The Novel Single Phase-Shift Modulation Scheme for Dual Active Bridge Converter

For the dual active bridge (DAB) converter, the single-phase shift (SPS) modulation scheme is simple and easy to control the transmission power. However, the zero-voltage switching (ZVS) operation is lost at the light load condition and the sizeable reactive power exists over a wide operation range, which results in low efficiency. Thus, a novel single-phase shift modulation scheme is proposed in this paper. First, without additional control variables, four different SPS schemes are formed, namely, SPS-I, SPS-II, SPS-III, SPS-IV. Then, the characteristics of these schemes are compared, mainly including the transmission power capacity, root-mean-square (RMS) current and soft-switching performance. Among these four schemes, the SPS-II scheme has the highest efficiency performance. Finally, an experimental prototype was built to validate the efficiency improvement of the proposed modulation scheme.