The flexible loop-closing device employs power electronic equipment to interconnect two or more distribution networks, enhancing the reliability and power quality of the distribution grid, balancing the load across interconnected networks, supplying power to faulty networks, and meeting the uninterrupted power supply needs of critical users. The company's flexible loop-closing device adopts a five-level back-to-back topology, which improves DC voltage utilization while reducing the size and weight requirements for AC-side filters.