特高压冲击电压测量系统线性度试验方法研究

随着特高压输电技术不断发展,为满足设备冲击耐受试验的要求,冲击电压测量系统的额定电压已升至7 000 kV左右,而目前冲击电压测量系统的校准电压在1 000 kV以内,其校准结果不能很好地满足实际试验需要,所以测量冲击电压测量系统在1 000 kV以上的线性度,是目前亟待解决的问题。笔者分析了现有的主要校准方法——直接比对校准、测量电容量,提出在1 000 kV内进行比对校准,1 000～5 000 kV采用增大电压等级逐级比对的实验方案,并以测量发生器效率变化的方法作为佐证,理论上该方案可基本满足7 500 kV冲击电压测量系统在1 000～5 000 kV范围内的工程试验需求。如果试验结果理想,可使用该方法建立一套传递标准,将全国所有特高压冲击测量系统进行比对。文章同时介绍了球隙、标准电容器、利用空间电荷、电场传感器等其他测量线性度的方法,讨论其各自的优缺点,如果投入实际应用,需要进一步的试验验证。

Experimental Methods Research on Linearity of UHV Impulse Voltage Measuring Systems

With the continuous development of UHV transmission technology,the rated voltage of impulse voltage measuring system has risen up to 7 000 kV for satisfying the withstand test requirements of electric devices.Based on the situation,the linearity measurement of impulse voltage measuring system above 1 000 kV is a problem needed to be resolved urgently since the calibrating voltage is below 1 000 kV which can’t be well positioned to meet the actual experimental requirements.The paper analyzes two existing calibration methods which are direct comparison calibration and capacitance measurement of dividers,and provides a testing plan to compare calibration when the voltage below 1 000 kV and to compare each level by increasing the voltage step by step when the voltage between 1 000 kV and 5 000 kV with measuring changes in generator efficiency as a proof.In theory,the plan can basically satisfies the engineering tests of 7 500 kV impulse voltage measuring system with the voltage is 1 000 kV to 5 000 kV.If the test results are satisfactory,a transfer standard can be built by the method in paper to compare all UHV impulse measuring systems in nation.The paper also introduces some other methods of measuring linearity such as sphere gap,standard capacitor,space charge,and field sensor.By discussing the methods’ respective advantages and disadvantages,they need further experimental verifications for practical application.