Multi-Objective Allocation of EV Charging Stations and RESs in Distribution Systems Considering Advanced Control Schemes

Abstract

Renewable energy sources (RESs) and electric vehicle charging stations (EVCSs) have been extensively incorporated into distribution systems. Due to the stochastic nature of RES generation and electric vehicles (EVs), risky operational challenges might impact the grid. Therefore, this paper proposes a multi-objective planning framework to optimally allocate EVCSs in conjunction with RESs. Specifically, the proposed RESs and EVCSs planning framework considers three sub-objectives to be minimized, i.e., voltage deviations, energy losses, and EVs owners' dissatisfaction. Further, active power curtailment of RESs is precluded while considering the diverse operational constraints of the grid, RESs, and EVCSs. To provide further benefits, advanced control schemes of the interconnecting RES inverters, grid-to-vehicle (G2V), and vehicle-to-grid (V2G) schemes are considered in the proposed framework. A two-level approach is developed to solve this holistic framework with competing sub-functions to obtain the Pareto-optimal solutions. The outer optimization level precisely optimizes the RES locations and sizes, along with the optimal places of the EVCS. On the other hand, the inner level determines the optimal EVCS charging considering stochastic EV power, RES inverter reactive power, and the time-of-use energy tariff. The proposed framework has been tested on the 69-bus distribution system. The simulation results reveal the efficacy of the proposed RES and EVCS planning framework. The total voltage deviation and energy losses achieved by the proposed framework are reduced by 96% and 74%, respectively, with respect to the uncontrolled charging of EVs, while the owners' satisfactions are met.