Abstract:As a large number of distributed power sources are connected to the distribution network,the structure of the distribution network is changed from a feed-supply radiation network to a multi-terminal power network. The pilot protection scheme is the most effective way to solve the protection problem of distribution network with DGs. Limited to the level of distribution network hardware and communication,data on both ends of lines can't be sampled synchronously by pilot protection. To solve the problem above,a fault information self-synchronizes technology is put forward. As the moment of fault is the same time for both ends of lines,the technology uses the moment of fault as a time reference. The measurement about the interval between two adjacent peak points of the same trend before and after the fault time is carried out,and then intervals is used to calculate the current phase changes direction,which can effectively overcome the difficulty of acquisition of the synchronous data in distribution network. Based on fault information self-synchronizes technology,the novel pilot protection determines the fault location by comparing the direction of phase change on both sides of the protected circuit. Simulation results verify the accuracy of fault information self-synchronization technology,the novel pilot protection has good operation characteristics.