Decentralized load frequency controller analysis and tuning for multi-area power systems

Decentralized load frequency control (LFC) for multi-area power systems is studied in this paper. A method to analyze the stability of a multi-area power system under a decentralized LFC is derived by accounting the inherent structure of the multi-area power system. The method separates the local transfer matrix from the tie-line power flow network, and the impacts of the tie-line power flow network and the local load frequency controllers on the power system can be easily checked. This result makes it possible to tune the local LFC controller for each area by first ignoring the tie-line power flow network. Decentralized LFC tuning on a three-area and a four-area power system shows that the proposed method is easy to apply for multi-area power systems and good damping performance can be achieved.