Available transfer capability enhancement by using Particle Swarm Optimization algorithm based FACTS allocation

With the introduction of competition in the existing electrical market, it becomes necessary to increase the transmission capability of the power through the existing transmission lines. Low cost and feasibly better improvement can be achieved by using power electronics based devices in the system. Such devices are called Flexible Alternating Current Transmission system (FACTS) devices. Available Transfer Capability (ATC) is what exactly the allowable power limit to accommodate new users without violating the commitments of the existing users. Thus in the deregulated environment, this transfer capability is of more concern. ATC is a dependent factor on the system thermal, stability and voltage limits. With the introduction of FACTS devices, the line overloads, bus voltage problems are considerably brought down. Series compensators like Thyristor Controlled Series Capacitors (TCSC) are used for line flow controls. The ATC can be increased by adjusting the settings of the FACTS device (such as reactance, phase angles, reactive power injection) with respect to the system parameters. Particle Swarm Optimization (PSO) is an evolutionary technique that is used to solve multi objective optimization problem. In this paper PSO technique is used to estimate the feasible optimal setting [2] for the TCSC device to enhance the power transfer capability of the system to an appreciable limit.