Analysis of capacitive voltage rise during off-line partial discharge tests on power transformers  

作　　者：王烜 曹晓珑 李云阁 刘英 

机构地区：[1]State Key Laboratory of Electrical Insulation for Power Equipment, Xi＇an Jiaotong University, Xi＇an 710049, P. R. China [2]High Voltage Department, China Electric Power Research Institute, Beijing 100085, P. R. China

出　　处：《Journal of Shanghai University(English Edition)》2007年第5期490-495,共6页上海大学学报（英文版）

摘　　要：Partial discharge test on a transformer is carried out according to the items in IEC 60. During the test, unproved measuring system is calibrated by proved system at a voltage no less than 50% the rated testing voltage. The result is then extrapolated linearly, leading to an error related to the distribution of stray capacitance, which varies with the testing frequency, especially to large transformers. In this paper a factor, named the capacitive rise fact, is introduced to assess the rise. The factor can be adjusted to some extent by changing the reactance that is connected to the LV side of the testing circuit to lower the capacity of the power source. However, the factor changes when the voltage divider on the high voltage side is removed after the voltage ratio has been calculated, and a great error is resulted under unfavorable conditios.Partial discharge test on a transformer is carried out according to the items in IEC 60. During the test, unproved measuring system is calibrated by proved system at a voltage no less than 50% the rated testing voltage. The result is then extrapolated linearly, leading to an error related to the distribution of stray capacitance, which varies with the testing frequency, especially to large transformers. In this paper a factor, named the capacitive rise fact, is introduced to assess the rise. The factor can be adjusted to some extent by changing the reactance that is connected to the LV side of the testing circuit to lower the capacity of the power source. However, the factor changes when the voltage divider on the high voltage side is removed after the voltage ratio has been calculated, and a great error is resulted under unfavorable conditios.

关 键 词：TRANSFORMER stray capacitance partial discharge test. 

分 类 号：TM4[电气工程—电器]