The magnetic field modulated variable speed permanent magnet (PM) brushless motor (MFMVS-PMBM) is a new type of power shunting device for hybrid electric vehicles (HEVs), which is composed of a magnetic gear (MG) and a PM brushless motor (PMBM). Compared with the conventional double rotor motor, the MFMVS-PMBM shows a more complex electromechanical energy conversion relationship due to its special magnetic field modulation principle. In order to obtain better electromagnetic characteristics of the motor, the key parameters of MG and PMBM are optimized in this study. The effects of gear ratio, the number of blocks per pole of the Halbach array, and the angle of connecting bridge and magnetic isolation bridge on the torque of MG are analyzed. The electromagnetic characteristics of the motor, such as pole slot matching, PM thickness, and slot opening width of PMBM, are also analyzed. Finally, the prototype is made, and the experimental platform is built. The results show that MFMVS-PMBM has a good sinusoidal back electromotive force (EMF), high transmission efficiency, and power factor.
10 January 2019 in IEEE Transactions on Applied Superconductivity
In order to improve the high torque density of coaxial magnetic gear, a novel high temperature superconducting (HTS) bulks CMG with an eccentric pole of inner rotor and Halbach arrays of outer rotor is proposed in this paper. According to the Meissner effect, the HTS bulks replace the traditional epoxy resin to improve the flux-modulation effect. Moreover, the HTS bulks CMG has an eccentric structure of permanent magnets (PMs) on inner rotor and has Halbach PMs arrays on the outer rotor. The proposed HTS bulks CMG topology with 4 inner and 23 outer pole pairs is established. The topology performance is assessed and verified by finite element analysis (FEA).
14 February 2022 in IEEE Transactions on Applied Superconductivity
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.
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.
The main factors of stress distribution in MCRs are the magnetostriction effect of the core materials and the magnetic force between gaps under DC bias excitation. This paper developed a coupling model for MCRs considering Maxwell magnetic force and magnetostriction under DC flux density biases. The constitutive equations of the magnetic field and strain field are constructed based on the magnetic property curves with a new measured and analyzed method to consider DC magnetic flux biases, which is the key contributions of this study. Then, the electromagnetic vibration properties of the MCR model are calculated and analyzed. To prove the validity of the proposed method, the vibration of a 4.4 kVar-220 V MCR is tested and analyzed.
11 April 2019 in Journal of Electrical Engineering & Technology