Upright type bushing current transformer

TLDR: In this article, a bushing current transformer is provided and includes an auxiliary current transformer mounted on the top of the bushing, which is connected parallel to each other and in series to an electrical power line having a high voltage and carrying a high current therethrough.

Abstract: A bushing current transformer is provided and includes an auxiliary current transformer mounted on the top of a bushing. The primary and secondary coils of the auxiliary current transformer are connected parallel to each other and in series to an electrical power line having a high voltage and carrying a high current therethrough. A conductive lead is connected to the secondary coil of the auxiliary current transformer and is conducted to the bottom of the bushing to thereby form a primary coil of a main current transformer which is positioned on the bottom of the bushing and then conducted upwards again through the bushing. With such an arrangement the size of the line conductor being introduced into the bottom of the bushing can be made smaller, since the current transformation ratio between the primary and secondary coils of the auxiliary current transformer can be adjusted. Also, the current transformer can be standardized and thereby adapted for mass production due to the ability to fix the secondary current of the auxiliary current transformer at a constant amplitude.