New Dual Active Bridge-Series Resonant Converter With Switching and Conduction Loss Reduction for HV-LV Converter in EV Application

In this article, a new HV-LV converter for electric vehicle applications is proposed. The topology combines a dual active bridge-series resonant converter (DAB-SRC) with an interleaved buck/ boost converter. An additional phase-shift control on the LV side is introduced, allowing the active switches to operate near-DCX, resulting in a significant reduction in switching loss. Furthermore, the circulating current is reduced by half compared to conventional [S. Inoue et al. 2017] when operating with a wide voltage range, leading to a reduction in conduction loss. As a result, the switching frequency is doubled compared to existing topology, improving power density by 20.7%. The effectiveness of the proposed topology is verified through experiments on a 6.1 kW prototype, with an LV-side voltage of 48 V/4 kW and 9–16 V/2.1 kW, an HV-side voltage of 400–840 V, and a switching frequency of 200 kHz. A peak efficiency of 96.44% and a power density of 7.5 kW/L were achieved.