電気トリー進展に伴う部分放電の極性効果と放射電磁波

抄録

We have investigated characteristics of radiated electromagnetic (EM) waves from positive and negative partial discharge (PD) in epoxy resin and cross-linked polyethylene. As a result, we found that there is correlation among EM level from PD, positive PD current and electrical tree. Therefore, growth of an electrical tree makes up a lot of positive PD.  Also, we have investigated characteristics of frequency region of radiated EM waves from PD in air, insulating oil and liquid epoxy in addition to above insulators. EM waves were detected in the frequency region of 40-300 MHz from positive and negative PD in epoxy resin and cross-linked polyethylene. Also, EM waves were detected in the frequency region of 40-150 MHz from positive and negative PD in air. And in the case of insulating oil and liquid epoxy, EM waves were detected in the frequency region of 40-150 MHz from positive PD, and 40-250 MHz from negative PD. Frequency region was different depending on materials or polarity of discharge. Results of the study, we considered that the cause is difference of the electric field strength at partial discharge occurring.