A New LMI-based procedure for the design of robust damping controllers for power systems

This paper presents a new procedure for the design of controllers to damp electromechanical oscillations in power systems. The new procedure is derived from a previously developed methodology, which can simultaneously satisfy a number of practical requirements for this type of controller, such as robustness, decentralization, zero steady-state gain and output feedback structure. However, the original methodology eventually yielded controllers with high gain in the electromechanical frequency range (due to the formulation of the control design as a feasibility problem). Controllers with lower gains (desired for practical reasons) are provided by this new procedure, which formulates the first stage of the design algorithm as an LQR problem. The tests show that the designed controllers are able to provide adequate damping for both local and inter-area modes