Design of robust power system stabilizers (PSS) using quantitative feedback theory

The adaptive stabilizer can overcome the problem of parameter variations but will result in a very complex control system compared to the conventional or even state-feedback type stabilizers. It also has its own problems such as convergence or stability in the presence of unmodelled dynamics. To overcome the problem of parameter variations and to maintain the simplicity of the stabilizer for practical implementations, a robust power system stabiliser (PSS) is proposed in this paper using the quantitative feedback theory. In the present design the power system under consideration is a single synchronous generator connected to an infinite bus through a transmission line. The control ratio is modelled, the templates of the power system are formed for a wide range of frequencies, the U-Contour and different bounds for power system uncertainties are determined. After shaping the open-loop transfer function of the control system, the controller is finally designed.