Improving the robustness of H/sub ∞/-PSSs using the polynomial approach

Abstract

This paper proposes a new design procedure of H/sub /spl infin//-PSS (H/sub /spl infin//-optimal PSS) by incorporating high-frequency roll-off into the design using improper weighting function. This design is based on the polynomial approach where the 'numerator-denominator' uncertainty representation is used for practical uncertainty representations. Furthermore, to improve the dynamic and transient stabilities of the control system, the partial pole placement technique is employed to reassign dominant poles at suitable locations in the left-half s-plane. The effectiveness of using /spl Delta//spl omega/ (shaft speed) input and /spl Delta/P/sub e/ (electrical power) input H/sub /spl infin//-PSSs to damp local oscillation modes is also investigated by comparing the performances of these H/sub /spl infin//-PSSs. Simulation results show that the proposed approach is effective in improving the performance and robustness of the system.