Long Zhaozhi, Liu Shaobo, Li Wenting, Lu Fei, Zhang Chi, Zhou Feng, Zhang Shuhan
National Center for High Voltage Measurement, China Electric Power Research Institute, Wuhan 430074, China.
State Grid Key Laboratory of On-Site Test Technology on High Voltage Power Apparatus, State Grid Hubei Electric Power Research Institute, Wuhan 430074, China.
Rev Sci Instrum. 2018 Nov;89(11):115007. doi: 10.1063/1.5031910.
In this paper, the theoretical analysis, design, and performance of a wide-band precision capacitive voltage divider are presented. Based on the equivalent circuit model of the traditional capacitive divider, the influence factors of response characteristic and non-linearity are analyzed. The advantage of a compressed-gas capacitor as the high voltage part of the wide-band capacitive voltage divider is studied. The measured high voltage capacitance of the compressed gas capacitor is 9.854 pF. The theoretical value of the temperature coefficient is 2 ppm/°C, and the relative variation of the capacitance is -50 ppm with AC voltage (50 Hz) from 50 kV to 550 kV. The scale factor is estimated by AC voltage calibration, and the complete result of the calibration is expressed: = 10 340(1% ± 0.026%) for a coverage probability of not less than 95% ( = 2). The step response and amplitude-frequency of the damped capacitive divider are analyzed and measured. Last but not least, the proposed capacitive divider prototype is tested to measure the switching impulse voltage and lightning impulse voltage. According to the test results, the proposed capacitive divider possesses good dynamic behavior and non-linearity and can measure the AC voltage, impulse voltage, and transient overvoltage in the field calibration.
本文介绍了一种宽带精密电容分压器的理论分析、设计及性能。基于传统电容分压器的等效电路模型，分析了响应特性和非线性的影响因素。研究了采用压缩气体电容器作为宽带电容分压器高压部分的优势。测得压缩气体电容器的高压电容为9.854皮法。温度系数的理论值为2ppm/°C，电容的相对变化在交流电压（50Hz）从50kV到550kV时为-50ppm。通过交流电压校准估算比例因子，校准的完整结果表示为：对于不小于95%的覆盖概率（k = 2），比例因子为10340(1% ± 0.026%)。对阻尼电容分压器的阶跃响应和幅频特性进行了分析和测量。最后，对所提出的电容分压器原型进行了测试，以测量操作冲击电压和雷电冲击电压。根据测试结果，所提出的电容分压器具有良好的动态特性和非线性，能够在现场校准中测量交流电压、冲击电压和暂态过电压。
