Study of Steady-state Performances for a Novel Line-start Single-phase Permanent Magnet Synchronous Motor With Three Parallel-connected Windings

对于三相感应电动机的单相运行,学者们已经提出了多种实用的接线方式,比如Smith接法、SEMIHEX接法。然而,对于三相异步起动永磁同步电动机的单相运行,很少有合适的接法提出。将并联式接法应用于三相异步起动永磁同步电动机的单相运行,提出了一种新型三绕组并联式异步起动单相永磁同步电动机。分析了三相异步起动永磁同步电动机同步运行时以及起动瞬间的正序、负序阻抗,基于对称分量法,对该接法电机的对称运行条件进行分析,得出了电容的确定方法,并利用遗传算法对电容值进行优化。提出了该新型电机稳态性能的计算方法;设计了一台高功率因数和一台低功率因数三相异步起动永磁同步电动机作为样机,并分别将其改接为三绕组高效单相永磁同步电动机,进行实验研究。实验结果表明,低功率因数的异步起动永磁同步电动机更适合改接成新型三绕组并联式单相永磁同步电动机。由低功率因数三相永磁同步电动机改接成的单相异步起动永磁同步电动机在额定负载下运行时,具有与同容量三相永磁同步电动机相近的效率和更高的功率因数。

Calculation for electromagnetic torque of double-stator-permanent magnet synchronous motor

Presents the mathematic model built for double stator permanent magnet synchronous motors through a brief analysis of their future development, and the equations established for calculation of their torques, and the development of prototypes, and discusses the comparison of the motor under development with the conventional motors with the same volume, stator structure, and magnet shape, and concludes the motor under development is one of the ways to improve the performance/volume ratio of motors.

Development of High-Thrust and Double-Sided Linear Synchronous Motor Module For Liquid Crystal Display Equipment

Recently,there is an increasing requirement for controlling linear motion up to a few hundred of millimeter strokes in the area of the liquid crystal display(LCD) production equipment.The requirements of the motion system for LCD production equipment are high acceleration and high velocity with positioning accuracy.To satisfy these requirements,it has to be designed with the high-thrust force and low velocity ripple.In this work, high-thrust and double-sided linear synchronous motor (LSM)module is proposed and the developed high-thrust and double-sided LSM module is verified by performance test.

EFFECTIVE DOUBLE LOOP CONTROL FOR A SQUARE WAVE BRUSHLESS DC MOTOR

A new type of brushless DC motor has been developed by using a square wave rare earth permanent magnet synchronous motor with its double loop control circuit. The double loop control scheme of the drive system yields a combination of desired characteristics including simplified control structure, small ripple torque, high speed accuracy, wide operating speed range, and fast dynamic response. Experimental results confirm excellent characteristics of the motor.

Discrimination of Motor Imagery Patterns by Electroencephalogram Phase Synchronization Combined With Frequency Band Energy

Central nerve signal evoked by thoughts can be directly used to control a robot or prosthetic devices without the involvement of the peripheral nerve and muscles.This is a new strategy of human-computer interaction.A method of electroencephalogram(EEG) phase synchronization combined with band energy was proposed to construct a feature vector for pattern recognition of brain-computer interaction based on EEG induced by motor imagery in this paper,rhythm and beta rhythm were first extracted from EEG by band pass filter and then the frequency band energy was calculated by the sliding time window;the instantaneous phase values were obtained using Hilbert transform and then the phase synchronization feature was calculated by the phase locking value(PLV) and the best time interval for extracting the phase synchronization feature was searched by the distribution of the PLV value in the time domain.Finally,discrimination of motor imagery patterns was performed by the support vector machine(SVM).The results showed that the phase synchronization feature more effective in4s-7s and the correct classification rate was 91.4%.Compared with the results achieved by a single EEG feature related to motor imagery,the correct classification rate was improved by 3.5 and4.3 percentage points by combining phase synchronization with band energy.These indicate that the proposed method is effective and it is expected that the study provides a way to improve the performance of the online real-time brain-computer interaction control system based on EEG related to motor imagery.

New Development in the Performance Improvement Synchronous Motor

Synchronous machines are dedicated to the specific application. They are generally employed in rolling mills, pumps, fans, and compressors like reprobating and centrifugal drives, pulp and paper processing, water treatment, mining, and in cement industries. As a synchronous motor, the performance is reduced for the given excitation while the load increases. When operated as synchronous generators, both power loads and lighting loads depend on the output from the armature winding. This paper presents an alternative choice in which by providing an additional winding in the stationary armature, when operated as a Double Winding Synchronous Motor (DWSyM), it becomes possible to operate in maximum power factor by adjusting the loads on both the stator windings. When operated as conventional motor, for the load current of 3.5 A, the efficiency is 55% and power factor is 0.55, for the same excitation when second winding is connected to a load current of 1 A, the efficiency is improved to 77.6% and power factor is improved to 0.66. The main focus of this machine is to improve the performance of the machine for the reduced excitation and minimum load. For the reduced excitation, the performance can be improved by loading both the windings. While operated as Double Winding Synchronous Generator (DWSyG), two stator outputs are available which help to separate the power and lighting circuits. Hence, interruption in the lighting circuit can be limited, this machine can be considered as Twin generator.

基于Motor-CAD的六相容错永磁同步电机仿真设计

为检验六相永磁同步电机的工作性能,对永磁同步电机的结构与特点进行分析,确定了其定转子内外径尺寸、气隙、槽型、轴向长度、极槽数等主要参数;基于Motor-CAD电机仿真软件,对六相容错永磁同步电机进行电磁计算,分析了不同齿宽、槽圆角半径、槽数、永磁体弧长下电机转矩脉动、齿槽转矩的变化,得到了转速为1500 r/min下的转矩脉动、齿槽转矩、电机最大可能转矩等电机性能指标,并采用螺旋水道水冷方式对电机进行冷却设计,求解出电机各部分的温度数据。通过仿真实验发现,设计的电机符合转矩和温度要求。

Simulation on model predictive control for PMSM drive system based on double extended state observer

A novel double extended state observer(DESO)based on model predictive torque control(MPTC)strategy is developed for three-phase permanent magnet synchronous motor(PMSM)drive system without current sensor.In general,to achieve high-precision control,two-phase current sensors are necessary for successful implementation of MPTC.For this purpose,two ESOs are used to estimate q-axis current and stator resistance respectively,and then based on this,d-axis current is estimated.Moreover,to reduce torque and flux ripple and to improve the performance of the torque and speed,MPTC strategy is designed.The simulation results validate the feasibility and effectiveness of the proposed scheme.

A Novel Sinusoidal-Wave Permanent Magnetic Motor with High Power Density

A novel high power-density PMSM (permanent magnetic synchronous motor) with independent magnetic flux path for each phase is proposed in the paper. The complex ma thematic model of PMSM is simplified by decoupling of magnetic flux paths between motor phases. In addition, harmonic components are lowered through optimum design of EMF (electric motive force) wave. Thus the ripple torque caused by EMF wave distortion is suppressed. Key words PMSM (permanent magnetic synchronous motor) - phase decoupling - optimum design of back EMF(electric motive force)

基于改进正交锁相环的永磁同步电机无位置传感器控制

针对传统正交锁相环(QPLL)应用于永磁同步电机无位置传感器控制中存在的反转失效与加、减速工况下出现显著的转子位置直流偏移误差问题,该文提出一种改进的正交锁相环(IQPLL)。其通过重构鉴相器环节,使得鉴相器的输出与永磁同步电机的转向不再相关,从而解决传统QPLL在电机反转时估算转子位置出现180°偏差的问题。此外,在新型鉴相器结构下,设计前馈环路以补偿加、减速工况下的位置直流偏移误差。并建立了IQPLL的小信号模型,根据系统的频率响应特性给出了IQPLL的参数设计方法。实验结果表明,相对于传统的QPLL,所提出的IQPLL可实现永磁同步电机无位置传感器控制正、反转稳定运行,并有效抑制了加、减速工况下的转子位置直流偏移误差。

PWM、S-PAM及PHASE电压联动控制技术在变频空调上的应用

目前,变频空调采用高效永磁同步(大发电常数Ke)压缩机已成趋势,且用于农村的低压地区。根据PWM、S-PAM以及PHASE电压联动控制技术,可使高效永磁同步(Ke值大)压缩机运行到更高的频率且损耗降低;在低压地区,使空调正常运行并保证输出足够的制冷制热能力;在同频率下,比以往的变频压缩机的电流更低,功耗小,更节能。此技术大幅的提高了变频机的运行效率以及降低了压缩机的功率,实现了高效节能的效果,是变频控制技术的节能效果又一次提升,是一种最合适的直流变频压缩机控制技术。

基于静止轴系改进高频方波注入同步磁阻电机无传感器控制

同步磁阻电机因为其成本低、可靠性高,发展前景可观。在低速域无传感器控制方面,因同步磁阻电机转子具有凸极性,使用高频方波信号注入方法进行转子角度估计最为合适。但是,电机在低速运行中伴随着交直轴电感交叉饱和问题,该问题影响着电机的动稳态性能。为此,对传统高频方波注入控制方法进行改进,提出基于静止轴系的双高频方波注入无传感器控制方法,降低高频幅值带来的高频转矩脉动,抑制因交叉饱和效应导致的角度估计误差,提高电机动稳态性能。在1.5 kW同步磁阻电机实验平台上进行实验验证。结果表明,与传统高频注入法相比,改进高频注入法消除了交叉饱合引起的角度估计误差,并降低高频信号带来的转矩脉动问题,提高了电机的动稳态性能。

双三相同步磁阻电机单相开路故障下的容错控制策略

双三相同步磁阻电机(dual three-phase synchronous reluctance motor,DTP-SynRM)转子不含永磁体,没有高温退磁风险,成本较低,且由于其系统自由度高、冗余性强,因此具有较好的容错性能。开路故障是双三相同步磁阻电机系统中最常见的故障类型之一,该文针对一种两套三相绕组中性点相互独立的双三相同步磁阻电机单相开路故障,建立DTP-SynRM矢量空间解耦模型,实现对电压、电流和磁链方程的完全解耦。在开路故障状态下仍将其视为一个正常的双三相电机,分析故障状态对电机的电流约束和信号传递的影响,并指出在开路故障下z2轴电流与β轴电流不再独立,电机由正常运行时的四阶系统降阶为三阶系统,而由于开路故障导致的电压信号传递不准确则会在dq坐标系中引入二次谐波电流,并产生二次和四次转矩波动。该文提出一种同时考虑电流约束和信号传递误差的故障容错方法,电机处于三闭环运行状态,补偿电压信号传递误差,抑制开路故障时电机的转矩波动并降低电流谐波。搭建实验平台进行实验,验证所提容错方法的有效性和可行性。

基于磁链相移原理的不对称交替极永磁辅助同步磁阻电机设计与分析

传统永磁辅助同步磁阻电机(PMaSynRM)无法充分利用永磁转矩和磁阻转矩,该文提出一种新型不对称交替极永磁辅助同步磁阻电机(ACP-PMaSynRM)。基于永磁磁链相移原理,将交替极永磁阵列、不对称磁极和磁障相结合,实现永磁转矩和磁阻转矩的最大值在相同电流相位下叠加,不但提高了永磁转矩和磁阻转矩的利用率,增强了电机输出转矩能力,而且减少了永磁体用量。采用有限元法对比分析了传统和新型ACP-PMaSynRM的电磁性能,验证了所提电机拓扑的可行性。最后,制造了一台48槽14极样机并对其进行了实验验证。

基于代理模型的双气隙混合转子低速大转矩同步电机优化设计

为解决常规低速大转矩电机普遍存在体转矩密度低、永磁体用量多等问题,提出了一种双气隙混合转子低速大转矩同步电机拓扑结构。然而,该种电机结构相对复杂、设计参数多、优化难度大,对此提出了一种基于代理模型的双气隙混合转子低速大转矩同步电机高效优化设计方法。首先,以提高输出转矩与降低转矩脉动为优化目标,对电机的参数进行敏感性分析,实现了在保证代理模型精确度的基础上精简优化变量。然后,为提高该种电机多目标优化设计的精确度和效率,同时缩短优化周期,提出了一种序贯子空间与模式搜索算法相结合的优化算法对电机进行优化处理。最后通过有限元仿真与实验方法验证了所构建代理模型的精确性、合理性和优化方法的有效性、先进性。

基于扩张状态观测器的永磁直线同步电机改进模型预测电流控制

针对永磁直线同步电机(PMLSM)模型预测电流控制(MPCC)中存在的电流脉动过大、在线计算复杂的问题,提出一种基于扩张状态观测器(ESO)的改进MPCC策略。利用最优电压矢量相角和重新划分后的电压矢量扇区,改进第一电压矢量的选取方式,减小第二电压矢量选择范围,以实现电压矢量的快速选取,进而降低电流脉动。同时,为了提高PMLSM抗负载扰动能力,通过ESO对扰动进行观测,将观测到的扰动转换为电流进行补偿,提高系统的鲁棒性,且补偿电流可起到进一步减小电流脉动的作用。仿真结果表明,所提出的控制方法切实可行,与MPCC相比,基于ESO的改进MPCC系统具有更好的控制性能、更小的电流脉动和较强的鲁棒性能。

考虑用电和馈电模式的变流器电驱系统建模与稳定性分析

由大量异步电机驱动设备构成的电力电子化交流配用电系统存在严重的次/超同步振荡问题。电驱系统正常工作时具有用电和馈电2种运行模式,现场振荡现象表明不同的运行模式对系统的稳定性影响也不同。建立了含机侧系统的电驱系统详细阻抗模型,利用阻抗分析法揭示了电驱系统接入电网的次/超同步振荡机理,分析了运行模式、电网强度、控制参数、交流电压幅值等因素对系统次/超同步稳定性的影响,并基于相位裕度灵敏度明确了主导影响因素。基于实际系统数据,搭建了时域仿真模型,仿真复现了振荡现象,并验证了理论分析的正确性。

双并列转子永磁电机非对称负载运行特性

双并列转子电机在驱动两侧非对称负载时,轻载侧电机的功角较低,产生了电机材料浪费,效率低等问题。为提升电机整体输出功率,基于双并列转子电机基本理论采用解析法求得电机驱动转矩平均值的表达式,进而提出轻载侧绕组提前的结构设计。而后以一台12极72槽双并列转子电机为例,建立其磁网络模型,通过麦克斯韦应力张量法得出驱动转矩的解析计算式,分析转子偏差角对电机基本转矩脉动的影响,得出最佳绕组提前槽数。最后,针对电机转矩脉动较大的问题,使用响应曲面法,以基本转矩脉动为目标函数,以永磁体偏心距、永磁体极弧系数、并接区高度作为自变量对电机进行优化,有效降低电机转矩脉动,验证了绕组前置的结构改进对提升电机非对称状态下的输出转矩具有显著效果。

基于新型自适应滑模观测器的PMSM无传感器控制

为了实现无位置传感器控制策略在永磁同步电机中的应用,在传统滑模观测器的基础上提出了一种改进型的自适应滑模观测器算法。提出的改进型自适应滑模观测器中使用更平滑的sigmoid函数取代了传统的符号函数,并结合反电动势的自适应律有效地减少了提取的反电动势中包含的高频分量,避免了低通滤波器在使用过程中带来的抖振和相位延迟现象。最后反电动势中包含的转子位置信息与速度信息通过锁相环提取。为了验证模型的可行性,基于MATLAB/Simulink搭建了仿真模型进行了仿真分析,并以TMS320F28377芯片为核心搭建了永磁同步电机硬件实验平台进行实验验证,仿真与实验结果验证了该方法的有效性和实用性。

双三相永磁同步电机改进型模型预测电流控制

针对双三相永磁同步电机模型预测共模电压抑制方法存在寻优计算量大、开关频率较高、稳态性能不佳的问题,提出一种改进型模型预测电流控制.首先,改进六相两电平逆变器,降低零矢量共模电压幅值;其次,选择小共模电压矢量构造虚拟电压矢量,简化价值函数的同时减小共模电压和电流谐波含量;再次,通过计算参考电压矢量直接选择最优电压矢量以减少寻优次数,并引入占空比控制提升电机控制精度,改善电机稳态性能.最后,仿真对比传统模型预测电流控制、RCMV(Reduced Common Mode Voltage)-1、RCMV-2和所提控制方法.结果表明,所提控制方法在减小共模电压的同时,降低了转矩脉动和谐波电流,且较RCMV-2方法开关频率明显降低;此外,寻优代码执行时间相较于RCMV-1和RCMV-2分别降低了约91%和65%,减小了计算量.