DC power distribution can be more effective than AC power distribution in the built environment. However, DC bus protection by using DC circuit breaker (CB) can be costly. This paper proposes a protection method which adopts power electronic-based methods to isolate the faulted segment instead of using CBs. Starting with investigations on the architecture of DC power distribution system for typical data center as an example of DC micro-grid, and the requirements on its protection, the currents of different kinds of faults and the possible ways to eliminate fault currents are discussed. Then, the details of the proposed protection method are introduced. Finally, the effectiveness of the proposed method is demonstrated by simulations and comparisons using the PSCAD platform.