光纤嵌入技术是实现变压器绕组分布式光纤传感的关键。变压器绕组在绕制过程中铜扁线需要进行一定程度的拉伸、弯曲和扭转, 光纤在此过程中常会受到较大的拉伸而断裂。为了对光纤嵌入变压器绕组线的工艺过程进行优化, 试验将200 m光纤嵌入到绕组线中, 并使用光纤布喇格光栅(FBG)对绕组线的完整加工过程进行了应变监测, 得到光纤在铜扁线绕制过程中不同环节所承受的应变值。试验结果表明: 光纤在铜线绕制过程中所受到的最大应变均位于收线机位置, 约4800 με, 在光纤的可承受范围之内; 光纤在整个过程未折断且FBG未发生啁啾现象。

Based on the principle of the fiber Bragg grating, a new type of fiber-optic pressure sensor for axial force measurement of transformer winding is designed, which is designed with the structure of bending plate beam, the optimization of the packaging process, and material of the sensor. Through the calibration experiment to calibrate the sensor, the field test results of the Taikai transformer factory show that the sensitivity of the sensor is 0.133 pm/kPa and the repeatability error is 2.7% FS. The data of the fiber-optic pressure sensor in different positions maintain consistent and repeatable, which can meet the requirement of the real-time monitoring of the axial force of transformer winding.

变压器绕组热点温度的在线实时监测对变压器的安全运行和工作寿命具有重要意义。通过ANSYS有限元分析, 仿真得到绕组的热点位置和温升范围。将一种以聚四氟乙烯材料作底板的FBG传感器通过匝间的垫片安装于绕组的热点位置, 通过光栅窄带滤波反射后, 解调拟合出光波长, 通过数学模型计算得到热点温度。采集数据显示, 测得的绕组热点温度为143.2℃, 通过与仿真结果333.4K对比, 能够及时在线地反映出绕组的热点温度, 可为变压器的安全运行提供重要的参考数据。