A Core Loss Measurement of the Magnetic Composite Material Utilized the Inductive Cancellation Method

Abstract

　Power converter used for switching power supplies is required to be smaller and more efficient. As the switching frequency increases and converter size reduced, the core loss will increase and have significant impact to the converter efficiency and temperature. The authors proposed magnetic composite material and evaluated them exhibited a lower core loss than Ni-Zn ferrite in MHz band. Among evaluation of magnetic material, accurate measurement of the core loss is especially important to development of magnetic material. However, the classic two-winding method is limited to low frequency band and high core losses because it is sensitive to phase discrepancies. In this paper, the Measurement method of the core loss evaluation of magnetic composite material utilized the inductive cancellation method proposed as the core loss measurement method in MHz band. From the experimental result, the magnetic composite material using 2.6 µm amorphous powder exhibited core loss of 1.0 W/cm³ at 10 MHz and 10 mT.