Application of Step-Response Test for Evaluation of Uncertainty of Standard Measuring System for Lightning-Impulse High Voltage

摘要

In evaluating the uncertainty of the standard measuring system for lightning-impulse high voltages, which is composed of a standard voltage divider, a digital recorder, and calibrators, step-response tests of the standard voltage divider may be useful. In this paper, a convolution algorithm is employed to calculate the output impulse voltage waveforms from measured step-response waveforms. The uncertainties of peak-value measurement due to the influence of the nominal epoch, uncertainty of the peak-value measurement due to dispersion of the AC scale factor, and uncertainty of the virtual front-time measurement due to long-term stability are evaluated. Furthermore, the error of the virtual front time of the output waveforms is discussed. The front part of the step-response waveform, t < T_(30%), does not influence the error of the virtual front time. Therefore, for the standard voltage divider, the step-response parameters, that is, the experimental response time, partial response time, settling time, and overshoot, have almost nothing to do with the error of the virtual front time.