An Optimal FOPID Controller of an Arc Welding Power Supply Incorporating a Novel PFC Converter

This article presents an intelligent optimization method using the particle swarm optimization (PSO) algorithm for fractional-order proportional, integral and derivative (FO-PID) controller design applicable to the active power factor corrector (PFC) circuit yield in arc welding power supply (AWPS). The role of the PSO algorithm is to determine the unknown parameters such as $\boldsymbol{K}_{\boldsymbol{p}},\ \boldsymbol{K}_{\boldsymbol{i}},\ \boldsymbol{K}_{\boldsymbol{d}},\ \boldsymbol{\lambda}$ and $\boldsymbol{\mu}$ of the FO-PID controller by minimizing an aggregated cost function based on the integral time absolute error (ITAE) between the welding voltage $\boldsymbol{V}_{\boldsymbol{w}}$ and its reference, this proposed controller is used to regulate the welding voltage and current. Also, another control scheme uses a FOPID controller to manage the DC-link capacitor voltage $\boldsymbol{V}_{\boldsymbol{dc}}$ of a bridgeless PFC converter. The optimally designed controllers have operated cooperatively and offer many exceptional features, like rapid response to the welding load and grid voltage variations, and inherent short-circuit current limit which results in an improved welding performance and weld bead quality. The performance of the developed controllers with the PFC circuit and full bridge buck converter are validated at different working conditions through MATLAB simulations. In addition, the performance of the PSO-FOPID controller has been compared to that of the others controllers such as FOPID and PI controller. And the simulation results proves that the proposed controllers gives a very well controlling of the welding voltage and a good smoothing of the PFC'output voltage under different operating mode condition, and under fluctuating in the welding load.