Abstract:Aiming at the difficulties that the existing fault location methods are complex to implement and the traveling wave transmission speed cannot be accurately calculated due to the influence of frequency-dependent changes in distribution network line parameters, a fault location method for complex distribution networks is proposed based on the multi-terminal traveling wave frequency matrix, which does not rely on wavefront time information. By analyzing the relationship between the inherent frequency principal component of the fault traveling wave and the transmission distance, the reference terminals of each branch node are defined, and the difference between the benchmark inherent frequency matrix before the actual fault occurs and the fault inherent frequency matrix after the actual fault occurs is calculated, ultimately obtaining the corresponding fault branch determination principle. Based on the determination of the fault branch, the reference terminal is selected according to the principle that the path from the fault point to the reference terminal does not pass through branch nodes or passes through the fewest number of branch nodes, and the wave speed under the principal component of the fault inherent frequency of the corresponding reference terminal is calculated, thereby accurately locating the fault point. Simulation results show that the proposed method does not require detecting the wavefront time of the traveling wave, accurately describes the situation of any branch fault in the distribution network topology by constructing a multi-terminal frequency matrix, ensures reliable determination of the fault branch, and achieves matching between the frequency component and the wave speed, greatly improving the accuracy of fault location. Moreover, the location results are not affected by the fault location, type, transition resistance or initial phase angle.