Stabilizing Control of Power System Using Fuzzy Control

Abstract

The paper presents an application of fuzzy control to enhance power system stability. The proposed control consists of the controller for large disturbance (FU 1), the fuzzy controller for small disturbance (FU 2) and the fuzzy judgement mechanism (FU 3).
FU 1 is determined based on the fuzzy controller _??_FU 1 (F)_??_ or the analog type power system stabilizer _??_FU 1 (P)_??_. The output signal of FU 1 (F) is determined according to the control rules and its input signals, i.e. speed deviation and acceleration at every sampling time of the machine. FU 2 consists of two controllers namely FU 2-ω and FU 2-P. FU 2-ω has the same mechanism as FU 1, while the output signal of FU 2-P is determined according to the rules together with the change of error of electrical power and terminal voltage. To obtain the optimal desired control signal, both during the large and the small disturbances, the operations of FU 1 and FU 2 are judged by FU 3, where the magnitude of speed deviation is chosen as its input signal. The determined control signal is fed to AVR of the machine.
The implementation of the proposed control is simple due to small amount of calculations and required data. The effectiveness of the proposed control is demonstrated by one machine infinite bus system model and very good system performance is obtained throughout all the simulations.