Study On The Methodology Of Diagnosis For Transformer Winding Insulation Defects

The transformer, as important electrical equipment in the electric power systems, is directly related to the safety operations of the power grid. The faults of transformer may bring great harms to the entire power grid and result in huge losses. Statistics show that the accident of transformer is mainly due to the deterioration of its insulation properties. So far, transformer fault diagnosis methods usually need synthetic judgment of several field tests, in which every one involves large or complicated equipments, strict anti-interference measures, special measurement and control instrument and professional tester. Therefore, study of the insulation damage detecting technique for the transformer winding is not only of important theoretical significance and practical engineering value, but also has enormous social and economic benefits.A novel three-dimensional surface mapping method is proposed in this paper to detect the insulation defects in transformer winding with an indication of the location and severity. Such results can be reached from the coordinate information of the peaks in the voltage-current correlation coefficient map for every winding. This method is relatively visual, intuitive, simple practical and strong operational, without involving large or complicated equipments. The paper presented using capacitance variations to simulate the severity of the damages, by researching the multi port electrical circuit simulation model of the severity of insulation damage for the transformer winding. Based on a large number of good results in the simulations of insulation defects with various locations and types, the method is proved effective and practical.