Identification of Phase Shift Variables to Match Multiobjective Optimization Strategy for EPS Modulated Dual Active Bridge DC–DC Converter

The modulation techniques of dual active bridge DC-DC converter (DABC) with higher degrees of freedom give opportunities for optimization. This paper investigates the effect of three existing optimization strategies that aim at minimizing current stress, backflow power and reactive power delivered by the leading H-bridge terminal of the converter. The study leads to proposing a novel optimization strategy to simultaneously achieve multiple objectives while ensuring reduced complexity in the control algorithm. The proposed strategy aims to minimize the reactive power seen by the equivalent leakage inductance of the high-frequency transformer (HFT), which is the difference in reactive power delivered by the leading and lagging H-bridge terminals of the converter. The steady-state performance of the converter is improved by attaining zero voltage switching (ZVS) for all the switches in a wider power range with reduced backflow power and current stress. Experimental results are presented to validate the theoretical analysis and effectiveness of the proposed optimization strategy.