International Journal of Automation and Power Engineering (IJAPE) Volume 3 Issue 3 May 2014 DOI: 10.14355/ijape.2014.0303.02
www.ijape.org
Congestion Management Using Real and Reactive Power Rescheduling Based on Big Bang-Big Crunch Optimization Algorithm FarzadVazinram*1, MajidGandomkar*2, Mehdi BayatMokhtari*3 Department of Electrical Engineering, Islamic Azad University of Saveh, Saveh, Iran
*
vazinram@aol.com; 2gandomkar_m@yahoo.com; 3mbayatm2013@rocketmail.com
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Received 29 October 2013; Accepted 1 December 2013; Published 13 May 2014 Š 2014 Science and Engineering Publishing Company
Abstract With appearance of deregulated electricity markets, line congestions in transmission systems is considered as critical problem for power system which may prevent dispatching all of the contracted power transactions. Many studies have been carried out to express techniques for congestion management (CM). In this paper real and reactive power rescheduling of generators approach is utilized. This method includes two steps. First one is optimum selection of generators on the basis of sensitivities of generator to power flow on congested line/lines. Next step is optimal rescheduling of generators and identification of capacitors required to provide real and reactive power support for CM. Optimization process in this paper is carried out using big bang-big crunch (BB-BC) algorithm which is improved by particle swarm optimization (PSO) method as hybrid BB-BC (HBB-BC) optimization for the first time. Effectiveness of proposed method has been tested on IEEE 30-bus system, the 39-bus New England system, and 75-bus Indian system and compared with the other proposed methodologies. Keywords Big Bang-Big Crunch; Congestion Management; Generator Sensitivity; Heuristic Optimization; Optimal Rescheduling; Reactive Power Support
Introduction With restructuring the electric power industry and the presence of the competitive electricity market, equality and balance of generating and consuming is one of the important issues. For secure and stable performing of power systems, transmission system must be operated the highest efficiency. However, various factors like thermal, voltage, and stability limitations can limit the capacity of transmission lines to specific value. When the demand and generation change in manner that
transmission system have to transmit more than whose permissible limitation and the values exceed owing to one or more mentioned limitation, it is called that system is congested (R.D. Christie, 2000). This issue, in continuous form, can conduce to the critical consequences like increasing the prices which can have direct effect on consumers. Because of this reason, congestion problems should be managed as soon as possible. Before the deregulation, CM concept had included control of output power of generators to keep the security and stability of system with minimum cost. With the presence of the restructuring of electric power systems, CM is combined not only with the power system but also with the competitive power market. Therefore, in congestion occurring and unbalanced situations, the independent system operator (ISO) attempts to increase the efficiency of market to keep the security and stability of system. So, ISO must make some specific and solid rules to prevent misuse of entities from the congestion occurred between two locations of grid (Ch. Venkaiah, 2011). Because the recent mentioned reasons, many researches are carried out for CM till now. To minimize the congestion costs of bilateral and pool models, active power re-dispatching of generators is considered (H. Singh, 1998)and re-dispatching based congestion removal method with contingency constrained limits is mentioned in (M.I. Alomoush, 2000). In the deregulated environment, distribution companies (DISCOs) and generation companies (GENCOs) are scheduling their transactions before their due date. At this moment, some transmission lines can be congested while transactions are
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