Decentralized disturbance rejection control of multi-area power systems using generalized extended state observer

In this paper, generalized extended state observer is implemented to the load-frequency control of a multi-area power system. By using this observer, there is no need to have an accurate dynamic model of the system and thus, leads to a more robust performance against the uncertainties of the system parameters and disturbances in comparison with conventional load-frequency control methods. Moreover, the higher order disturbances rather than just step disturbances can be rejected by the proposed method, because of estimating the both disturbance and its derivative. A generalized disturbance signal is defined for each area. It consists of unmodeled dynamics of the system, external disturbances, and the interactions of the other areas. In the proposed control strategy, the generalized disturbance is estimated using local input and output data by a local state observer. Then, the estimation of generalized disturbance is used in a local state feedback controller to reject it and track the related references. The simulation results show the effectiveness of the proposed method.