抄録
A reliable technique is needed for accurate measurement of very fast transient overvoltages such as disconnector-induced surges occurring in GIS which have very steep front and high frequency oscillation. Recently, capacitive voltage sensors with very short response times have been proposed for this purpose. How-ever, few studies have been made on the dielectric properties of materials used for a low-voltage-side capacitor, as well as frequency bandwidth of the measuring system.
In the present work, we propose a thin mica plate for a low-voltage-side capacitor which has a surface coated with silver on both sides. This material has been shown to have stable and high static capacitance up to a high frequency range. We also give a quantitative estimate for the frequency bandwidth of the measuring system. Furthermore, we have developed a practical-scale sensor of this type which can successfully measure simulated disconnector-induced surges of several hundred kV under similar conditions in GIS.
