• Lightning-induced overvoltages in residential EV chargers are quantified via ATP-EMTP. • Coordinated surge protection is evaluated under direct lightning strikes up to 200 kA. • Distribution board SPDs are insufficient for protecting residential EV chargers. • EV charger SPDs reduce overvoltages but may not fully protect EVs in extreme cases. • The need for extended surge protection highlighted, including SPD integrated into EVs. A representative model of a three-story residential building incorporating a three-phase 22 kW electric vehicle (EV) charging station is developed in ATP-EMTP to investigate lightning-induced fast-front overvoltages. Direct negative and positive lightning strikes with peak currents of 10–200 kA and soil resistivities of 100–1000 Ωm are considered. Computed overvoltages at distribution boards, the EV charger, and the connected vehicle are compared against rated impulse withstand voltage (RIWV) levels to assess failure risk. The results show that, without low-voltage surge protective devices (SPDs), overvoltages exceed the RIWV of the charger and vehicle for all severe lightning scenarios. Protection schemes relying solely on distribution-board SPDs are insufficient, as critical overvoltages persist at the charger terminals. The installation of a dedicated SPD at the EV charger limits charger overvoltages to below 4 kV for all examined cases; however, the connected vehicle remains vulnerable for peak currents higher than 100 kA and high soil resistivity (> 700 Ωm). These findings demonstrate the necessity of EV charger SPDs and indicate the need for enhanced protection concepts for resilient residential EV charging infrastructure.
Gektidis et al. (Thu,) studied this question.