| In power system, the high voltage switchgear has been seen as an important component,its main function is to open and close power line, monitor the operating parameter, and line fault protection, etc. The switchgear has an irreplaceable position in the electric field due to the advantages of safe and reliable, and high integration of components, and save space because of its small size, and the strong operability. There will be the large voltage, strong current, large space magnetic field when the switchgear is working, the fire could take place because the high temperature of the component joint when the long-term working. The serious economic losses or casualties will be caused if not found in time, so it is important to monitor the parameter of temperature in high voltage switchgear. Through monitoring the operating temperature of the contact continuously, there will has an early warning instructions when the temperature is higher than the upper limit of preset value, and then some measures will be taken to protect the switchgear’s safety, all this can improve the safety and reliability of the operation of the power system.In this paper, based on the analysis of research status at home and abroad and the technology of fluorescence optical fiber temperature measurement, The overall program of switchgear contact temperature monitoring system was given, and then the multichannel temperature measurement was realized. Using ANSYS finite element analysis software to analysis contact temperature field for learning the temperature distribution, this provides the theoretical basis for ensuring the optimum laying position of the temperature sensor probe.Comparing USB2851 data acquisition card and the others, the USB2851 data acquisition card was selected to collect data real-timely, and the program was written by LabVIEW and MATLAB software, least-square method, the integral area ratio method and Prony algorithm could be switched arbitrarily to process the same data. Comparing the advantages and disadvantages of several methods, the least squares method is largely influenced by the DC component, the fluorescence afterglow life τ values is different when DC component is taken in different location for one data, though the integral area ratio method is not influenced by DC component, but the sensitivity is lower than the requires of system, the Prony algorithm is not affected by DC component and has a high sensitivity, so the Prony algorithm is chosen as the way to obtain fluorescence afterglow life τ value.Finally, in order to verify the accuracy, and real-time performance of contact temperature monitoring system. In the laboratory environment, analog the change of switchgear contact working temperature, and carries on the real-time monitoring. The results show that this system meet the requirement of measurement, and the safe and reliable of operation of power system can be guaranteed. |
