Robust decentralised control design using genetic algorithms in power system damping control

The paper presents the design of linear robust decentralised fixed-structure power system damping controllers using genetic algorithms (GA). The designed controllers follow a classical structure consisting of a gain, a wash-out stage and two lead-lag stages. To each controller is associated a set of three parameters representing the controller gain and the controller phase characteristics. The GA searches for an optimum solution over the parameter space. Controller robustness is taken into account as the design procedure considers a prespecified set of operating conditions to be either stabilised or improved in the sense of damping ratio enhancement. A truly decentralised control design is achieved as the loop control channels are closed simultaneously. The approach is used to design SVC and TCSC damping controllers to enhance the damping of the interarea modes in a three-area six-machine system. Local voltage and current measurements are used to synthesise remote feedback signals.