Studies On Characteristic Produces And Detection Method Of Transformer Solid-insulation Aging

With the constant development of China power grid, it has been more and moretransformers whose service times are more than twenty years. Those transformers arefacing the increasingly serious insulation aging problems that must increase theprobability of accidents. Therefore, studying the characteristic produces and detectionmethod of transformer solid-insulation aging, have great significance for the safety ofthe power grid operation.Two types of samples which are formed by25#transformer oil and insulation paper,are thermally aged in different temperatures of100,120and140℃. Then furfural,5-hydroxymethyl furfural, sugar material in the oil and insulating paper degree ofpolymerization are detected in a month or two months later. The results show that：(1)thetransformer solid insulation aging can be divided into two stages. In the initial period thesolid insulation is aging rapidly, and the rate of aging becomes slow in a certain agingstage;(2)Ribose, fucose can not be used as efficient characteristics products which canreflect the transformer solid insulation aging status;(3)5-hydroxymethyl furfural’sconcentration would have a rapid increase when the over-temperature situation appears;(4)Furfural’s concentration during the rapid aging and slow aging stage has certain differentchanges. Therefore, in order to more timely and accurate judge the transformer solidinsulation aging status,we should pay more attention to the dynamic change of furfural’sconcentration.Considering the high cost, the long period and the complex operation of highperformance liquid chromatography, the interval of the detection test of the furfural is verylong in the current power system. And the short-term dynamic changes of the furfuralconcentration will be easily neglected. So the site detection methods of the furfuralcontent need to be found. Compared to the high-performance liquid chromatography, theUV spectroscopy is simpler and easier to operate. And it is more suitable for the real-timemonitoring technology for the development of the environmental components. UVspectroscopy is used as a rapid detection method to measure furfural’s concentration in manyfields now. And in this dissertation, we find that UV spectroscopy can be used to measure the furfural’s concentration in the transformer oil. Besides that, we find BHT in the mineraloil should be removed because it has certain effect on the detection of furfural.