Study on Magneto-Optic Balance Type of Optical Fiber Current Transformer Used in Extra-High Voltage Measurement

To suppress the effect of the linear birefringence in optical fiber sensor on measurement accuracy, a new topology and control strategy of optical fiber current transformer (FOCT) based on the principle of magneto-optic balance was proposed, and the corresponding mathematical model was built, which proves the feasibility of this topology and control strategy, a simulation also conducted. The result shows that even if linear birefringence is high and Faraday rotation angle is large, the linear relationship still exists between measured quality and detectable quality.