Abstract
In evaluating the uncertainty of the standard measuring system for lightning-impulse high voltage, which is composed of the standard voltage divider, the digital recorder and the calibrators, step-response tests of the standard voltage divider may be useful. In this paper, convolution algorithm is employed to calculate output impulse-voltage waveforms from measured step-response waveforms. The uncertainties of the peak-value measurement due to influence of a 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, error of the virtual front time of output waveforms is discussed. The front part of the step-response waveform, t<T30%, does not influences the error of the virtual front time. Therefore, for the standard voltage divider, step-response parameters, i.e. experimental response time, partial response time, settling time, and overshoot have almost nothing to do with the error of the virtual front time.
