Driver-Centric Direct Current Fast Charging of Electric Vehicles via Energy Optimal Thermal Management

Charging a battery electric vehicle at extreme temperatures can lead to battery deterioration without proper thermal management. To avoid battery degradation, charging current is generally limited at extreme hot and cold battery temperatures. Splitting the wall power between charging and the thermal management system with the aim of minimizing charging time is a challenging problem especially with the strong thermal coupling with the charging current. Existing research focus on formulating the battery thermal management control problem as a minimum charging time optimal control problem. The current control strategy forces the driver to charge with minimum time and higher charging cost irrespective of their driving schedule. This paper presents a driver-centric DCFC control framework by formulating the power split between thermal management and charging as an optimal control problem with the goal of improving the wall-to-vehicle energy efficiency. Proposed energy-efficient charging strategy would provide a solution as per the driver’s itinerary or chosen charging time, allowing the driver to choose the trade-off between charging time and cost. A reduced order single particle model is used to model the battery states and limit the charging current, ensuring battery longevity. Detailed simulation study is performed to analyze the trade-off between the charging time and energy consumption.