Traceability Method of 100kA Impulse Current Measuring System

The impulse current is a transient current waveform, which has a short duration and cannot be repeated, so it is difficult to evaluate the influencing factors of measurement errors. This paper studies the traceability method and uncertainty evaluation model of impulse current measurement device, and the influencing factors of measurement error are analyzed. The impulse calibrator which can output standard double exponential impulse current waveform with specific time parameters (8/20) is developed. The peak value and time parameters can be traced back to the national standards of DC voltage and capacitance, inductance and resistance. The measuring system consists of standard impulse shunt and measuring instrument, whose peak current and time parameters can be traced respectively. The impulse scale factor of the impulse current measuring system is the product of the impulse scale factors of shunt and digital recorder. Finally, the performance of the measuring system is evaluated, and the expanded uncertainty of scale factor and time parameter is 0.4% (k=2) and 0.8% (k=2) respectively.