Rotor Strength Analysis of High-speed Permanent Magnet Synchronous Motors

为了对转子进行有效的冷却，在满足电机电磁性能的前提下，可通过减小保护套的厚度来尽可能增大定转子之间的气隙，因而必须对保护套和永磁体进行强度校核。将转子受力状况简化为平面应变问题，在此基础上推导出了两层过盈配合、三层过盈配合转子的应力场、应变场、位移场的解析公式，并利用有限元方法验证了解析公式的正确性。归纳了高速情况下热套式永磁转子强度设计准则，为转子的优化设计提供了理论依据。以一台额定转速120kr／min、10kW的高速永磁同步电机为例，给出了两种常用过盈配合高速电机转子的强度设计方法。

Experimental Studies on Support Systems of High Speed Motors With Flexible Squirrel-cage Support and Squeeze Film Dampers

以100kW级工作转速为45000r／min的高速永磁同步电机为实验样机，对采用鼠笼式弹性支撑和挤油膜阻尼器的滚动轴承支撑系统进行研究。分析了弹性支撑和挤压油膜阻尼器的刚度和阻尼特性，在此基础上分别计算出刚性支撑和弹性阻尼支撑时轴承一转子系统的临界转速和瞬态动力特性。最后在样机上进行对比实验，并对电机机壳振动加速度和弹性支撑笼条微应变信号进行分析。结果表明，弹性阻尼支撑可以使转子以较低的转速通过其刚体模态，同时对转子的振动起到良好的抑制作用。实验样机稳定运行在设计工作转速，其分析和实验结果为高速电机轴系设计和动力学分析提供了参考。

LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.

MECHANICAL-ELECTRIC COUPLING DYNAMICAL CHARACTERISTICS OF AN ULTRA-HIGH SPEED GRINDING MOTORIZED SPINDLE SYSTEM

On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches into further consideration, a modified mechanical-electric coupling model is created. The created model consists of an inverter, a motorized spindle, a grinding wheel and grinding loads. Some typical non-stationary processes of the grinding system with two different supplies, including the starting, the speed rising and the break in grinding loads, are compared by making use of the created model. One supply is an ideal sinusoidal voltage source, the other is an inverter. The theoretical analysis of the high-order harmonic is also compared with the experimental result. The material strategy of suppressing high-order harmonic mechanical-electric coupling vibration by optimizing inverter operating parameters is proposed.

Research Progress of Key Technology of High-Speed and High Precision Motorized Spindles

High speed machining and high precision machining are two tendencies of themanufacturing technology worldwide. The motorized spindle is the core component of the machine toolsfor achieving the high speed and high precise machining, which affects the general developmentlevel of the machine tools to a great extent. Progress of the key techniques is reviewed in thispaper, in which the high speed and high precision spindle bearings, the dynamical and thermalcharacteristics of spindles, the design technique of the high frequency motors and the drivers, theanti-electromagnetic damage technique of the motors, and the machining and assembling technique areinvolved. Finally, tha development tendencies of the motorized spindles are presented.

Investigation of Optimal Split Ratio of 6-Slot/2-pole High Speed Permanent Magnet Motor with Toroidal Winding

Split ratio,i.e.the ratio of stator inner diameter to outer diameter,has a closed relationship with electromagnetic performance of permanent magnet(PM)motors.In this paper,the toroidal windings with short end-winding axial length are employed in the 6-slot/2-pole(6s/2p)PM motor for high speed applications.The split ratio is optimized together with the ratio of inner slot to outer slot area,i.e.slot ratio,considering stator total loss(stator iron loss and copper loss).In addition,the influence of maximum stator iron flux density and tooth-tip on the optimal split ratio,slot ratio,and average torque is investigated.The analytical predictions show that when the slot ratio is 0.5,the maximum torque can be achieved,and the optimal split ratio increases with the decrease of slot ratio,as confirmed by the finite element(FE)analyses.Finally,some of predicted results are verified by the measured results of 6s/2p prototype motor with 0.5 slot ratio.

Analysis for Rotor Losses of High Speed Permanent Magnet Synchronous Motor

This paper presents an analysis based on analytical method for solid rotor motors for determining the rotor eddy current losses due to the current harmonics of the stator winding. The accuracy of the analytical results is verified by experiments.

A Study on the Structure of Linear Synchronous Motor for 600 km/h Very High Speed Train

Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated through a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, a comparative analysis on electromagnetic characteristics according to the structural combinations on the stator-mover of LSM （linear synchronous motor） for VHST （very high speed train） maintaining the conventional wheel-rail method is conducted, and the structure of coreless superconducting LSM suitable for 600 km/h VHST is finally proposed in this paper.

CFD Study of Forced Air Cooling and Windage Losses in a High Speed Electric Motor

High speed and high efficiency synchronized electric motors are favored in the automotive industry and turbo machinery industry worldwide because of the demands placed on efficiency. Herein an electric motor thermal control system using cooling air which enters from the drive end of the motor and exits from the non-drive end of the motor as the rotor experiences dissipates heat is addressed using CFD. Analyses using CFD can help to find the appropriate mass flow rate and windage losses while satisfying temperature requirements on the motor. Here, the air flow through a small annular gap is fed at 620 L/min (0.011 kg/sec) as the rotor spins at 100,000 rpm (10,472 rad/sec) and the rotor dissipates 200 W. The CFD results are compared with experimental results. Based upon the CFD findings, a novel heat transfer correlation suitable for large axial Reynolds number, large Taylor number, small annular gap Taylor-Couette flows subject to axial cross-flow is proposed herein.

A HIGH VELOCITY FEED UNIT DRIVEN BY LINEAR MOTOR

In order to realize high speed machining, the special requirements for feed transmission system of the CNC machine tool have to be satisfied. A high velocity feed unit driven by a induction linear motor is developed. The compositions of the high velocity CNC feed unit and main problems in the unit design are discussed.

High Speed SRM Using Vector Control for Electric Vehicle

The high speed motor is effective to realize downsizing motor in an electric vehicle(EV).Switched Reluctance Motor(SRM)is possible to the high speed drive because the rotor structure has simple and robust.However,the vibration and the acoustic noise are large from the drive principle.Moreover,the conventional complicated current excitation results in the difficulty of the torque controller design.To overcome these problems,the vector control has been proposed for SRM drive.However,the vector control has not been applied to the SRM in the high speed drive.In this paper,the drive conditions such as switching frequency,bus voltage for driving the SRM in the high speed region are clarified.It is shown that the proposed SRM can be driven by the vector control in the high speed region and can realize low vibration.

基于信息图-MCKD的高速列车牵引电机轴承故障诊断算法研究

高速列车牵引电机轴承故障特征微弱且干扰噪声强,为解决电机轴承故障特征难以提取的问题,文章提出了一种基于谱负熵信息图与最大相关峭度解卷积(MCKD)的电机轴承故障诊断方法。首先,对故障轴承振动信号进行基于谱负熵的信息图处理,确定最佳中心频带和带宽,从而对轴承振动信号进行带通滤波;然后,对滤波后的信号采用MCKD方法进行故障特征增强;最后,对故障特征增强后的信号进行包络分析,识别出电机轴承的故障特征。经仿真信号和台架试验数据验证,结果表明,信息图-MCKD方法对牵引电机轴承故障诊断具有良好效果。

Heating and Life Problem of High Power Density Induction Motor

An induction motor with its speed modulated by frequency features wide transfer speed range, high systematie efficiency, simple structure and long life, and it therefore becomes one of the best driving motors used in electrical vehicles. The present research trend of it is high power, high speed, high efficiency and long life. How to meet the above requirements by using the electromagnetic design, structure design and beat design, becomes a matter that needs to be resolved now. In this paper, the characters of the motor in operation are analyzed, all kinds of factors that relate to life are laid out, its heating and loss are discussed and analyzed. The key reasons affecting the motor life are presented, and different characters of a high induction motor are compared with these of a general induction motor. A design idea is described, that is : we should consider how to improve the efficiency and reliability as well as bow to reduce the heating by changing the electromagnet, structure, dissipation and operation of the motor. How to reduce its losses and to improve its dissipation has been presented in the paper.

A Study on the Dynamic Behavior of Wheel-Type Train Propelled by Superconducting Linear Synchronous Motor

This paper deals with a study on the dynamic behavior of 600 km/h wheel-type train propelled by superconducting linear synchronous motor (LSM). This train is of a traditional wheel-on-rail type with traction motors on wheel-bogies. However, for the 600 km/h speed, on the both sides of each vehicle, superconducting LSMs are attached and the ground coils are installed on the guideway. In this case, the guideway irregularities act as disturbance to the vehicle causing deterioration of ride comfort. And besides thrust force, the normal force could be created in superconducting LSM control, which influences vehicle dynamics during running. In this study, to examine the effect of guideway irregularity and normal force on dynamic behavior of proposed train, the vehicle dynamic model is driven and frequency analysis is performed through simulation. The simulation results show that the lateral directional acceleration is mainly influential to ride comfort;however this could be reduced effectively by electromagnetic damping force from linear generator. It is also shown that the normal force effect from superconducting LSM control is limited even though the attractive normal force acts favorably to ride comfort.

Theoretical and Technological Aspects on the Inverse Structure in the Fields of High Speed Electric Machines

The paper presents the design and technological aspects on the high speed electrical machines which include the mechanical radial and axial strees because of the centrifugal forces. It presents a reverse structure with outlet rotor and inlet stator that have high speed 20.000 rpm-24.000 rpm and power 1 kW for the pecific of the ventilanting centrifugal fan domain. This unconventional type of machine is not still in the phase of specific tests.

270km·h^(-1)高速动车模态分析

按弹性体考虑,建立由车体、前后构架和4个轮对轴箱构成的270 km.h-1高速动车模型。采用弹簧单元和拉杆单元模拟一系、二系悬挂及牵引拉杆和轴箱拉杆;设置节点自由度耦合来模拟顶盖与车体其他部件的螺栓连接;在各设备质心位置创建质量单元,用弹簧单元将质量单元与底架上相应设备的支点连接起来以模拟设备质量的影响。用ANSYS软件的Block Lanczos算法提取了270 km.h-1高速动车在考虑设备质量和不考虑设备质量两种情况下的前200阶特征值和特征向量,并对这两种情况下的整车振动特性进行比较分析,得到如下结论:不加设备质量时,与垂向变形相关的振型,其频率明显高于加设备质量时的相应频率;与其他方向变形相关的振型,其相应频率在这两种情况下差异不大;整车刚度按二系悬挂、一系悬挂、车体、构架、车轴的顺序由弱变强;整备状态下车体出现垂向弯曲振型的最低频率为10.42 Hz,满足《200km.h-1以上速度级铁道车辆强度设计及试验规范鉴定暂行规定》的要求。

高速永磁电机转子-轴承系统动力学特性分析

为研究高速永磁电机在高转速工作条件下的振动特性,将其简化为转子-轴承系统,建立数学模型,利用Runge-Kutta法进行计算,得出支承刚度、阻尼、加速度和支承位置对转子振动特性的影响。研究结果表明:改变支承刚度可以改变临界转速值,不改变临界转速对应的最大振幅值;增大阻尼可以降低振幅值,不改变系统的临界转速值;增大转子的加速度可以降低最大振动幅值,但会增加系统的控制力矩;y方向支承位置改变产生的振动幅值大于x方向支承位置改变产生的振动幅值,且轴承在靠近轴承推力盘的位置产生的振幅大。最后可以通过控制加速度和刚度的方法来降低振动幅值,避开共振区。

270km·h^(-1)高速动车动强度分析

为使机车车辆在复杂的动态受力情况下,既有足够的强度和刚度,又达到轻量化的目的,将车体、转向架构架及轮对轴箱均作为弹性体考虑。在合理模拟270km·h-1高速动车悬挂元件、设备质量及各种载荷的基础上,利用ANSYS软件瞬态动力学分析功能计算该车在270km·h-1,300km·h-1等速度下运行时的动应力,得到应力—时间历程曲线。对车体主要部件的动强度进行研究,并与试验数据进行比较,结果比较吻合。进一步分析表明:270km·h-1高速动车除车体前、后两端变压器梁与牵引支座交接处最大应力达到了110MPa,其它各点最大应力基本上都在100MPa以内;运行条件相同的情况下,受低激扰谱轨道随机不平顺激扰时车体的应力低于受高激扰谱轨道随机不平顺激扰时的应力;列车运行于300km·h-1时,车体总体应力大于列车运行于270km·h-1时车体对应点的应力,且应力波动频率更高。

300km·h^(-1)电动车组制动参数研究

在我国研制的先锋号电动车组制动系统的基础上 ,借鉴国外高速列车的经验 ,对自行研制 30 0km·h-1高速动车组制动系统的重要参数进行了研究 ,并提出了可供运用的设计值 .通过对先锋号动车组和 30 0km·h-1高速动车组制动参数的比较分析 ,指出先锋号制动系统的模式比较适合于 30 0km·h-1动车组 .

基于逆变器-电动机动态特性仿真的高速电主轴电动机的研究

建立了逆变器—电动机数学模型,开发了"逆变器—电动机—载荷"系统的动态特性仿真软件,实现了对逆变供电条件下高次谐波特性的定量仿真。利用该软件对所设计的不同绕组节距、型式和不同转子槽形的电主轴电动机方案进行了比较研究,定量分析了设计参数对逆变供电条件下电动机实际运行性能特别是高次谐波损耗及高次谐波振动特性的影响,在对比研究的基础上确定了优化的异步电主轴电动机设计方案,通过实际设计案例证实了所提出的设计方法的有效性。