Laser Scattering Measurement Technology of Micro-water in Transformer Oil
The micro-water in transformer oil is an important factor that affects the insulation performance.In order to overcome the shortcomings of existing detection methods,such as poor stability,strong subjectivity and harsh use condi-tions.The gray level of the scattering light column formed by the 650 nm laser in the oil is quantified by digital image,combined with the theoretical characteristics of Mie scattering and Rayleigh scattering.The temperature,particle size and micro-water content of transformer oil are compared by means of light intensity attenuation and interval gray pixel statis-tics.It is found that the scattering light intensity is mainly related to the size of micro-water particles,but it is affected by oil temperature and particle size.The increase of temperature in the oil will promote the combination of micro-water par-ticles with micro-water content less than or equal to 10×10-6(mass fraction)to be dominant,while when the micro-water content is larger than 10×10-6(mass fraction),the decomposition and combination of micro-water particles will gradually reach a balance.The oil micro-water and the light column show obvious an exponential relationship.By adjusting the sensitivity of the digital image gray level to increase the pixel statistics to match the micro-water in different regions,the numerical fluctuation can be reduced.An example of linear calibration of particle size and temperature is given.The re-search results show that this method can be adopted to realize the measurement of micro-water content in transformer oil and can be used for the detection of micro-water in oil of oil-immersed transformer.
万方数据
维普
