Wide-area PSS design considering the time-delay of feedback signals

Aimed at the inter-area low frequency oscillation in interconnected power system, the Wide-area PSS considering the time-delay of feedback signals is designed in this paper. The Wide-area PSS is composed with two-channel, the inputs of one channel are local signals without time-delay, the inputs of the other one are global signals with time-delay. Then the state equations of the closed-loop system including Wide-area PSS is presented, the sufficient condition of the time-delay system stability analyzed by Lyapunov function with LMI approach. The Multi-objective Adaptive Particle Swarm Optimization Algorithm (MAPSO) is proposed to design the parameters of Wide-area PSS, which takes the time-delay stability and the control effect of the controller as the optimization objects. At last the Wide-area PSS is applied to a practical system to control the poor damping inter-area low frequency oscillations. Simulation results indicate that the controller can provide good supplementary damping to the system and improve the robustness of time-delay.