Bidirectional Soft Switching Current Source DC-DC Converter for Residential DC Microgrids

This paper presents a novel asymmetric bidirectional isolated DC-DC converter topology with current source and voltage source terminals. The topology can be implemented in renewable, supercapacitor, battery and dc microgrid applications. It features two bidirectional and two reverse-conducting switches in the current-source bridge side. Thanks to special control algorithm it provides soft switching of all semiconductors under wide range of operating conditions with low energy circulation. This is achieved without any dedicated snubbers or clamp circuits. The converter theoretical performance at various operating conditions is assessed and compared with other competitive solutions in terms of rms current stress on the transformer and semiconductors. Steady-state operation and design aspects of the converter are presented and verified experimentally with 500 W prototype.