Conceptual Verification of AC and DC Hybrid Interconnection System for Decentralized DC Microgrids with Flexible Power Supply Configuration Using Multi Level Virtual Conductor

This research verifies the concept of a decentralized hybrid power conditioner that is interconnected to the conventional AC commercial grid and performs bidirectional power supply/demand coordination through the additional household DC distribution network. It is expected to realize a disaster-resistant and highly operational power infrastructure by enabling free placement of renewable energy and bidirectional power distribution among households using an additional DC bus. Conceptual simulation results confirmed that the decentralized interconnection system can supply power from power sources in the DC grid to the conventional AC load while preventing reverse power flow to the AC commercial grid. It was also shown that this system can operate as an uninterruptible power supply (UPS) against AC grid blackout, and it was possible to compensate for a power shortage in one household from the power sources of another household via DC bus without any communication among sources. Furthermore, it was confirmed that the reverse power flow prevention was realized through a prototype experiment.