Application Of Photoacoustic DGA Online Monitoring System Using Localized Fiber Acoustic Wave Sensor

In the world today,power system plays the most important role in energy production and transmission.Reliable supply of electricity is related to all aspects of human life and production.Timely and rapid discovery of faults in critical equipment such as transformers is of great significance for improving the reliability of power supply systems.For fault detection of oil-filled power equipment,the most commonly used method is analyzing dissolved gases in oil.Traditional online gas chromatography analysis has the disadvantages of complex components,high operating cost and poor safety.The on-line monitoring using photoacoustic spectroscopy has many advantages such as high detection sensitivity,convenient maintenance,short detection time,and so on.Therefore,it has become the research direction in this field.This paper describes the gas production mechanism of insulating oil in transformers,and compares the current various fault gas detection technologies.On this basis,the oil and gas separation module with thermostat and the photoacoustic spectroscopy gas group content measurement module based on DFB semiconductor laser are designed.Aiming at the actual situation of 110 kV Gangtou substation,this paper studies a fault detection system using photoacoustic spectroscopy technology,which can simultaneously monitor 7 kinds of fault gases(H2,CH4,C2H4,C2H6,C2H2,CO,CO2)and micro-water.The relative standard deviations of the contents of seven kinds of fault characteristic gases detected are all less than 5%,which are within the allowable range of errors and basically meet the requirements.It proves the reliability and stability of the independent research and development system,but the stability and accuracy of the equipment still need to be improved.The system is easy to operate,accurate in measurement,easy to maintain,and relatively low in cost.It is expected to have a good application prospect in China.