Numerical Model for Eddy-Current Loss of Wound Core in Single-Phase Transformer

Taking the wound core transformer widely used in the field of traction energy saving as the research object and considering its unique geometric structure, combined with the magnetic circuit theory and finite element calculation of Ansys Maxwell software, the phenomenon of the magnetic flux distortion of the wound core is revealed, and the influence degree of various factors is analyzed; based on the Maxwell equation system of the magnetic quasi-static field, the calculation model of the magnetic flux distortion considering joints is deduced, and then, the numerical calculation model of the eddy-current loss of the wound core considering the magnetic flux distortion is presented, which is verified by no-load tests and can reflect the change of the eddy-current loss caused by the geometry of the core with different frequencies and magnetic flux densities, and it can be applied to large-capacity traction transformer with calculation error less than 3%. The numerical model can quickly calculate the eddy-current loss by core structure parameters and material properties without sample preparation and simulation in design stage, which greatly saves engineering cost and can be used for structural design and optimization of the wound core.