Impact of Different Plug-in Electric Vehicle Categories on Distribution Systems

Abstract

In recent years, electric vehicles (EVs) have had a huge growth, which leads to decrease of the fuel consumption, emissions, and aid in keeping the clean environment but, this will have an effect on distribution systems operation if the plug-in vehicles are not managed. Therefore it is urgent to choose the ideal charging/discharging methods. This paper presents a comprehensive analysis of four scenarios for plug-in EVs to the distribution system. Firstly, base case, secondly, uncontrolled plug-in EVs charging, thirdly, controlled plug-in EVs charging, and fourthly controlled plug-in EVs charging/discharging. A fuzzy logic control (FLC) system is proposed to determine the charging/discharging priority level of each EV based on the associated state-of-charge (SOC) level of the battery and the electricity tariff. The fuzzy logic controller is used to control the EV charging/discharging process to achieve benefits for the electricity network and EVs owners, as well. The benefits for the electricity network are the improving voltage profile, potential shifting of charging to the off-peak period and discharging during the on-peak period to minimize the system loading. Benefits for EVs owners are the charging the EV at low cost and discharging at a high cost to motivate the EVs owners. A 400 V low voltage (LV) distribution network is selected as a case study in this paper to execute simulations. It is based on a real distribution network located in New Toshka city, Aswan, Egypt. MATLAB/SIMULINK is used to perform simulations and test the effectiveness of the proposed control method. The results demonstrate that the proposed controlled plug-in EVs charging/discharging method improves the distribution system performance more than other methods.