Impact of Rising Number of Electric Vehicle Charging Points on Electrical Utility

This paper presents an investigation of the impact of a rising number of electric-vehicle charging points on an interconnected distribution system. Using the PSCAD 4.6 software, this study simulates an electric-vehicle charging station consisting of a charging unit with 2 DC charging and a maximum power of 100 kW. The station receives power from a 23 kV substation through a step-down transformer at 400 V and provides power through the charging unit. The unit regulates the voltage level at 500 V and has a maximum charging capacity of 50 kW each. In addition, the study replicates an actual distribution system of the Provincial Electricity Authority (PEA) in the section spanning the Si Samrong to Sawankhalok substations in Sukhothai Province, Thailand. The effects of the following study conditions on the power quality are observed in the simulation: (1) variable location of charging panels, (2) variable number of charging panels, and (3) additional sets of charging panels in the distribution system. The results show that the charging-panel installation location and number of charging panels are significant factors that affect the power quality, including the voltage level. Therefore, optimizing the design of EV charging stations should consider the location and number of charging panels as important factors.