MOEP based design of PSS and FACTS for transient stability improvement under symmetrical and unsymmetrical fault conditions

A Multi-Objective Evolutionary Programming (MOEP) based approach to Static Synchronous Series Compensator (SSSC) has been presented in this paper. The multi-objective optimization problem is formulated to the design problem of SSSC, in which the system transient stability is improved by minimizing several system behavior measure criterions. Then, MOEP is used to design the Flexible Alternating Current Transmission Systems (FACTS) controller parameters. The usefulness of the proposed control scheme was demonstrated with a three machine nine bus power system under different fault conditions. The nonlinear simulation results show the effectiveness of the proposed method to damp out the rotor oscillations and enhance greatly the system stability over a wide range of system configurations. By minimizing the time-domain based multi objective function, in which the deviations in the oscillatory rotor angle, rotor speed and accelerating power of the generator are involved, stability performance of the system is greatly improved. The proposed method is an effective one for the tuning of multi-controllers in large power systems.