Premagnetization of High-Power Low-Frequency DC-Inductors in Power Electronic Applications

摘要

In the power electronics area, low-frequency inductors are subject to the saturation magnetic flux density of soft magnetic materials, which often suffer from large volumes and number of turns. In this paper, a premagnetization solution for high-power, low-frequency DC inductors is presented. The sintered NdFeB magnets are used to increase the usable saturation flux density range up to 3 T of the soft magnetic material, thereby the number of turns and volume of the premagnetized inductor can be significantly reduced. In order to decrease the hard magnetic losses, which are caused by the eddy currents, the hard magnet is divided into small pieces. Magnetic circuit calculations and finite element simulations are shown for the design of the premagnetized inductor. Finally, the theoretical results will be verified by experiments. Furthermore, the optimal geometry is also being discussed.