2022 年 30 巻 1 号 p. 9-14
This article describes magnetic components in high-frequency-switching power converters from the viewpoint of structures. Not only permeability and magnetic flux density but also eddy current and self-resonance should be considered to design the magnetic components in high frequency. As examples, first, air-core planar inductors which can suppress the increase in resistance and the decrease in inductance due to eddy currents at high frequencies, is described. Next, toroidal transformer which can adjust leakage inductance by a wire guide produced by a 3-D printer, is explained. Third, a load test method for high-frequency transformers using two power supplies, is described. In the proposed method, the two power supplies only need to supply power losses of the transformer because the power is circulated between a primary side and a secondary side. Hence, the load test of high-frequency transformers whose capacity is larger than that of the power supply, can be performed without a high-frequency load.
