A grid-integrated photovoltaic EV charging system using a PSO-optimized quadratic SEPIC converter

Abstract The present paper introduces a grid-connected PV-based EV charging system using a high-gain Quadratic SEPIC DC-DC Converter and a Particle Swarm Optimization (PSO)-optimized PI controller to attain better voltage regulation and improved power quality. The Quadratic SEPIC Converter is used to step up the voltage from 160 V to 400 V with moderate duty cycle operation, yielding better gain characteristics compared to conventional SEPIC and CUK converters. Moreover, the PSO-optimized PI controller improves the dynamic response to attain a 57% reduction in voltage tracking error (RMSE reduced from 9.84 V to 4.21 V), along with a reduction in settling time from 0.30 s to 0.10 s. The system exhibits an average efficiency of 97.63%, which is 3%–5% better than conventional configurations. Furthermore, the total harmonic distortion (THD) in the grid current is limited to 0.20%, which is well within the IEEE standards to attain near-unity power factor operation. Robustness tests were performed to ensure that the system operates within the specified limits even in the presence of irradiance, load, and grid voltage perturbations. The results show that the system operates with efficiencies greater than 97% and THD less than 0.3%, proving that the proposed system is efficient, has low THD in the grid current, and is dynamically robust to operate in renewable energy-based EV charging systems.