Interlinking Unipolar and Bipolar DC Microgrids Using a Bidirectional DC-DC Converter With Voltage Balancer Support

Due to the integration of renewable energy sources into the electrical networks, DC microgrids are becoming a very interesting alternative to AC networks. This paper presents a new bidirectional DC-DC power converter designed to interlink unipolar and bipolar DC microgrids. The proposed converter allows bidirectional power flow and, under unbalanced conditions and also supports the voltage balance of bipolar DC microgrids. The DC-DC converter was also designed to provide an input-output high-voltage gain ratio in buck or boost mode, achieving quadratic gains in certain modes. The proposed converter is also able to operate as a standalone voltage balancer for the bipolar DC micro grid whenever necessary, depending on the requirements and control strategy. Some simulation results of this new bidirectional DC-DC converter are presented and discussed.