Modeling and Controllability Evaluation of EV Charging Facilities Changed from Gas Stations with Renewable Energy Sources

Abstract

The widespread use of renewable energy and electric vehicle charging and changing facilities has promoted the progress of renewable energy such as photovoltaic. In this context, the energy demand for regional automobiles refueled at gas stations is replaced by electric vehicles (EV) recharged at charging stations or household charger. The operation characteristics of charging stations and gas stations are analyzed and the transformation function between gas stations and charging stations is formulation by adopting membership matrix and queuing theory. The impact of additional charging load for EVs at newly installed charging facilities on the existing electric power network is firstly estimated. The power flow and the power quality are analyzed quantitatively in the power network with renewable energy and charging facilities changed from gas stations. The adjustable parameters of the EV charging facilities in the transformation model between gas and charging stations are determined and then the control strategy is investigated based on the optimal dispatching of power networks. A two-stage hybrid optimization algorithm is derived to solve the formulated mixed integer nonlinear programming problem consisting the variables of charging facilities. Finally, to verify the proposed modeling of EV charging facilities supplying the energy for the needs of automobiles and the controllability evaluation method by comparing the uncontrolled charging scenario and the optimized EV charging case which exploiting the bounded variables in the operation of EV charging facilities.