Research on partial discharge monitoring system of switchgear based on wireless distributed TEV sensors

Metal enclosed switchgears, which have been widely used, play an important role in power distribution network. PD detection is an effective way to identify potential faults and inspect insulation defects for high-voltage switchgear. Occurring inside a switchgear, PD would emit electromagnetic (EM) wave that propagates and leaks to the outside, and it also excites the surface current on the metal wall of the switchgear. As a result of current and impedance of the material, it would produce a transient earth voltage (TEV) that could be detected by TEV sensor. Therefore, PD monitoring based on the non-intrusive TEV method has the great engineering application value for estimating insulation condition of switchgear. A wireless distributed on-line monitoring system based on TEV detection method is proposed in this paper. The results show that the TEV PD online monitoring system has the characteristics of high reliability, anti-interference ability, less maintenance.