compensation) Tap:09

Swing Bus Voltage:

125.40 kV

Case-2:

(With Compensation)

Tap:09

Swing Bus Voltage:

125.40 kV

Case-3:

(With Compensation)

Tap:03

Swing Bus Voltage:

125.40 kV

Case-4:

(With Compensation)

Tap:09

Swing Bus Voltage:

128.96 kV

1 132kv Grid Voltage 125.40 kV

(0.955 PU)

125.40 kV

(0.955 PU)

125.40 kV

(0.955 PU)

128.96 kV

(0.955 PU)

2 132/33kV S/S 132kV Side Voltage 124.42 kV 124.79 kV 124.83 kV 128.40 kV

33kV Side Voltage 30.08 kV 30.70 kV 32.01 kV 31.66 kV

3 33/11kV Chitrakoot

S/S Transformer

HT Side Voltage 27.99 kV 29.22 kV 30.66 kV 30.28 kV

LT Side Voltage 9.19 kV 9.67 kV 10.16 kV 10.03 kV

4 33/11kV Nirmannagar

S/S Transformer



5 33/11kV Mansarovar

S/S Transformer



6 33/11kV Durgapura

S/S Transformer



7 33/11kV

Srigopalpuranagar S/S

Transformer



Impact of Capacitor Bank and OLTC Operation on Energy Savings ♦ 113

switching of capacitor and OLTC, showing result of efficient utilization of already installed capacitor banks.

REFERENCES [1] Abdallah R. Al-Zyoud and Jalal M. Abdallah, “Investigation of power

losses in Jordian Electrical power system” European Journal of Scientific Research ISSN 1450-216X , pp. 612-622,Vol.20 No. 3 (2008)

[2] Borka Miloˇsevic, Miroslav Begovic, “Capacitor Placement for Conservative Voltage Reduction on Distribution Feeders” IEEE Trans. On Power Delivery Vol. 19, July 2004, pp:1360-1367

[3] V.A. Venikov, V.A. Streov, V.I. Idelchick, V.I. Tarasov, Estimation of electric power system steady state stability in load flow calculation, IEEE Trans., Power Appar. Syst. PAS-94 (1975) 1034-1041.

[4] H.G. Kwanty, A.K. Pasrija, L.Y. Bahar, Loss of steady state stability and voltage collapse in electric power systems, Proceedings of Twenty fourth IEEE Conference Decision and Control, Fort Lauderdale, FL, 1985.

[5] D.L. Demarco, T.J. Overbye, An energy based security measure for assessing vulnerability to voltage collapse, IEEE Trans. Power Syst. 5 (1990) 419-429.

[6] R.A. Schlueter, I. Hu, T.Y. Guo, L.H. Fink, Dynamic/static voltage stability security criteria Proceedings of the Workshop Bulk Power System Voltage Phenomena: voltage stability and security, Deep Creek Lake, MD, USA, 1991, Energy and Control Consultants, Fairfax, VA, pp. 265-310.

[7] P.W. Sauer, M.A. Pai, Power system steady state stability and load flow Jacobian, IEEE Trans. Power Syst. 5 (1992) 1374-1383.

[8] C.K. Chanda, A. Chakraborti and S.Dey, “Development of Globale Voltage Security Indicator (VSI) and Role of SVC on it in Longitudinal Power Supply (Lps) System”, ELSEVIER (electrical power system research 68), pp.1-9, 2004

[9] P. Kundur, Power System Stability and Control. New York: McGraw-Hill, 1994

[10] Abdellatif Hamouda, Khaled Zehar, ”Improvement of the Power Transmission of Distribution Feeders by Fixed Capacitor Banks” Acta Polytechnica Hungarica Journal, Vol. 4, No. 2, 2007, pp:47-62

[11] Das, D., Nagi, H.S., Kothari and D.P., “Novel Method for Solving Radial Distribution Networks”, IEEE ProceedingsGeneration, Transmission and Distribution, pp. 291-298, 1994.

[1] Abdallah, R. Al-Zyoud and Abdallah, Jalal M. (2008), “Investigation of Power Losses in Jordian Electrical Power System”, European Journal of Scientific Research, Vol. 20(3), pp. 612–622, ISSN 1450-216X.

[2] Miloˇsevic, Borka and Begovic, Miroslav (2004), “Capacitor Placement for Conservative Voltage Reduction on Distribution Feeders”, IEEE Trans. On Power Delivery, Vol. 19, pp. 1360–1367, July 2004.

[3] Venikov, V.A., Streov, V.A., Idelchick, V.I., Tarasov, V.I. (1975), Estimation of Electric Power System Steady State Stability in Load Flow Calculation, IEEE Trans., Power Appar. Syst. PAS-94, pp. 1034–1041.

[4] Kwanty, H.G., Pasrija, A.K. and Bahar, L.Y. (1985), “Loss of Steady State Stability and Voltage Collapse in Electric Power Systems”, Proceedings of Twenty Fourth IEEE Conference Decision and Control, Fort Lauderdale, FL.

[5] Demarco, D.L. and Overbye, T.J. (1990), “An Energy based Security Measure for Assessing Vulnerability to Voltage Collapse, IEEE Trans. Power Syst. 5, pp. 419–429.

[6] Schlueter, R.A., Hu, I., Guo, T.Y. and Fink, L.H. (1991), “Dynamic/Static Voltage Stability Security Criteria Proceedings of the Workshop Bulk Power System Voltage Phenomena: Voltage Stability and Security, Deep Creek Lake, MD, USA, Energy and Control Consultants, Fairfax, VA, pp. 265–310.

[7] Sauer, P.W., Pai and M.A. (1992), “Power System Steady State Stability and Load Flow Jacobian”, IEEE Trans. Power Syst. 5, pp. 1374–1383.

[8] Chanda, C.K., Chakraborti, A. and Dey, S. (2004), “Development of Globale Voltage Security Indicator (VSI) and Role of SVC on it in Longitudinal Power Supply (LPS) System”, ELSEVIER (Electrical Power System Research 68), pp. 1–9.

[9] Kundur, P. (1994), “Power System Stability and Control”, New York: McGraw-Hill.

[10] Hamouda, Abdellatif and Zehar, Khaled (2007), “Improvement of the Power Transmission of Distribution Feeders by Fixed Capacitor Banks”, Acta Polytechnica Hungarica Journal, Vol. 4(2), pp. 47–62.

[11] Das, D., Nagi, H.S. and Kothari, D.P. (1994), “Novel Method for Solving Radial Distribution Networks”, IEEE Proceedings Generation, Transmission and Distribution, pp. 291–298.

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