For distribution networks with high-permeability inverter-interfaced distributed generations (IIDGs), the fault characteristics of IIDG are firstly analyzed, then, a method for analyzing the maximum short-circuit current that can be provided by IIDGs in active distribution network is proposed. Furthermore, a novel integrated current amplitude protection principle is proposed by comparing the two ends of the line positive phase current amplitude which achieves low-cost and high-reliability compatibility. The model of 10kV active distribution network was built by PSCAD to comprehensively simulate the influence of different DG permeability, fault type, transition resistance and other factors on the protection principle. After theoretical analysis and simulation, it is proved that the scheme can accurately solve the fault location problems, the data used is simple, the resistance to transition resistance is excellent, and the ability of resisting synchronization error is strong.

active distribution network; IIDG; fault characteristics; current amplitude comparison; positive sequence components.