An indirect adaptive fuzzy-logic power system stabiliser

An indirect adaptive fuzzy power system stabiliser (AFPSS) is developed using the concept of fuzzy basis functions. The power system is modelled using differential equations with nonlinear parameters which are functions of the state of the system. These nonlinear functions may not be known, however, some linguistic information is available about them. Utilising this information, fuzzy logic systems are designed to model the system behaviour. The control law is obtained using the uncertainty principle. Based on the Lyapunov's synthesis method, adaptation rules are developed to make the controller adaptive to changes in operating conditions of the power system. The simulation studies are carried out for an industrial cogenerator and utilise a one-machine infinite-bus model. Nonlinear simulations reveal that the performance of AFPSS is better than the performance of a conventional (linear) power system stabiliser for a wide range of operating conditions.