刘浩,姜春阳,余也凤,袁建平,刘俭.屏蔽泄露变化对电压互感器串联加法的影响研究[J].电测与仪表,2019,56(9):124-127. liuhao,jiangchunyang,yuyefeng,yuanjianping,liujian.The Influence Caused by Shielding Leakage variation on the method of Series summation for Voltage Transformers[J].Electrical Measurement & Instrumentation,2019,56(9):124-127.
屏蔽泄露变化对电压互感器串联加法的影响研究
The Influence Caused by Shielding Leakage variation on the method of Series summation for Voltage Transformers
The method of Series summation for voltage transformers is an important theory and basis of the traceability of the national power frequency voltage proportional standard system. In the condition of high voltage, the working state of the upper transformer changes during the measurement process. The difference of the potential difference between the primary high voltage winding and shielding leads to the change of leakage current, which affects the measurement results. Considering the influence of shielding leakage, this paper re-deduces the series summation method, and analyses the measurement error caused by shielding leakage theoretically. Moreover, this paper proposes an improved method, which brings the leakage error equivalent into the measurement process skillfully. In this way, the leakage remains unchanged throughout the measurement process. The improved method is tested and validated in the end. The test results show that: the maximum deviation of specific deviation is 4.6 ppm for ratio error and 5 u rad for phase error. The improved measurement results are closer to the method of capacitor voltage coefficient that commonly used in the world.
