Winding loss mechanism analysis and the design for a new structure high-frequency gapped inductor

An inductor with air-gap used in high-frequency switch-mode power supply has high extra eddy current winding losses due to the air-gap, resulting in low efficiency and high temperature rise in the inductor. In order to reduce the extra winding losses, many techniques are proposed. But all these techniques make the winding and core structures much more complicated. In this work, by 2D eddy current finite element analysis (FEA) field simulation, eddy current winding loss mechanism in the inductor with air-gap was deeply investigated and then a new simple inductor structure was proposed to reduce the winding losses greatly. Moreover, analysis and design for the new structure was also performed.