Abstract
An improved, accurate and reliable high-voltage measuring system utilizing a bushing-type capacitor is proposed in this study. This system measures voltages and phase angles of three-phase 22.9 kV power distribution lines and provides enough current to charge a battery for a motor-driven load switch and to operate the measuring and communication circuits for the distribution automation. For reliability, epoxy resin was used as the dielectric material of the bushing-type capacitor since the dielectric strength of epoxy resin is very stable over the wide range of temperature. Capacitances were investigated and found to be stable over the wide range of temperature and applied voltage, and the results indicate that the proposed measurement system is very reliable.