Examination on Magnetic Tape Wrapped Rectangular Aluminum Winding for Weight and Copper Loss Reductions of High-frequency Transformer for Railway

Abstract

　There is an extremely high demand for smaller size, lighter weight, and higher efficiency of magnetic parts used in transportation equipment such as railway, automobile, and aircraft. Weight reduction is possible by using aluminum winding instead of copper winding for the winding. However, the loss of the aluminum winding is larger than the loss of the copper winding, because the resistivity of aluminum is higher than that of copper. Therefore, the authors propose the magnetic tape wrapped rectangular aluminum winding (hereinafter called MAW) that achieves both weight reduction and low loss. Analysis confirmed that applying MAW to high-frequency transformer for railway reduced copper loss by 11.5% compared to rectangular copper winding and 30.2% compared to rectangular aluminum winding. In addition, it is 40.3% lighter than a high-frequency transformer for railway that using rectangular copper winding.