Hybrid optical fiber current transformer based on DSP and ultra-low-power. consumption micro-controller

With excellent insulation and resistance to electromagnetic interference, the optical current instrument has been considered as a viable solution for high voltage current. In this paper, a new hybrid optical fiber current transformer (HOCT) is designed. Its construction and principle are described in detail. An ultra-low-power microcontroller is used in this system to combine the low-power consumption and increased function. The error compensation algorithm, to enhance the measurement accuracy, is performed by means of digital signal processor (DSP). The sensor head mounted on line is powered optically from the ground potential. A conventional accurate current transformer and a Rogowski coil are used as detecting elements at the meantime, so that the new system can be applied for both metering and relaying.