Optimal Utilization of IPFC for Congestion Management Using Disparity Line Utilization Factor and Cuckoo Search Algorithm Akanksha Mishra, G. V. Nagesh Kumar * Department of EEE, GITAM Institute of Technology, GITAM University, Visakhapatnam, India. * Corresponding author. Tel.: 9000573759; email: drgvnk14@gmail.com Manuscript submitted May 21, 2015; accepted December 8, 2015. doi: 10.17706/ijcee.2015.7.6.370-386 Abstract: Recently, due to adoption of power reforms there is a marked increase of contracted power that flows in the transmission line and the spontaneous power exchanges leading to complex power transmission congestion problems. Appearance of FACTS devices specifically IPFC has opened up new opportunities to overcome the congestion problem by increasing the system loadability. Proper placement and tuning of IPFC in this respect is very important for maximum utilization of its benefits. This paper proposes a Disparity Line Utilization Factor (DLUF) for the optimal placement of IPFC to control the congestion in transmission lines. DLUF determines the difference between the percentage MVA utilization of each line connected to the same bus. The IPFC is placed in the lines with maximum DLUF. The multi objective function consisting of the reduction of active power loss, minimization of total voltage deviations, and minimization of security margin with the usage of minimum value of installed IPFC is considered for the optimal tuning of IPFC using Cuckoo Search. The proposed method is implemented for IEEE-30 bus test system under different loading conditions and the results are presented and analyzed to ascertain the effectiveness for the reduction of congestion. Key words: Congestion, cuckoo search algorithm, interline power flow controller, line utilization factor, optimal placement, optimal tuning. 1. Introduction Lately, deregulated electric power industries have changed the way of operation, structure, ownership and management of the utilities. The issue of transmission congestion is more prominent in deregulated and competitive markets, and it needs an appropriate management strategy [1]. In the new competitive electric market, it is now mandatory for the electric utilities to operate such that it makes better utilization of the existing transmission facilities in conjunction with maintaining the security, stability and reliability of the supplied power [2]. Therefore the use of FACTS devices has become inevitable. Economic constraints put a limitation on the number of FACTS devices that can be used. Hence, optimal placement and tuning of FACTS devices in power system is mandatory. Several authors [1]-[3] have suggested different methods for congestion management. Minguez et al. [4] have propose a method of optimal placement of IPFC such that the load margin is maximized. Mandala et al. [5], proposed a method to determine the optimal location of thyristor controlled series compensators (TCSCs) for Congestion management. The optimal location is determined based on the real power International Journal of Computer and Electrical Engineering 370 Volume 7, Number 6, December 2015