基于电压加法原理的直流分压器校准方法  

Calibration Method for High DC Voltage Dividers Based on Voltage Summation

作　　者：章述汉 王乐仁 

机构地区：[1]国家高电压计量站,武汉430074

出　　处：《高电压技术》2006年第11期53-56,共4页High Voltage Engineering

摘　　要：电阻分压器在低电压下的分压比可以用高压臂和低压臂电阻计算,但高电压下的分压比还需要确定其电压系数。过去使用标准分压臂插入法测量直流分压器的电压系数,不确定度难以达到10-4量级。用影响量分项评估综合方法又不能给出实际值。应用直流电压加法技术,可以用计量测试手段实测直流高压分压器在各个工作电压下的误差和不确定度,测量结果的标准不确定度在500 kV等级可达到1.2×10-5。When applietl voltage is raising a high DC voltage divider is heated, and the ambient electric and temperature fields are varied. It causes the change in ratio of the divider. This phenomenon is called voltage dependence ratio variation. Ratio of a resistive divider can be determined by measuring resistances of ratio arms. But the ratio varia- tion under higher voltage should be known. Last days voltage dependence ratio variation of a high DC voltage divider could be measured by connecting auxiliary standard divider in series with tested divider. But the accuracy can rarely reach the range of 10^-4. So far the voltage dependence of high DC; voltage dividers are derived by considering together with corona, temperature, leakage current of dielectric media and thermo-electromotive. The actual amount of voltage dependence is left unknown. The DC voltage summation method is a new way to measure voltage dependence of resistive dividers at rated voltage up to 500 kV and higher. The procedure is inter-comparison with three resistive voltage dividers： one tested divider, one auxiliary divider with the same rated ratio as the former, the third one also has the same ratio but keeps another extended ratio that is half of the common ratio. The last two dividers can be connected in series and compared once more with the first one. The results of comparison after three times can give us information of the error variation of the tested divider at a certain voltage. The calibration uncertainty ever reaches 1.2×10^-5 at voltage 500 kV.

关 键 词：直流分压器 电压加法 校准 电压系数 屏蔽 测量不确定度 

分 类 号：TM933.213[电气工程—电力电子与电力传动]