DC Microgrid Testbed for Testing Operation between Power Converter and DC Microgrid under Fault Situations using PHIL Simulation Technique

Abstract

A DC microgrid has received a lot of attention since it can link various distributed power sources. Accordingly, studies related to grid fault situations such as line to line and line to the ground fault have been conducted to improve grid reliability. However, a utility grid failure and a DC bus voltage oscillation have not been reported or have not been fully validated by previous research. In this paper, a 20-kW DC microgrid testbed that can simulate various grid fault conditions without any additional grid facilities and dangerous experiments is proposed. It can emulate the blackout of the DC microgrid due to the utility grid failure, drastic load increments, and the DC bus voltage oscillation. The effectiveness of the proposed testbed is verified by using the OP5707 real-time simulator with a 3-kW prototype three-port dual-active-bridge (DAB) converter.