Decentralised load-frequency controller design based on structured singular values

The decentralised load-frequency controller design problem concerned is translated into an equivalent problem of decentralised controller design for a multi-input multi-output (MIMO) control system. It is shown that, subject to a condition based on the structured singular values, each local area load-frequency controller can be designed independently. The stability condition for the overall power system can be stated as to achieve a sufficient interaction margin and a sufficient gain and phase margin defined in classical feedback theory during each independent design. It is demonstrated by computer simulation that within this general framework, very simple local controllers can be designed to achieve satisfactory performances for a sample two-area power system and a simplified four-area power system. Under the proposed framework, based on the structured singular values, other design methods for local area controllers may also be applied