Optimization of Multiport DC Fast Charging Stations Operating With Power Cap Policy

Direct-current fast charging (DCFC) stations are necessary to provide coverage for long-range travel and promote widespread adoption of electric vehicles (EVs). Since many DCFCs are currently underutilized, they suffer financially from high demand charges and are difficult to operate as a business case. This study investigates a new method to design and operate a multiport DCFC station with a power cap policy in order to mitigate high operation costs (OCs) while providing sufficient service quality to the customers. Different policies, which distribute available power capacity between multiple charging ports in a fair manner, are simulated and compared. It is shown that OCs can be reduced, while the quality of service is preserved. The impact of the station design on the optimal power cap is simulated and analyzed. By adjusting the power cap with the increasing charging demand over the lifetime of the station and by optimizing the station design, a total profit of up to U.S.
$\$ $
950k and unit costs as low as U.S.
$\$ $
0.2/kWh can be achieved.