The Electric Discharge Detection Method in the Low Vacuum Region of Vacuum Interrupter

Abstract

SUMMARY The vacuum circuit breaker (VCB) achieves the high current interrupting capability in the pressure lower than 10 Pa to 5 Pa. When gas pressure increases, the breakdown voltage of a VCB decreases according to Paschen's law, and in the case of small leak, the partial discharge will occur in the VCB and the high frequency electromagnetic waves are radiated. So, we have developed the partial discharge detection system using an antenna with the region from 200 MHz to 300 MHz placed inside the VCB. However, if the partial discharge occurs outside the VCB, the detection system leads to misdetection as the partial discharge inside the VCB. In order to improve the performance of partial discharge detection, the outputs of antenna voltages inside and outside the VCB are investigated.

Real-Time Monitoring of the Vacuum Degree Based on the Partial Discharge and an Insulation Supplement Design for a Distribution Class Vacuum Interrupter

“…shows the Paschen curve of the gas. Based on prior research [9][10][11] and in Figure 2, it can be seen that the dielectric strength rapidly decreases at a certain vacuum degree. Figure 3 shows that partial discharge occurs in the VI in relation to an increase in the internal pressure.…”

“…Moreover, real-time monitoring of the vacuum degree is difficult, and related research is scarce. Prior to the research carried out in [8][9][10][11][12][13][14][15], only studies on the partial discharge characteristics of the VI according to the vacuum degree were conducted while important factors of real-time monitoring, such as the problem of the trigger value and the duration of the partial discharge signal, were not investigated.…”