单斩电流滞环控制的双凸极永磁电机三相桥式功率变换器中的电流尾巴

双凸极永磁电机的功率控制器通常采用电流滞环斩波控制.文中基于12/8极转子斜槽式双凸极永磁电机,研究了单斩电流滞环控制的三相桥式功率控制电路;提出采用这种控制方案的三相桥式变换器,每相绕组在关断时段内,会出现两段电流尾巴,削弱电机出力,增加系统损耗.文中首先介绍了单斩电流滞环控制方案,给出基于这种控制方案的三相桥式功率变换器稳态工作原理分析,阐述了电流尾巴的产生机理,给出电流尾巴出现时刻及电流尾巴大小的解析式,指出其危害性,并讨论了三相绕组反电势对称性及霍尔位置调整的准确度对电流尾巴的影响,实验结果证明了文中研究及结论的正确性.     

基于DSP双凸极永磁电机数字控制器的研究

双凸极永磁电动机定、转子结构为双凸极结构，定子为集中绕组，转子无绕组．是一种新型可控调速系统。介绍基于TMS320F240电机控制专用DSP控制的双凸极永磁无刷直流电动机系统设计．重点解决DSP用于系统中硬件资源优化配置和控制时序的设计，给出了相应的控制策略及实验结果；证明采用DSP控制的双凸极永磁电机系统具有结构简单和控制灵活等优点。     

双凸极永磁电机的设计、控制和运行(Ⅱ)

阐述了双凸极永磁电机调速系统的控制方法和运行理论。说明了驱动电路结构和影响其结构选择的主要因素，在总结已有扩展双凸极水磁电机运行范围方法的基础上，提出了分裂绕组拓展双凸极水磁电机恒功率运行范围新方法，最后分析了所研制的样机的稳态和动态性能。对进一步全面深入的研究和应用具有参考价值。     

转子齿宽对双凸极永磁轮毂电机性能的影响

转子齿宽对基于磁阻工作原理的双凸极永磁轮毂电机特性有重要影响。以二维有限元计算方法为基础,画出空载时电机的场图分布,给出第三气隙与转子齿宽的数值关系,得到不同转子齿宽时的绕组磁链曲线和对应的绕组反电势波形,同时讨论转子齿宽与绕组磁链变化率和反电势波形的关系,这些结论为设计出性能更趋完善的双凸极永磁电机提供了参考。     

双凸极无刷直流电动机机械特性研究

分析了双凸极电动机的转矩构成和绕组电流变化规律以及机械特性.结合永磁双凸极电动机和混合励磁双凸极电动机样机实验,揭示了不同运行条件下的机械特性,验证了文中分析及结论的正确性,为双凸极电动机的分析设计提供了理论依据.     

空气压缩机用永磁同步电机电磁仿真设计

介绍了一款空气压缩机用永磁同步电机的电磁设计。针对客户对电机弱磁调速性能的要求，采用转子磁钢内置的结构，对转子磁钢V字型结构进行设计。利用有限元法对电机效率、损耗、转矩、反电势和输出功率等相关参数进行分析。通过转子磁钢斜极的方法，改善转矩波动和反电势波形。型式试验结果表明，电机的额定转速和弱磁调速性能可以满足设计要求。     

防爆双绕组双速三相异步电动机绕组设计

双绕组双速三相异步电动机,定子绕组为两套绕组,每套绕组可以为单层或双层。通过对高、低速绕组极相组线圈的正确连接,使得非工作极的每条并联支路在工作极通电运行时的合成电势为0,从而得到更多可行的绕组设计方案,极大地拓展了设计空间,为设计综合性能优异的双绕组双速三相异步电动机创造了条件。     

永磁双凸极电动机区间等效电感特性及对电机的影响

对于12/8极斜槽转子永磁双凸极电动机,给出其在三相六状态换流模式下各区间等效电感表达式的分析,应用数值计算方法得出各区间等效电感特性,讨论了其对绕组电流变化率、斩波频率及系统闭环设计的影响,从而为永磁双凸极电动机的合理设计和控制提供了参考依据.     

双凸极变速永磁电机的静态特性

用二维有限元法对一种新型双凸极变速永磁电机（ＤＳＰＭ 电机） 空载、单绕组通电及双绕组通电的磁场分布和气隙磁密分布进行了较为全面深入的分析计算, 在此基础上得到了绕组永磁磁链、自感、互感以及空载电势随转子位置变化的特性曲线, 分析了永磁体磁场和电枢磁场之间的相互耦合作用对电感特性的影响。样机的实测结果验证了理论分析的正确性。所得结果为该电机的设计、性能分析以及运行控制等提供了依据     

新型双凸极永磁双转子电动机的电磁性能分析

为满足混合动力汽车多能源功率传输的需求,提出了一种新型双凸极永磁型双转子电动机。在确定其结构尺寸的基础上,通过有限元分析法对电机的磁链、反电势以及电感等电磁性能进行了分析,并通过场路耦合法建立电机及其驱动控制系统的瞬态联合仿真模型,仿真结果表明该电机继承了双凸极永磁电动机优点,结构简单且具有较高的可靠性和功率密度,同时由于双转子的存在,能实现不同工况下的内、外电机能量流的合成与分配,验证了该电机在混合动力系统中的可行性,也为研究该类电机的系统控制策略提供理论基础。     

9kW双凸极永磁电动机三相桥式逆变器的研究

详细阐述基于理想工作情况下的双凸极永磁电动机三相桥式功率变换器的工作原理,给出在电动机反电势不对称、霍尔传感器位置信号不准确以及输入电压变化等情况下功率变换器的工作情况的分析,并通过实验证明了分析的正确性。     

双凸极电机非导通相电流尾巴的研究

文中基于采用单斩桥臂上管PWM调制方式的12/8极转子斜槽式双凸极电机,对每个导通区间内非导通相的电流尾巴进行了深入研究。给出非导通相工作特性的分析,阐述了非导通相电机尾巴的产生机理,给出电流尾巴出现时刻、消失时刻及电流尾巴大小的解析式,分析其对电机运行的影响,并讨论了输入电压变化、三相绕组反电势变化、负载变化及霍尔位置调整准确度等多种因素对电流尾巴的影响,从而揭示了电流尾巴的产生与单斩电流滞环控制机理及三相绕组瞬时变化之间的内在关系,及影响电流尾巴大小的诸多因素,并通过实验验证了文中分析及结论的正确性。     

高频供电条件下的PCB定子盘式永磁电机绕组优化设计

PCB定子盘式永磁无铁心电机的定子采用印制电路板(printed circuit board,PCB)结构,其电机的损耗主要来源于绕组上的交流附加铜耗和直流铜耗,因此定子绕组的设计直接影响电机整体性能。针对应用在较高频率且工况稳定的PCB电机,该文提出一种新型分布式绕组。首先建立反电势、直流铜耗、交流附加铜耗和电阻的解析表达式,分析PCB电机的空载特性。其次,以提高电机的效率为目的,提出在绕组有效导体部分加入绝缘材料。对新型绕组进行优化找到最合适的导体线宽,然后根据有限元理论对比分析新型分布式绕组和已有绕组负载特性。结果表明新型绕组不仅可以降低总铜耗,提高电机效率,有效降低定子稳定温升,并且新型结构也不会影响电机输出性能。最后制作一台16极600W样机进行验证,对PCB定子盘式永磁电机设计具有一定的参考价值。     

System Design Method for a Load Commutated Inverter-Synchronous Motor Drive

In a thyristorized load commutated inverter synchronous motor drive system, the inverter relies on the back EMF of the synchronous motor to provide the reverse voltage for commutation. The level of the back EMF is a function of both the synchronous motor's field current and rotational speed. The inverter operating frequency is determined by the motor speed and number of pole pairs. For a fixed thyristor firing angle, an increase inmthe level of armature current decreases the available thyristor turn-off time due to overlap of the incoming and outgoing thyristor. This overlap time is a function of the commutating reactance of the synchronous motor. These factors, field current, motor speed, inverter frequency, and armature current, together with a thyristor turnoff time specification, set a maximum limit on the value of motor commutating reactance. The motor designer and inverter designer must perform a tradeoff study of these factors to arrive at a satisfactory drive system. The results are presented of an analysis that allows the synchronous motor reactance to be specified based on the other given parameters of the inverter-synchronous motor drive system. Test data are provided from a 20-kVA 500-1000 Hz load commutated inverter/ inductor type synchronous motor drive system. The effects of motor speed and field excitation on the operating condition of the drive are discussed.     

Control and operation of a new 8/6-pole doubly salient permanent-magnet motor drive

This paper proposes a new 8/6-pole doubly salient permanent-magnet (DSPM) motor drive, which offers the advantages of higher power density, higher efficiency, and wider speed range. The corresponding control and operation of the motor drive are presented. A variable proportional-integral (PI) controller combined with bang-bang control for the DSPM motor drive is developed. Two operation modes, namely, four-phase and two-phase operation modes, are proposed for the 8/6-pole DSPM motor drive. The drive system is implemented and tested. The results show that the developed control scheme can operate the DSPM motor properly, and the DSPM motor drive offers high efficiency over wide power range and good dynamic performance. Furthermore, the two-phase operation mode of the 8/6-pole DSPM motor offers the possibility of eliminating the torque ripple of the motor drive.     

无刷直流电动机的无速度传感器数字控制系统设计

设计了一种无刷直流电动机BLDCM(BrushLess DC Motor)无速度传感器变频调速系统.以数字信号处理器DSP(Digital Signal Processor)为数字控制器、智能功率模块IPM(Intelligent PowerModule)为功率逆变器组成硬件系统,采用反电势过零检测法进行电子换向,实现了BLDCM的无速度传感器转速跟踪.介绍了功率驱动主电路,交、直流变换部分采用单相桥式不控整流电路,以提高逆变电路所需的直流电压.通过检测关断相的反电势过零点来获得转子的位置信号,以控制绕组电流的切换,驱动电动机运转.论述了转速与电流反馈信号的检测.使用T法测转速;采用霍尔电流传感器检测直流侧母线电流;系统中转速和电流均由PID控制器进行调节.控制系统软件由主程序和中断程序组成,给出了系统软件的流程图.实验结果表明,系统调速性能良好.     

Experimental verification of optimal flux weakening in surface PM Machines using concentrated windings

Previous analytical work has shown that it is possible to design surface permanent-magnet (SPM) machines using fractional-slot concentrated windings to achieve wide speed ranges of constant power operation by satisfying the optimal flux-weakening condition. This paper presents a 6-kW 36-slot/30-pole concentrated winding prototype SPM machine that has been designed using a closed-form analytical technique developed specifically for this class of machines. Experimental testing of this machine has been carried out to determine its performance capabilities, including flux-weakening operation. Detailed comparisons between analytical, finite-element analysis (FEA), and experimental results are presented, which confirm the ability of fractional-slot concentrated winding SPM machines to achieve their high-speed operating objectives. Important issues including the machine's back EMF voltage at top speed, eddy-current losses in the magnets, and inverter performance are analyzed and discussed in detail.     

Comparison of vibration sources between symmetric and asymmetricHDD spindle motors with rotor eccentricity

The permanent-magnet motor is often the most important element in hard disk drive (HDD) spindles and is also a frequent source of vibration and acoustic noise. Eccentricity between the stator and rotor is inevitably introduced during the manufacturing process, and includes mass unbalance, shaft bow and bearing tolerances. This paper analytically discusses the effects of rotor eccentricity on motor performance for symmetric and asymmetric motors, such as local traction, unbalanced force, cogging torque, back electromotive force (EMF), phase current and torque ripple. An asymmetric motor, mostly chosen to reduce the cogging torque, shows a worse effect on cogging torque and unbalanced force when the eccentricity exists. It also adversely affects the flux linkage and introduces variation of the phase back EMF depending on winding and rotating eccentricity, thus yielding increased mutual torque ripple     

PCB定子无铁心盘式电机绕组结构设计与优化

为改善盘式定子无铁心电机空载反电动势波形的正弦性和降低反电动势的高次谐波,本文提出了一种PCB绕组盘串联叠加的定子结构,且叠加的定子绕组盘之间具有角度差。首先采用理论的方法得到了电机绕组的基波和谐波反电动势有效值的解析式,并建立了电机绕组结构的优化模型以确定叠加绕组盘间角度差的范围。通过三维有限元分析,确定了最佳角度差。最后对样机进行空载反电动势实验,可以发现实验结果与仿真结果基本吻合,证明了本文提出的定子结构对提高电机反电动势正弦性的有效性。     

Fault detection and management system for fault-tolerant switchedreluctance motor drives

The superior fault tolerance characteristics of the switched reluctance motor (SRM) have been proved in a working laboratory drive system. The program started by defining the performance effects of various types of motor winding faults. Motor winding fault detection devices were developed, along with control circuitry, to isolate a faulted winding by blocking the gating signals to the semiconductor power switches of the affected phase. The developments were implemented on a laboratory demonstration drive to determine the efficacy of the various fault detectors. The laboratory drive demonstrates that winding faults can be applied to the running drive and can be immediately detected and isolated without causing damage to the inverter circuitry and without causing drive misoperation