Breakdown and Partial Discharge Inception Voltages Characteristics in N2, CO2, Dry air and SF6 at Lightning Impulse Voltage

Summary

The authors investigated partial discharge inception voltages (PDIVs) and breakdown voltages (BDVs) of the potential gases like N2, CO2 and dry air as well as SF6 under the quasi-uniform field (clean condition) and the non-uniform field (particle condition). The non-uniform field was formed by a metallic particle with 3 mm in length which was attached on the high voltage sphere electrode. The gas pressure was changed from 0.1 MPa to 0.5 MPa, and standard lightning impulse voltages were applied. As a result, under the quasi-uniform field, the negative minimum BDVs of all the gases were lower than those of the positive ones in general. The negative minimum BDVs of the potential gases ware about 35% to 45% of that of SF6. Under the non-uniform field, the 50% PDIVs of SF6, CO2 and dry air increased linearly as the gas pressure increased, while the positive 50% BDVs of SF6, CO2 and dry air seemed to saturate to the gas pressure. The positive 50% BDVs of the potential gases were about 30% to 70% of that of SF6. Using these results, the authors discussed the influence of a metallic particle on the BDV. The values of VBD(particle)/VBD(clean) in all the gases decreased as the gas pressure increased. Under the same gas pressure in the range between 0.2 MPa and 0.6 MPa, the value of VBD(particle)/VBD(clean) in SF6 was about 20% smaller than those in all the potential gases. In terms of PD detection, the authors discussed the relationship between PDIVs and BDVs for all the gases.

Additional informations

Authors

Goto Shigehiko, Kobayashi Kinya, Kato Tatsuro, Rokunohe Toshiaki, Zhang Qiaogen, Petrovic