High-power and high-density dc transformers (DCXs) are critical components in data center power supplies, energy storage systems, medium-voltage solid-state transformers, and transportation electrification. The challenges associated with designing high-power and high-frequency transformers are considerable. The electronic-embedded transformer (EET) concept, proposed in [1], is a response to these challenges, integrating semiconductor electronics into the transformer windings. In light of this concept, this paper presents two significant modifications. First, it replaces the complete full bridge with a low-voltage bidirectional ac switch. Second, it introduces a resonant commutation (RC) to realize a quasi-trapezoidal transformer current with a smaller rms value. Compared to the triangular current produced by the original EET-DCX in [1], the rms current can be decreased by 15%. Finally, a 12 kW 300 kHz prototype of SB-DCX was built to verify the operation. The experimental results matched well with the simulation results.
