Optimal Placement and Sizing of Capacitor Banks Based on Voltage Profile and Losses in Radial Distribution System and Effects of DG Addition

By Prashanta Sarkar (11PEE010)

M.Tech,Power System

Supervisors Saheli Ray & Dr. Subhadeep Bhattacharjee

 

 

DEPARTMENT OF ELECTRICAL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY AGARTALA

MAY- 2013

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Outline of Presentation

Introduction.Test System.Problem formulation. Result and discussion. Conclusion. Future Scope.PublicationReferences.

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IntroductionReactive power compensation.

Optimal capacitor placement(OCP) using GA

Compensation using capacitor banks & ….Distributed Generation(DG)

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Test System

Load Loss Load-MW 12.817 Loss-KW 393

Load-MVAR 6.6 Loss-KVAR 806.

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PROBLEM FORMULATION

Two goals for determining the formula that are used in point of start 1. Loss Reductions.

2. Voltage profile Improvement.  

The main constraints in the optimization process in the proposed methodology are:

1. Loss with OCP ≤ Loss without OCP 2. V bus min ≤ V bus ≤ V bus max

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The objective function, with composing constraints and goals, is determined as following:

k1, k2 , k3 : Emphasis or penalty factors

n : Number of Buses

m : Number of Branches.

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21

31

10, % %

0,

,

n

iwithOCP iwithoutOCPi

m

jwithoutOCP jwithOCPj

m

jwithoutOCP jwithOCPj

MaxF K Max Voltage Voltagen

K Max P P

K Max o Q Q

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Optimal capacitor placement using GA in ETAP Simulating the system in ETAP 38 no. of capacitor can be placed for OCP

Min voltage (%)

Min voltage(%) before OCP Min voltage(%) after OCP

93.01 96.41

Max voltage (%)

Max voltage(%) before OCP Max voltage(%) after OCP

98.45 100.06

Power losses in

…….. KW

Power losses in KW before OCP

Power losses in KW after OCP

393 325

Capacitor cost($)----------------- 1260000.00

Cost of real power loss

($)

Cost of real power loss before OCP

Cost of real power loss after OCP

1205 1009

Benefit($/year)Benefit($/year) after OCP Benefit($/year) after OCP

----------------------- 118981.00

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Accumulative profit of the total planning period gives a profit of 1105820.00 $.

Voltage profile between optimal capacitor placements and uncompensated system

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MANUAL PLACEMENT OF CAPACITOR

Urge for manual capacitor placementPlacing of 2 capacitor banks at bus no 10, 58 of 700,1400 KVAR rating

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Placing of 3 capacitor banks at bus no 16, 52 & 58 of 650,800 & 600 KVAR

Placing of 4 capacitor banks at bus no 10,16, 52 & 58 of 500,200,700 & 600 KVAR

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Placing of 5 capacitor banks at bus no 10,16, 47 ,52 & 58 of 550,100,550,450 & 300 KVAR

Voltage profile between all the cases of capacitor banks placements and uncompensated system

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Comparison between multiple capacitor bank placements

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Element2 capacitor

bank3 capacitor bank 4 capacitor bank 5 capacitor bank Un

Compensatedsystem

Minvoltage (%)

95.01 95.00 95.00 95.00 93.01

Maxvoltage (%)

98.87 98.85 98.85 98.84 98.45

Active Power losses (KW)

366 KW 367 KW 364 KW 364 KW 393 KW

Reactive Power losses (KVAR)

754 KVAR 747 KVAR 743 KVAR 741 KVAR 806 KVAR

COMPENSATION USING CAPACITOR BANKS & DG

Placing of 5 capacitor banks at bus no 10,16, 47 ,52 & 58 of 550,100,550,450 & 300 KVAR & 3 DG at bus no. 21,42 & 56 of 0.5 MW Rating

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Placing of 5 capacitor banks at bus no 10,16, 47 ,52 & 58 of 550,100,550,450 & 300 KVAR & 3 DG at bus no. 21,42 & 56 of 1 MW

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Voltage (%) profile improvement curve with DG rating 0.5 MW & 1 MW

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Voltage & Power Loss comparisons with Capacitor Banks & DG

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Element

5 capacitor bank & 3 DG of 0.5 MW rating

5 capacitor bank & 3 DG of 1 MW rating

Min voltage(%) 96.09 97.04

Max voltage(%) 99.10 99.34

Active Power losses (KW) 261 KW 197 KW

Reactive Power losses (KVAR) 570 KVAR 465 KVAR

Conclusion

The study of OCP in 60 bus radial distribution system is helpful in long term investment.

Manual placement of capacitor may result lower investment .

The compensation of reactive power is limited to some extent, but for good solution of optimization both active and reactive power compensation is essential.

DG in the system may resolve many other issues (power islanding, stability).

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Future scope

Implementing a switching technology for exact

combination of DG and capacitor bank.

Soft computing technique to determine DG & capacitor …ratings.

Selection of DG technology.

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Publication

Prashanta Sarkar, Soumesh Chatterjee, Saheli Ray, Optimal Placement of Capacitor for Voltage Support and Minimizing Overall Cost in Radial Distribution System, International Journal of Computer Applications (0975 – 8887) Volume 65– No.2, March 2013

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Reference [1] An Introduction to Reactive Power,The National Grid Company plc, Market ,Development: October 2001,pp.1-3. [2] Pravin Chopade and Dr. Marwan Bikdash “Minimizing Cost and Power loss by Optimal Placement of Capacitor using ETAP”,978-1- 4244 - 9593-1, 2011 … IEEE,pp.24-29.

[3] H. Omidi, B. Mozafari, A. Parastar, M.A. Khaburi, “Voltage Stability Margin Improvement using Shunt Capacitors and Active and Reactive Power Management”,978-1-4244-4509-7/09, pp 1 - 5.

[4] Narain G. Hingoranl, Laszlo Gyugyi, Understanding Facts, 0-7803-3455- 8,Chapter 5, pp.135-205. [5] Aoki k, Ichimori T, Kanezashi M. (1985), “Normal state optimal load allocation in distribution systems”, IEEE Trans Power Delivery, Volume 3(issue 1), pp. 147-155. [6] ETAP 7.0.0 Product Overview – Power System Enterprise Solution, Operation Technology Inc.

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[7] Soumesh Chatterjee, Sharmistha Sharma, “Advantage of DG To Mitigate Voltage Collapse over Facts Devices”, International Journal of Engineering Research and Applications; Vol. 2, Issue6, November- December 2012, pp.1253-1257.

[8] H. Lee Willis, “Analytical methods and rules of thumb for modeling DG-distribution interaction”, 0-7803-6420-1/00,IEEE,pp. 1643-1644.

[9] IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems , IEEE Std. 519-1992, 1993.

[10] Y. Alinejad - Beromi, M. Sedighizadeh, M. R. Bayat and M. E. Khodayar,“Using genetic algoritm for distributed generation allocation to reduce losses and improve voltage profile”, UPEC 2007 – 954.pp. 1-6.

[11] R. Srinivasa Rao and S. V. L. Narasimham, “Optimal Capacitor Placement in a Radial Distribution System using Plant Growth Simulation Algorithm”,World Academy of Science, Engineering and Technology 21 2008.pp 715-722.

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[12] Gunnet Kour, Dr. G.S Brar & Dr. Jaswanti , “Optimal placement of static var compensators in power system”, IJEST, vol. 4 No. 05 May 2012, pp. 2030-2036

[13]Mohammad Hadi Molaei Ardakani, Mohammad Zarei Mahmud Abadi, Mohammad Hossein Zabihi Mahmud Abadi and Azim khodadadi,“Distributed Generation and Capacitor Banks Placement in Order to Achieve the Optimal Real Power losses using GA”, IJCST Vol. 2, Issue 4, Oct . - Dec. 2011,pp. 400-404.

 

[14] B.F. Wollenberg, “Transmission system reactive power compensation”, IEEE Power Engineering Society Winter Meeting, 27-31 Jan. 2002, vol.1, pp. 507 – 508.

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Thank You

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