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无轴承开关磁阻电机径向电磁力模型 总被引:10,自引:2,他引:10
针对现有无轴承开关磁阻电机数学模型忽略磁饱和或对磁饱和考虑不充分的不足,将麦克斯韦张量法和磁路分析法结合起来,提出了一种计算无轴承开关磁阻电机径向电磁力的方法.该方法考虑了电机运行过程中磁饱和以及转子的偏心位移,能够准确的描述电机径向电磁力的特性,为电机运行状态的离线分析和电机的设计提供了更为可靠的理论依据;该模型同时为无轴承开关磁阻电机电磁振动和噪声的预测与控制提供了理论依据.以一台实验样机为例,建立了考虑磁饱和的无轴承开关磁电机有限元分析模型.仿真结果证明了该解析模型的有效性. 相似文献
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针对无轴承异步电机电枢绕组气隙磁链幅值和相位辨识问题,采用电流模型辩识电枢绕组气隙磁链;为了消除悬浮控制算法对气隙磁链相位的影响,应用预测控制实现电枢绕组气隙磁链控制相位零延迟.对无轴承电机径向悬浮力控制、基于电流模型的电枢绕组气隙磁链辩识算法以及气隙磁链相位预测进行研究;对样机在空载运行、3 000 r/min下恒速及1 000~3 000 r/min变速情况下进行悬浮控制实验.实验结果表明,电流模型法满足悬浮控制系统辨识电枢绕组气隙磁链的要求,相位角预测消除了控制延迟对气隙磁链相位的影响. 相似文献
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针对气隙磁密对无轴承永磁电机可靠性、转矩脉动及径向悬浮力的影响,提出了Halbach阵列永磁转子结构。从无轴承永磁电机的转子结构出发,对常规面贴式永磁转子和Halbach阵列永磁转子进行了比较分析,并用Ansoft进行了有限元分析,得出了两种不同转子结构的磁力线分布图及气隙磁密波形,分别对两种转子结构的无轴承永磁电机的径向悬浮力与悬浮力绕组电流的关系进行了对比。分析结果表明:Halbach阵列应用在无轴承永磁电机中能显著提高气隙磁密及其正弦特性,增大径向悬浮力。Halbach阵列应用于无轴承永磁电机具有可行性和可靠性。 相似文献
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单绕组磁悬浮开关磁阻电机的原理与解耦控制 总被引:2,自引:0,他引:2
针对瞬时悬浮力与瞬时转矩非线性、强耦合的特点,研究了一种新型单绕组磁悬浮开关磁阻电机的运行机理,提出瞬时悬浮力与平均转矩分相产生的双相导通解耦控制策略。构建单绕组磁悬浮开关磁阻电机相周期内悬浮力与转矩的全角度数学模型,基于悬浮力有效产生区间内平均转矩为零的特点,提出双相导通运行策略,并以提高悬浮力响应速度及电机动态运行性能为目标,给出了电流斩波幅值和关断角的优化控制方法。针对12/8极实验样机,开展相关的仿真与实验研究,结果表明了双相导通解耦控制策略的有效性与优越性,闭环系统具有良好的动静态性能。 相似文献
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为了研究无轴承薄片电机的被动悬浮特性,通过2D磁路分析的方法,建立了非永磁薄片电机的2D轴向悬浮力模型和回复力矩模型,并进行了有限元仿真验证。直接采用有限元分析的方法,得出了永磁薄片电机的被动悬浮力与电机各参量之间的关系。结果表明:电机的轴向悬浮力基本与轴向偏移、电机半径成线性关系,但与电机的轴向长度无明显关系,且气隙磁密越大悬浮力越大;电机的回复力矩随扭转角度增长而增长,电机的长径比较大、等效气隙较小时将难以产生回复力矩,回复力矩随着电机的轴向长度增加而增加,达到最大值后逐渐下降直至反向。 相似文献
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无轴承异步电机气隙磁场辨识方法与应用 总被引:2,自引:0,他引:2
针对无轴承异步电机电磁转矩与径向悬浮力这一强耦合的非线性复杂系统,依据转子磁场定向控制的特点,研制了转矩绕组采用转子磁场定向控制,径向悬浮控制所需的气隙磁场通过I-ω法适时辨识的控制系统.应用Matlab/Simulink建立了系统仿真模型.计算机仿真结果表明,实现了电磁转矩与径向悬浮力之间的完全解耦,具有良好的动、静态性能,验证了本文所提方案的有效性. 相似文献
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Radial force and speed detection for improved magnetic suspension in bearingless motors 总被引:2,自引:0,他引:2
Chiba A. Kiryu K. Rahman M.A. Fukao T. 《Industry Applications, IEEE Transactions on》2006,42(2):415-422
In this paper, radial forces and speeds are detected and used in negative feedback loops to enhance damping factors and response speed in bearingless induction motors. Radial forces and speeds are calculated from the detected radial force fluxes. Both radial force and torque generating fluxes are detected from search coil fluxes wound around stator teeth. The effectiveness on improving damping of radial positioning is shown both theoretically and experimentally. 相似文献
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永磁型无轴承电机无径向位移传感器运行研究 总被引:1,自引:0,他引:1
在分析悬浮绕组电感与转子径向位移线性关系的基础上,针对永磁型无轴承电机无径向位移传感器运行的需要,分析了一种基于悬浮绕组高频信号注入的转子径向位移估算自检测方法,讨论了利用高频信号注入、悬浮绕组差分电压提取及转子径向位移跟踪观测器设计等位移检测原理和实现技术,并应用这种位移检测方法建立了永磁型无轴承电机无径向位移传感器控制系统.仿真研究表明,该位移自检测方法能在永磁型无轴承电机全速范围内准确地观测出转子的径向位移,实现无径向位移传感器方式的稳定悬浮运行. 相似文献
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This paper presents the control characteristics of switched reluctance (SR) motors defined for the maximum efficiency of the motor or the motor–converter system and for the minimum ripple level of electromagnetic torque. Curves for control variables—switch-on and switch-off angles (or conduction angle) and average phase voltage—are obtained by computations from a simple mathematical model. This lumped-parameter model takes into account the magnetic saturation of the motor and the parameters of the power converter necessary to guarantee reliable results concerning power losses in the system. The investigations were carried out for two typical SRM with the number of teeth Ns/Nr=8/6 and 6/4 for a battery supply and for a 310-V rectifier supply. Time curves obtained from mathematical model and control characteristics resulting from numerous optimization computations were validated by thorough measurements performed on a special test rig.List of symbols D viscous friction damping, Nms - ek back EMF in the kth winding, V - ik current in the kth winding, A - J moment of inertia, kg/m2 - L() phase winding's inductance in unsaturated state H - L(,i) phase winding's inductance considering saturation H - m number of phases - Ns/Nr number of teeth: stator/rotor - n rotational speed, 1/s - R phase winding's resistance, - Ri current measurement resistor value, - Rk total resistance in the kth phase circuit, - Rs resistance of a power source, - RTDSat drain-source resistance of a transistor in the saturated state - rD dynamic resistance of a diode, - Te electromagnetic torque, Nm - Tl load torque, Nm - uk voltage of the kth phase, V - U phase voltage RMS value, V - Uav phase voltage average value, V - on switch-on angle, rad - off switch-off angle, rad - z=on–off conduction angle, rad - stroke angle of the motor, rad - s efficiency of a motor - u efficiency of a motor–converter system - rotor position angle, rad - (,i) saturation function of the winding's inductance - mp level of the torque ripples, % - r=2/Nr, rad rotor tooth pitch - k rotor position angle reduced to the kth tooth-pitch, rad - (,i) flux linkage of a phase winding, Wb -
angular velocity, rad/s -
angular acceleration, rad/s2 相似文献
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P. Vas M.Sc. E.E. J. Vas M.Sc. E.E. 《Electrical Engineering (Archiv fur Elektrotechnik)》1977,59(2):121-127
Contents Steady-state analysis of three-phase induction motors with asymmetrical stator external impedances is presented by the application of the symmetrical components theory. New and general equivalent circuits are derived, and it is shown how they can be extended for constant-speed transients, too. State-variable equations are given for the case of asymmetrical stator voltages and external resistances. — By the application of a new two-phase symmetrical component transformation, steady-state equations of an asymmetrical two-phase machine with nonquadrature windings are set up; a new equivalent circuit is also derived. Transient equations are also given.
Übersicht Das stationäre Verhalten von Asynchronmaschinen mit Unsymmetrien im Statorkreis wird mit Hilfe symmetrischer Komponenten behandelt. Neue und allgemeine Ersatzstromkreise werden abgeleitet und ferner wird gezeigt, wie die Ersatzschaltbilder für den transienten Betrieb bei konstanter Drehzahl erweitert werden können. Für die Berechnung des transienten Verhaltens werden allgemeine Zustandsgleichungen angegeben, wenn unsymmetrische Statorspannungen und äußerliche Widerstände existieren. Bei Anwendung einer neuen Zweiphasen symmetrischen Komponentenumstellung werden stationäre Betriebsgleichungen einer unsymmetrischen Zweiphasenmaschine mit nichtrechtwinkligen Wicklungen aufgestellt, und man findet einen neuen Ersatzstromkreis. Transiente Gleichungen werden auch gegeben.相似文献
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In this paper, the authors propose and investigate a new algorithm for shaft position sensorless operation of permanent magnet motors, based on flux linkage and line current estimation. Measured line current and terminal voltage are used to estimate the flux linkage of the motor. The algorithm has a two current-loop structure, with the outer loop used to correct the position, and the inner loop utilised to correct the estimated flux linkage. The theoretical basis of the algorithm and individual definition of the system blocks is explained. Dependencies on motor parameters and measurement errors are discussed to show the effectiveness of the method using real data. As well as giving a detailed explanation of the new algorithm, the paper presents a wide range of computed and experimental results, demonstrating the reliability of the method even during acceleration of the motor from rest 相似文献
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Contents Steady-state analysis of induction motors with asymmetrical rotor impedances is presented by the application of the symmetrical-components method. New and general equivalent circuits are derived, and the analogy is pointed out between the equivalent circuits of this type of rotor asymmetries and other types. It is shown how the equivalent circuits can be extended for the case of transient operation when the rotor speed is constant.General state-variable equations are given for the calculation of transients. These can be easily solved by a digital computer using well known techniques.
Übersicht Das stationäre Verhalten von Asynchronmaschinen mit Unsymmetrien im Rotorkreis wird mit Hilfe symmetrischer Komponenten behandelt. Neue und allgemeine Ersatzstromkreise werden abgeleitet und die Analogie zwischen den Ersatzbildern für diese Art von Rotorasymmetrie und anderen Arten aufgezeigt.Ferner wird gezeigt, wie die Ersatzschaltbilder für den nichtstationären Betrieb bei konstanter Drehzahl erweitert werden können. Für die Berechnung des nichtstationären Verhaltens werden allgemeine Zustandsgleichungen angegeben, die mit bekannten Verfahren einfach auf Digitalrechnern gelöst werden können.相似文献
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Suzuki T. Chiba A. Azizur Rahman M. Fukao T. 《Industry Applications, IEEE Transactions on》2000,36(4):1069-1076
A bearingless induction machine has combined characteristics of an induction motor and magnetic bearings. It is known that the magnetic suspension of the rotor becomes unstable at overload operation, particularly in transient conditions. A novel air-gap-flux-oriented vector control scheme has been proposed to operate the bearingless induction motor during the high torque acceleration period. It has been found that there is an optimal flux orientation for complete decoupling in radial force generation. Test results in a laboratory bearingless induction motor validates the performance efficacy of proposed controller at overload conditions 相似文献
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Swamy M.M. Kume T. Maemura A. Morimoto S. 《Industry Applications, IEEE Transactions on》2006,42(3):742-752
In many applications, it is often needed to extend the speed range of an electric motor. In permanent-magnet ac motors (PMAC), the maximum speed is limited by the available voltage for a given counter electromotive force value. The extension of the speed range can be achieved to some extent by using the field-weakening principle, resulting in constant-power characteristics, but is limited by machine parameters and inverter rating. In an induction-motor-based spindle drive for machine-tool applications, the wye/delta switchover method remains popular for extending the constant-power range without sacrificing the torque capability at higher speeds. Conventionally, the wye/delta method employs mechanical contactors that have limited life and are associated with dead time in the range of tens to hundreds of milliseconds due to mechanical constraints. Power-electronic versions of the contactors have been proposed, but they are rather complicated and involve many switching devices. This paper describes a novel and simple switching technique involving only two three-phase diode bridges and two insulated gate bipolar transistor (IGBT) switches to extend the speed range of ac machines (induction as well as permanent-magnet type). The proposed method requires a center tap to be placed in each phase of the motor with access to the ends and the center tap, making the motor a nine-lead machine. Test results carried out on a nonsalient-type PMAC motor and an induction motor are given to support the idea. 相似文献