Bidirectional DC-DC Converter with High Voltage Step-Up/Down Ratio for the Interconnection of Unipolar and Bipolar DC Microgrids

In the context of actual electrical energy distribution systems, DC microgrids are beginning to become very significant. There are several possible structures for this kind of microgrids. However, there are two structures that have been emerged as the most adopted, namely the unipolar and the bipolar DC microgrids. In this way, their interconnection could be fundamental for several applications. Since these microgrids can be characterized by very different voltage levels, the interconnection must take this into consideration. So, in this paper, a new bidirectional DC DC converter with a high voltage step-up/down ratio is proposed for the interconnection of these two DC microgrids. The converter is also characterized by a non-isolated configuration and is able to transfer energy between the DC microgrids in a way that supports the balance of the bipolar infrastructure. Simulation studies of the proposed solution for transferring energy in both directions are presented. The results show that the proposed solution is in accordance with what was expected.