T35.3 - Electro-Thermal Co-Design of a High-Density Power-Stage for a Reconfigurable-Battery-Assisted Electric-Vehicle Fast-Charger Using Multi-Physics Co-Simulation and Topology Optimization

This paper focuses on the electro-thermal design, co-simulation, and prototyping of a multi-phase linear-current regulator (LR) for use in battery-assisted Electric Vehicle (EV) DC fast charging stations. The LR consists of two MOSFETs in common-source configuration. The proposed LR leverages a stationary reconfigurable battery energy storage system to provide a high-density, fault-tolerant replacement for the switched-mode dc-dc converters of conventional battery-assisted EV DC fast charging stations without using high-current magnetic components, high-frequency semi-conductor devices, or high-voltage capacitors. To reduce the volume and cost of the LR cooling solution, the individual gate voltages of the LR MOSFETs are dynamically varied to balance the waste-heat thermal load, while an optimized heatsink ensures uniform case temperatures for non-uniform waste-heat loads. In a 400V, 250A fast-charge station, the proposed LR has an effective density of 67kW/Litre, including thermal solution.