A Hybrid Modulation Strategy of Dual Active Bridge Converters for Electric Vehicle Charging in Microgrid Applications

The Dual Active Bridge (DAB) converter is widely recognized for its adaptability and efficiency in electric vehicle (EV) charging applications, offering bidirectional power flow and galvanic isolation. However, optimizing the DAB operation across a wide range of powers at different voltage levels represents a challenge that often implies the use of combined modulation techniques. Therefore, this paper proposes a DAB hybrid modulation control strategy that combines phase shift modulation (PSM) and trapezoidal modulation (TPM) for enhanced performance in EV charging for microgrid applications. The control strategy uses TPM at low power levels, while PSM is employed at higher power levels to ensure maximum power throughput. This proposed approach adapts dynamically to the EV charging power requirements, ensuring high performance across a wide operating range. A comprehensive analysis of the operational principles, power transfer characteristics and control mechanisms of the hybrid modulation technique is presented.