Abstract
This article presents a method for tuning the parameters of a fixed-structure supplementary modulation controller of flexible AC transmission systems devices to enhance the damping of inter-area oscillations. The flexible AC transmission systems device considered in this work is the static VAR compensator. Conventional lead/lag structure of the supplementary modulation controller is retained, but its parameters are tuned using the real-coded genetic algorithm. The advantage of the proposed method is that it retains the simplicity of the conventional fixed-structure controller and also ensures robust acceptable performance over a wide range of system and operating conditions. The proposed approach has been applied to the controller design of the static VAR compensator connected in a two-area four-machine system. The details of implementation and simulation results are presented. Simulation results show that the method can be used for the designing of a supplementary modulation controller, which guarantees a robust closed-loop performance over a pre-specified range of operating and system conditions.