EDDY-CURRENT FIELDS AND OVERHEATING PROBLEMS DUE TO HEAVY CURRENT-CARRYING CONDUCTORS

Large complex problems, eddy current fields and local overheating due to heavy current carrying conductors(HCCC) including leads and connect ing bus bars in a 360MVA/500kV power transformer, are analyzed by the boundary element method. To improve numerical accuracy, this paper cho oses triangle polar coordinate mapping and addition-substraction techn iques to evaluate singular integrals. The distributions of magnetic fl ux and eddy current densities in metallic parts of different materials are discussed. According to the criterion of overheating, permissible lead current and limiting distance between HCCC and metallic parts an d arrangements of HCCC am suggested.