New Reference Measurement System for Calibration of VLF High Voltage

A reference measuring system for 200 kV from very low frequencies (0.1 Hz, VLF) up to 50 Hz based on traditional high-voltage components, such as compressed gas capacitors, has been developed and verified. The verification of the measuring system has been performed by two experimental methods, one directly measuring the scale factor and one using measurements over the frequency and voltage range of the components of the measuring system. The frequency dependence of the measuring system proved to be one of the dominating uncertainties and was extensively researched. Proper correction for known errors and estimation of uncertainty contributions proved that traceable measurement of VLF voltage can be made with an uncertainty of less than 0.038% up to a voltage of 200 kV. This measurement service has been notified to be included in SP entries for Bureau International des Poids et Mesures key comparison database and can serve an important need for the cable industry.