Magnetic field and performance analysis of a tubular permanent magnet linear synchronous motor applied in elevator door system

A novel elevator door driven by tubular permanent magnet linear synchronous motor （TPMLSM） is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet （PM）, on magnetic field was studied and the best values were given by the finite element analysis （FEA）. The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.     

新型磁通切换永磁直线电动机的静态特性

提出了一种应用于直线驱动数控机床的新型磁通切换永磁直线电动机.首先,给出了该电机的二维和三维拓扑结构,介绍了该直线电动机的基本工作原理,并分析了2种典型位置的磁场情况.其次,采用二维有限元的方法,对电机的磁链特性、反电动势特性、电感特性等静态特性进行了深入的研究.对2种不同铁芯结构磁通切换永磁直线电机的定位力进行了对比...     

永磁直线同步电机磁阻力优化的设计

The detent force of a permanent magnet linear synchronous motor （PMLSM） is analyzed and the corresponding optimization methods are presented to reduce it. The detent force, which is divided into two components, i.e. resulting from the end effect and resulting from the slotting effect, can be analyzed respectively by the finite element method （FEM）. To reduce the detent force arising from the end effect, several optimal design techniques are utilized, namely, adopting the suitable length and end shape of the primary armature. The detent force resulting from the slotting effect is reduced by means of skewing and adjusting the width of the magnets mounted on the secondary armature, and adopting the fractional slots of the primary armature. The validity of the analytical detent force predictions and the effectiveness of the detent force reduction techniques are verified by the experimental measurements.     

用于精密控制的直线磁通切换永磁电动机的暂态性能分析

提出了一种适用于精密控制的新型直线磁通切换永磁(LFSPM)电机的动态dq数学模型.通过采用有限元法对LFSPM原型机进行数值仿真,分析该电机的运行原理并计算其反电动势、磁链等电磁参量.仿真和测量表明,该电机的反电动势和磁链均按正弦规律变化,并且在运行时具有与直线表面永磁电机(LSPM)相似的磁链变化规律.在此基础上,...     

永磁开关电磁吸力特性有限元分析

采用有限元电磁仿真的方法,对永磁开关的电磁吸力进行了仿真分析,同时设计了测试样机对电磁吸力进行了测试。电磁吸力的仿真结果和测试结果的比较证明了仿真结果的正确性。采用本文提供的有限元方法,可以进行永磁开关的进一步优化设计。     

Design,construction and ocean testing of wave energy conversion system with permanent magnet tubular linear generator

In this paper, the design, construction and ocean testing of a wave energy conversion system are studied. Based on the motion characteristics of double buoys in ocean waves, a wave energy conversion system with permanent magnet tubular linear generator (PMTLG) is proposed to convert ocean wave energy into electricity. The wave energy conversion system was installed in the Yellow Sea near Lianyungang, China. The ocean test results indicate that it had dynamic and static performance, and obtained an expected amount of electricity. The calculation result indicates the average output power was about 1,000,W, and the conversion efficiency from wave energy into electricity was 1.4%,. In addition, the wireless data communication, mechanics and oceanography were also discussed.     

永磁同步电动机驱动的电动汽车仿真研究

在研究永磁同步电动机驱动系统的基础上。建立了永磁同步电动机驱动的电动汽车数学模型，并对拟开发电动汽车进行了计算机仿真，包括电动汽平路稳定转速运行仿真、变车速运行仿真等。仿真结果表明，所开发的永磁同步电动机驱动系统能够很好地满足电动汽车性能要求，永磁同步电动机在电动汽车驱动中具有很大优越性。     

直驱永磁风电机组低电压穿越的一种控制策略

为提高并网直驱永磁风电机组低电压穿越运行能力,提出一种适用于双PWM变换器并网的永磁直驱风电机组低电压穿越运行的电机侧及电网侧变换器协调控制策略。电网电压跌落时,根据输入电网的电磁功率的变化控制电机侧变换器来限制发电机的电磁功率以平衡输入直流侧电容的功率,稳定直流侧电压;根据电网电压跌落深度控制电网侧变换器,提供一定的无功电流,有利于电网电压稳定与恢复,提高风电机组的低电压穿越能力。仿真结果表明,所提控制方案无需硬件装置,能有效实现永磁直驱风电机组的低电压穿越运行。     

稀土永磁铁磁场特性分析及有限元仿真分析

提供力学服务是永磁装置重要的用途之一,因而磁场力的计算是磁力在机械设计、应用的重要内容。本文介绍了公式算法的推导结果,通过公式法和ANSYS有限元分析两种方法对永磁铁样本进行磁场模拟计算,得到永磁体铁块的磁场特性和磁吸附力。最后通过实际测量永磁铁样本的磁感应强度验证了公式算法和有限元分析方式的合理性、可行性,分析了公式算法和有限元分析两种方式计算的磁力与实际磁场力的误差大小,并得到了永磁铁表面磁感应强度的变化规律。     

Study on inverter fault-tolerant operation of PMSM DTC

This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed. To avoid the loss or even disaster caused by the inverter faults, a topology-modified inverter with fault-tolerant capability is introduced, which is reconfigured as a 3-phase 4-switch inverter. The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous, disturbance-flee drive system. The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance.     

New analytical solution for the analysis and design of permanent magnet thrust bearings

On the basis of the current sheet model, a new analytical solution for permanent magnet （PM） bearings is developed. Compared with analytical methods based on the coupling energy model and the magnetic dipole model, the proposed one is more physically intuitive and convenient for engineering designers. According to the analytical model, the thrust characteristics of a novel PM thrust bearing is studied and verified by finite element analysis （FEA）. In the proposed thrust bearing configuration, the rotor is composed of stacked PM tings with alternative axial magnetization directions, and the stator with alternative radial magnetization directions while copper rings are used to separate adjacent PM rings. A prototype PM thrust bearing with the proposed configuration is designed and fabricated. The performances of the PM thrust beating are experimentally validated. It is shown that the calculation accuracy of the presented analytical solution is satisfying.     

中频发电机变频电源的自抗扰技术研究

针对目前中频发电机在满载时,采用开环控制运行下,系统抗干扰能力较差的问题,提出了一种基于自抗扰控制器（ADRC）的逆变器控制方法。自抗扰控制器完全独立于被控对象的具体数学模型,把系统所有不确定因素与外部扰动归结于系统总扰动,通过扩张状态观测器（ESO）对扰动进行观测,然后利用非线性状态误差反馈律（NLSEF）进行补偿。仿真和实验结果表明,所设计的自抗扰控制器能有效抑制负载及永磁发电机的干扰,具有良好的动态特性及较强的鲁棒性。     

基于CMAC学习控制的永磁同步电机仿真研究

将一种基于CMAC神经网络的PID控制器引入到永磁同步电动机交流调速系统中,取代传统的PMSM双环控制系统中的转速外环PI控制器.仿真结果表明,运用该控制方法与规则自校正模糊控制相比具有较快的响应速度、较高的稳态精度和较强的鲁棒性.     

Schedulability analysis for linear transactions under fixed priority hybrid scheduling

In hard real-time systems, schedulability analysis is not only one of the important means of guaranteeing the timelines of embedded software but also one of the fundamental theories of applying other new techniques, such as energy savings and fault tolerance. However, most of the existing schedulability analysis methods assume that schedulers use preemptive scheduling or non-preemptive scheduling. In this paper, we present a schedulability analysis method, i.e., the worst-case hybrid scheduling （WCHS） algorithm, which considers the influence of release jitters of transactions and extends schedulability analysis theory to timing analysis of linear transactions under fixed priority hybrid scheduling. To the best of our knowledge, this method is the first one on timing analysis of linear transactions under hybrid scheduling. An example is employed to demonstrate the use of this method. Experiments show that this method has lower computational complexity while keeping correctness, and that hybrid scheduling has little influence on the average worst-case response time （WCRT）, but a negative impact on the schedulability of systems.     

A New Technique: Research and industrial application of a novel compound permanent magnet synchronous machine

We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the wave0form of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 6 1. 1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.     

有限元软件在电机教学中的应用

随着计算机的应用日益广泛深入,电机教学也强调引进最新的工程计算方法,有限元软件作为一种使用方便的软件越来越多地应用在工程实践中。为了实现教学和科研相结合,该文介绍了ANSYS软件,应用软件对永磁发电机在多种条件下的磁场进行了计算,并且通过动画表明了旋转磁场和静态磁场的形成和分布,便于学生理解和学习。     

A linear rotary magnetorheological damper for vehicles

1.IntroductionOneofthemostimportantperformanceparameterofautomobilesisthecushioningability.Soallkindsofvibrationdampersareassembledinvehicles,amongwhichthefullest-blownoneisthehydraulicdamperworkingthroughreciprocatingmovementofhinderedpistoninahydrauliccylinderabsorbingvibrationwithself-containedspring.Butsuchkindofdampercannotchangewiththechangeincharacteristicsofavibrationsource(suchasamplitudeofvibrationandphase),lackingofenoughself-adaptingability.Magnetorheologicaldamperfluid(MRF)isaty…     

Research and industrial application of a novel compound permanent magnet synchronous machine

We propose a novel kind of compound permanent magnet synchronous machine （CPMSM）, which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional （3D） magnetic fields, to determine the no-load leakage coefficient and the waveform of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consUmption of the direct-drive pumping unit driven by CPMSM is 61.1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.     

霍尔式肌张力换能器原理与医学物理实验设计

采用线性霍尔电路和永磁体,基于悬臂梁弹性体系统,研制了一种霍尔式肌张力换能器。2个线性霍尔电路以永磁体为对称中心,构成对称互补取样电路,以差分方式输出信号电压;张力使悬臂梁发生弹性形变,携带磁体产生位移并引起磁场变化,应用霍尔效应实现了肌张力与信号电压的线性变换。取样系统的对称互补式设计,抵消了非线性变量对测量的影响,换能器具有高线性度指标;差分式输出能够抑制共模干扰和零点漂移,并增大了信号幅度;非接触式的测量方法,提高了换能器的可靠性。新型换能器应用于医学物理实验,灵敏度高、抗干扰能力强,实验效果优于应变式换能器。     

一种基于正六面体划分的永磁球形电机

针对永磁球形电机的结构,结合应用永磁同步电机矢量控制方法和球面的正多面体均匀划分,提出一种基于正六面体改进型的永磁球形电机结构。通过对球面多面体划分,优化永磁球形电机转子的永磁体和定子的线圈位置,使永磁球形电机可以分别绕三个正交轴独立旋转,令传统的矢量控制可以直接应用于球形电机的控制系统中。本文给出了电机结构的三维图并阐述了该电机的控制方法。