Assessing The Impact Of Electric Vehicle Charging On Low Voltage Distribution System Of Takoradi

Abstract

This research assessed the impact that EV charging has on low voltage (LV) distribution systems at different penetration levels. The existing electric power distribution system of Takoradi, the Western Regional capital city of Ghana was modelled using the power analysis software Electrical Transient and Analysis Program (ETAP 19.0.1). Load flow analysis was then performed on the low voltage distribution system to further assess the total amount of EVs the distribution system can handle. EVs charging impacts on the current LV distribution system were assessed under three different scenarios; current state, minimum and maximum uptakes penetration levels of EVs. Two different EV charger models were employed to represent home charging (HC)-7.4 kW level-2 and fast charging (FC)-50 kW level-3. Voltage variations and transformer loading at twelve substations were meticulously noted in all simulations. The load flow simulation did not show any significant impact on the distribution system at the current state and minimum uptake penetration levels. However, at a maximum penetration level of 1.88% for HC and 1.11% for FC, under voltage conditions were observed at most of the buses with the condition deteriorating to the highest penetration level of 11.63% and 6.87% for HC and FC respectively where the system tend to fail. Domestic/ household loads significantly increased along with the increment of EV penetration levels over the years which contributed to total instability of Takoradi Distribution System (TDS). The impact that EV charging has on low voltage systems are expected to differ from one region to another, based on how many vehicles that are used in a locality, the current power demand, and the layout of the network. In effect, EV loads operating under different charging types have observable impacts on both the load and the voltage variables. The findings of this thesis will assist policy-makers take the appropriate actions needed to manage EV loads.