particle swarm optimization algorithem

In this paper, in order to reduce disturbance attenuation in the single-machine infinite-bus system a STATCOM by an improved robust back-stepping algorithm based on a particle swarm optimization approach is proposed. In the proposed approach, the adaptive back-stepping method is used to construct the storage function to reduce internal and external disturbances. Also, a nonlinear controller with interference rejection feature and update of the nonlinear parameter substitution law are applied simultaneously. In this research, in order to maintain non-linearities feature, the real-time estimation of uncertain parameters, ensure robustness and insensitivity to large disturbances of the STATCOM system, the adaptive back-stepping sliding mode control method is applied in terms of error compensation design. It should be noted that the proposed controller has a large number of design parameters which affect its efficiency and performance. So, here the particle swarm optimization approach is used to determine the design parameters based on the cost function of the integral of the magnitude of the error. Finally, the simulation results are performed by MATLAB software, confirmed the better performance of the proposed optimal back-stepping sliding mode control method compared to traditional adaptive back-stepping in terms of the speed of adaptation and the response of the STATCOM system.