全光纤电流互感器温度性能优化方法

摘要

论述了全光纤电流互感器(FOCT)的光路结构及其工作原理,分析了温度对FOCT性能影响的几个因素和特点:线性双折射会对光纤传感头的温度特性造成比较大的影响,圆双折射具有抵消线性双折射的特点;传感光纤Verdet常数受温度的影响,与温度具有线性关系;1/4波片误差造成的影响与温度也具有线性关系.提出了综合解决FOCT温度影响的方法:通过把传感光纤绕制成螺线管增大圆双折射,减小线性双折射,从而减少温度的影响;通过调整1/4波片参数,在温度变化时,使其引入的误差正好补偿Verdet常数受温度影响造成的误差.试验结果表明,采用该方法的FOCT温度性能良好,已经可以满足数字化变电站实际应用的需求.%The topology and operational principle of FOCT(Fiber Optical Current Transducer) are introduced and several factors affecting its temperature performance are analyzed:the larger circular birefringence and smaller linear birefringence of fiber sensing coil,Verdet constant of sensing fiber and the quarter-wave plate error parameter. Methods to avoid the influence of temperature on FOCT performance are presented:the helically-wound sensing fiber to increase circular birefringence and decrease linear birefringence,the adjustment of quarter-wave plate parameters to compensate the influence of temperature. Test results show that the temperature performance of improved FOCT is excellent,meeting the requirements of digital substation.