Fiber optic sensor for transformer temperature detection

Abstract The safe and stable operation of the transformer is affected by the internal temperature. Therefore, it is very necessary to accurately and effectively detect the temperature of the transformer winding. To realize the effective detection of the internal temperature of the transformer, a fiber optic temperature sensor based on the structure of multimode fiber (MMF)–no core fiber (NCF)–multimode fiber (MMF) (i.e., MMF–NCF–MMF) is studied. The temperature sensitivity reaches 0.0313 nm/°C. Moreover, to enhance the accuracy of the test, the sensitive material polydimethylsiloxane (PDMS) is coated on the sensing area (the position of the NCF), and its temperature sensitivity reaches 0.123 nm/°C. By comparison, it was found that the temperature detection sensitivity increased by 3.93 times after coating PDMS. The sensor has the characteristics of simple structure, high sensitivity, and high integration, which provides research and application directions for temperature detection in the field of transformer health detection.