Iron Loss Evaluation of Reactor Core With Air Gaps by Magnetic Field Analysis Under High-Frequency Excitation

It is revealed by magnetic field analysis that a difference between an actual reactor loss and a material datasheet loss, which was observed by measurement using an actual reactor with air gaps under high-frequency excitation, is caused by leakage magnetic flux near the air gaps of a reactor. In our previous measurement, an actual reactor loss under high-frequency excitation became large compared with a datasheet loss of the reactor core material. To clarify the reason, we carry out a 3-D magnetic field analysis. As a result, due to the increasing eddy current losses by leakage magnetic flux density near reactor gaps and due to the ununiform distributions of an iron loss caused by leakage magnetic flux, the reactor loss becomes larger than that of the datasheet loss.