Optimized Frequency and Phase-Shifted Control of Series-Resonant Dual Active Bridge Converter Considering Battery Voltage

Abstract

This paper proposes a frequency and phase control method to optimize the efficiency of an series-resonant dual-active bridge converter (SRDABC) across the entire battery charging range. The operation of the converter is analyzed in the time domain, and a precise mathematical loss model, including zero voltage switching (ZVS) and zero current switching (ZCS) losses, is developed. Optimal frequency and phase shift pairs are determined for each battery voltage and stored in a lookup table for real-time control. This method uses battery voltage feedback to apply the optimal parameters, maximizing efficiency while mitigating current deviations during constant current (CC) charging. A parameter selection algorithm and proportional-Integral (PI) control were implemented to ensure stable operation. Experimental validation demonstrated up to 1.18% efficiency improvement in a single voltage range and an average improvement of 0.41% across all voltage ranges compared to conventional methods.