Design and Performance Test for Fiber Bragg Grating Sensors of Transformer Winding Temperature Measurement

In order to directly measure the winding temperature of oil-immersed transformers,the winding electromagnetic wire with built-in fiber Bragg grating(FBG) sensors was designed and its production process was discussed.The structure of winding electromagnetic wire and the winding production process were improved.The strain of FBG sensors was monitored in the electromagnetic wire production process,and the temperature sensing performances of FBG sensors were obtained.The results show that the strain in the electromagnetic wire production process has minor impact on the mechanical strength and the temperature sensing performances of FBG sensors.The linearity of the FBG sensors is above 0.99,and the sensitivity is about 10 pm/°C,and the accuracy is about ±0.5 °C,indicating that the winding electromagnetic wire built-in FBG sensors can be used to measure the winding temperature of oil-immersed transformers accurately.