Design and Implementation of a Multi-Output Flyback Auxiliary Power Supply for Bipolar DC Grids

This article introduces an auxiliary power supply (APS) designed explicitly for bipolar DC grids, utilizing a flyback topology for robust and efficient operation. Central to our design is a high-voltage 3300 V silicon carbide (SiC) MOSFET and a planar transformer comprising one primary, one auxiliary, and two secondary windings. This APS uniquely addresses the resilience requirements of bipolar grids by enabling seamless switching between poles in the event of a pole failure, thus maintaining continuous power supply. Control is achieved through the UC3844A integrated circuit from Texas Instruments. The converter’s effectiveness is demonstrated through experimental validations, confirming its suitability for advanced bipolar DC grid applications.