A Z-Source-Based Bidirectional DC Circuit Breaker With Fault Current Limitation and Interruption Capabilities

DC microgrids have some attractive characteristics, which have being investigated to utilize in future electrical power systems. However, they have several essential challenges, such as limiting and interrupting fault current, which should be rectified to have high-performance dcmicrogrids. In this paper, an efficient dc bidirectional fault current limiter and interrupter (FCLI) based on Z-source topology is proposed to overcome some of the challenges in dc microgrids. The FCLI is a multifunction device, by which power flow direction control, circuit breaking, fault current limiting, and interrupting in a dc system can be handled. Analytical analysis of the FCLI is discussed in detail for different operation modes. Performance of the proposed FCLI in the different operation modes is evaluated using some simulations and experiments. The results confirm high capability of the device to realize appropriate operation in dc systems. Fast response time of fault current limitation and interruption, simple and reliable structure, and negligible conduction loss are the main features of the proposed FCLI.