Plug-in Hybrids vs Battery Powered Vehicles – Optimisation Model for Charging Infrastructure at a University Campus

Abstract

University campuses, as well as other workplaces, provide great opportunity for electric vehicle (EV) charging. A simulation model was created in GAMS (General Algebraic Modeling System) for the optimization study concerning charging infrastructure at the Faculty of Mechanical Engineering at Brno University of Technology. The study was conducted for 20 plug-in hybrid electric vehicles (PHEVs) and 20 battery electric vehicles (BEVs). This assumption was based on the similar sales of PHEVs and BEVs in the EU in 2021. The PHEVs could only be charged at alternating current (AC) chargers (using the EV’s built-in chargers) while the BEVs could be charged at both the AC chargers and the high-power DC (direct current) chargers. The AC chargers are much cheaper to install but because of the relatively small power of the BEV’s built-in chargers the charging at AC chargers takes a long time. As the university employees have flexible working hours, varying arrival times of the EVs as well as the varying duration of their stay on the campus was considered. The state of charge (SOC) of the EV’s batteries at the time of arrival on the campus was also considered. For the considered sets of parameters 3 DC chargers and 6 AC chargers covered 96 % of the total demand. A replacement of one DC charger with two AC chargers led to the decrease of coverage to 95 % but with significant reduction of capital costs.