Optimal RE Hybrid with Electric Vehicle Charging Station in Thailand Distribution System Considering Bus Voltage and Line Capacity Limits

As the popularity of electric vehicles (EVs) keeps growing, the distribution system (DS) must prepare for the integration of electric vehicle charging stations (EVCSs) into the power grid. Because people would rather spend less time charging their electric vehicles, commercial establishments would likely provide rapid charging stations to their customers. However, electric vehicle charging events (EVCEs), especially fast-charging events, may impact the distribution constraints, including bus voltage and line capacity constraints. This research, therefore, proposes an approach to evaluate the optimal EVCS installation size for each bus in the DS based on bus voltage and line capacity limits. This paper also investigates the sensitivity analysis regarding the installation of additional EVCS on each bus. The proposed approach for solving the optimization issue utilizes the iterative methodology. The case study is in Thailand’s Metropolitan Electricity Authority (MEA) medium-voltage DS. The findings demonstrate that installing EVCS closer to the substation reduces the bus voltage drop. Moreover, the bus voltage drop is less affected by adding EVCS in a medium-voltage DS. In contrast, the line capacity limits the maximum EVCS installation size that can be connected to a medium-voltage DS. Furthermore, if a load bus is connected to multiple branches with a line loading exceeding 60 percent of its line capacity limit, this indicates that the load bus is more sensitive to the installation of additional EVCS than other buses. Additionally, the results suggest that the maximum amount of EVCSs deployed in the medium-voltage DS is sufficient to meet future needs.