This paper proposes a sensitivity based approach for congestion management in deregulated environment. The congestion management problem is formulated to minimize the cost of re-dispatching the participating generators subject to operational and security constraints and considering the presence of Bilateral/Multilateral market contracts. The strategy employed is different from earlier approaches in respect that 1) sensitivities of line flows with respect to bus injections are obtained from full AC power flow, 2) the transmission losses are incorporated by real and reactive load flow equations, and 3) the incremental / decremental bids of participating generators are obtained by linearizing their quadratic cost curve around the initial point of operation. The proposed formulation is solved with sequential quadratic programming in MATLAB environment. The effectiveness of the method is tested on standard IEEE 30-Bus system and results obtained are compared with commonly used DC sensitivity based approach.
Index Terms - Congestion Management, Deregulated Environment, Rescheduling, Sensitivity
[...] Singh, “Optimal Rescheduling of Generators for Congestion Management Based on Particle Swarm Optimization,” IEEE Trans. Power Syst., vol no.4, pp.1560-1569, Nov J. Peschon, d.S. Piercy, W.F. Tinney, and O.J. Tveit, “Sensitivity in Power Systems,” IEEE Trans. Power App. Syst., vol.PAS-87, no pp. 1687-1695, Aug D.K. Khatod, V. Pant and J. Sharma, Novel Approach for Sensitivity Calculations in the Radial Distribution System,” IEEE Trans. Power Delivery, vol no pp. 2048-2057, Oct S.H. Song, J.U. Lim, and S. Moon, “Installation and Operation of FACTS devices for Enhancing Steady State Security,” Electric Power Syst. [...]
[...] i = ith bus voltage phasor V j = V j j = j bus voltage phasor th decision variables for congestion management problem; increment in real power generations, decrement in real power generations, increment in reactive power generations, decrement in reactive power generations, bus voltage magnitudes and bus voltage angles vectors with individual entries as ively. up down up down , , , , Vi , δ i respect- yij = gij + jbij = series admittance of line i-j Yij ∠θij = i-jth elements of bus admittance matrix sh 0 bij Pij Qij = initial real and reactive line flow over i-jth line, = half line charging susceptance of line i-j 2 respectively δ-r = vector of bus voltage angles other than slack bus Pgi , Qgi = initial real and reactive power generated by ith V-r = vector of bus voltage magnitudes other than slack generator bus, respectively bus Pdi , Qdi = respectively real and reactive power demand at ith bus, minimum real power min min min Pgi , Pramp , Qgi , Vi min = generation, real power ramp, reactive power generation, and bus voltage magnitude limits at ith bus, respectively max max max Pgi , Pramp , Qgi , Vi max = maximum real power generation, real power ramp, reactive power generation, and bus voltage magnitude limits at ith bus, respectively BC = bilateral contract matrix with individual entry as bcij MC k = kth multilateral contract matrix with individual k entry as mcij c b m S gi , S gi , S gi = complex power generation at bus i due to bilateral, multilateral and overall contracts b m c Sdi , Sdi , Sdi = complex power demand at bus i due to bilateral, multilateral and overall contracts ith the prevailing deregulated environment in electricity sector over the globe, a number of generation companies, distribution companies and transmission owners have emerged into the picture and replaced the vertically integrated structure of electric utilities. [...]
[...] Singh, Zonal Congestion Management Approach Using Real and Reactive Power Rescheduling,” IEEE Trans. Power Syst., vol no pp. 554-562, Feb C.Z. Karatekin and C. Uçak, “Sensitivity Analysis Based on Transmission Line Susceptance for Congestion Management,” Electric Power Syst. Res., vol pp. 1485-1493, Mar 2008. F.D. Galiana, M. Phelan, “Allocation of Transmission Losses to Bilateral Contracts in a Competitive Environment”, IEEE Trans. Power Syst., Vol No pp. 143-150, Feb X. BIOGRAPHIES Kanwardeep Singh (S' 08) received his Bachelor's Degree (in Electrical Engineering) from Punjabi University, Patiala and Master's Degree (in Power Systems) from NIT, Kurukshetra, in 1996 and 2000 respectively. [...]
[...] CONCLUSION An ac sensitivity based approach has been followed in this paper to determine real and reactive power rescheduling of participating generators for congestion management. The congestion management problem is formulated considering the deregulated environment to minimize incremental/ decremental cost bids of participating generators subject to operational and security constraints. Participation of all the system generators guarantees the optimal solution of congestion management problem. The modeling of bilateral/ multilateral market contracts is also included. The incremental/ decremental cost bids of participating generators are obtained by linearizing their input-output curve around the Y. [...]
[...] Wangensteen, “Transmission management in the deregulated environment,” Proc. IEEE, vol no pp. 170-195, Feb A. Kumar, S.C. Srivastava, and S.N. Singh, “Congestion Management in Competitive Power Market: A Bibliographical Survey,” Electric Power Syst. Res., vol pp. 153-164, July 2005. E. Bompard, P. Correia, G. Gross, and M. Amelin, “CongestionManagement Schemes: A Comparative Analysis Under a Unified Framework,” IEEE Trans. Power Syst., vol.18, no pp. 346-352, Feb H. Singh, S. Hao, and A. Papalexopoulos, “Transmission Congestion Management in Competitive Electricity Markets,” IEEE Trans. [...]
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