DC Microgrid is a small-scale power system including loads, distributed generation units, and energy storage devices. Due to the grid structure and local production and consumption, all microgrids have the benefits of higher efficiency, greater reliability, and more efficient energy management systems than conventional power systems. In addition, DC microgrids also have some advantages such as easy integration of distributed generation, much transmission capacity, great safety, and eliminating resources synchronization problems. Nowadays, DC microgrids can be a good alternative to parts of the traditional power systems while DC microgrids protection are considered as one of the main barriers to achieving this goal. DC microgrid protection has many challenges including the special fault current characteristic coupled with the extreme transient caused by the capacitor discharge current, the absence of a complete and comprehensive standard for DC fault current, absence of zero crossing in the DC current, impact of earth system on earth fault current, very fast protection requirement to prevent damage to some equipment , high cost of DC protective device, more limited performance of the conventional protection, and the much dependency of the protection schemes on the fault resistance. These problems have made DC microgrids protection as an attractive research and engineering subject. Keywords: DC microgrid - Power Systems protection - Overcurrent protection - Differential protection – DC microgrid fault current characteristic
