ROBUST REDESIGN OF POWER-SYSTEM DAMPING CONTROLLERS

This paper presents a model-matching robustness design procedure based on H-infinity-optimization theory for the robust redesign of nominal controllers. The approach directly uses a control law designed for the nominal operating condition and tunes the nominal control law to enha nce the robustness with respect to the off-nominal operating condition s. The procedure is applied to the design of a power system stabilizer (PSS) for a single-machine infinite-bus system which has a range of p ossible operating conditions. The results show that the redesigned con troller contains features similar to the nominal controller, but yet i mproves significantly the damping of the machine swing modes at the of f-nominal conditions.