Proposal and Feasibility Study of the Integrated Diode Synchronous Motor

This paper presents a new type of magnet‐free motor that has concentrated stator windings and rotor coils with a pair of diodes. The most important feature of this motor is that currents in the rotor coils can be generated by utilizing the changes in the spatial second harmonic of the magnetic fields due to the concentrated stator windings, which normally increase motor losses. A prototype of the motor was designed and fabricated, and its basic performance was evaluated. First, using simplified analytic models, we explain the mechanism of inducing currents in the rotor coils by the changes in the spatial second harmonic of the magnetic fields. Second, we compare the torque performance of the proposed motor and that of other types of motors including a magnet motor through finite‐element analyses. The analyzed data show that the proposed motor can possess greater torque/volume ratio than that of the other motors. Finally, using the measured data, we validate the mechanism of inducing currents in the rotor coils, and examine the torque and power characteristics of the motor.     

Design of Unskewed Interior Permanent Magnet Traction Motor with Asymmetric Flux Barriers and Shifted Magnets for Electric Vehicles

Abstract

Interior permanent magnet synchronous motors (IPMSMs) are commonly used in electric and hybrid electric vehicles. Nissan Leaf electric vehicle (EV) uses skewed-rotor IPMSM as a traction motor. This motor is considered as a benchmark in this work. Although, skewing improves the torque quality of the motor by reducing the torque ripple, it reduces the average torque and increases the motor manufacturing complexity and cost. This article proposes improvements to the benchmark motor torque quality without skewing. The proposed motor uses the same stator winding and rotor magnet topologies of the benchmark motor with the same geometric constraints and magnet volume. Modifications are applied to the placement of the magnets in the rotor and the shape of the flux barriers to achieve the performance requirements. The design procedure of the proposed unskewed design is illustrated. Moreover, the electromagnetic performance of the proposed design is investigated. The design shows competitive performance in terms of the average torque, torque ripple, cogging torque, and efficiency compared to the benchmark motor. The mechanical integrity of the design is also verified. The proposed design is found to be a suitable alternative to the benchmark traction motor with a reduced rotor weight and without skewing.     

异步起动永磁同步电机非正常工况退磁分析

为了研究异步起动永磁同步电机非正常工况运行时的退磁磁场对永磁体的影响,通过建立有限元模型,计算分析了包括三相突然短路、缺相运行、过载运行、降电压运行、失步运行和堵转运行6种常见非正常工况运行时定子电流、转速和永磁体工作点磁密的变化。结果表明,起动过程电流均大于非正常工况运行时的冲击电流,直接影响了作用在永磁体上的去磁磁动势,定、转子合成磁动势作用在永磁体上,将使得永磁体工作点磁密最小,退磁风险最大。当电机在同步状态运行时,永磁体工作点磁密为恒定的值;当电机在失步状态运行时,转子导条产生感应电流,定子电流和转子导条电流产生的合成磁场使永磁体工作点磁密做周期性波动。     

电动汽车用新型轴向磁场车轮电机的设计

车轮电机由于取消了齿轮和机械差动器,减小了驱动链的组件,因而减小了整个驱动链的重量,提高整个系统的可靠性和效率。该文对一种新型的应用于电动车辆驱动的直驱轮用轴向磁场永磁同步电动机的进行了设计。电机的电枢铁心由各个在磁路上没有联系的定子极组成,省去了定子铁心轭部,电机结构简单易制造。采用等效磁路法对电机进行了电磁设计,并用有限元法进行了验证。设计和仿真结果证明所提议的结构是可行的。     

Robust Control of the Brushless DC Motor with Variable Torque Load for Automotive Applications

Abstract

The design of an Active Disturbance Rejection Controller for the Brushless DC motor (BLDC) that compensates load torque variations in the rotor shaft without the measurement of the rotor shaft speed is presented. The reconstruction of the unknown load and motor speed is accomplished by the combination of a generalized Proportional Integral Control (PI) and a Luenberger observer, while the stator current regulation is designed around a passivity based controller. Using parameters of a commercial motor designed for a small electric vehicle under different driving conditions, numerical simulation results are included that validate the effectiveness of the proposed scheme both in terms of transient response to changes in set points and in tracking variable speed references.     

基于滑模变结构的PMSM直接转矩控制

分析了永磁同步电机(PMSM)数学模型,设计了一种新颖的基于空间矢量脉宽调制技术的直接转矩控制(SVM-DTC)系统。利用两个PI控制器分别调节磁链和转矩实现对电机空间矢量中转矩和磁链两分量的解耦,同时采用基于转子位置和定子电流的定子磁链估算方法观测定子磁链,并设计滑模变结构无速度传感器来估算转子位置。仿真结果表明,所提出的方法能有效地估算定子磁链与转速,减小电磁转矩和定子磁链脉动,从而使系统具有较好的动、静性能。     

分数槽集中绕组定子磁动势的分解

介绍了单元电机的基本概念。以12槽双层的分数槽集中绕组为例,给出绕线原则,并在不确定单元电机极对数的情况下,用交流电机绕组理论、函数的傅里叶级数展开两种方法,从一个线圈、一组线圈、一相绕组到三相绕组详细推导了分数槽集中绕组各次谐波的绕组因数和磁动势,得出了分数槽集中绕组的一般特点和普遍规律。最后指出转子极对数接近但不等于定子槽数的一半是采用分数槽集中绕组的永磁电机的最佳选择。     

油摩损耗对电潜泵用永磁电机流固耦合传热计算的影响

电潜泵用永磁电机工作在高温高压的特殊环境下,采用润滑油作为潜油电机的润滑和冷却物质,润滑油随着转子在气隙中运动。以往研究只考虑了转子油摩损耗,然而相比于空冷、水冷等冷却方式,油冷时,润滑油黏度较大的特性是不可忽略的因素。且电潜泵用电机转速较高,润滑油对定子侧产生的油摩损耗是否可以忽略及其对电机温升的影响需进一步探究。因此,以一台15 kW潜油永磁电机为例,推导出了定子油摩损耗近似解析式,提出了定子油摩损耗与转子油摩损耗的关系规律。基于计算流体力学和流固耦合传热理论,研究了气隙处流体流动特性,证明了定子油摩损耗近似解析式的准确性,得出了电机各部件温升分布,并分析了定子油摩损耗对电机的温升影响。     

广域高效车用轴向磁通永磁同步电机的设计分析

针对车用驱动电机转矩和转速多变,运行范围宽广,需要提升电机在全域运行范围的高效率能量转换的问题,提出以高效率区间占比为设计目标的车用轴向磁通永磁电机设计方法。提出了考虑PWM供电影响的电机铁耗工程计算方法。基于等效磁网络法和集总参数热网络法构建了轴向磁通永磁同步电机的快速磁-热耦合设计模型,提高了车用轴向磁通永磁同步电机的设计精度。基于磁热耦合模型,分析了极弧系数、每槽导体数、气隙长度、永磁体尺寸、定子槽型尺寸等关键设计参数对车用轴向磁通永磁同步电机高效率区间占比的影响。设计并制造了样机一台,开展了电机效率和温升测试实验,获取了全域运行范围内的电机效率及电压分布,测试结果验证了磁热耦合模型和设计结果的有效性。     

利用定子槽口宽度削弱永磁电机电磁噪声研究

着重研究了永磁电机定子槽口宽度对电磁噪声的影响。通过电磁力解析计算得出电磁力与定子槽口宽度的计算关系。利用Ansoft软件对1台电动汽车用永磁电机进行电磁场计算,求解改变定子槽口宽度对电磁力波的影响,并用ANSYS软件对该永磁电机进行不同定子槽口宽度的2D声场计算。进行了试验验证,仿真计算与试验结果基本一致,可为该类电机削弱噪声设计计算提供参考。     

电动汽车驱动电机三维CFD热分析与温升测试研究

针对电动汽车驱动电机在整车极限工况下的温升问题,采用流-固共轭传热数值计算方法对永磁同步电机的散热性能进行了仿真计算,得到了不同工况下电机定转子的温度分布规律。利用滑环模块解决了转子温升测试的难题,将不同整车工况下电机的温升测试数据和计算流体动力学(CFD)仿真结果对比,验证了仿真计算模型及方法的准确性,为整车在各种行驶路况下准确获取电机内永磁体工作温度提供了理论支持。     

Design Method for Improving Motor Efficiency of Switched Reluctance Motor

The motor efficiencies of switched reluctance motors (SRMs) are inferior to those of permanent magnet synchronous motors. This paper describes a design procedure for an SRM to obtain a higher motor efficiency. The first step in the design procedure makes clear the principle for improving the motor efficiency. The cross‐sectional and axial shapes of the rotor and stator cores are designed by magnetic field analysis with the two‐dimensional (2D) and 3D finite element method. A high‐efficiency SRM with 12 stator poles and eight rotor poles is designed. The designed SRM was produced experimentally, and was tested to verify its performance. The motor efficiency was improved in comparison to the standard SRM with six stator poles and four rotor poles.     

永磁球形步进电机的结构研究与设计

介绍了一种新型永磁球形步进电机的基本结构,分析了永磁体和定子线圈在实际电机模型中的球面定位,然后介绍了一种以单相电流跟踪PWM控制实验为基础的定子线圈的选择方法。选择合适的部件设计出了永磁球形步进电机的转子球、永磁体、定子支座、定子线圈等各部分的实际参数,给出了详细设计方案,并绘出了该电机的CAD模型图,为永磁球形步进电机的进一步设计和优化提供了依据。     

轴向磁通永磁电机的设计与优化

本文根据一款家用乘用车的结构和运行性能需求,设计出了额定功率95kW,峰值功率190kW的轴向磁通永磁电机。电机采用内单定子外双转子结构,定子铁心采用分块式设计形式。基于永磁电机设计理论,总结归纳轴向磁通永磁电机的初始设计流程,并对其电磁性能进行初始评估。采用有限元法建立电磁分析三维模型,对采用多种转子结构电机的电磁转矩、齿槽转矩、转矩脉动及永磁体涡流损耗等进行计算和分析。文中所归纳的电动汽车驱动用轴向磁通永磁电机设计流程及降低齿槽转矩、转矩脉动和永磁体涡流措施的效果对比,为此类电机的设计及优化提供借鉴经验。     

航空电推进电机转子结构对比及模块化定子分析

本文针对航空领域电推进系统,以高效高性能为目的对电推进电机进行研究。首先建立了三种转子结构电机模型,在满足电机运行指标前提下,利用解析计算和有限元软件,从电,热和力三个方面对电机性能进行综合对比,从而得到了最优转子结构。之后根据航空领域电机的特殊需求特点,将模块化定子概念引入到该电机设计中。通过比较定子模块化前后一些电机性能指标变化,证明了模块化定子电机具有质量更低和效率更高的优点,进一步说明了模块化定子在航空电推进领域的可行性。本文对航空领域电推进电机进一步深入研究和电机轻量化设计具有参考价值。     

电动汽车用永磁无刷直流电机的有限元分析

设计了一种电动汽车用永磁无刷直流电机，采用外转子结构，其目的是嵌在汽车的轮毂内以实现直接驱动，而不需齿轮传动装置，可以实现低速，高转矩，高效率，变速运行，文中着重叙述用Ansys软件对该种电机的磁通，磁感应强度以及转矩进行有限元分析。     

基于定子磁障的分数槽集中绕组永磁同步电机应用设计与分析

分数槽集中式绕组（FSCW）存在谐波含量大的缺点,易引起定转子铁心损耗和振动噪声问题,限制了其在高端领域的应用。以采用FSCW的12槽14极永磁同步电机(PMSM)为研究对象,使用有限元软件进行仿真,分析定子非绕线齿中的磁障对磁动势谐波、电磁转矩、铁心损耗及径向电磁力的影响,并与传统永磁电机进行对比。仿真结果表明,采用定子磁障的电机能够有效降低绕组磁动势低次谐波,1、3、5次谐波分别下降了87%、84%和30%,铁心损耗减小了21.1%,低阶径向电磁力减小了20%以上,实现了对噪声和振动的有效抑制。     

分数槽自起动永磁同步电机的设计研究

介绍了分数槽自起动永磁同步电机的设计方法,讨论了分数槽绕组、永磁体、定/转子设计中要注意的问题,并基于Ansoft的RMxprt磁路分析软件对电机参数进行磁路计算分析.设计并建立了较为准确的分数槽电机模型.主要研究了转子阻尼槽槽型尺寸对电机性能的影响,为分数槽绕组永磁电机的优化设计提供了可靠的参考依据.     

The Analysis of Losses in High-Power Fault-Tolerant Machines for Aerospace Applications

This paper discusses the design of a fault-tolerant electric motor for an aircraft main engine fuel pump. The motor in question is a four-phase fault-tolerant motor with separated windings and a six-pole permanent magnet rotor. Methods of reducing machine losses in both the rotor and stator are introduced and discussed. The methods used to calculate rotor eddy current losses are examined. Full three-dimensional finite-element (FE) time stepping, two-dimensional (2-D) FE time stepping, and 2-D FE harmonic methods are discussed, and the differences between them and the results they produce were investigated. Conclusions are drawn about the accuracy of the results produced and how the methods in question will help the machine designer.     

基于博弈论的电动汽车轮毂电机热源损耗优化

为降低具有高功率、高转矩密度等特点的电动汽车轮毂电机热源损耗,提出了基于博弈论的外转子式永磁同步轮毂电机的多目标优化设计方法。首先应用磁路法推导了电机各项损耗的解析表达式;其次以定子槽形的尺寸为设计变量,以定子铁耗、绕组铜耗、永磁体涡流损耗和电机效率为优化目标,建立电机优化设计数学模型;最后应用基于博弈论的多目标优化算法(Game Theory Optimization Algorithm,GTO),同时结合改进粒子群算法(Advanced Particle Swarm Optimization Algorithm,APSO)对电机定子槽型进行优化设计,并借助有限元仿真软件进行了辅助计算。研究结果表明：相较于原设计方案,优化后电机功率损耗减少32.6%,效率提高6.12%。