Soft magnetic composite (SMC) is composed of ferromagnetic particles surrounded by electrical insulation layer. During the manufacturing process, the electric insulation layer may be destroyed and thus the eddy current will be induced, which makes it difficult to calculate the accurate eddy current loss. In this paper, the inter-particle eddy current loss is calculated at the macro-scale by modeling the actual sample and using the measured conductivity of the sample, moreover intra-particle eddy current loss is calculated by modeling single particle of SMC base on the existing model. Then, under different particle sizes and frequencies, the influence of skin effect on the calculation of eddy current loss is analyzed. Finally, to verify the proposed model, the iron losses of two SMC materials are calculated and they are compared with measured results. It can be seen that when the inter-particle eddy current loss has been considered, then the core loss of SMC will be agreed very well with the measurement results, thus the proposed model can be used for the actual core loss calculation for the electrical machine or other electromagnetic device with SMC cores.

The Preisach model is widely used to simulate the magnetic performance of transformers and motors in industrial applications. However, its parameter identification problem is still a complicated task. This paper proposed a new parameter identification method based on the velocity-controlled particle swarm optimization (VCPSO) algorithm combined with the closed-form Everett function. Firstly, the Preisach model is built through the closed-form Everett function, which gives an explicit form Preisach model. Secondly, the Preisach model’s parameter identification is realized by using the VCPSO algorithm, which only needs the limiting static hysteresis loop of the material. During the optimization process, the particle velocity is automatically adjusted to avoid falling into the optimal local solution. Finally, the obtained results are compared with the experimental hysteresis loop of the B30P150 silicon steel.

For the difficulty of accurate simulation of dynamic hysteresis loop at high frequency, a simple and effective method is proposed. Firstly, combined with accuracy and generality, the classical inverse Jile-Atherton (J-A) model is selected to simulate the hysteresis characteristics. The parameters of the J-A model are identified by the velocity controlled particle swarm optimization (VCPSO); Secondly, combined with the characteristics of high-frequency magnetic field distribution of silicon steel, an improvement of the parametric magneto dynamics is proposed to accurately calculate the magnetic field corresponding to eddy current loss. Finally, according to the theory of Bertotti model, the magnetic field corresponding to excess loss is introduced to ensure the accuracy of total dynamic magnetic field strength simulation. The effectiveness of the method is verified by a comparison with the measured hysteresis cycle. In addition, under the coupling of improved parametric magneto dynamics (IPMD) model and J-A model, the high-frequency power loss can be accurately predicted.

MetglasTM 2826MB foils of 25–30 μm thickness with the composition of Fe40Ni38Mo4B18 have been used for magnetoelastic sensors in various applications over many years. This work is directed at the investigation of ∼3 μm thick iron-nickel-molybdenum-boron (FeNiMoB) thin films that are intended for integrated microsystems. The films are deposited on Si substrate by co-sputtering of iron-nickel (FeNi), molybdenum (Mo), and boron (B) targets. The results show that dopants of Mo and B can significantly change the microstructure and magnetic properties of FeNi materials. When FeNi is doped with only Mo its crystal structure changes from polycrystalline to amorphous with the increase of dopant concentration; the transition point is found at about 10 at. % of Mo content. A significant change in anisotropic magnetic properties of FeNi is also observed as the Mo dopant level increases. The coercivity of FeNi films doped with Mo decreases to a value less than one third of the value without dopant. Doping the FeNi with B together with Mo considerably decreases the value of coercivity and the out-of-plane magnetic anisotropy properties, and it also greatly changes the microstructure of the material. In addition, doping B to FeNiMo remarkably reduces the remanence of the material. The film material that is fabricated using an optimized process is magnetically as soft as amorphous MetglasTM 2826MB with a coercivity of less than 40 Am−1. The findings of this study provide us a better understanding of the effects of the compositions and microstructure of FeNiMoB thin film materials on their magnetic properties.

Magnetically controlled reactors (MCRs) are widely used as reactive power compensation equipment owing to their favorable properties of smoothly adjusting their inductance value through dc bias. However, the dc bias and the rotational magnetization at corner and T-joint areas make the cores of MCRs saturated, resulting in high magnetostriction and vibration. Thus, the electromagnetic vibration analysis of MCRs must consider the vector hysteretic magnetostriction effect. In this article, a vector hysteretic magnetostriction model of silicon steel is proposed by combining the quadratic domain rotation model with the vector inverse Jiles–Atherton model firstly. Then, based on the measured magnetization and magnetostrictive characteristics curves of silicon steel, the model’s parameters are optimized by velocity controllable particle swarm optimization (VCPSO). Finally, the vector hysteretic magnetostriction model is combined with the finite element method (FEM) to simulate the vector vibration characteristics of MCR under dc bias. The simulation results show that the vector property of electromagnetic vibration and magnetic field at the T-joint area is higher than that at other areas. And the MCR vibration test results are consistent with the simulation results, which verify the accuracy of the proposed model in simulating electromagnetic vibration.