A New Method for Determining the C-Divider Capacitances of a Capacitor Voltage Transformer with Frequency Measurements
Thomas Bischof, D. Gopp, Dmitry Atlas · 2023
The capacitor voltage divider of a (coupling) capacitor voltage transformer (CVT, CCVT) ages during its lifetime, which can lead to decreasing measurement accuracy and even major failures with sudden explosions. For this reason, CVTs are regularly checked during maintenance work. The possibility to directly determine capacitance values of the capacitive divider C1and C2depends on the CVT design. In this paper, a new method for determining the capacitance values of the capacitive divider C1and C2is presented. The method is not dependent on the respective CVT design and is subsequently called “CVT-short-circuit-frequency-sweep” (CVT-SCI-f). The measured capacitances using the CVT-SCI-f method are compared either with measured reference capacitance values or with rated values.