Abstract:The 10kV feeders’ protection of the active distribution network generally adopts the traditional relay protection scheme, but the access of the DGs make the grid structure of the distribution network complicated, and the traditional protection method cannot meet the protection requirements of the active distribution network. In order to solve the problem that the existing protection methods are vulnerable to factors such as system parameters and fault types, and it is not easy to identify single-phase ground faults, a virtual impedance-based feeder segmentation protection configuration scheme is proposed. The fault identification principle based on virtual impedance method is analyzed. The ratio of the voltage sequence component and the corresponding current sequence component is taken as the virtual impedance. The fault location can be completed by discriminating the characteristics of the virtual impedance. The distribution network model is built by MATLAB/SIMULINK. The simulation results show that the virtual impedance criterion can quickly and accurately identify various types of short-circuit faults. The protection action is faster when faults occur in the area, and the protection does not act when the faults occur outside the area, and the discrimination result is not affected by the system parameters, and is suitable for the complex and variable active distribution network, with high reliability and selectivity.