Fuzzy Logic Controller for Decentralized Stabilization of Multimachine Power Systems

Although fuzzy logic has been successfully implemented in many industries, the acceptance of fuzzy logic within the power industry has met with limited success due to the requirement for prior information about an extremely complex system. A decentralized fuzzy logic controller (FLC) proposed in this paper has been designed, however, using a systematic analytical method based on a performance index in order to bypass the need for prior knowledge about the system. The proposed FLC tracks speed deviations to zero in order to stabilize the power output of the generator, while, at the same time, it controls and stabilizes the terminal voltage of the generator. This paper introduces an analytical method for the design of an FLC that successfully stabilizes both voltage and power oscillations following small and large disturbances in a power system. Simulations are performed with a multimachine power system, which includes a four-machine and a ten-machine (New England) system. The results obtained clearly demonstrate the effectiveness of designed FLCs in stabilizing the system. The responses of the system with FLCs are also compared with those obtained using classical power system stabilizers (PSSs) tuned by a conventional linear sequential tuning method (LSM) and optimization-based method.