无刷直流电动机分数槽集中绕组槽极数组合选择与应用(连载之四)

在文献[1]基础上,继续展开对分数槽集中绕组槽极数组合的讨论,分析影响槽极数组合选择的若干制约因素,如奇数槽或偶数槽、单层绕组或双层绕组、绕组磁势谐波与转子涡流损耗、组合的最小公倍数和齿槽转矩、绕组排列与径向不平衡磁拉力、纹波转矩等.结论可供设计者参考.     

分数槽集中绕组式无刷力矩电机极槽组合研究

制造引起电机定子和转子相对偏心是客观存在的,因此研究不同极槽组合下偏心对转矩波动影响,对极槽组合设计有重要的参考意义。采用有限元仿真方法分析了分数槽集中绕组式无刷力矩电机不同极槽组合下静、动态偏心对转矩波动影响,并进行了样机试验,结果表明：宜优选绕组线圈分成多组对称均布且极槽数最小公倍数大的偶数槽组合。     

三相无刷直流电动机分数槽集中绕组槽极数组合规律研究(连载之一)

分数槽集中绕组在无刷直流电动机应用日渐广泛。研究无刷直流电动机分数槽绕组的相数m、槽数Z、极对数p等设计参数之间的相互关系和约束条件,着重分析三相无刷直流电动机分数槽集中绕组槽极数Z/p组合规律,给出符合分数槽集中绕组条件的Z/p组合选择表。过去关于分数槽集中绕组文献多只提及表示为Z0=2、p0±1和Z0=2、p0±2的组合,文中给出更多的槽极数组合;同时引入了单元电机和虚拟电机概念,讨论了分数槽绕组和整数槽绕组的绕组分布系数对应关系等问题,可供设计者参考。     

无刷直流电机集中式绕组槽极数选择优化分析

本文着重对无刷直流电机采用集中式绕组时定子槽数与极数的配合问题进行分析研究,选择适当的槽极数来降低电机铁心损耗和电机齿槽转矩,以达到优化电机性能的目的.     

奇偶数槽对永磁无刷直流电机性能的影响

介绍了永磁无刷直流电机设计过程中绕组形式的确定,并利用Maxwell2D有限元软件建立电机模型进行处理,从而集中分析了电枢奇偶数槽Z的不同对永磁无刷直流电机性能的影响。结果表明,Z为奇数的Z／p会产生不平衡径向磁拉力,不利于电机的整体性能。     

每极每相槽数和相数对集中绕组无刷直流电动机反电动势的影响

提出了组合定子铁心集中绕组无刷直流电动机反电动势的分析方法,推导出了计算公式,得出了计算波形,并讨论了相数和每极每相槽数对反电动势的影响.     

分数槽绕组与永磁无刷电动机

从分数槽绕组的基本概念出发，简述了分数槽绕组的基本特征和对称条件，介绍了它在永磁无刷电动机和永磁交流伺服电动机中的应用；重点对中小型永磁无刷电动机中广泛使用的y=1的分数槽绕组进行分析，给出了常用的槽极配合和绕组设计计算参数，阐明了分数槽绕组对齿谐波电势和齿槽转矩削弱的规律。     

极槽配合对分数槽外转子无刷直流电机性能影响研究

介绍了无刷直流电机(BLDC)分数槽绕组的极槽配合原则,分析了极槽配合对外转子无刷直流电机绕组连接方式、绕组系数、气隙磁场、计算极弧系数、齿槽转矩、定子磁动势谐波、定子铁损耗等影响,并通过Ansoft和Matlab软件对12槽8极、12槽10极、12槽14极和12槽16极四种极槽配合电机进行仿真,验证了理论分析的结果,为电机设计提供了理论依据。     

绕组类型与极槽配合对永磁同步电动机性能的影响

主要研究了单双层绕组及不同的极槽配合对分数槽绕组永磁同步电动机性能的影响.通过建立8极18槽、16极18槽、20极18槽的单、双层绕组分布的永磁同步电动机的二维模型,得到绕组分布图.分别进行有限元仿真计算,得到各模型的磁力线分布图、电磁转矩波形、转矩脉动波形、齿槽转矩波形和空载反电动势波形,通过对这些波形的分析得出不同绕组类型与极槽配合对电机性能影响的规律.     

三相无刷直流电动机分数槽集中绕组槽极数组合规律研究(连载之七)多极分数槽集中绕组无刷电机霍尔传感器位置确定方法分析

分析了分数槽集中绕组无刷电机在常用的三相全波工作方式下霍尔传感器位置确定的方法.分析表明,分数槽集中绕组每个单元电机内都可以找到6个霍尔传感器的特异点位置,它们对正定子铁心的槽中线或齿中线.其分布规律与单元电机的槽数或极数是奇数还是偶数、绕组是双层还是单层相关.     

Parasitic Effects in PM Machines With Concentrated Windings

Permanent-magnet machines using concentrated windings are gaining popularity at the expense of distributed windings in various applications, mainly due to cost savings. The result is often an increased amount of parasitic effects like ripple torque, alternating magnetic fields in the rotor, unbalanced radial forces, and magnetic noise. This paper describes the reasons for the parasitic effects, in which machine topologies are particularly sensitive, and suggests measures in order to reduce their importance. Both traditional and modular concentrated windings are analyzed, as well as double-layer and single-layer windings. Measurements on a prototype motor and three commercial servomotors have demonstrated that modular motors are favorable regarding ripple torque minimization.     

多相感应电动机的气隙磁势谐波分析

采用绕组函数法分析多相感应电动机定子绕组为正弦分布、集中整距和短距分布等形式时气隙磁势谐波的分布,在此基础上简单讨论建立对应的电机数学模型。由于多相电机具有转矩大,定子绕组分布和激励形式灵活的特点,相比传统三相电机其优点显著。     

五相集中整距绕组感应电机缺相容错控制

定子绕组开路是多相电机调速系统中的常见故障。建立了五相集中整距绕组感应电机绕组开路后的方程,计算了电机绕组开路后的稳态输出电磁转矩,分析了减小转矩脉动的条件,提出了五相电机缺相容错控制方法。此方法在无需额外增加硬件的前提下,可以保证电机继续平稳地运行。对于电机定子绕组多相同时开路,建立相应的变换矩阵、重新计算电感参数后,也可以采用提出的控制方法。对电机定子绕组一相开路进行的仿真和实验结果表明,该容错控制方法可以大大减小电机缺相运行时的转矩脉动。     

集中绕组永磁同步电动机削弱齿槽转矩的方法

通过对单齿单绕集中式绕组永磁同步电动机的有限元分析、试制和设计改进,总结出削弱齿槽转矩的几个方法。     

Proposal and Feasibility Study of the Integrated Diode Synchronous Motor

This paper presents a new type of magnet‐free motor that has concentrated stator windings and rotor coils with a pair of diodes. The most important feature of this motor is that currents in the rotor coils can be generated by utilizing the changes in the spatial second harmonic of the magnetic fields due to the concentrated stator windings, which normally increase motor losses. A prototype of the motor was designed and fabricated, and its basic performance was evaluated. First, using simplified analytic models, we explain the mechanism of inducing currents in the rotor coils by the changes in the spatial second harmonic of the magnetic fields. Second, we compare the torque performance of the proposed motor and that of other types of motors including a magnet motor through finite‐element analyses. The analyzed data show that the proposed motor can possess greater torque/volume ratio than that of the other motors. Finally, using the measured data, we validate the mechanism of inducing currents in the rotor coils, and examine the torque and power characteristics of the motor.     

Design and performance of field regulated reluctance machine

A unique topological configuration for rotating electromagnetic machines that can produce significantly higher force density than an induction machine is investigated. The stator is constructed using full pitch concentrated windings embedded in conventional slots. Rotor saliency is produced using poles constructed of axially oriented laminations. Operation is such that all of the conductors are actively taking part in torque production all of the time. The means for exciting the stator windings allows for independent control of torque and regulation of the rotor flux. A force density comparison is made based on operation with equal surface current density, conduction losses, and peak air-gap flux density. Construction and testing of a prototype 500 RPM, 28 kW laboratory machine, power converter, and controller are described     

一类高性能集中绕组永磁同步电动机的径向不平衡力

介绍了一类极槽数只相差1的集中绕组永磁同步电动机。这类电动机具有较高的绕组系数以及较低的定位力矩,可以作高性能的伺服电机使用。但是这类电机因为绕组在转子表面的分布具有不对称性,转子不可避免地受到一个径向不平衡力。以有限元方法对这种径向不平衡力进行了定量计算,并分析了其对电机性能可能造成的影响,对该类电机的实际应用提供了参考。     

新型整距绕组双凸极永磁电机工作原理及特性

提出了一种新型整距绕组双凸极永磁(DSPM)电机,分析了其工作原理,通过有限元方法计算4/6极整距绕组电机的磁场并对电机磁链、反电动势、电感及转矩等特性进行的分析表明,整距绕组DSPM电机具有双极性的磁链,在不改变结构的情况下电机的输出功率与集中绕组DSPM电机相等,可以减少铜导体用量,提高运行效率.在此基础上提出了两种增加整距绕组DSPM电机输出功率的方法,并对改进的三相24/10极整距绕组DSPM电机的反电动势进行了理论分析和实验研究,所得结果不仅证明了本文理论分析的正确性,而且首次揭示了磁通切换型永磁(FSPM)电机本质上就是一种整距绕组双凸极永磁电机,FSPM电机其功率密度高的内在原因并非磁链的双极性,而是多用了永磁材料,增强了气隙磁密.同时也说明了新型整距绕组DSPM电机较传统的集中绕组DSPM电机具有更高的做功能力.     

Optimal flux weakening in surface PM machines using fractional-slot concentrated windings

A design approach is presented for achieving optimal flux-weakening operation in surface permanent-magnet (SPM) synchronous machines by properly designing the machine's stator windings using concentrated, fractional-slot stator windings. This technique makes it possible to significantly increase the machine inductance in order to achieve the critical condition for providing wide speed ranges of constant-power operation. The conditions for optimal flux weakening can be achieved while simultaneously delivering sinusoidal line-to-line back-electromotive-force waveforms and low cogging torque. A closed-form analytical model is described that can be used to design SPM machines to achieve optimal flux-weakening conditions. This technique is applied to design a 6-kW SPM machine that achieves constant-power operation over a wide speed range. Performance characteristics of this machine are compared using both closed-form and finite-element analysis.