Winding Arrangement of High-frequency Amorphous Transformers for MW-class DC-DC Converters

摘要

??Many offshore wind-power generators over MW-class are currently in operation in Europe and are now starting to be used in Japan. In order to develop large-scale offshore wind-power plants, we need to reduce the size and weight of power converters, including isolating transformers. A dc-dc converter with a high-frequency transformer is one of the best ways to reduce the size and weight. However, copper loss of the transformer due to proximity effect is a problem because the operating frequency is increased from the commercial frequency to several kHz. In this work, we investigate an interleaved winding arrangement for the high-frequency transformer. We compared the winding resistances of the interleaved and non-interleaved winding arrangements in an experiment using a test amorphous transformer and found that the interleaved winding arrangement inhibits the proximity effect and reduces the winding resistance. We designed an MW-class high-frequency amorphous transformer with the interleaved winding and demonstrated its very high efficiency.