A Method for Suppressing Core Eddy Current Loss Caused by Leakage Flux in Nanocrystalline High-frequency Transformer

High-frequency transformer is a crucial component in isolated DC/DC converters, and its stable operation has a decisive impact on the reliability, efficiency, and power density of power systems. Nanocrystalline material, as a magnetic core, has been widely used due to its excellent performance. However, nanocrystalline alloys have a high electrical conductivity, which may induce strong eddy currents when high-frequency leakage flux passes through the surface of the tape, resulting in potential heat problems. To solve this problem, this paper proposes a method to suppress core eddy current losses in nanocrystalline high-frequency transformers. First, the distribution characteristics of core eddy current losses in leakage flux are determined by finite element simulation. Then, in the area where eddy current losses are concentrated, slots are cut on the outer nanocrystalline tape to block the eddy current loop and increase the equivalent resistance. Finally, the effectiveness of the method is verified by finite element simulation.