By combining particle swarm optimization (PSO) and fuzzy logic controller (FLC), the ability of these methods to solve complex and nonlinear problems effectively improves power system stability. Setting the power system stabilizer parameters using the PSO method is presented in this paper. Fuzzy logic controller has been used for simultaneous weighting of the automatic voltage regulator and power system stabilizer output. First, the simulation has been carried out in a single-machine power system, where the optimal PSS parameters have been obtained using the PSO algorithm. Then, by simultaneously adjusting the voltage and damping by the fuzzy logic controller, the effectiveness of the proposed method is verified compared to the PSS based on the linear optimization controller. In the following, the simulation results of a multi-machine system are shown. The efficiency of the method has been shown in response to a variety of disorders تفاصيل المقالة