A Novel Approach for Optimal Location and Sizing of Multi-type Facts Devices for Multi-objective Voltage Stability Optimization Using Hybrid Pso-gsa Algorithm

A new modified severity function is proposed, based on which the N-2 line contingencies in the IEEE 30 bus system are analyzed and ranked. FACTS devices like Static VAR Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) are used for achieving reduction in under voltage severity value and reduction in voltage deviation from the nominal value. A hybrid combination of two heuristic algorithms, Particle Swarm Optimization (PSO) and Gravitational Search Algorithm (GSA) are used, which combines the exploiting and exploring features of the two algorithms respectively, to determine the objective of optimal placement and optimal size of the FACTS devices. A tradeoff analysis of the choice of the SVC and TCSC devices, their optimal MVAr requirement in view of the system stability and system severity has been performed. The test results of the proposed work are compared with the conventional PSO algorithm. The computational time substantiate the feasibility of the proposed method to application in real time environment for voltage security assessment and enhancement. KEYWORDSN-2 contingency ranking, Voltage stability, Modified Severity Index, Hybrid PSO-GSA, SVC, TCSC, Optimal Location and sizing.