Priority Based Critical Load Selection Algorithm for Grid Integrated PV Powered EV Charging System with Optimal DC Link Control

This article presents a single phase double stage photovoltaic (PV) array powered grid connected residential premise integrated with electric vehicle (EV) charging functionality. Taking criticality of the loads into consideration, a unique multi-modal control is developed which ensures incessant power supply to the loads via EVs in case of common occurrences of power interruption thereby enhancing the power security of the system. Favourable regulation of DC link voltage is achieved via proportional integral (PI) controller (DCVPI). Comparison between genetic algorithm (GA) and modified particle swarm optimisation (PSO) based tuning proves modified PSO tuned DCVPI achieves faster convergence and better fitness function evaluation. The system is subjected to various dynamic conditions during which modified PSO tuned DCVPI stabilises to the reference voltage faster and results in 1.38% reduction in overshoots opposed to the manual tuning. The proposed system is designed to work both in grid connected mode as well as islanded mode of operation. Moreover, a resynchronisation control is developed to achieve a seamless transition from islanded mode to grid connected mode post the mitigation of power failure. The proposed system achieves unity power factor and complies with the IEEE -519 power quality standard