摘要详情

ID / 提交时间

41 / 2024-03-29 16:48:18

标题

Prediction of Lightning Impulse Voltage Induced Breakdown in Contact Gap of Vacuum Interrupters

关键字

prediction of breakdown voltage, lightning impulse voltage, vacuum interrupter, contact gap, anode temperature

主题及专题

7)Fundamental physics in Switchgear

状态

终稿

作者

Weigang Feng / Shaanxi Baoguang Vacuum Electric Device Co., Ltd.

Hongtao Xie / Shaanxi Baoguang Vacuum Electric Device Co., Ltd.

Zhiyuan Liu / Xi’an Jiaotong University

Yongxue Yue / Shaanxi Baoguang Vacuum Electric Device Co., Ltd.

Peng Li / Shaanxi Baoguang Vacuum Electric Device Co., Ltd.

Hui Ma / State Key Laboratory of Electrical Insulation and Power Equipment； China； Xi’an Jiaotong University； Xi’an 710049

Beibei Li / Shaanxi Baoguang Vacuum Electric Device Co., Ltd.

摘要

Breakdown voltages of contact gaps are important for the design of vacuum interrupters, especially for high voltage vacuum interrupters. In order to increase the accuracy for insulation design of the vacuum interrupter, breakdown voltage should be predicted to determine the contact gap. The breakdown theory of contact gap in vacuum was unclear. Furthermore, the breakdown of contact gap in vacuum was influenced by many complex factors. By analyses the process and characteristics of the breakdown in contact gap, we proposed a hypothesis that the maximum temperatures were equal at breakdown moment for two anodes which had identical materials and production processes. Base on this hypothesis, we established an expression to associate the breakdown voltage of a contact gap at two different gap distances. We designed a special vacuum interrupter to measure the breakdown voltage for the contact gap at different gap distances. Negative polarity lightning impulse voltage (1.2×50 μs

) was applied by an up-and-down method. Moreover, the 50% breakdown voltage was used to represent the breakdown voltage. The measured U₅₀ were used to calculate and verify the breakdown voltage of the contact gap. Experiment results proved that the U₅₀ from this prediction method was very closed to the U₅₀ from measurement. The relative error of the calculated U₅₀ from this prediction method didn’t exceed 6% when the difference between two contact gap distances was small than 3.5 times. Furthermore, the relative error of U₅₀ from this prediction method was much less than relative error of U₅₀ from Slade’s prediction method. So that the prediction method is useful for vacuum interrupter design.