A Design and Optimization for High Isolation Medium Voltage Auxiliary Power Supply Module

With the continuous development of SiC MOSFETs as the third generation of power semiconductors, higher power, and voltage medium voltage power electronic equipment has been put on the agenda, which demands a higher auxiliary power supply. Currently, laboratory high-voltage power electronic converters predominantly rely on additional isolation power supplies. Research materials concerning the auxiliary power supply module for the high-voltage input side are scarce, and practical implementations of such modules have largely remained at a functional stage. Detailed studies on the cost and efficiency of the auxiliary power modules have not been conducted. This paper proposes a two-stage DC power supply module, using commercially available independent switching devices and employing the converter with a Buck and Half-Bridge LLC combined with a high-isolation transformer to achieve medium voltage DC power supply. This approach proposes a high isolation design while improving the overall module efficiency and also meets the need for further increasing voltage levels.