A soft-switching solid-state power transformer, including: a high-frequency (HF) transformer comprising first and second winding connections; a first auxiliary resonant circuit coupled to the first winding connection, the first auxiliary resonant circuit comprising: a resonant capacitor coupled across the first winding connection, a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor, and a damping feature coupled across the first winding connection in series with the resonant capacitor and the resonant inductor; a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions; a second auxiliary resonant circuit coupled to the second winding connection; and a second CSI bridge coupled to the second auxiliary resonant circuit, the second CSI bridge comprising reverse blocking switches.