Partial Power Converter Based on the Gate Voltage Self-Balancing Supercascode Power Switch

To simplify the topology and control under mediumvoltage DC input, a novel partial power DC transformer (DCX) based on gate voltage self-balancing supercascode power switches (GVSB-SCPSs) is proposed. The front stage of DCX is constructed by GVSB-SCPSs, which realize the medium-voltage DC input of a single module and fixed voltage ratio. The closed-loop stabilized voltage output is achieved through the proposed partial power processing (PPP) circuit, which handles a small portion of output power. In the proposed converter, the high-frequency operation process of GVSB-SCPSs and the unique gate switching pattern during the dead time are analyzed. Based on this, the boundary condition of soft switching in the proposed converter is derived. Under this condition, the loss of the proposed converter is analyzed and the dead time is optimally designed. Based on the proposed topology, a partial power converter experimental prototype is built. The prototype is constructed through the designed GVSBSCPSs, which have been tested at 10kV and demonstrates outstanding switching characteristics. The experimental results of the partial power converter prototype show that all the GVSBSCPSs realize ZVS soft switch at 4kV, 20kHz. Furthermore, the closed-loop stabilized voltage output is achieved, verifying the feasibility of the proposed PPP and DCX circuit.