Research On Detecting Technique Of Gas Dissolved In Transformer Oil

With the development of modern society, the electric power has become anindispensable energy to production and life, at the same time, people also make higherdemands for the safety of power grid. The transformers are the most important parts inpower grid, and the transformers’ reliability determines the security of the power gridin a sense. At present, transformer oil gas detection is the main way of transformerfault diagnosis and lifetime prediction, but the traditional method of gas detection hassome disadvantage, such as lack of the type of gas, low accuracy, high cost ofmaintenance and vulnerable to environmental impact. These disadvantages could notsatisfy the current situation of the power grid security. So people desperately hope tofind a kind of new detection method for better detection effect, lower cost, and whichcan be used in industrial environment.This paper adopted photoacoustic spectroscopy technology in transformer oil gasdetection, and designed the photoacoustic spectroscopy detecting system based onARM to realize high precision detection.Firstly, this paper makes the theoretical analysis of the photoacousticspectroscopy technology, expounds the photoacoustic spectroscopy gas detectiontheory, and analyses the photoacoustic signals which based on the resonantphotoacoustic cell. Secondly, according to the photoacoustic spectroscopy theory, thispaper designs the hardware and software of the photoacoustic spectroscopy detectingsystem. The hardware part includes light module, chopper device module, theARM-controller module, photoacoustic cell module, signal processing module; Thesoftware part includes the system of chopper device module, the operating system andapplication program of photoacoustic spectroscopy detecting system. Thirdly, with the least square method, this paper makes the relationship between photoacoustic signalsand concentration of gas such as CH₄or C₂H₂. Finally, according to the experimentaldata, this paper evaluates the performance of photoacoustic spectroscopy detectingsystem.The experimental results show that the photoacoustic spectroscopy technologycan be used in transformer oil gas detection, and the photoacoustic spectroscopydetecting system has the advantages of the high precision and does not loss sample gas.