International Journal of Electrical and Computer Engineering (IJECE) Vol. 9, No. 2, April 2019, pp. 875~883 ISSN: 2088-8708, DOI: 10.11591/ijece.v9i2.pp875-883 875 Journal homepage: http://iaescore.com/journals/index.php/IJECE Optimal power flow based congestion management using enhanced genetic algorithms Seong-Cheol Kim, Surender Reddy Salkut Department of Railroad and Electrical Engineering, Woosong University, Republic of Korea Article Info ABSTRACT Article history: Received May 12, 2018 Revised Nov 10, 2018 Accepted Dec 23, 2018 Congestion management (CM) in the deregulated power systems is germane and of central importance to the power industry. In this paper, an optimal power flow (OPF) based CM approach is proposed whose objective is to minimize the absolute MW of rescheduling. The proposed optimization problem is solved with the objectives of total generation cost minimization and the total congestion cost minimization. In the centralized market clearing model, the sellers (i.e., the competitive generators) submit their incremental and decremental bid prices in a real-time balancing market. These can then be incorporated in the OPF problem to yield the incremental/ decremental change in the generator outputs. In the bilateral market model, every transaction contract will include a compensation price that the buyer- seller pair is willing to accept for its transaction to be curtailed. The modeling of bilateral transactions are equivalent to the modifying the power injections at seller and buyer buses. The proposed CM approach is solved by using the evolutionary based Enhanced Genetic Algorithms (EGA). IEEE 30 bus system is considered to show the effectiveness of proposed CM approach. Keywords: Bilateral transactions Congestion cost Congestion management Evolutionary algorithms Multi-lateral transactions Optimal power flow Copyright © 2019 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Surender Reddy Salkuti, Department of Railroad and Electrical Engineering, Woosong University, Jayan-dong, Dong-gu, Daejeon, Republic of Korea 300718. Email: surender@wsu.ac.kr NOMENCLATURE Incremental cost coefficients of i th generating unit. Decremental cost coefficients of i th generating unit.  ,  Rescheduled power outputs from preferred schedule in positive or negative side of i th generator. P Gi Amount of power injections added at i th seller bus.      Lower and upper bounds for active power outputs of i th generator. P Dj Amount of power taken at j th buyer bus. S L max Line flow capacity/thermal limit of L th transmission line. Q Gi , Q Di Reactive power generation and demand at i th bus.      Lower and upper bounds for reactive power outputs of i th generating unit. V i min , V i max Lower and upper bounds of voltages at i th bus. 1. INTRODUCTION With the increasing demand for electric power all around the globe, electric utilities have been forced to meet the same by increasing their power generation. However, the electric power that can be transmitted between two locations on a transmission network is limited by several transfer limits such as