Airgap-harmonic-oriented Partitioned Design Method of PMV Motor with Improved Torque Performances

Here,we introduce a partitioned design method that is oriented toward airgap harmonic for permanent magnet vernier(PMV)motors.The method proposes the utilization of airgap flux harmonics as an effective bridge between the torque design region and the torque performances.To illustrate the efficacy of this method,a partitioned design PMV motor is presented and compared with the initial design.Firstly,the torque design region of the rotor is artfully divided into the torque enhancement region and ripple reduction region.Meanwhile,the main harmonics that generate output torque are chosen and enhanced,optimization.Moreover,the harmonics that generate torque ripple are selected and reduced based on torque harmonics optimization.Finally,the functions of the partitioned PMV motor torque are assessed based on the finite element method.By the purposeful design of these two regions,the output torque is strengthened while torque ripple is inhibited effectively,verifying the effectiveness and reasonability of the proposed design method.

Design and Analysis of a V-Shaped Permanent Magnet Vernier Motor for High Torque Density

This paper proposes a V-shaped permanent magnet vernier(V-PMV)motor for potential applications in direct drive system.By designing suitable pole slot ratio and adopting the V-shaped PM topology and dummy slots in rotor,the flux leakage can be avoided effectively.Meanwhile,the high-order harmonics with large amplitude in the airgap magnetic field are fully utilized and served as the effective working harmonics,which aim at enhancing the output torque and reducing the torque ripple.Moreover,to extensively explore the performance advantages of the V-PMV motor,a multi-objective optimization study is carried out.And,the electromagnetic performances of the V-PMV motors are analyzed and compared in detail.Finally,a prototype machine is built and tested.Both theoretical analysis and experimental results verify the validity of the motor and multi-objective optimization design approach.

Torque analysis for double-stator permanent-magnet motor

In addition to the characteristics of a conventional motor, a novel direct-drive double-stator permanent-magnet brushless motor proposed can operate in the state of either a generator or a motor as appropriate. Through numerical calculation and analysis, the output torque of double-stator permanent-magnet brushless motor of the same volume as the traditional machine is discussed, and the reduction of torque ripple by using the structure features of this motor is investigated. The results indicate that lower torque ripple under the condition of ideal effective torque can be obtained by the rational design of motor. The prototype motors tested show that this kind of motor structure has a higher power density.

A New-style Permanent-magnet Motor with Double-stator Structure

A new-style direct drive motor with double-stator structure is proposed. The structure and principle of the permanent-magnet (PM) brushless motor are discussed. On the basis of numerical calculation, the cogging torque waveforms of the prototype motor when staggering two stators are analyzed. The method that can reduce torque ripple making use of the structure features of this motor is investigated. The results of numerical calculation and experiment indicate that designing motor with this kind of structure is a good scheme for increasing the power density.

一种交替极永磁游标电机设计与分析

提出了一种使用低成本铁氧体磁体的交替极永磁游标电机(CPPMVM).介绍了该电机拓扑结构,提出了基于特定磁导函数的等效磁场模型来推导主磁密、调制磁密和反电动势.通过解析法和有限元法分析该电机电磁性能、气隙磁密和谐波分布.结果表明:与常规表贴式永磁游标电机(SPMVM)相比,所提出的交替极永磁游标电机机械结构简单、成本低、谐波调制作用有效、转矩密度高、抗退磁能力强.

聚磁式交替极永磁游标电机分析与设计

为了在减少传统聚磁永磁游标电机永磁体用量时,仍能保持较大的转矩密度,提出一种新型聚磁式交替极永磁游标电机。与传统聚磁式永磁游标电机相比,新型拓扑结构电机通过交替极转子设计在减少永磁体用量时仍能保持较好的转矩输出特性。该文首先介绍了聚磁式交替极游标永磁电机的结构特点及工作原理。其次,以输出转矩最大为目标,利用有限元法对所提新结构电机关键参数进行优化分析。最后对比分析了新型聚磁式交替极永磁游标电机与传统聚磁式永磁游标电机的电磁性能,包括气隙磁密、反电势及转矩性能,结果表明在相同的体积下,所提新拓扑电机具有更高的转矩密度及更少的永磁体用量。因此,它在低速大转矩直驱应用场合具有广阔的应用前景。

基于FOCA的永磁游标电机PI参数自整定

针对磁场定向控制中电流内环和转速外环比例积分(PI)控制器参数整定困难且耗时长的问题,基于Matlab/Simulink的磁场定向控制自整定(FOCA)模块搭建了永磁游标电机磁场定向控制双闭环调速系统参数自整定模型。该模块在PI控制器输出端注入正弦扰动信号,根据系统输入输出数据计算频率响应,基于频率响应自动整定PI参数,同时实现指定的目标带宽和相位裕度。最后通过仿真对比分析各个环路整定前后的控制性能,仿真结果表明使用FOCA模块能够快速自动整定PI控制器参数并且拥有良好的控制性能。

基于联合仿真的表贴式永磁游标电机的伺服系统设计

研究了表贴式永磁游标电机的伺服系统,设计电机三环(即电流环、速度环、位置环)结构的伺服控制系统控制器,并分析伺服系统的动、静态性能。利用Maxwell、Simplorer及MATLAB/Simulink软件建立了表贴式永磁游标电机伺服控制系统联合仿真模型,研究了位置环参数对位置跟随系统快速性和准确性的影响。对比分析了电机三环结构伺服控制系统场路耦合仿真与定参数仿真。仿真结果表明,此控制策略可以实现表贴式永磁游标电机精准定位、无超调,且具有良好的快速性和抗干扰性。

分裂齿集中绕组永磁游标电机电磁转矩特性分析

为了研究分裂齿集中绕组永磁游标电机(PMVM)的电磁转矩特性,基于磁场调制原理建立PMVM的磁动势磁导模型,给出永磁体和电枢绕组单独作用下气隙磁密谐波的次数和转速表达式,分析产生平均转矩和转矩脉动的谐波次数。采用麦克斯韦应力张量法计算各主次谐波产生转矩的大小,确定各主次谐波对电磁转矩的影响。通过有限元分析对结果进行了验证。结果表明:PMVM的电磁平均转矩绝大部分由16次谐波产生,占比98.83%,转矩脉动主要由16、34、48次谐波产生,占比52.29%。PMVM电磁平均转矩的来源主要为永磁体产生的气隙磁密基波,因此可改变永磁体的用量和形状增大其产生的气隙磁密基波以提升PMVM电磁转矩性能。

基于高功率因数的游标电机设计思路

为解决游标电机功率因数偏低的问题,提出了一种提高功率因数的电机设计优化思路。首先,使用绕组函数法计算出分数槽集中双层绕组的电感,推导出游标电机的功率因数表达式,分析影响功率因数的主要设计参数;其次,结合有限元法研究各设计参数改变时电机性能的变化规律,进而总结出设计思路;然后,以一台裂齿式游标电机为基准样机,按照所提思路重新设计一台高功率因数的电机,并采用遗传算法对电机主要设计参数进行多目标优化;最后,与基准样机进行性能对比,结果表明所设计电机的功率因数更高,验证了理论分析和所提设计思路的有效性。

内置式永磁游标轮毂电机结构参数多目标优化

外转子内置式永磁游标电机采用了磁调制原理,其内嵌永磁的结构能够提供额外的磁阻转矩,在低速大转矩方面有显著优势。研究了V形内置永磁游标电机,针对其磁路结构复杂、电磁参数多、不同性能指标之间难以平衡的问题,选取电磁结构参数作为优化对象,采用有限元的计算方法建立了BP神经网络代理模型,并利用NSGA-Ⅱ进行多目标优化,电机转矩和铁心损耗的优化率均达到10%以上,验证了多目标优化算法在内置式永磁游标电机设计方面的优越性。

永磁容错游标轮缘推进电机改进模型预测转矩控制

为提高永磁容错游标轮缘推进电机(FTPMV-RDM)在正常状态和一相开路故障状态下的控制性能,本文提出了一种基于电压矢量预选的改进模型预测转矩(MPTC)控制方法.针对六相独立H桥逆变器提供的备选电压矢量数量多导致MPTC系统计算量大的问题,首先,采用直接转矩控制中利用转矩、磁链误差及定子磁链位置信息确定预选电压矢量,减少MPTC系统中电压矢量的枚举次数.然后,利用价值函数进行二次筛选得到最优电压矢量.为了实现开路故障下的容错控制,提出了一种更换备选电压矢量表的开路故障容错控制策略.实验结果表明,基于电压矢量预选的FTPMV-RDM模型,本文预测转矩控制算法能够在无故障和一相开路故障下抑制电流畸变,进而有效降低转矩和磁链脉动.

Design to Improve Thrust Force Performance of Dual-side Primary Permanent-magnet Vernier Linear Motor

A novel dual-side primary permanent-magnet vernier linear(DS-PPMVL)motors is proposed.The novelty of the proposed motors is the design of asymmetric consequent poles on the mover,which can effectively enforce the flux-modulation effect and improve the thrust force performance.First,the topologies and operation principle are introduced.Subsequently,the structure relationships between the existing and proposed motors are discussed.Then,a unified analytical model is built.Accordingly,the magnetic field generated by the consequent pole is calculated.Meanwhile,the performance improvement mechanism with the asymmetric consequent pole is analyzed.To improve the efficiency of motor optimization,multi-objective optimization method is adopted to obtain the global optimal solution combination of structure parameters.The proposed motors exhibit higher thrust force,higher force density,less PM consumption,and better overload performance than the existing DS-PPMVL motor.Finally,experiments are conducted based on the existing prototype to verify the accuracy of the design and analysis.

Design of a Transverse-flux Permanent-magnet Linear Generator and Controller for Use with a Free-piston Stirling Engine

Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is developed.The impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor.The relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a goal.At last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is achieved.The power factor is improved and the process complexity is decreased.This research provides the instruction to design high-power factor permanent-magnet linear generator.

Remedial Phase-Angle Control of a Five-Phase Fault-Tolerant Permanent- Magnet Vernier Machine With Short-Circuit Fault

A fault-tolerant permanent-magnet vernier(FT-PMV)machine incorporates the merits of high fault-tolerant capability and high torque density.In this paper,a remedial phase-angle control(RPAC)strategy is proposed for a five-phase FT-PMV machine with short-circuit fault.Firstly,the proposed strategy can reduce the amount of unknown quantities by structuring the phase-angles of the normal phases.It can simplify the calculation of the remedial currents.Then,in order to obtain the desired torque,only the amplitudes of the remedial currents need to be calculated.Based on the principle of instantaneous electrical input power and mechanical output power balance condition,the real components are used to maintain the torque capability,while the reactive components are limited zero to minimize the torque ripple.Both simulations and experiments are presented to verify the proposed RPAC strategy.

Design of Axial-Flux Motor for Traction Application

This paper deals with the design of high power – low dimensions axial-flux permanent-magnet motor intended for trac-tion application. First, two motor configurations are analytically designed and compared using finite element calcula-tion. Then, the configuration yielding the best performances is integrated and modelled with the whole traction chain under MATLAB/SIMULINK environment in order to demonstrate the motor operation on a large speed band.

永磁游标电动机双绕组低谐波设计与磁热性能比较

为削弱永磁游标电动机的电枢反应磁场中的无效谐波含量,实现电动机高效运行,基于磁场调制理论提出一种双绕组低谐波永磁游标电动机.首先,阐明谐波抵消原理;其次考虑到温升对导线和永磁体性能的影响,利用有限元法对传统永磁游标电动机和双绕组低谐波永磁游标电动机的电磁场和温度场进行双向耦合计算,并对气隙磁密、转矩和温升等性能参数进行对比.研究结果表明:得益于低谐波设计,双绕组低谐波永磁游标电动机的转矩和效率得到改善,相比传统永磁游标电动机,在常温20℃时,所提出的双绕组低谐波永磁游标电动机的平均转矩和效率分别增长2.62%和0.55%,转矩脉动下降50.15%;温度收敛至稳态后,双绕组低谐波永磁游标电动机的平均转矩和效率分别增长2.66%和0.57%,脉动下降50.16%,验证了该低谐波设计方案的有效性.

采用改进子域模型的表贴式永磁游标电机磁场解析计算

针对传统子域解析方法在计算气隙谐波磁场丰富的表贴式永磁游标电机磁场时,出现系数矩阵维数高、计算过程复杂的问题,提出了一种改进的子域解析模型。该模型通过坐标变换,将各子域矢量磁位在二维极坐标系下的拉普拉斯方程或泊松方程变换为准笛卡尔坐标系下的方程形式,利用分离变量法计算各子域矢量磁位方程的通解,根据边界条件计算待定系数,以双曲函数的形式表示各矢量磁位的解析解。计算了空载反电动势、气隙磁密和电磁转矩,与传统子域解析方法、有限元法计算结果进行对比。仿真结果表明:改进子域解析方法与有限元法的相对误差均小于1%;与传统子域解析方法相比,空载反电动势、气隙磁密和电磁转矩计算精度分别提升了1.7%、0.87%和3.66%。实验样机的空载反电动势计算波形和测试波形也基本吻合,验证了该方法的有效性和可行性。

永磁游标电机的多目标正交-粒子群优化

永磁游标电机有低速大转矩运行、直接驱动等优点,在保证转矩密度的同时降低转矩脉动是该类电机优化的主要目标。以内转子永磁游标电机为研究对象,利用敏感性分析确定优化因素,采用多目标正交优化、粒子群算法对该电机进行了优化,提出了二者相结合的正交-粒子群优化算法。利用有限元法对上述3种优化结果进行仿真,结果表明,该方法解决了正交优化精度不足和粒子群优化计算量大的问题;优化后使电机电磁转矩增加8.5%,转矩脉动减小8.23%,提升了电机的性能。

裂齿式永磁游标电动机性能分析与比较

针对永磁游标电动机(permanent magnet vernier motor, PMVM)转矩密度大和功率密度高的特点,将其与传统永磁同步电动机(permanent magnet synchronous motor, PMSM)的性能进行比较研究.给出了6槽32极裂齿式PMVM的结构及工作原理,采用有限元仿真软件JMAG对其永磁磁场和电枢反应磁场的气隙磁密、空载感应电势、转矩、损耗等进行了分析,并与两台具有相同直径、轴长、定子齿数的PMSM进行了定量比较.结果表明:相比于6槽32极和6槽4极PMSM,6槽32极裂齿式PMVM平均转矩分别增加约45.0%和76.2%,转矩脉动减小约90.5%和95.0%,这揭示了PMVM转矩密度大、转矩脉动小的优点.然而,由于PMVM气隙中含有大量不同极对数、不同旋转速度的谐波磁场,导致其铁耗和永磁体涡流损耗较大.