Nonlinear time-response optimisation method for tuning power system stabilisers

A power system is an inherently highly nonlinear and complex system. Many tuning methods involving parameter optimisation used in the past, were often based on small-signal stability theory and linearised system equations. Such optimisation usually involves the optimising of frequency-domain characteristics such as damping and damping factors of the system critical eigenvalues. The use of frequency-domain information does not allow for the direct improvement of the time-domain characteristics of the system response, e.g. settling time. A simple method is proposed that directly optimises the nonlinear system by using system time response to large disturbances. The properties of the method and its application specifics are discussed in detail. The effectiveness of the method in the co-ordinated tuning of multiple power system stabilisers is illustrated on a multimachine test power system.