The calculation of eddy current losses in tube wound high current transformer windings

In this paper an efficient water cooled power transformer with an application to high frequency induction heating is presented. The secondary side of the transformer is realized by a water cooled copper tube with rectangular cross section. The main advantage of the construction is the combination of copper band and copper tube windings. This winding configuration allows the interleaving of the windings with the direct consequence of considerably reduced copper losses due to the well known proximity effect. Furthermore a very low leakage inductance of the transformer is obtained. Finite element simulations are conducted to investigate the copper losses and the leakage inductance with respect to different winding arrangements. The model is finally verified by means of experimental data drawn from a realized prototype.