Research on DC Microgrid Protection Scheme Based on Fault Current Controller

Abstract

With the development of distributed power supply and the increasing application of DC load, DC micro-grid can more effectively access to distributed power supply and DC load and it will be widely used in the future power grid. Because the DC micro-network can be connected to many distributed power sources, when a branch of the system fails, each power source will provide fault current to the fault point, which makes the current flowing on many circuit breakers rise rapidly, and leads to the protection misoperation. In this paper, the inter-pole fault of DC microgrid is taken as the research object, and the fault characteristics of DC microgrid are analyzed. On this basis, a protection scheme based on fault current controller is proposed to limit the current, so that the protection can operate accurately. Finally, the feasibility of the proposed scheme is verified by simulation with PSCAD/EMTDC.