冲击电压分压器线性度试验研究

冲击电压测量系统在溯源过程中通常使用低压直流源或冲击电压校准器测量分压器的刻度因数,因而必须考虑分压器线性度对测量系统测量不确定度的影响问题。在现今我国尚未建立标准系统的情况下,提出用试验的方法测量分压器的线性度:首先用线性度可忽略的电阻分压器R200S得到冲击电压发生器的线性度,采用直流分压器测量冲击电压发生器的充电电压,测量试品分压器HCR600示值与充电电压的比值,修正发生器的影响后得到分压器的线性度,结果显示HCR600的线性度单调下降,从+0.4%至-0.8%,正负极性最大差值为0.14%,且负极性的线性度优于正极性。然后进行试验验证:用线性度已知的500kV电阻分压器与HCR 600进行比对而得到线性度变化曲线,并与之前的试验结果进行比较,两者变化趋势相同,相同电压下最大差值点仅为0.15%。说明此方法可较准确地测量分压器的线性度,可用于冲击电压建标时的试验验证,发生器等试验设备满足一定条件时此方法也可用于特高压冲击设备的校准。

Experimental Research on Linearity of Impulse Voltage Divider

In the process of tracing of impulse voltage measuring system,a low voltage DC source or a low voltage impulse calibrator is always used to measure the scale factor of divider,and the effect of linearity of divider on uncertainty of measurement system must be considered.Under the condition that the national standard is not yet established,we proposed an experimental method for measuring the linearity of divider with the voltage rise.We used low voltage resistance divider R200Sto measure the linearity of generator,and obtained the linearity curve.With the increase of charging voltage,the linearity of divider could be obtained by precisely measuring the charging voltage of impulse voltage generator and the ratio of the indicating value of the corrected sample divider HCR600to the charging voltage.The result shows that,the linearity of HCR600decreases from +0.4% to-0.8%;the maximum difference between positive polarity and negative polarity is 0.14%,and the linearity of negative polarity is superior to that of positive polarity.Moreover,we used a 500kV resistance divider,of which the linearity was compared with that of HCR600,to obtain the linearity curve,showing that two curves matched basically,and the maximum difference between them was 0.15%at the same voltage.The results show that the proposed method can be used to accurately measure the linearity of divider,can be used as experimental verification in the process of establishing the national standard,and can be used to calibrate the ultrahigh voltage impulse voltage of measuring equipment when equipment satisfies some requirements.