Three-level DC-DC GaN-based Converter with Active Thermal Control for Powertrain applications in Electric Vehicles

The use of electric vehicles (EVs) has grown notably in the last years and with it new challenges for power electronics have appeared. Since typically the main energy storage system in EVs consists of batteries, one of these challenges is the efficient and reliable management of power flows in charging/discharging mode. This paper presents an electrical and thermal modelling of a three-level buck-boost DC-DC converter (TLBBC) with semiconductors based on gallium nitride (GaN) technology. Also an active thermal control (ATC) scheme to mitigate the thermal stress in the semiconductor is proposed, together with control schemes for DC-link voltage and voltage balance between capacitors in the TLBBC. The TLBBC is designed to operate in a boost mode at rated power of 25 kW, using a parallel design with GaN semiconductors. Proposed control schemes are implemented using linear controllers. Finally, comprehensive simulation results confirm and validate the proposed control schemes.