Design of the portable fiber-optic current transformer for electrolytic aluminum industry

A portable fiber-optic current transformer (P-FOCT) based on the Faraday effect utilizing the fiber jumper and the flexible sensing coil is proposed to enhance the portability and improve the design for disassembly of FOCT in the electrolytic aluminum industry. To ensure the accuracy of P-FOCT, the polarization crosstalk of fiber jumper and the conductor eccentric error are studied. According to the theoretical analysis and experimental results, the relative error of P-FOCT would decrease as the distance between the current conductor and the non-closed node of the sensing coil increases. A new sensing head is designed and experiments show that the error is 0.31 % at variable temperature from 233K to 343K, which meets the requirement for accuracy in the electrolytic aluminum industry.