A 3rd Gen 10-kV SiC MOSFET High-Frequency Power Conversion Block for MV Applications

HV SiC power modules enable simpler two-level HV medium-voltage (MV) converter topologies, reducing control and system-level complexities, while simultaneously increasing power density and efficiency. A requirement of galvanic isolation is often provided by high-frequency transformers (HFTs) making use of the well-known dual-active-bridge topology. Unfortunately, their parasitic capacitances and high dv/dt characteristics of SiC MOSFETs pose a significant challenge, leading to high-frequency oscillations (HFOs) resulting in unwanted voltage spikes, current resonances, and losses when not addressed them in the design stages. This paper combines 3rd-generation 10-kV SiC MOSFET power modules and a three-phase HFT to develop and test a high-frequency three-phase 150-kW power conversion block for MV applications. The importance of considering winding arrangements is explored to lower stray capacitances, which can effectively minimize HFO amplitudes and lead to higher oscillation frequencies. Experiments on the 150-kW converter are conducted to validate the proposed design.