Simultaneous adjustment of AVR and optimized PSS outputs effect in power systems for stability improvement

Due to the problems related to low-frequency oscillations (LFOs) and power systems complexities, using intelligent methods and optimization techniques is essential for solving power system stabilizer (PSS) problems. In this paper, power system stabilizer, based on the PSOPSS, is designed to set the parameters of PSS. Then, the FLC is designed to simultaneously weighting the automated voltage regulator and power system stabilizer outputs, to adjust the excitation controller facing with disturbance. The ability to optimize particle swarm algorithm, in combination with FLC ability to solve complex and nonlinear problems, will effectively improve the stability of the power system. Initially, the simulation was performed on a single machine system in which the PSS optimal parameters were obtained using particle swarm optimization (PSO). Afterwards, with simultaneous regulation of the voltage and damping by the fuzzy logic controller, the effectiveness of the proposed approach, compared with the PSS based on the linear optimization controller, is confirmed. Next, more effective results can be obtained on a multi-machine system with effective placement of the FLPSS, compared with the conventional PSS and with simultaneous adjustment of the output weights of voltage and damping controllers using FLC. The efficiency of the proposed method in response to a variety of disturbances is determined.