Design of Robust Damping Controllers for Power Systems Based on a Mixed Classical/Robust Control Technique

This paper proposes a mixed procedure to design robust controllers to damp low-frequency electromechanical oscillations in power systems. The proposed procedure is based on a mixed classical/robust control technique, which allows overcoming the disadvantages and exploring the advantages inherent to each adopted control technique. The design procedure is systematic and provides controllers with a simple structure, which is acceptable by power system engineers and already implemented in many power stations around the world. Such structure is adopted to allow the implementation of the proposed controllers in the current framework, without changing the structure of the controllers already implemented. Besides guaranteeing a minimum performance index for the closed loop system, the proposed procedure also guarantees the controller robustness at the design stage. The procedure may be used to redesign controllers already implemented and/or design controllers only for power plant(s) of interest. The obtained results have shown the effectiveness of the methodology when applied to the power system oscillation damping problem