2020 年 28 巻 2 号 p. 128-133
Transformers used in switching power supplies can be reduced in size by increasing the frequency. However, transformer loss increases with higher frequencies, which hinders higher efficiency. Therefore, transformer using interleaved winding is being considered. The authors consider the reduction of copper loss in the planar transformer for LLC resonant converter using interleaved winding. It was confirmed by analysis that the AC resistance was reduced by 55.4 % from 217.6 mΩ to 97.1 mΩ by applying interleaved winding. In addition, an interleaved planar transformer with a substrate pattern as a winding was manufactured, and through experiments, the efficiency of an LLC resonant converter using a transformer with an interleaved winding was measured, and the copper loss reduction effect of the transformer was demonstrated.
