DC microgrids have gained increasing attention over the decades. Compared to AC micro grids, they have higher power delivery ability, higher efficiency, and fewer control levels. Although DC microgrid has better performance in many areas, they still face a significant challenge in protection. That is due to the feature of DC fault with no zero-crossing point, and there is no standard for protection. Thus, it is essential for DC microgrid to detect faults timely and have a comprehensive protection scheme to ensure the system work in a stable state. In this thesis, a comprehensive review of fault types and the protection scheme in the DC microgrid is presented. A hybrid protection method, including all-phase FFT and the window-by-window method, is proposed to detect the DC series arcing fault, which can detect the fault timely. Moreover, discrete wavelet transforms together with the derivative of teager energy method are provided to detect different fault types, such as line-to-line fault and DC series arcing fault. The extensive case studies including different series arc fault models and different disturbances have been conducted. Moreover, a novel differential evolution-based protection framework for DC microgrids is presented. Firstly, a simplified DC microgrid model is adopted to provide the analytical basis of the DE (differential evolution) algorithm. The simplified model does not sacrifice performance criteria in steady-state simulation, which is verified through extensive simulation studies. A DE-based novel overcurrent protection scheme is then proposed to protect DC microgrid. This DE method provides an innovative way to calculate the maximum line viii current, which can be used for the overcurrent protection threshold setting and the relay coordination time setting. The detailed load condition, battery discharging power, and solar irradiance can be obtained by the proposed DE-based method to work out each maximum line current. Finally, extensive case studies involving faults at different locations are performed to validate the proposed strategy’s effectiveness. The expandability of the proposed DE-based overcurrent protection framework has been confirmed by further case studies in seven bus mesh systems.