To protect the power converter station systems and cables that constitute the DC distribution system, it is significant to limit the steep increase in the fault currents and isolate the fault section quickly. And almost short fault in the distribution system consists of temporary incidents. Therefore, in this case, it is important to implement restarting DC systems without the propagation of power supply after isolation and clearance of faults. Different from AC systems, DC systems have no current zero-crossing intervals, which results in the occurrence of switching surges and over-currents when restarting operation whether the fault is cleared or not. Accordingly, not only fault detection and protection ability but also an effective protection coordination strategy are required for the stability and reliability of DC distribution systems. In this paper, a DC Short fault protection circuit for a DC output converter is proposed, and the analysis and design parameters of protection circuit is presented. In addition, compared to conventional reclosing techniques, proposed soft-reclosing enables fast fault detection and stable recovery from transient faults.
