The distributed fiber optic temperature measurement system integrates fiber optic sensing, optical fiber, optical fiber communication systems, optical control, computers and other technologies. It has the advantages of intrinsic safety, long-term reliability, immunity to electromagnetic interference, high temperature measurement accuracy and real-time online operation, realizing multi-point, real-time and online monitoring of power system operating equipment. Below we introduce the sensing process of the distributed fiber optic temperature measurement system — corrections are welcome!

The sensing process of the distributed fiber optic temperature measurement system is as follows: the computer controls the synchronous pulse generator to generate pulses with a certain repetition frequency. This pulse modulates the pulsed laser on one hand to generate a series of high-power light pulses, and provides synchronous pulses to the high-speed data acquisition card on the other hand, entering the data acquisition state. The light pulse enters the sensing fiber through one port of the wavelength division multiplexer, generating backward scattered light at each point in the fiber, which returns to the wavelength division multiplexer. The backward scattered light passes through the thin-film interference filters in the wavelength division multiplexer to filter out Stokes light and anti-Stokes light respectively, which are output from the other two ports of the multiplexer and enter the photodetectors (APD) and amplifiers for photoelectric conversion and amplification, amplifying the signal to a level that the data acquisition card can collect. Finally, the data acquisition card stores and processes the data for temperature calculation. The distributed fiber optic temperature measurement system has been applied and recognized in the power systems of countries around the world. Further improving the stability and safety of the system will make its application prospects in the power system even broader.