Contingency-based optimal placement of Optimal Unified Power Flow Controller (OUPFC) in electrical energy transmission systems

This paper presents a new approach to determine the optimal location of an Optimal Unified Power Flow Controller (OUPFC) as an energy flow controller, under a single line contingency (N−1 contingency), to satisfy operational decisions. A contingency analysis is performed to detect and rank the faulted contingencies on the basis of their severity in electrical energy transmission systems. Minimization of the average loadability on all energy transmission lines is considered as the optimization objective function, while the network settings are set to minimize active power losses under pre-contingency conditions. The optimization problem is modeled using a Non-Linear Programming (NLP) framework and solved using the CONOPT solver. The proposed algorithm is implemented in MATLAB and GAMS software on the IEEE 14- and 30-bus test systems. The simulation results demonstrate the effectiveness of the proposed algorithm in enhancing energy system security under a single line contingency. Furthermore, the OUPFC is outperformed by a Unified Power Flow Controller (UPFC) in normal and contingency operations of electrical energy transmission systems, from technical and economical points of view.