An Active Low-Voltage Capacitor for Capacitive HV Dividers

This paper describes the setup of an active low-voltage capacitor designed to realize capacitive voltage dividers by means of compressed-gas, high-voltage capacitors for rated primary voltages between 5 kV and 800 kV/√3. In the future, this divider, which has a negligible voltage dependency and low phase errors around 50/60 Hz, will be used to realize a fundamental step-up calibration method for the standard voltage transformers at PTB. Initial measurements indicate an attainable uncertainty of below 2 ppm for the ratio error (short-term) and 1 μrad for the phase displacement of the capacitive divider.