Reference Switching Impulse Voltage Measuring System Based on Correcting the Voltage Divider Response With Software

The performance of a high-voltage switching impulse (SI) measurement system is highly dependent on the characteristics of the used voltage divider. Self-built or commercial voltage dividers do not always fulfill the requirements set for reference-level devices. Software corrections to improve the non-ideal divider response are easy to implement. This article describes the traceability and performance of the SI measurement systems of VTT MIKES up to 400 kV. Traceability is based on a calculable impulse voltage calibrator, which is used for calibration of a reference digitizer and a 10-kV divider. The 10-kV divider is then used to calibrate the 400-kV modular divider. Responses of both dividers are corrected using two different software methods. Implementation of these software methods allows state-of-the-art impulse parameter uncertainties. The most significant uncertainty component of time to peak is related to its definition and evaluation according to IEC 60060-1:2010 and IEC 61083–2:2013.