Impact of electric vehicle charging simultaneity factor on the hosting capacity of LV feeder

What is the maximum charging rate that a distribution network (DN) can permit for electric vehicles (EVs)? This is the question we answer in this work by proposing a "multi-period risk-based stochastic EV hosting capacity (EV-HC) framework"that explicitly considers the EV charging profiles and implicitly the arrival and departure times. Realistic EV charging profiles are employed to generate Monte Carlo (MC) scenarios that are subsequently utilized for EV-HC calculations. The EV-HC outcomes are assessed for critical times (CT) when distribution network incidents (DNIs) such as voltage, transformer loading, and line loading limit violations are observed. The EV charging simultaneity factor (SF) is calculated for these CT instances. We quantify the impact of SF on the EV-HC for the first time. Showcasing the efficacy of the proposed EV-HC framework and analyzing the SF and CT, we perform three realistic case studies for European DNs. These case studies vary in size (small and medium-size) and geographically different network topologies, i.e., rural, urban, and semi- urban. The EV-HC is assessed based on four distinct power levels of the chargers: 2.7 kW, 3.5 kW, 7 kW, and 11 kW. The results indicate that the EV-HC of the Belgian feeder is 7 kW and 3.5 kW per single charger for the EVs with high and low daily charging energy, respectively. We also observe that either nodal voltage violation or line or transformer overload could be the dominant attribute for EV-HC calculations. Furthermore, either at peak load time or off-peak time, the simulation results show that high SF values result in DNIs. However, peak-load periods are crucial because a low SF value can limit EV-HC.