Quantum-inspired optimization for current stress reduction in DAB converters for ultra-fast EV charging

Ultra-fast charging (UFC) of electric vehicles (EVs) pushes the limits of conventional power converter design, demanding breakthroughs in efficiency, thermal management, and reliability. Among the various converter options, the Dual Active Bridge (DAB) has emerged as a strong candidate for such high-power DC charging applications. In this paper, a new phase-shift modulation strategy for the DAB is proposed aimed at minimizing current stress, thereby enhancing overall efficiency and reliability, and lowering switching and conduction losses. Unlike the conventional single-phase shift (SPS) method, that employs a single delay angle, the proposed method utilizes two phase-shift delays, providing greater control over power flow and reducing current stress. To achieve optimal operation, Quantum-Inspired Optimization (QIO) is used to fine-tune the phase delays, ensuring efficient performance. Comparative analysis with SPS demonstrates that the novel method achieves Zero Voltage Switching (ZVS) for all switches, reduces current stress by up to 50%, and therefore, significantly enhances the converter reliability. Additionally, the simplicity of implementation improves feasibility and scalability for next-generation UFC infrastructure. Both simulation and experimental validations confirm the effectiveness of the proposed technique, establishing its suitability for high-power EV charging systems.