Lead-lag PSS design based on H∞ control theory and genetic algorithm

The aim of this paper is to describe how to reduce the dimension of a power system stabilizer (PSS) based on H_∞ control theory. In recent years, robust PSS designs that adopt an H_∞ controller have been investigated in order to guarantee the performance when the state of the system configuration and power flow change. However the H_∞ controller has not been widely adopted into practical use because of the intricate nature of its theory and structure. We consider the H_∞ control problem under the condition that PSS structure is fixed to be a lead-lag compensator. We optimize the parameters of the Lead-Lag PSS by a genetic algorithm that has an evaluation function which takes into account a closed loop H_∞ norm and a desired response. In this way, we design a PSS which has a conventional controller structure and guarantees its control performance.