Optimization of current controller for grid-connected inverters using a PSO algorithm

Abstract

Renewable energy resources - wind and solar - are increasing very strongly for sustainability and environment with enormous potential. However, their drawbacks are diluted and discontinuous. Thus, in order to become a stable, quality, and cheap power source, they need to be connected to the power grid by using power semi-conductor inverters wherein the current controllers affect significantly output harmonics. Therefore, the power quality of grid-connected inverters depends much on these coefficients of inverters. Since the closed-loop transfer function of grid-connected inverters is infinite. Thus, there are numerous values of the coefficients that can satisfy the transfer function to stabilize system. However, the manual determinations of the coefficients basing on the transfer functions like Bode diagram can provide the local minimum values. This paper proposes a method for determining the optimal coefficients of current controllers using Particle Swarm Optimization (PSO) algorithm. The proposed method does not require much time, strength, and experience of designers. To validate the performance of the proposed technique, the simulation results generated by the proposed technique are compared to those of the method relying on the transfer function.