Single phase to ground fault location method of overhead line based on magnetic field detection and multi-criteria fusion

Abstract

The distribution network has many branches and complex structure, and the existing protection is difficult to achieve accurate fault section location. Moreover, the monitoring device based on electrical quantity has some problems, such as high cost, power failure in installation and maintenance, and the information collected can not meet the requirements of distribution network for operation monitoring. Therefore, fault location is still a difficult problem in the existing distribution network. The magnetic field (MF) under the overhead line can reflect the change of line current, locate the fault position between two pole towers, and the magnetoresistive sensor has the advantages of low cost and uninterrupted installation and maintenance. Therefore, in recent years, the non-contact fault feeder detection and location method based on MF has begun to develop rapidly. Based on the similarity analysis of MF waveform under overhead line from different aspects by using five criteria: relative entropy, Frobenius norm, maximum mean discrepancy, cosine similarity and correlation coefficient, it proposed a multi criteria fusion fault location method based on D-S evidence theory, which makes full use of the advantages of each criterion and overcomes the limitations of single criterion. Simulation results show that the method is not affected by conductor sag, galloping and data window length, and it fit for the noise interference and high impedance fault (HIF). Compared with the other MF method, the method has stronger adaptability.