绝缘子保护的FBG温度传感器研究

Research of FBG temperature sensor protected by insulators

电力系统的输变电设备长期暴露在自然条件下,电气设备绝缘表面容易劣化,导致输电线路的故障。研制了具有绝缘子保护的光纤Bragg光栅(FBG)温度传感器用于检测电气设备常见发热部分,光纤外表面包覆单片或者多片硅橡胶材料的光纤绝缘子,整个传感器采用室温硫化硅橡胶材料一体成型结构加工而成。绝缘子保护光纤,使得传感器可以实现电气设备高电压下的检测,传感器测温时,测点温度变化会引起FBG反射波长的改变。对具有绝缘子保护的FBG温度传感器进行性能测试,实验采用恒温槽加热并用国家二级精度的水银温度计作为测量标准,对传感器进行20次从20～90℃的升温试验,温度每升高10℃记录一次波长。试验结果表明:传感器的灵敏度系数为10.2 pm/℃,线性度为0.70%FS。

Because transmission and distribution equipments of the electric power system long-term exposure under natural conditions,insulating surface of the electrical equipment is easily degraded, which may lead to fault of transmission line. A fiber Bragg grating（FBG） temperature sensor protected by insulators is developed to detect the common heating parts of electrical equipment, the outer surface of the fiber is coated with single-or multi-chip insulators of silicon rubber material, and the sensor is processed by RTV silicon rubber material forming one structure. Insulators protecting the fiber,the sensor can achieve the detection of high-voltage electrical equipment. When the sensor detects the temperature of the electrical equipment ,the temperature change of the measuring point will cause the reflective wavelength shift of FBG. Performance test on the FBG temperature sensor protected by insulators is done. Thermostatic bath heating and mercury thermometer of national two level precision as measuring standard are 20 times heating experiments on sensor is carried out from 20 to 90 ℃, wavelength is recorded once while temperature is increased by 10℃. Experimental results indicates that the temperature sensitivity coefficient of the senor is 10.2 pm/℃ ,the linearity is 0.70 % FS.