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.

A coaxial magnetic gear (CMG) with double-layer permanent magnets (PMs) and Spoke structure is proposed to replace the mechanical gearbox in tidal power generation system. For the inner rotor PMs, the distributions of PMs are the spoke structure with different sizes, and the magnetization direction is Halbach array. The outer rotor PMs have two layers, one is Halbach array, and the other is radial magnetization. According to the sensitivity of parameters, the response surface method and multiobjective genetic algorithm are used for optimization analysis to determine the optimal structural dimension parameters of CMG. A CMG topology with 4 inner poles and 17 outer poles is established. Compared with the conventional CMG, the output torque of the proposed CMG is increased by 33.42%. Finally, a prototype was made and a test platform was built. The experimental results show that the transmission ratio of the proposed model is consistent with the theoretical value, the no-load loss is relatively small, and the efficiency is high.

The magnetic gear integrated permanent magnet brushless machine (MG-IPMBM) is a kind of compact structure with high torque density and complex electromagnetic energy transfer. In order to analyze the transient characteristics of the machine, an analysis method of field circuit coupling is proposed. Both magnetic gear (MG) and permanent magnet motor are magnetized by Halbach array. Combining the analytical model of the MG magnetic field with MATLAB motor simulation module, a joint simulation model of field circuit coupling double closed-loop control system based on the Simulink-analytical method is established. The electromechanical transient response characteristics of machine under load starting, load mutation, and overload self-protection are analyzed. The simulation results show that the output speed and torque of machine can accurately follow the given value, and its unique overload self-protection ability greatly improves the safety of machine operation. In addition, a prototype is made and an experimental platform is built. The experimental results show that the output torque follows quickly, the torque ripple is small, and transient performance of the machine is good.

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).

In this paper, a novel flux switching permanent- magnet machine (FSPM) with consequent-pole magnets and flux bridges in the stator core is proposed to improve the torque capability of FSPMs with high pole ratios. The stator yoke and flux bridges adjacent to the magnets can provide magnetic paths for the main working harmonic field, thus the magnetic reluctance of the working harmonic field is reduced, and the flux modulation effect, winding back-electromotive force (EMF) and output torque of the proposed FSPM can be significantly improved compared to the regular FSPM with high pole ratios. The operation principles and stator-slot/rotor-slot combinations of the proposed FSPM are introduced. Then, the influences of pole ratio, split ratio, slot opening ratio and PM width on torque density of the proposed FSPM is investigated using finite element analysis (FEA). Moreover, after the investigations, a proposed FSPM is compared to a regular FSPM in terms of back-EMF, rated torque, power factor, etc. Finally, to verify the theoretical analysis, a 12-stator-slot/14-rotor-slot FSPM is built and tested.

To improve the reliability and continuous navigation of ship propulsion, a magnetic variable speed diesel–electric hybrid motor with auxiliary teeth for ship propulsion is proposed in this article. The inner rotor permanent magnet of the motor adopts an eccentric structure and is magnetized by the Halbach array. The auxiliary teeth are inserted into the stator, which not only has the function of magnetic regulation but also can realize phase-to-phase isolation. Moreover, it can increase the reliability of the motor. The working modes of the motor in the marine propulsion system mainly include diesel engine driving mode, electric propulsion mode, and hybrid propulsion mode. In this study, finite element software is employed to build the motor's parametric model. According to the results of comprehensive sensitivity analysis, the electromagnetic torque and torque ripple are optimized by combining evolutionary algorithm and response surface method. Finally, a prototype is manufactured and an experimental platform is built. The experimental results show that the motor exhibits excellent dynamic response performance, a small torque ripple, a good sinusoidal back electromotive force, and low loss.