Optimal Planning of Single-Port and Multi-Port Charging Stations for Electric Vehicles in Medium Voltage Distribution Networks

This paper describes a method to cost-optimally locate and size chargers for electric vehicles (EVs) in power distribution grids as a function of the driving demand while respecting the grid’s constraints. The problem accounts for the notion of single-port chargers (SPCs), where a charger can interface one EV maximum, and multi-port chargers (MPCs), where the same charger can interface multiple EVs, leading to possible cost savings and improved arbitrage of the charging power. The formulation is capable of accounting for and modeling the flexibility of EV owners’ in plugging and unplugging their EVs from and to chargers at different hours of the day, a factor that can impact chargers’ utilization and thus charging infrastructure requirements. Simulation results from a synthetic case study show that implementing MPCs is cost-beneficial over both SPCs and owners’ flexibility for EVs with small batteries (16 kWh). However, this cost benefit vanishes when considering EVs with larger batteries (60 kWh).