Dual-Active-Bridge Converter with Triple Phase Shift Control for a Wide Operating Voltage Range

An optimal modulation scheme with Triple-Phase-Shift (TPS) control that increase efficiency in the whole load range is presented for a Dual Active Bridge (DAB) converter under wide output voltage range conditions. This paper provides a comprehensive analysis of the DAB with TPS modulation, identifying all the switching modes to operate the DAB where expressions for the transfer functions, the peak inductor current and RMS inductor current are provided. An analysis of minimum Peak Current and minimum RMS Current Control also are investigated. On this basic all-ZVS modulation scheme is originally proposed to improve light-load efficiency and to reduce the switching losses. A 15 kW prototype circuit is applied, and experimental results are presented to validate that the modulation and efficiency improvement are realized by applying the optimized modulation scheme. The experimental results also verify the effectiveness of the closed-loop control strategy.