Single-Stage Hybrid Three-Level DAB Type Resonant AC–DC Converter

In order to extend the application of single-stage dual active bridge type isolated ac–dc converter and improve its current characteristics, in this article, a novel topology with a three-level half-bridge matrix converter and a resonant tank is proposed. The operation principle and steady-state characteristics are analyzed in detail based on the PWM plus phase shift modulation. Furthermore, the relationship of the equivalent three-phase shifts to realize a minimum rms value of resonant current is introduced to enhance the operation efficiency. The proposed converter reduces the voltage stress of the power switches of the ac side matrix converter to half the ac voltage, and it is helpful to reduce the power loss and cost. Especially, it is valuable to realize the excellent high-frequency power conversion in medium-voltage applications. Furthermore, the current stress of the power switches is decreased by using the resonant tank as the temporary energy storage loop. The detailed experimental results verify the correctness and feasibility of the proposed topology and theoretical analysis.