提高单相自起动永磁同步电机起动性能研究

单相自起动永磁同步电机就是在感应电机的转子铁心内放置永磁体,依靠笼型转子绕组产生的异步转矩实现起动。由转子永磁体产生的磁场与定子绕组产生的旋转磁场相互作用产生恒定的转矩而稳定运行。自起动永磁同步电机的优点是效率高、功率因数高且经济运行范围宽,但是由于转子上存在永磁体产生的制动转矩和齿槽转矩,使得电机起动变得较为困难,影响电机可靠性。本文对单相自起动永磁同步电机起动过程转矩及其与电机参数之间的关系进行了详细的分析,并据此提出了优化电机参数来提高其起动性能的方法。最后通过有限元仿真和试验测试验证了方法的准确性。     

表面-内置式永磁转子同步电机的永磁体优化

针对表面-内置式永磁转子同步电机的结构特点,采用有限元法对表面-内置式永磁转子同步电机的表面式永磁体进行优化。建立表面-内置式永磁转子同步电机不同充磁方式和结构的有限元模型,计算其瞬态磁场,研究额定负载下的气隙磁密分布。分析其不同充磁方式和结构对空载反电势正弦特性、齿槽转矩、转矩波动和功率因数的影响,求解出表面-内置式永磁转子同步电机最佳的充磁方式和结构。分析结果表明,优化后的表面-内置式永磁转子同步电机的性能得到有效改善。     

永磁同步发电机不同转子结构的对比分析

永磁同步电机具有结构简单、体积小、功率因数和效率较高等众多优点,在众多领域有着广阔的应用前景。在其三种转子结构中,内嵌式永磁同步发电机的优越性更为突出。现利用Ansoft有限元分析软件对内嵌式永磁同步发电机转子永磁体分别采用双"一"型和双"U"型结构进行了研究,对比分析了两种电机的磁力线分布、磁场云图分布、气隙磁密、绕组磁链、电枢绕组输出电压和电磁转矩。结果表明,双"U"型永磁同步发电机的转子饱和程度低,基波气隙磁密含量较高,无用谐波含量较低,永磁体的利用率相对较高,成本较低,电机性能较优。     

低速直驱外转子永磁同步电机的设计

永磁同步电机具有转矩密度高、功率因数高的特点,极对数的增加也不会降低功率因数,但齿槽转矩的存在,影响输出转矩的稳定性。本文设计了一台72槽60极400kW的直驱外转子永磁同步电机,利用ANSYS Maxwell建立的二维有限元仿真模型,分析空载反电势、齿槽转矩、气隙磁场、同步电感和负载转矩,验证了电机结构和参数的合理性。重点研究了齿槽转矩和转子损耗的优化,采用优化定子齿槽宽度和开辅助槽的方法,削弱齿槽转矩,采用转子磁极分块的方法,限制涡流通过路径,以降低转子损耗。仿真结果表明,所设计的电机能够满足性能指标,为电机的设计、齿槽转矩和转子损耗的优化提供了依据。     

新型切向电机永磁体设计方法研究分析

切向永磁同步电机内永磁体设计直接影响电机的转矩密度、功率密度及电机效率,本文针对铁氧体切向式永磁同步电机的永磁体结构及尺寸设计进行研究,在转子的极限尺寸约束范围内,通过扫描永磁体各方向的尺寸仿真电机效率,根据电机最高效率分析永磁体厚度、宽度设计的最优取值区间,为高效切向永磁同步电机永磁体设计提供参考。     

永磁同步电机转子结构优化设计

为降低内置式永磁同步电机输出转矩脉动,研究了一种采用折线形永磁体,转子铁心表面采用分段圆弧结构,并在圆弧连接点处开角形槽的转子优化设计方法。介绍了转子的拓扑结构,并对磁场及齿槽转矩进行了解析分析;利用Maxwell 2D软件分析了反电动势谐波与齿槽转矩分布情况;采用Taguchi法确定关键参数的最佳取值组合,并与传统"一"形结构电机性能进行对比。仿真结果表明,该优化设计方法能有效降低内置式永磁同步电机的输出转矩脉动。     

阶梯气隙结构对U型单相永磁电机自起动性能的影响

针时单相永磁同步电机不能自行起动的问题,采用阶梯气隙结构,使电机静止时在定位转矩的作用下定转子磁场之间存在相位差角,从而实现自起动.利用二维有限元计算的方法,分析阶梯气隙结构对电机电枢磁场和永磁体磁场的影响.针对永磁磁场,利用虚位移法对电机转子在不同位置时的定位转矩进行计算,求得永磁电机的转子初始相位角.得到一系列有关定位转矩、初始相位角与阶梯气隙结构参数之间的关系曲线.利用时步有限元法对U型单相永磁同步电机的起动过程进行动态模拟仿真,通过转速曲线证明了合理的阶梯气隙结构有利于永磁电机实现自起动.     

低转矩脉动永磁电机的转子结构设计

本文对一台采用内置V型磁极结构的永磁同步电机进行低转矩脉动设计。首先,基于有限元方法,通过参数化仿真,确定了永磁体V形夹角对转矩脉动的影响。然后,以降低转矩脉动为目标设计转子结构,通过不等宽度隔磁桥与转子开孔设计,降低转矩脉动。仿真结果表明,转子采用新结构以后,不仅低了转矩脉动,同时利用转子铁磁材料的磁饱和效应,对加工误差有一定的容许度,具有良好的稳健性     

一种多自由度电机三维磁场分析及永磁体设计

在简述永磁球形多自由度电机的优越性能的基础上,针对一种新型永磁球形多自由度电机提出了4种永磁转子设计方案,对每一种永磁体结构进行了静磁场磁通密度模值和磁场分布计算,建立了球坐标下永磁体磁场解析求解模型,进行对比分析.同时基于三维有限元软件,对各种永磁转子结构的球形多自由度电机转矩特性进行了计算和仿真.设计制备了5个圆柱体组合结构的钕铁硼永磁转子来代替球形结构,制作了模型样机.理论分析和实验结果表明了所设计结构的有效性,转子易于实现三自由度偏转运动,并对转子永磁体的受力进行了测试,与仿真计算结果一致.     

表面-内嵌式电机永磁体设计及特性分析

针对表面式永磁电机具有弱磁调速范围小,功率密度低;内嵌式永磁电机存在转矩脉动大,漏磁凸出缺陷,本文提出一种新型表面-内嵌永磁转子同步电机新结构.在满足永磁同步电机的性能达到最优的条件下,建立电机的有限元模型,分析了改变永磁体的极弧系数和磁化方向的等方式对电机转矩波动、效率、功率因数等性能的影响,比较分析得出比较合理永磁体情况下的新型混合式永磁同步电机模型.     

辅助磁障永磁同步电动机的电磁分析与参数优化

辅助磁障永磁同步电动机既具有永磁同步电动机高功率密度、高效率、高功率因数等优势,又兼具同步磁阻电机的宽调速范围、无高温退磁等优点,在调速驱动领域具有广阔的应用前景。在优化辅助磁障永磁同步电动机磁障形状、周边磁桥形状、磁障层数和永磁体占比的基础上,将其与“一”字型和“V”字型内置式永磁同步电动机进行对比分析,借助二维有限元仿真软件对三种结构的负载转矩、转矩脉动、损耗及效率等运行性能进行全面对比。以减小齿槽转矩有效值、减小空载反电势谐波含量和提高负载转矩有效值为目标对辅助磁障永磁同步电动机进行转子结构优化,对辅助磁障永磁同步电机的推广应用具有一定的参考价值。     

High torque induction motor with rotating magnets in the rotor

This paper describes a new type high torque induction motor which has the rotating magnets in the rotor. The motor basically consists of a usual stator, cylindrical rotor, and inner cylinder of which the surface is covered by a set of magnets. The rotor turns at somewhat less than synchronous speed. The inner cylinder with magnets can revolve freely against a rotor shaft. The magnets revolve synchronized by the rotating magnetic field induced by the stator current. The magnets make the flux in the rotor. Then we can expect torque increase by the increase of the flux. The results of magnetic field analysis indicate the flux is increased. In the experimental results of a test motor which is a 400 W prototype machine, we have obtained the torque increase by approximately 20 percent as anticipated in the magnetic field analysis. Moreover, test results show improvements of efficiency and power factor in the motor operations. The efficiency of the test motor is obtained as high as 10 percent at the rated output over those of a same size conventional induction motor. Although power factor of conventional induction motors is lagging at all times, the test motor can be operated with near unity, leading or lagging by adjusting the ac supplied source voltage.     

内置式永磁电机齿槽转矩的分析研究

内置式永磁电机因其高转矩及能量密度,在许多高性能装置中得到广泛应用.但永磁电机结构的特殊性,转子永磁体和定子齿槽之间相互作用产生的齿槽转矩会引起振动和噪声,同时齿槽转矩会降低速度和位置控制系统的低速时的性能.研究了一种内置式结构永磁电机的齿槽转矩,其转子磁极永磁体分段.根据分析可知,在相同的等级及尺寸条件下,永磁体分段的内置式永磁电机(SIPMM)比传统非分段内置式永磁电机(IPMM)的齿槽转矩低得多,然后利用有限元软件Maxwell 2D计算分析比较了SIPMM与IPMM的齿槽转矩.此外,还分析了两种不同转子结构的内置式永磁电机的齿槽转矩情况.     

Technical evolution of permanent magnet synchronous motors for home appliances

This paper reports on the highly efficient motor technologies used in home appliances in Japan. The permanent magnet synchronous motor (PMSM) is especially suitable because the use of permanent magnets does not require any extra current to produce magnetic power in the rotor, or any other kind of energy. In Japan, there has been a rapid shift from induction motors to PMSMs, and in this paper we will show several examples of PMSMs as applied to the home appliance field. It can be seen that great improvements have been made in high‐efficiency motor technologies. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

不同转子拓扑对永磁同步电机性能的影响

永磁同步电机因其高功率密度、高转矩密度、高效率等优点,目前已在众多行业领域得到广泛应用,在新能源电动汽车领域尤为突出。永磁同步电机采用不同的转子拓扑结构得到不同的电机性能。采用有限元方法基于Ansoft软件对一款新能源车用永磁同步电机不同转子拓扑结构进行仿真分析。从电机的距角特性、磁阻转矩特性、磁链特性、输出转矩外特性、输出功率外特性、电机性能参数对比表等方面比较不同转子拓扑结构电机的性能特点,分析各种拓扑结构的优缺点,并指出不同转子拓扑结构的适用场合。     

内置式永磁同步电动机转子结构的优化设计

为减小永磁同步电动机齿槽转矩和转动惯量,通过对永磁电机的齿槽转矩数学模型和空载轭部磁场进行分析,得出了通过采取辅助槽有效降低齿槽转矩,并在不影响其性能的前提下凿空转子铁心以减小转动惯量,然后以一台7.5 kW的内置式永磁同步电动机为例,采用上述方法对其转子结构进行了优化设计,最后通过Ansoft软件有限元分析验证了该方法是有效的。     

New Simple Torque‐Sensorless Torque Control for Quasi‐perfect Compensation of Sixth‐Harmonic Torque Ripple Due to Nonsinusoidal Distribution of Back EMF of PMSM

This paper proposes a new torque‐sensorless torque control method for permanent‐magnet synchronous motors (PMSMs). The proposed method can almost perfectly compensate the sixth harmonic torque ripple that is caused by nonsinusoidal distributions of the back electromagnetic force and the rotor magnetic flux of PMSMs. The torque control system is, in principle, constructed on the basis of vector control, but has two new, dedicated speed‐varying devices: a harmonic torque observer and a current controller. The speed‐varying harmonic torque observer can estimate the harmonic component over a wide range of speeds, even when the generated torque is constant, and produce a suitable compensation signal. The speed‐varying current controller shows stable control performance over a wide range of speeds; it can fully track the compensated current command containing the DC and sixth harmonic components. The effectiveness of the proposed method is examined and verified through extensive numerical experiments.     

Dual-stator Interior Permanent Magnet Vernier Machine Having Torque Density and Power Factor Improvement

—An improved topology for a low-speed permanent magnet vernier machine, called a dual-stator interior permanent magnet vernier machine, is introduced to significantly increase torque density and power factor. A dual-stator is adopted in the design for more torque and improving space utilization. An interior spoke-type magnet array in the rotor is designed for magnet flux focusing, which can effectively increase useful flux and force flux lines to pass through the entire machine during operation as opposed to two separate torque components as in a normal dual-stator permanent magnet machine. To clearly place the advantages of the proposed topology in perspective, the proposed dual-stator interior permanent magnet vernier machine is compared to a well-known dual-stator surface-mounted permanent magnet vernier machine. This article discusses the operation principle and magnetic field analysis of the proposed machine and reports comparison simulation results taken from the finite-element method. In addition, the stator tooth is optimized for further better performance on torque density and power factor.     

Performance evaluation of axially-laminated anisotropic (ALA) rotorreluctance synchronous motors

Axially laminated anisotropic (ALA) rotor reluctance synchronous motors (RSMs) for use in variable speed drives, have a very high ratio of L_d/L_q and high L_d-L_q values, and do not carry rotor current. Consequently, an ALA rotor RSM has a high torque density, power factor, and efficiency, and its vector control is fairly simple. This paper presents an approach to the performance analysis of RSM and the test results on a prototype ALA-rotor RSM. The theory is based on the machine parameter determination by field computation via analytical and finite element methods. Design criteria derived from theoretical analysis and the nature of the magnetic field obtained from finite element analysis for the ALA-rotor RSM are presented. Test results on a prototype are presented to validate the theoretical calculations and to demonstrate the high performance of the ALA-rotor RSM. The high L_d/L_q ratio of 16 under rated magnetic saturation conditions, high power factor of 0.91, and above 84% efficiency are obtained for a 2-pole, 2 HP laboratory ALA-rotor RSM