Long‐Term Stability of Reference Measuring System for Impulse High Voltage

Long‐term stabilities of shielded resistive voltage dividers for lightning and switching impulse, employed as the reference dividers of Japan High‐voltage Impulse testing Laboratory Liaison (JHILL) are investigated. The DC scale factors and the step‐response parameters have been annually measured for 20 years. Annual variations of impulse parameters, namely the peak value, the front time, and the time to half value of the calculated waveform from the step‐response waveforms by the convolution algorithm are investigated. Furthermore, long‐term stabilities of reference low‐voltage impulse calibrators are investigated. The parameters of circuit elements of the calibrators have been annually measured for 18 years. The impulse parameters of the output waveforms of the calibrators are calculated, and the annual variations of them are investigated. After the detailed evaluation, it can be expected that the measurement system employing the voltage dividers and the calibrators, including the analytical method of the data, has the similar performance to those of NMIs of developed countries. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.