A Segmented Paper Modeling Method of Open Transformer with Three-Dimensional Wound Core by Introducing Equivalent Conductivities

The current method to the solution of equivalent conductivity for laminated core transformer is difficult to satisfy the request of three-dimensional wound core transformer (TDWCT) due to its particular structure. In this paper, a segmented method is proposed to calculate the equivalent conductivity for TDWCT. Based on the above method, a finite-element model is set up and the simulation calculation in 3D eddy current field is performed. This paper studies the influence of the eddy current loss on the wound core at varied folding angle. It was found that there are less loss on the wound core at the folding angle are 30° and 60°, especially at 30°, However, for the other folding angle, the eddy current loss is twice as much as that of at 30°.The simulation results are useful for analyzing the influence of folding angle to wound core eddy current loss and it can provide a theoretical basis for the optimum design of TDWCT.