LOCAL OVERHEATING PROBLEMS DUE TO BOTH WINDINGS AND HEAVY CURRENT LEADS IN LARGE POWER TRANSFORMERS

摘要

The eddy current field due to both windings and heavy current leads(HCL) in large power transformer is analyzed by using the improved T-Ω method. The local overheating on the pull-plate and tank wall near the magnetic shield gap is then calculated and analyzed, and the improving measures are proposed. On the basis of these work, a combined shield is analyzed and optimized. The numerical results show that the eddy current losses have been reduced and the local overheating has been removed by using this combined shield.