Robust load frequency control in multi-area power system: An LMI approach

In an interconnected power system, both frequency and tie-line power exchange vary as load demand varies randomly. In this paper, a robust controller is designed to reduce the frequency deviations and tie line power error due to different load disturbances in multi-area interconnected power system. The robust H-infinity (H∞) controllers are designed both for two area power system with two reheat turbine units and three-area power system with non-reheat, reheat, and hydro turbine units. Using the concept of Linear Matrix Inequality (LMI), H∞ design specification has been realized and LMI approach has been used for the design of output-feedback H∞ controller. The resulting controller gives the robust performance in presence of parameter variations and other uncertainties. The performances of the controller is also compared with the performance of Robust Distributed Model Predictive Controller (RDMPC).