A New Approach to Adaptive Power System Stabilizers

This paper considers the problem of designing an adaptive power system stabilizer (PSS) for a synchronous generator connected to an infinite bus through a transmission line. The solution proposed is different from those available and consists of designing several PSS, each for a particular operating condition, and operating them simultaneously in parallel. The control signal for stabilization is obtained as a weighted sum of the outputs of the individual PSS. The weighting factors are adjusted in accordance with the operating conditions. A method for choosing the weighting factors has been developed. The proposed scheme is shown to give performance significantly superior to the conventional nonadaptive PSS, for changing operating conditions and different system strengths. Furthermore, it avoids the complexities of the traditional adaptive PSS, is simple to implement and is fast in adaptation.