An on-line transformer windings temperature measurement system based on fiber Bragg grating

Actual temperature distribution inside the transformer is unknown currently, since it is difficult to measure temperature of transformer winding by traditional transformer condition monitoring methods. To solve this problem, this paper proposes an on-line temperature measurement system based on fiber Bragg grating (FBG) which can obtain the actual temperature of winding during transformer operation. The measurement system is consist of FBG temperature sensors that are embedded in specially designed magnet wire, and FBG demodulator. Performance of those sensors was tested in the laboratory, the sensitivity and linearity of those sensors was analyzed. Finally, a prototype of transformer coil with FBG temperature sensors was built and simulation experiment was processed. Temperature variation was monitored during the experiment and temperature distribution in transformer coils was achieved. The experiment results prove the reliability and feasibility of the proposed transformer temperature measurement system.