Voltage Stability Analysis of Distribution Systems in the presence of Electric Vehicle Charging Stations with Uncoordinated Charging Scheme

The nature of Electric Vehicle (EV) loads is highly uncertain in terms of charging times and affect load profile of a system, altering the peak times and the base load of the system. Thus, it is necessary to study the impact of the EVs on the distribution system to ensure a stable operation. This work aims to establish a load profile for the EV Charging Stations (EVCS) connected to a distribution system and then study the impact of the EVCS on the static voltage profile of the distribution system. A novel generalized procedure for evaluating the impact of EVCS on a distribution system has been proposed. A 24-hour load profile of EVCS is established using the travel patterns of EV users in this work. Radial Load Flow is performed on the distribution system when the EVCS is connected to the system to determine the voltage profile of the system. Voltage Stability Index (VSI) and Voltage Stability Factor (VSF) are computed for the system with and without EVCS under multiple cases. An analysis of the same indices under different scenarios has been performed.