Particle swarm optimization based reactive power planning for line stability improvement

Now a day the transmission lines are operated under the heavily stressed condition, hence there is risk of the consequent voltage instability. This paper proposes a particle swarm optimization method for solving optimal reactive power planning (ORPP) problem using Thyristor Controlled Series Compensator (TCSC). The proposed PSO have been applied for the ORPP problem to improve the system line stability by minimizing the line stability index (Lmn) and to minimize the investment cost of TCSC devices, satisfying various constraints of power flow equation, generator voltage limits, TCSC´s reactance limits, transformer tap changer limits, and transmission line limits. The Line Stability Index (Lmn) are used to identify the stressed lines which will receive the FACTS devices (TCSC). The proposed method has been examined and tested on the Algerian electric power system 114-bus and the obtained results are compared with two other methods, namely, Genetic Algorithm (GA), interior point method (IPM). The result comparisons demonstrate the potential of the proposed approach and show its effectiveness and robustness to solve the ORPP problem. Therefore, the proposed PSO can be a promising solution method for dealing the ORPP problem.