A new protection scheme for DC microgrid using line current derivative

Protection scheme for AC transmission systems are well understood and matured. On the other hand, DC system is still facing a challenge in developing proper protection scheme because of its natural characteristics. A protection scheme, which utilizes some of the developed techniques for AC system, and modified to suit the DC system characteristics, is proposed in this paper. The scheme is based on the concept of DC current profile under transients, which depends on the fault location. This property is combined with the directional feature to achieve the protection of a DC microgrid. The proposed scheme is demonstrated on the ring type DC microgrid system, which is able to detect the fault in the DC system, and also ensure its backup protection. The proposed concept is verified and tested through MATLAB/Simulink simulations.