The conventional power transmission system of electric vehicles typically distributes driving torque equally between the left and right wheels, which restricts the potential to enhance the vehicle’s chassis dynamic performance. To solve this problem, a novel torque vectoring drive-axle (TVDa) is proposed, it can achieve the driving torque precise distribution between the two-side wheels, thereby effectively improving the vehicle's active safety and handling stability. First, the structure design principle and torque distribution mechanism of the novel TVDa is theoretically analyzed in this paper, and establishes the design criteria for key structural parameters. Second, the motor parameters of the TVDa are systematically matched to meet the practical application requirements of the vehicle. Next, a virtual prototype model of an electric vehicle equipped with the TVDa is built, and the functional feasibility of the TVDa impact on vehicle dynamic performance has been verified. Finally, simulation results demonstrate that the novel TVDa can significantly improves the vehicle’s maneuverability and trafficability through distributing driving torque between the two-side wheels, while maintaining low energy consumption in the torque vectoring motor, indicating strong potential for engineering applications.

To address the issues of high noise in switched reluctance motors (SRMs) and low torque in synchronous reluctance motors (SynRMs), this study investigates and optimizes a novel switched-synchronous dual-mode reluctance motor (SSDRM) drive system, which integrates SRM and SynRM modes through innovative control strategy reconfiguration. First, a unified mathematical model connecting the SRM and SynRM coordinate systems is established. The analysis reveals a critical design constraint for dual-mode compatibility: either the AC component of self-inductance (ls2) or mutual inductance (ms2) must be minimized. Guided by this, a novel rotor structure integrating a central flat-top with edge modulation curves is proposed to balance high torque density in SRM mode and low torque ripple in SynRM mode. In terms of system implementation, a parallel dual three-phase bridge inverter is adopted. This topology enables seamless mode switching using only 12 power switches, which is significantly fewer than existing dual-mode drive schemes. Both simulation and experimental results demonstrate that the proposed SSDRM successfully integrates the merits of both modes, achieving a high average torque of 4.92 N·m in SRM mode and a remarkably low torque ripple of 8.39% in SynRM mode, while greatly extending the constant-power speed range.

The reverse-salient permanent magnet motors (RSPMMs) have attracted widespread attention in the field of electric vehicles (EVs) due to their wide constant power speed range and strong overload capacity. However, there are few studies on the design and optimization of RSPMMs used for EVs. In this article, a reverse-salient hybrid permanent magnet motor (RSHPMM) is proposed. By analyzing the motor parameters that affect the distribution of the operating interval, the optimization objectives are reasonably selected. To reduce the difficulty of optimization, the Sobol global sensitivity analysis is introduced for parameter analysis. This approach fully considers the interactions between two parameters. After eliminating noncritical parameters, a genetic algorithm is employed for multiobjective optimization. The electromagnetic performance of the RSHPMM is investigated by the finite element method and is compared with a conventional interior permanent magnet motor (CIPMM). Finally, a prototype is manufactured and tested. The results show that the RSHPMM has lower ripple torque, stronger flux-weakening ability, wider constant-power speed range, and higher efficiency at a high speed than the CIPMM. The amount of rare-earth permanent magnets (PMs) is only 44% of that of CIPMM. The validity of the design and optimization approaches of the RSHPMM used for EVs is verified.

To address the high noise and limited high-speed performance of conventional switched reluctance motors (SRMs), this paper proposes a switched-synchronous dual-mode reluctance motor (SSDRM). The proposed motor, through an innovative redesign of its control system architecture, integrates two excitation schemes: unipolar rectangular wave excitation and bipolar sinusoidal wave excitation. This dual-mode excitation strategy allows the motor to fully retain the advantages of SRM while reducing operational noise and increasing the speed range. While this design offers significant benefits, the dual-inverter configuration introduces a zero-sequence current (ZSC) path. Thus, suppressing the zero-sequence current becomes a critical issue for the proposed motor. This challenge distinguishes it from conventional SRMs and must be resolved. To suppress the ZSC, its generation mechanism is analyzed. An analytical model based on the Fourier series of the inductance profile is established to derive a mathematical model of the zero-sequence circuit voltage. Subsequently, by equivalently representing the SVPWM algorithm as a combination of a third harmonic and SPWM, an expression for the common-mode voltage in the dual-inverter system is derived. Based on this theoretical analysis, a phase-compensation ZSC suppression strategy is proposed for the SSDRM to achieve harmonic cancellation. The performance of the proposed motor and the effectiveness of the ZSC suppression algorithm are validated through finite element simulations and experiments.

Abstract As a novel motor topology, the asymmetric unequal-pole fractional-slot permanent magnet synchronous motor (AUFS-PMSM) weakens the high pole-frequency vibration problem of traditional motors. However, its unique permanent magnet arrangement enhances the torque density while increasing the local tangential electromagnetic force density.To mitigate the vibration problems induced by the asymmetric unequal-pole structure, this paper conducts vibration analysis and optimization of the AUFS-PMSM from the perspective of the modulated tangential force translation theorem(MTFT). Firstly, the theoretical derivations of the radial and tangential electromagnetic force formulas are presented. Then, by applying the MTFT, it is discovered that tangential forces of different spatial orders at the same temporal order have varying effects on the motor' s radial vibration. Therefore,a multi-sensitivity hierarchical optimization method considering tangential force is proposed to reduce vibration by decreasing the tangential force. Finally, the theoretical analysis and optimization design are validated by fabricating and testing a prototype. The research results emphasize the importance of considering tangential forces and provide a novel perspective for vibrations reduction in permanent magnet synchronous motors.

As a new motor topology, the modular stator permanent magnet motor has advantages such as high fault tolerance and high torque density. However, its unique stator structure can aggravate the vibration problem of the motor. Therefore, to alleviate the vibration problem caused by the modular stator, this paper presents the vibration analysis and optimization of the proposed new E-type modular stator permanent magnet synchronous motor (ETMS-PMSM) from the perspective of the stator teeth modulation effect. Firstly, the effects of electromagnetic force, the stator teeth modulation effect and its diversity on vibration are theoretically analyzed. On the basis, a hierarchical multi-objective evolutionary optimization method with comprehensive sensitivity analysis is proposed, focusing on the low-order and high-order harmonics of the electromagnetic forces, and the electromagnetic and vibration characteristics of the motor before and after the optimization are compared and analyzed. Finally, a prototype is manufactured and tested to verify the effectiveness of the theoretical analysis and optimization design.

As a novel topological structure, modular stator permanent magnet motors offer advantages such as high torque density and high fault tolerance. However, this special structure also presents issues with motor temperature rise. Therefore, to improve the temperature rise issue, this paper proposes a novel built-in waterway structure, which can be integrated into the modular stator of the motor. Without increasing the overall motor volume, this design enhances output torque by shortening the magnetic path through the magnetic concentration effect of the modular stator. Meanwhile, the integrated cooling channels directly target the primary heat source areas, addressing motor temperature rise issues, achieving synergistic optimization of electromagnetic performance and thermal dissipation. First, establish two motor models with built-in circular and square waterway between adjacent gaps in the modular stator and perform finite element analysis. Analysis results show that the modular stator with built-in circular waterway permanent magnet synchronous motor (MCW-PMSM) shows more excellent performance in both output capability and heat dissipation. To enhance the efficiency of motor temperature calculations, a modular stator-waterway integrated 3D thermal network model (MSWI-3DTNM) was constructed based on the MCW-PMSM prototype. For the special topological structure of the modular stator, three-dimensional heat transfer pathways were established in the axial, radial, and circumferential directions. The temperature prediction results from the thermal network model exhibited an error within 4 % compared to finite element simulation. Finally, a prototype was constructed, and an experimental platform was established to validate theoretical analysis and structural design.

To reduce reliance on rare-earth permanent magnet materials while enhancing torque output capability, this paper proposes a Magnetic-Axis-Offset Hybrid-Pole Interior Permanent Magnet Motor (MAOHP-IPMM). The motor features an asymmetric magnetic barrier geometry combined with biased hybrid poles, which induces a Magnetic Axis Offset (MAO) effect. This configuration shifts the permanent magnet flux linkage, thereby reducing the current phase difference between the peak permanent magnet torque and reluctance torque. Firstly, the topology and torqueenhancement mechanism of the MAOHP-IPMM are elaborated. A mathematical model is then derived from the power balance equation, incorporating the magnetic axis offset angle to quantify the MAO effect. Subsequently, a hierarchical optimization strategy is adopted, integrating the Box-Behnken Design (BBD) response surface methodology and multiobjective genetic algorithm (MOGA-II) to perform multiobjective optimization of critical design parameters. Finite element simulations show that, compared to the conventional interior permanent magnet motor (TIPMM), the MAOHPIPMM increases average torque by 5.5% while reducing NdFeB magnet consumption by 15.6%, confirming its significant torque enhancement. Experimental validation via prototype testing verifies both the MAO effect and the torque enhancement capability of the MAOHP-IPMM.

To reduce the current phase angle difference between the maximum permanent magnet (PM) torque and reluctance torque in the permanent magnet assisted synchronous reluctance motor (PMASynRM) and increase the motor output torque at the same time, a novel asymmetric hybrid pole-PMASynRM (AHP-PMASynRM) is proposed in this study. By asymmetrically arranging the PMs and air barriers in the rotor, the PM flux linkage is deflected. The mathematical model of AHP-PMASynRM is established, and the relationships between the magnetic-pole-shift effect and the degree of asymmetry in PM configurations are studied. Furthermore, a multiobjective optimization process is proposed for the asymmetric rotor structure. Finite element analysis results show that the optimized motor has a 4.32% increase in output torque compared to the traditional symmetric PMASynRM. Then, the electromagnetic characteristics of the two motors are compared and analyzed. Finally, prototype experiments are conducted to validate the finite element analysis results.

Axial flux permanent magnet motors (AFPM) are optimal for hub drives in electric vehicles due to their compact size and high power and torque density. However, the surface-mounted pole structure of the AFPM is susceptible to significant eddy current losses, which can result in irreversible demagnetization of the poles. Furthermore, hub motors for electric vehicles require superior electromagnetic performance. In order to comprehensively consider the eddy current losses and the electromagnetic performance of the motors, this paper proposes a novel topology of an unequal thickness segmented magnetic pole axial flux permanent magnet hub motor (UTSMP-AFPM). Firstly, a mathematical model of eddy current loss in the permanent magnet of an axial flux permanent magnet motor is derived theoretically. The mechanism of pole segmentation to reduce eddy current loss in the permanent magnet is analyzed, and an analytical formula for the electromagnetic characteristics of the motor is established. The performance of the motor is further optimized. Subsequently, finite element simulations are conducted to assess the permanent magnet eddy current loss, rotor temperature rise and electromagnetic performance of the proposed motor in comparison to that of the traditional YASA motor. Finally, a prototype is constructed and the proposed structure is validated through experimentation.

As a starter, the switched reluctance machine (SRM) features a significant output torque. As a generator, the doubly salient electromagnetic machine (DSEM) has excellent voltage regulation characteristics. To combine the benefits of both types of machines and reduce the length of flux paths, a segmental rotor dual mode reluctance starter generator (SR-DMRSG) for vehicles is proposed in this article. This machine transitions between two operating modes by adjusting the linkage between the armature winding and the variable winding. First, the research object is identified as the SR-DMRSG with a 12/8-pole structure by establishing the corresponding relationship between the number of stator poles and the number of segmented rotors. The magnetic chain, electric potential, and other electromagnetic characteristics of the SR-DMRSG are analyzed by using the finite element method. The study findings demonstrate that the SR-DMRSG displays a 5.46% increase in peak torque when compared with a conventional SRM. Moreover, it operates as a generator which is effortless to regulate. The total harmonic distortion (THD) of the back electromotive force (EMF) of the armature winding decreases by 8.1%. The machine's feasibility has been verified by simulation and experimental results. It has been confirmed that the SR-DMRSG has high starting torque and effective voltage regulation.

Aiming at the high cost of permanent magnet synchronous motor and the reduction of motor output performance caused by high cogging torque and torque ripple, an asymmetric hybrid‐magnet offset motor is proposed. Based on the winding function theory and the equivalent magnetic circuit method, the expressions of stator and rotor magnetic potential are derived respectively, and the analytical model of torque ripple is established by combining with the Lorentz force law. By using the magnetic pole offset method, the phase offset model of the cogging torque is established, and the analytical expressions of the cogging torque and the magnetic pole offset angle are derived. The results of the simulation and experiments show that the asymmetric hybrid‐magnet offset motor has lower no‐load back‐EMF harmonic content and rare‐earth material ratio than the traditional permanent magnet motor, and its performance in terms of the cogging torque and the torque ripple is better than that of the traditional permanent magnet motor. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Negative-salient permanent magnet motors (NSPMMs) have a potential application in the field of electric vehicles (EVs) due to their wide constant-power speed range and high efficiency. However, the researches of NSPMMs used for EVs and the relationships between the design parameters of the motor and drive performances of the EV are still absent. First, the operating characteristics of permanent magnet drive motors are investigated. Second, the relationships between the distribution of the driving cycles of the EV and the design parameters of the motor are summarized. Then, a negative-salient hybrid permanent magnet motor with excellent performances in the full-speed range and remedies for its negative impact are proposed. The electromagnetic performances of the proposed topology are compared with the conventional motor by finite element method and the performance evaluation of the electrical driving system is carried out. Finally, a prototype is manufactured and tested. The simulation and experimental results show that the proposed motor exhibits favorable characteristics such as low torque ripple, wide constant-power speed range, high efficiency in a wide speed range and low rare-earth consumption. The results verify the feasibility of the proposed topology applied to EVs.

培养创新型人才是高校人才培养的目标,如何正确看待和处理创新创业与教育教学的关系已成为目前教育界的热点问题.首先,建立大学生创新创业教育发展的时间轴,将二者关系分为相互制约、协同发展、相互促进三个阶段.其次,分析现阶段制约二者发展的因素,并以问卷调查法统计分析不同专业学生对于二者关系的现状认识.最后,从如何实现二者之间的良性互动入手,分析如何在二者之间建立深度融合关系.

Internal combustion engines emit high-temperature, high-pressure, and text high-speed exhaust gases, resulting in wasted energy and low thermal efficiency. In order to recover the available residual energy in the exhaust gas, this paper proposes a new topology of the text disk-type axial flux stator-excited doubly salient generator (AFSDSG) with partitioned stator suitable for high-temperature and high-speed operation. Based on the analysis of the above generator inductance characteristics, the influence mechanism of three text pole-slot structures on the induced electromotive force (IEMF) of the armature winding is clarified, the equivalent magnetic circuit method is used to analyze the influence of different winding arrangements on the text no-load performance of the generator, and the principles of text pole-slot structure optimization and winding arrangement are summarized. The finite element software is used to model and simulate different configuration. After focusing on the analysis of transient characteristics such as inductance, armature winding IEMF, and air-gap flux, it is concluded that different from the conventional text pole-slot structure and winding connection method make that only the overlapping area of the stator and the rotor changes linearly can produce a constant voltage, the winding arrangement of Winding Partition Excitation Span 2 has a high IEMF amplitude value and low harmonic content. Finally, the prototype of a three-phase 12/8-pole was trial manufactured and tested. The consistency of the simulation results and experimental results is verified the innovation and feasibility of the new topology proposed in this paper.

With a wide speed range, high overload capacity and preventing permanent magnet demagnetization, negative-salient permanent magnet motors have a wide range of applications in the field of electric vehicles. In view of the multiple operating conditions of the electric vehicle drive motor, this paper proposes a new type of combined magnetic pole negative-salient permanent magnet motor considering the driving conditions. Firstly, the optimization parameters of the motors are determined according to the analysis of the mathematical model. The design parameters are layered by the comprehensive sensitivity analysis, and the response surface Box-Behnken Design method and multi-objective genetic algorithm-II are used for optimization. Then, the electromagnetic performance of the proposed motor and the traditional interior permanent magnet motors are compared and analyzed through the finite element simulation. Finally, a prototype is manufactured and the rationality of the proposed motor structure is verified by experiments.

针对传统电励磁双凸极发电机磁路长、本体质量大以及电机可靠性低的问题,提出了一种U形转子定子励磁发电机(UR-SEG).该电机转子为分块U形结构以缩短电机磁路、减轻本体质量并改善了电机电动势波形.通过有限元仿真分析UR-SEG的电磁特性,其空载、负载电动势总谐波失真较传统电励磁双凸极发电机分别下降6.86％和7.28％,电机转子质量下降14.23％,改善了电机的发电质量.

永磁同步电机因使用磁钢提供磁通,简化了电机转子结构从而提高了电机的运行可靠性;另外,因无需励磁电流省去了励磁损耗,从而具有高效率、高功率密度等优点.但传统永磁同步电机由于存在齿槽转矩和磁阻转矩,存在电机输出转矩脉动较大的问题.针对该问题,以提高电机平均输出转矩、降低电机输出转矩脉动和减小电机气隙磁密总谐波失真为优化多目标,建立一种分段磁钢永磁同步电机模型.选择电机转子关键结构参数为优化参数,通过田口算法优选出对优化目标影响较大的结构参数,再采用响应面法拟合优化目标曲线确定最优参数组合,实现分段磁钢永磁同步电机多目标优化,并通过仿真验证了有效性.最后试制了一台三相48/8极的样机并进行了试验,试验结果验证了电机结构及优化方法的合理性.

In order to reduce the torque ripple of the vehicle motor and increase the range of high-efficiency working area, this paper proposes an Asymmetric Multi-layer Barrier Permanent Magnet Synchronous Motor (AMBPMSM). The equivalent magnetic circuit model is established, and the characteristics of flux leakage, air gap flux density and inductance are analyzed, and the parameters affecting the magnetic density of air gap are determined. The influence of each parameter on the performance is analyzed by using the response surface method (CCB), and the parameters are optimized and analyzed by MOGA. Through Finite Element Analysis, it is proved that the proposed motor has lower torque ripple, less back EMF harmonics and a wider range of high-efficiency regions.

An asymmetric hybrid permanent magnet motor (AHPMM) is proposed for the traditional permanent magnet motor (TPMM) with a large amount of rare earth materials and high cogging torque. The equivalent magnetic circuit model of the motor is established and the factors affecting the fluctuation of cogging torque are analyzed. With the objective of reducing the torque ripple and cogging torque of the AHPMM, the motor is parametrically modeled and analyzed, and multi-objective hierarchical optimization of the motor parameters is carried out using a hybrid algorithm combining the response surface algorithm and the single scan method, which ultimately determines the optimal combination of motor dimensional parameters. The electromagnetic performance of the AHPMM compared to the TPMM is analyzed using the finite element method. The results show that, without any decrease in output torque, the use of rare-earth materials is reduced by 18.5%, the cogging torque and the total harmonic distortion of the No-load back EMF waveform are reduced by 0.78 Nm and 4.7% respectively compared to the TPMM. Finally, a prototype motor is manufactured and the validity of the theoretical analysis and design of the AHPMM is verified through experiments.