Abstract: A design of open-close fiber optic current transformer for high-current measurement on line was presented, which can be mounted and demounted real-time. When sensing head was open, rubber frame would generate uniform deformation inside sensing head, and the fiber winded on the rubber frame have minute stress variation. For temperature performance stability, inner frames was made of quartz glass material mainly, which were fixed to sensing head by holders with slotted hole for compensating mi-smachining tolerances of quartz glass frames. An all digital closed-loop method with square wave modulation and digital ramp for feed back was used for signal processing. The test results show that the ratio error is less than 0.5% when sensing head is close after multiple opening states,and the open-close fiber optic current transformer is viable.%介绍了一种可以用于在线测量、实时安装、拆卸的开合式光纤电流互感器方案.在传感头开启过程中,利用传感头内部一段橡胶骨架的弹性产生均匀变形,使绕制在上面的光纤应力变化较小.为了保证互感器的温度稳定性,传感头内部骨架主要为石英材料,由于石英骨架加工的误差比较大,所以采用长圆孔的支架将其固定在传感头结构上.信号处理部分基于全数字闭环检测,采用方波调制方案,并通过数字阶梯波反馈实现闭环检测.在开合过程后对开合式互感器进行测试分析,实验结果表明系统的变比稳定性可以达到了0.5％的精度,可以满足实际应用的要求.
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