Traveling Wave Fault Location Technology in Distribution Network Based on Non-Contact Sensor

Abstract

In view of the fact that traditional traveling wave sensors need to be directly connected with primary high-voltage equipment, the layout is not flexible, construction is inconvenient, and the traditional ferromagnetic coil traveling wave sensors have problems such as low sensitivity and magnetic saturation. The use of magnetoresistance chip to design non-contact traveling wave sensor is proposed. Theoretical analysis of the magnetoresistance chip is carried out, and the tunnel magnetoresistance chip is selected as the non-contact sensor magnetic sensitive element; the non-contact sensor hardware circuit is designed, the sample is trial-produced, and the experimental test is carried out. The experiment shows that the non-contact sensor can detect a traveling wave signal with a bandwidth of 100kHz∼5MHz, which meets the requirements of traveling wave detection for common fault types in the distribution network. A demonstration project has been built, and operation shows that the non-contact sensor can successfully detect single-phase grounding, interphase short circuit, lightning strikes and other fault types traveling wave signal, sensitivity is higher than traditional traveling wave sensor, positioning error is less than 150m.