标准冲击电压校准器的研制与溯源

Traceability and Design of a Standard Impulse Voltage Calibrator

冲击电压测试设备及仪器需要进行校准以保证冲击电压试验结果的准确性,为此研制了一种校准冲击电压测试设备仪器的冲击电压校准器。在介绍了设计原理后进行了不确定度分析和量值溯源。校准器的电压量程范围为30～1000V,能产生满足IEC60060-1:1989的标准雷电和操作冲击波,并且通过高精度直流电压源以及组成冲击回路的高精度、高稳定度的电感、电容、电阻等基本元器件,从而将冲击电压的参数经过这些元件的不确定度传递到相应的直流电压标准及元件标准上去。经过不确定度来源的分析和评估,校准器所产生冲击电压峰值的不确定度为0.05%,时间参数的不确定度<0.5%,可作为校准冲击电压测试设备以及仪器的标准波源。

The lightning and switching impulse voltages are standardized in IEC 60060-1 and they are used in high voltage testing of high voltage apparatus. As a part of calibrating a system for measuring high voltage lightning impulses, a method of calibration is needed to characterize the response of the digitizer, attenuators, and cables used to measure the output of a high-voltage impulse divider. A new method is to apply a known impulse waveform with calculated uncertainties and to measure the response of the various system configurations. The waveform generators that accomplish this are termed ＂impulse calibrators. ＂ The calibrator described in the paper is intended for calibrating the output of a divider. The design and construction of a calibrator for lightning and switching impulse voltage measuring instruments are presented. The calibration system consists of a controlling computer, programmable voltage source, digital voltmeter, and a set of impulse circuits for different standardized impulse shapes. The calibrator generates standard lightning and switching impulses according to IEC 60060-1：1989. The peak value, time to peak, front time, and time to half value of the generated impulse are calculated from the calibrated values of the components of the impulse forming network. The operating voltage range of the calibrator is from 30V to 1000 V. The estimated uncertainty for the impulse peak value is 0. 05 % and for the time parameters, less than 0. 5 %. The calibrator can be used as the primary reference of impulse voltages for calibration of high voltage and EMC surge measuring instruments.