Characterization of a 300 kW Isolated DCDC Converter using 3.3 kV SiC-MOSFETs

In the solid state transformers, the efficiency is an essential criterion. Additionally, it is recommended to have a sufficiently high switching frequency in order to reduce filter elements, noise pollution, volume and mass of the transformer. Therefore, the concept of soft switching is indispensable for reasonably meet these constraints. Essentially, it is not possible to extrapolate the switching energy curves for zero current switching (ZCS) or zero voltage switching (ZVS) using the device’s datasheet. Therefore, an experimental test bench, rated for full power, is fundamental to achieve results far beyond those that theoretical calculations and simulations could provide. Finally, aiming to obtain further efficiency improvement, this article presents an experimental comparison regarding two different current ratings of 3.3 kV SiC-MOSFETs focusing on the influence caused by the output capacitance of the devices.