Examination on Copper Loss Reduction of High-frequency Transformers for Trains Using Magnetic Flux Path Control Technology

A rectangular wire is used for the windings of a train transformer in order to improve the space factor. However, as the frequency is increased, copper loss due to skin and proximity effects occurs and heat generation becomes a problem. The authors investigated reduction of copper loss in order to suppress heat generation in the transformer winding. By changing the winding structure, copper loss could be reduced by 8.1% more than before change. Furthermore, by applying magnetic-flux path-control technology, the copper loss generated in the transformer could be reduced by 19.9%.