Evaluation of Voltage Margin under EV Charging in Distribution Systems with High PV Penetration

This study investigates the impact of electric vehicle(EV) charging on voltage margin in distribution systems with high photovoltaic(PV) penetration in tourist regions. Using Jeju Island as a case study, the Voltage Margin Evaluation Index(VMEI) is applied to assess voltage stability under different charging scenarios. Results show that daytime EV charging in tourist areas naturally coincides with PV generation, mitigating overvoltage by absorbing surplus output, with greater improvements observed in feeders with higher PV penetration. These findings highlight the potential of EV charging as a passive voltage stabilization resource, offering practical insights for charging infrastructure planning and grid operation in high PV penetration tourist regions.