绕组连接方式对开关磁阻电机振动影响的研究

开关磁阻电机（SRM）具有结构简单坚固、控制灵活简便等优点,但较大的振动和噪声在一定程度上制约了其在各行业的广泛应用。SR电机的绕组连接方式不仅会对电机的电磁性能带来影响,也会影响电机振动噪声的大小。径向力是引起开关磁阻电机电磁噪声的主要原因。本文针对四相8/6开关磁阻电机,分析NNNNSSSS、NSNSSNSN这两种常用绕组连接方式下磁链和径向力差异;并以径向力为激励建立SR电机振动的有限元模型,研究不同绕组连接方式对振动响应的影响。通过实验进行验证得到结论:当SR电机运行在磁路饱和工作状态下,采用NNNNSSSS定子极性排布的连接方式更有利于减小电机运行时的振动。     

Analytical Method Applying a Mathematical Model for Axial‐Gap‐Switched Reluctance Motor

In this paper, an analytical method using a mathematical model for switched reluctance motors (SR motors) is proposed. The feature of this method is the representation of the effect of the mutual flux on the integral model by applying transient analysis utilizing preprocessed inductance tables. The advantage of this method is that the analysis time is reduced in comparison with the finite element method (FEM). The calculation results for the torque show little difference between the FEM and the proposed method, and the computation time was shortened. A 3.7‐kW prototype axial‐gap SR motor designed using the proposed method delivered the specified performance.     

气隙偏心对车用永磁同步电机噪声特性的影响分析

新能源汽车领域竞争的加剧,对驱动电机噪声、振动与声振粗糙度(NVH)性能提出了更高的要求。其中气隙偏心可能导致车用电机出现振动和噪声问题。本文以一台额定功率35 kW的车用永磁同步电机为研究对象,采用解析和有限元仿真相结合的方法分别分析转子动偏心和转子静偏心对车用电机电磁力特性的影响。并建立了电机结构的有限元模态仿真模型,准确分析车用电机的工作模态。在声学仿真分析基础之上,分析了不同程度的动偏心率和静偏心率对汽车电机两个关键工作点电磁噪声频谱特性的影响。最后,通过半消音室内的电机噪声测试试验验证理论分析的正确性。     

开关磁阻轮毂电机非线性建模及驱动控制仿真

针对开关磁阻轮毂电机气隙偏心产生的不平衡径向力对车辆平顺性造成的不利影响,提出一种基于电流斩波的脉冲调制控制（PWM）的方法抑制开关磁阻轮毂电机不平衡径向力,从根本上改善车辆平顺性。首先通过Ansoft Maxwell 对一台8/6极四相开关磁阻电机进行有限元分析,在获取电机特殊位置电感数据的基础上,采用傅里叶级数拟合的方法建立开关磁阻电机非线性模型,并与有限元分析结果做对比验证了该模型的准确性。在此基础上建立开关磁阻轮毂电机驱动模型和轮毂电机驱动电动汽车机电耦合一体化模型,将所提出基于电流斩波的PWM控制方法与传统电流斩波控制方法对车辆平顺性影响做对比,仿真结果显示基于电流斩波的PWM控制方法能有效降低开关磁阻轮毂电机不平衡径向力的大小,在提高电机输出转矩的同时改善轮毂电机驱动电动汽车平顺性。     

矩形与面包形磁钢永磁同步电机噪声对比分析

为了对比分析矩形磁钢和面包形磁钢永磁同步电机运行时产生的0阶振动噪声,从理论上对电机的径向电磁力波进行推导,对力波的的磁密来源进行了分析,讨论了两种不同磁钢形状的永磁同步电机的0阶振动噪声。基于Workbench仿真平台,对这两种不同磁钢形状的36槽24极永磁同步电机进行仿真分析,得到两种电机的0阶6倍频力波的组成和0阶径向电磁力波的傅里叶分析结果;对电机定子的结构分别进行有限元建模和解析计算,得出电机结构的固有模态;通过解析计算的方法,得到电机定子表面的0阶电磁力振动位移频谱图;最后,通过计算电机的声辐射效率,对电机外部声场进行快速建模,计算出电机0阶电磁力声功率级频谱图。研究表明:面包形磁钢永磁同步电机的振动噪声要远小于矩形磁钢永磁同步电机的振动噪声。     

基于有限元法的磁悬浮开关磁阻电机数学模型

当电机高速运行时，为避免机械磨损，采用电磁力进行悬浮支撑，而磁轴承占用轴向空间，限制临界转速。磁悬浮开关磁阻电机利用电机定子与轴承机械结构的相似性，在原有的电机定子绕组上附加一套径向力绕组，通过一定的控制策略，同时实现电机的旋转和悬浮。该文在利用有限元软件Ansoft/ Maxwell 2D分析磁悬浮开关磁阻电机磁场的基础上，结合等效磁回路法并根据虚位移定理，推导出磁悬浮开关磁阻电机在考虑a、b轴方向径向偏移及其耦合时的径向力和转矩的数学模型，并用有限元分析结果验证了该模型的正确性和有效性。     

潜水电机电磁噪声分析和对比

针对传统的潜水感应电机和一种具有更高效率的新型潜水永磁辅助同步磁阻电机（PMASRM）,利用多物理场耦合有限元仿真,分析和对比其电磁噪声。在电磁场有限元软件中对电机的气隙磁密和径向电磁力波结果进行二维傅里叶分解,分析了气隙磁场和径向力波的时空特性。PMASRM转子磁导作用产生的气隙磁密谐波空间阶次更高,造成的径向电磁力波阶次更高,可以降低电磁噪声水平。声学仿真结果验证了上述结论。     

Topology Optimization of Rotor Pole in Switched Reluctance Motor for Minimum Torque Ripple

Torque ripple is a major problem for switched reluctance motors, which may cause undesirable vibration and acoustic noise, especially at low speed. This paper presents an optimal topology structure of rotor for 8/6 pole switched reluctance motor by using the level set method. The nonlinear ferromagnetic material boundary of rotor pole is implicitly represented through an embedded level set function. This method is applied to obtaining the optimal distributions of material in the design domain for minimizing torque ripple and maximizing average torque. In the optimization objective function, the reluctivity of ferromagnetic material is selected as the design variable. The normal velocity is derived from sensitivity analysis, where the adjoint variable method is utilized. Two-dimensional finite element method is employed to calculate the electromagnetic parameters of this electric machine. Analysis results obtained from the transient simulation of electromagnetic field coupled with control circuit show that the torque ripple is reduced effectively by using the optimized rotor structure.     

小型无刷直流电动机振动与噪声的研究

该文首先综述了无刷直流电动机的优点,比较了少槽小型无刷直流电动机的特点。给出了电动机相电势矢量图及绕组构成,分析了电动机径向不平衡电磁力产生的原因。然后对9槽无刷直流电动机电磁转矩进行了计算,比较了不同极数下电动机的转矩特性。利用磁场解析定量研究了具体电动机在矩形波驱动电流换相时的径向不平衡电磁力,比较了在产生相同电磁转矩情况下电机径向不平衡电磁力的相对大小关系,分析了对电动机振动及噪声的影响。最后利用超小型加速度传感器对样机径向振动进行了测试,在无音实验室对样机的噪声进行了测试。实验证明了计算分析结论的正确性,为小型无刷直流电动机的设计提供了参考。     

Recent technical trends in permanent magnet synchronous motors

This paper presents an overview of the recent technical trends in permanent magnet synchronous motors (PMSMs), especially the rare earth (RE)‐less PMSMs that have been developed in Japan. The RE‐less PMSMs, along with PMSMs with reduced RE permanent magnets (PMs), PM‐assisted synchronous reluctance motors (PMASynRM) with ferrite PMs, spoke‐type interior PMSMs (IPMSMs) with ferrite PMs, and axial‐gap PMSMs with ferrite PMs, are reviewed. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

轴径向气隙混合磁路多边耦合电机轴向励磁绕组的反电势及其位置传感器机理

无传感器控制是比较理想的电机驱动模式,是电机及电力传动领域的研究热点之一.该文在混合式步进电动机的基础上提出一种轴径向气隙混合磁路多边耦合电机,电机在提高单位体积出力的同时,在不增加传感器的条件下实现了电机的闭环控制.这种电机的结构特点决定了电机控制的灵活性,轴向励磁绕组既可以控制轴向磁通,还可以兼作转子位置传感器.该文结合轴径向气隙结构混合磁路多边耦合电机的特点,在对该种结构电机轴向绕组谐波反电势解析分析和实验研究的基础上,提出基于轴向补偿励磁线圈同时作为电机位置传感器的思想,探求了轴向励磁补偿控制绕组的传感器机理,并给出具体电路,确认了其实现的可行性.研究表明,当定子绕组三相同时通有电流的时候,轴向线圈的反电势频率是定子绕组电势的3倍,根据这个反电势信号,轴径向气隙结构混合磁路多边耦合电机可以方便的实施无传感器控制.     

散热片数对湿式潜水感应电机噪声影响分析

针对感应电机运行中的噪声问题,通过对一台160 kW潜水感应电机进行多物理场耦合有限元计算,结合解析法对径向电磁力的阶次和频率进行探究,分析了电机气隙中径向电磁力波的时空特性,并通过声学仿真进行了噪声的相关计算。考虑径向电磁力的二维傅里叶分解得到的结果和机壳模型模态的阶次与频率,分析说明了噪声的来源,提出可通过如调整电机机壳散热片数等方式改变电机模态在阶次与频率上的分布或降低机壳振动系数实现噪声控制的目的。     

New block diagrams using vector signals in the general frame of reference for AC motors with stator core losses

This paper presents new block diagrams for induction and synchronous motors with stator core losses such as eddy‐current and hysteresis losses. The proposed block diagrams succeed in realizing simple and clear configurations with physically meaningful vector signals, which are helpful for understanding motor electromagnetic mechanism and useful for designing controllers for them. Vector signals, which are defined in the general reference frame, are utilized as transfer signals between blocks. The proposed vector‐signal block diagram in the frame can be directly and easily reduced to the one in such a specific frame as a stationary or synchronous frame simply by adding certain constraints to it. Shown are three configurations for induction motor, two for synchronous motors including permanent magnet cylindrical motor, permanent magnet salient‐pole motor, and reluctance motor. © 2001 Scripta Technica, Electr Eng Jpn, 138(2): 59–70, 2002     

基于物理模型开关磁阻电机定子模态和固有频率的研究

准确计算定子模态和固有频率是降低电机噪声和振动的基础。该文基于开关磁阻电机(SR电机)物理模型，利用3维有限元软件，全面研究了定子模态和固有频率，系统分析了绕组、端盖和安装对定子模态和固有频率的影响。研究表明，对小功率SR电机，2阶模态对噪声和振动的贡献最大。定子绕组对固有频率的影响非常严重，弹性模数远低于实心铜材，绕组不宜采用质量计入磁极或铁心的方式处理。端盖、底脚安装均导致定子固有频率明显升高。最后讨论了2维有限元模型与3维有限元模型计算结果的差异。计算结果与试验结果进行了比较验证。     

抑制开关磁阻电机振动的结构设计研究

开关磁阻电机(SRM)应用于众多领域,但是本身的结构使其比其他传统电机有更大的振动和噪声,因此抑制SRM振动仍是研究的热门领域。为了抑制电机的振动,设计了一种新型的电机结构,即在转子两侧开孔,并在此基础上对定子齿顶开槽。以一台7.5 kW、1 500 r/min、12/8极SRM为例,通过有限元分析仿真,对新型电机结构进行参数化计算,并得到最优结构。在保证平均转矩基本保持不变的情况下,减小了转矩脉动以及径向力。与原始电机相比,转矩脉动系数下降了16.01%,径向力峰值下降了19.96%。因此,证明了该方法对SRM振动抑制有较好的效果,对后续SRM设计及控制具有一定的借鉴意义。     

Characteristics of axial force and rotating torque and their control of permanent magnet type axial gap self‐bearing motor

This paper introduces an axial gap type self‐bearing motor. It is intended for a disk type flat motor to have both functions of rotation and axial position control. This motor is simple in construction and requires a simple control system. A permanent magnet type motor is analyzed theoretically and tested experimentally. The torque characteristics of the tested motor are measured at various values of axial force and air gap. Independent control of the axial force and torque is introduced for the servo motor control and synchronous motor control. The results show the high possibility of the proposed motor and control system. © 2000 Scripta Technica, Electr Eng Jpn, 132(1): 81–91, 2000     

Causes and characteristics of the electromagnetic vibration of a squirrel cage induction motor under load

Three-phase squirrel cage induction motors (IM) have been used in all types of industry, because of their robustness and simplicity of structure, low cost, and ease of maintenance. Due to the resultant air gap flux wave, an IM produces electromagnetic vibration and noise more or less regardless of the slot combination. Recently, reduction of electromagnetic vibration and noise has become important from the standpoint of environmental improvement. Vibration caused by an IM at no-load has been studied for many years and its basic factors have been analyzed. However, electromagnetic vibration under load has not been analyzed sufficiently. Since vibration under load conditions is affected by load and installation, analysis of this vibration is a rather difficult task. But study of the electromagnetic vibration of the motor itself under load is basically the most important item. This paper clarifies, theoretically and experimentally, the causes and characteristics of the electromagnetic vibration of an IM under load conditions. First, general equations are derived for the dominant electromagnetic force waves that produce electromagnetic vibration. Causes and vibration modes are clearly classified and a theoretical analysis provides a basic concept for electromagnetic vibrations. Second, electromagnetic vibrations for various loads are measured taking the effect of natural frequency of the motor into consideration. The measured data are classified and analyzed in detail, based on the proposed theory. © Scripta Technica, Inc. Electr Eng Jpn, 120(4): 81–89, 1997     

Torque and suspension force in a bearingless switched reluctance motor

Bearingless switched reluctance motors, which can control rotor radial positions with magnetic force, have been proposed. The bearingless switched reluctance motors are characterized by integration of switched reluctance motors and magnetic bearings. These motors have two kinds of stator windings composed of motor main windings and suspension windings in the same stator in order to produce suspension force that can realize rotor shaft suspension without mechanical contacts or lubrication. For successful stable operation, accurate theoretical formulas of instantaneous torque and suspension force are necessary to a rotational speed controller and a rotor radial position controller. This paper derives the theoretical formulas of the instantaneous torque and the suspension force from an assumption of simple permeance distribution. This derivation process makes an assumption that fringing fluxes are distributed on elliptical lines. It is shown with experimental results that the derived theoretical formulas are very accurate in terms of practical application. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(2): 72–82, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20157     

径向斜槽转子潜水电机电磁噪声优化

相比于一般电机,大型潜水感应电机目前存在电磁噪声过大的问题。采用径向斜槽结构可以削弱大型潜水电机的电磁噪声,但仍存在部分不足。基于径向斜槽结构,通过调整径向斜槽扭斜距离进一步削弱电磁噪声,并提高电机其他性能。利用多物理场耦合有限元仿真分析对比各方案的电磁噪声,验证了上述方法的正确性。     

Unified Calculation Method for Motor Torque in Reluctance Network Analysis

A reluctance network analysis (RNA), which is an improved magnetic circuit method, has some advantages: the analytical model is simple, the calculation accuracy is relatively high, and a coupled analysis with an electric circuit, a heat circuit, a motion equation, and so on, is fundamentally easy. The RNA has been applied to the dynamic analysis of several motors such as a surface permanent magnet (SPM) motor, an interior permanent magnet (IPM) motor, and a switched reluctance (SR) motor. The dynamic characteristics of these motors including starting and a sudden load change can be calculated by an RNA. However, the torque calculation methods for these motors are different from each other. This paper presents a unified calculation method for the motor torque in an RNA, which does not depend on the types and structures of motors. The validity and availability of the proposed method are demonstrated by a finite element method (FEM) and an experiment.