Calculation Of Leakage Magnetic Field And Tank Eddy Current Loss Of Large Transformer

Work in the power system, large transformers play an important part in voltageconversion and power transmission, and their safe operation will by related to safety andstability of the whole power system directly. Oil tank is one of very important parts as aperipheral containment equipment in the power transformer. The leakage magnetic fieldand stray loss produced by oil tank and structural component increases obviously as theincreasing of single capacity of the power transformer. Therefore, it has a vitalengineering significance accurately and deeply that studying on the leakage magneticfield and box’s eddy current loss of large transformer.The purpose and significance of the calculation of leakage magnetic field and box’seddy current loss of large transformer was introduced in this paper, and the developmentof the leakage magnetic field and box’s eddy current loss of large transformer at homeand abroad was discussed as well. Firstly, taking real large transformer for example,2-Dmodel of leakage magnetic field of transformer was established in2-D field afterreasonably simplified; the maximum value of leakage magnetic was obtained in the gap,discussed the effects caused by the leakage magnetic field.Secondly,3-D eddy current field model was established after reasonably simplifiedunder the rated tap, the loss distribution and the value of eddy current loss on the tankwere obtained after calculated, and the numerical results satisfied the precisionrequirement on the engineering application was improved after analyzed the result.Finally, the model of copper shield, aluminum shield and magnetic shield wererespectively established on the base of the analysis of3-D eddy current field in order toreduce eddy current loss of the tank. The eddy current loss on the outer wall was reducedeffectively by the way of loading shield on the outer wall, and obtained practicalsuggestions after analyzing shields.