The Optimization Design Of Inductor With Magnet Pre-bias

With the rapid development of science and technology, electronic products areincreasingly becoming the necessities of life. The magnetic components account for alarge component of these products,but the traditional components are characterized byits heavy and bulky.However, the advantages of miniaturization, integration of magneticcomponents to make small space occupation and convenience largely contribute to itspopularity. Witch is more prominent in the field of power electronics. Particularly insome of the biasing circuit, in order to avoid the core saturation, the magnetic devicestend to be made greater. For example, in the circuit containing the DC component,magnetic potential generated by the DC component will lead the core of inductor toserious bias magnetic saturation. How to effectively prevent bias magnetic saturation isbecoming a major technical difficulty in optimizing the magnetic elements. Althoughthe inductor with pre-biased permanent magnet can prevent saturation, the practicemaking soft magnetic and hard magnetic materials mixed together increases thedifficulty of the design.This paper introduces the electromagnetic theory with some commonly usedpermeability and carries out a detailed analysis of the magnetic circuit of the inductorwith pre-biased permanent magnet. Starting from the magnetic material optimization,the method that using the permanent magnetic pre-biased technology encounter the DCbiased magnetic potential is proposed. And the basic parameters of the pre-biasinginductors are quantified combining soft and hard magnetic BH curve, the curve ofpermanent magnet Φ-F. The inductor model is made the electromagnetic simulationanalysis by using the finite element calculation software Ansoft V12. The ideal fluxdistribution can be got, so as to achieve the purpose of reducing the inductor size.In the analysis of ferromagnetic parameters, we reduce the mathematicalexpressions about the permeability of ferromagnetic material on residual flux density,the coercive force and the air-gap length though the hysteresis loops of the core withair-gap or without air-gap. In the four-dimensional visual data field, the influences onthe core magnetic permeability made by the length of the magnetic circuit, the air-gapand the magnetic field strength are disclosed, and the method to solve the best length ofair-gap is put forward. Further the influences on the core magnetic permeability made by the magnetic field strength, remanence, coactivity and the ratio of length of magneticcircuit and the length of the air-gap also are showed in the five-dimensional visual datafield. That directly reveals the global distribution and the change trends of the nonlinearequation on the permeability.In this paper, simulation and experiment results show that the volume of theinductor is reduced, and the power density ratio of pre-bias inductor, air-gap inductorand inductor without air-gap reaches2.9:1.5:1.