Performance of a nonlinear controller in power system stabilisation

This paper describes a nonlinear control strategy for the design of a controller (stabiliser) for a synchronous generator. It is first shown that a nonlinear model, which is derived from the equations of the generator and power system, describes the nonlinear relationship between the electric power output and the excitation control input and, hence, inherently tracks the system dynamics due to changes in the system operating point. Based on the nonlinear model, a nonlinear controller which incorporates the nonlinearities of the power system into the design of the control law is proposed. Simulation studies on the power system reveal that its damping performance due to the nonlinear controller is better than that due to a corresponding adaptive linear device discussed in the literature.