全光纤电流互感器的温度特性

Temperature Characteristic of Fiber Optic Current Sensor

全光纤电流互感器（FOCT）比差随温度漂移会引起FOCT准确度下降。为解决这一问题,首先阐述了温度波动对全光纤电流互感器影响的机理,并依据该机理分别建立了温度对线性双折射影响的数学模型和线性双折射对全光纤电流互感器影响的数学模型。进而推导出温度对全光纤电流互感器影响的数学模型,通过该数学模型量化研究了FOCT比差随温度漂移问题。得到了FOCT温度特性为：在试验温度范围即10~60℃内,比差与线性双折射相位差和温度都近似呈线性关系。进一步试验验证了FOCT比差与温度的近似线性关系,且基于该关系对互感器进行温度补偿,可使其精度满足0.2级的要求。

The error drift of fiber optic current transformer （FOCT） caused temperature shift reduces the accuracy of FOCT. To solve the problem, we explained the mechanism of temperature fluctuation influencing FOCT, and accordingly established a mathematical module representing the effect of temperature on linear bi-refringence, and another model representing the influence of linear-birefringence on FOCT. Using two models, we quantitatively researched the error ra- tio drift, and obtained temperature characteristics of FOCT： within the tested range of temperature （10-60 ~C）, both the FOCT ratio error and linear-birefringence phase difference varied linearly with temperature. The relation between FOCT ratio error and temperature was further confirmed by experiments, and was applied to conduct temperature compensation to FOCT so as to fulfill the requirements of degree 0.2 of accuracy.