Optimal location and size of TCSC for voltage stability enhancement using PSO-TVAC

Maintaining Voltage stability is one of the most important issues in electrical power systems operation. Voltage instability is a major problem that occurs due to deficit of reactive power at load buses in power system under increased loading or during contingencies. Voltage stability of a power system can be improved using Flexible AC transmission systems (FACTS) controllers like thyristor controlled series compensator (TCSC), static var compensator etc. Like other FACTS controllers, TCSC is a costly device involving huge investment. Hence, it is important to find its optimal location and its size, in order to improve voltage stability in a power system. In this paper, Particle Swarm Optimization with time varying acceleration coefficients (PSO-TVAC) has been proposed to find out the optimal location and size of TCSC for voltage stability improvement of a power system. This paper considers line stability index (LSI) for determining the optimal location of TCSC. Line stability index provides information about the stability condition of a power system and its proximity to voltage collapse. The effectiveness of proposed method has been demonstrated on a standard IEEE 30-bus system.