Distributed Temperature Sensing Technology In The Cable Temperature Monitoring Study

With the rapid increase of the power load in recent years, fault location and monitoring technology in the transmission and distribution network is urgently needed, in order to keep the stability of Electric Power Supply. The relevant data of Power Cable Fault is important and the Accuracy should be improved. Temperature is an important parameter. During operation, before an electrical fault the local temperature will increase which leading to cable insulation damage. Cable temperature should be measured in real time; preferably temperature distribution of a continuous length cable of change can be detected. So the risks of cable can be eliminated, and the security of grid operation is ensured.Distributed Temperature Sensing (DTS) represents the latest trends in cable temperature monitoring. In the scale of several kilometers even tens of kilometers, the point in danger can be find in time. Sensor is the fiber itself, but also can display the temperature value corresponding to the location. The theory and technology of power cable temperature monitoring system based on Raman scattering is studied in this paper.The details of domestic and international power cable monitoring technology is repotted in the first, and field research is also done. Then Raman-based distributed optical fiber temperature sensor cable temperature monitoring system in structure is analyses and designed. And the sensitivity and high sampling rate requirements is also taken into account in temperature acquisition module in the system design. Meanwhile, the temperature signal demodulation methods are compared to optimized signal to noise ratio, which makes improve measurement sensitivity. A programmable logic device (Cyclone II) is used as timing controller and data acquisition. And DSP is used to process the collected data and transmitted data to the host computer. Dynamic display software for cable temperature is written using VC++ 6.0, so the temperature distribution of the cable length can be real-time displayed. Finally, a good test results is gotten in field tests.