Power Quality Impact of Charging Station on MV Distribution Networks: A Case Study in PEA Electrical Power System

This paper presents a study of the load profile and harmonic impact of a charging station on medium voltage in a distribution system. The charging stations are likely to increase due to the need to reduce the battery charging time of electric vehicles. Normally, the fast charger has a rated power of 50 kW, but some chargers have a charging rate of 150 kW and 350-400 kW (350-400A). To study the effects of the power quality and variation of the harmonics profile of the charging stations a simulation of the Chiang Mai (Thailand) 22 kV network of the Provincial Electricity Authority was used, and the Chiang Mai 4 substation was selected. This study used DIgSILENT Power Factory as a simulation tool. The simulation results have shown that the load profile in peak load during the summer retains the original shape in this case without a charging station load, but at 9:00 a.m., the increasing of the load demand is more than without a charging station load. For the light load of substation peak load, time will change from 6 p.m. to 3 p.m. For voltage at 22 kV bus, in all case studies, they maintained the standard level. The peak of harmonic distortion occurs during the period of 9-10 a.m.