共查询到19条相似文献,搜索用时 140 毫秒
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多相异步电机不对称运行的研究 总被引:4,自引:0,他引:4
文章从三相异步电机的分析出发,对六相异步电机缺相的不对称运行进行了分析。通过两者的比较,可以发现六相异步电机具有优越的性能。在此基础上推导出具有普遍意义的多相异步电机在缺相状态下的矢量调制。 相似文献
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对于功率小于4kW的农用三相异步电动机一般不设缺相保护,因此常常因缺相运行而被烧毁。笔者用白炽灯泡监视电动机是否缺相运行,很好的避免了农用电动机因缺 相似文献
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对六相异步电动机能耗制动的瞬态过程进行仿真分析。为了得到瞬态特性,建立了六相异步电动机在静止d-q-0坐标系下的混合磁链瞬态数学模型。编写计算机仿真程序,通过实例对六相异步电动机的能耗制动的瞬态过程进行仿真计算。仿真结果表明六相异步电动机可以在两套绕组中通入较小的直流电流获得较强的恒定磁场,从而产生较大的制动转矩。 相似文献
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异步电动机不对称运行时出现负序电流,通过检测负序电流可以避免缺相运行,但对于正反转运行的异步电动机则无法实现有效保护,利用P241灵活的逻辑编程功能,通过内部功能的组合实现正反转缺相保护功能,保障电动机的可靠运行。 相似文献
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异步电动机不对称运行时出现负序电流,通过检测负序电流可以避免缺相运行,但对于正反转运行的异步电动机则无法实现有效保护,利用P241灵活的逻辑编程功能,通过内部功能的组合实现正反转缺相保护功能,保障电动机的可靠运行. 相似文献
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双排槽单相异步电动机是最近问世的一种新型吊扇用电动机。双排槽单相异步电动机是指电动机定子铁心上有槽形、槽尺寸不尽相同的两种槽(见图),其中槽较浅的称为高槽,在这个槽里嵌放单相异步电机的主绕组,所以也称为主槽;槽较深的称之为低槽,在这个槽里嵌放单相异步电机的副绕组,故又称为副槽。双排槽单相异步电机也称为高低槽单相异步电动机。以往的吊扇用单相异步电动机都是单排槽单相异步电机,这种电动机定子铁心上只有一种槽,即 相似文献
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结合工厂实际,运用电力拖动的基本原理,对影响三相异步电动机缺相运行电流大小的因素进行了讨论,指出缺相运行是否过电流与三相异步电动机接法、负载的机械特性、电网电压、负载率有关,并给出了具体数据和实例。 相似文献
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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。 相似文献
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《Electric Power Systems Research》2002,61(2):139-147
Due to the potential benefits resulting from the use of a phase order higher than three in transmission, some interest has also grown in the area of multi-phase machine. For machine drive applications, multi-phase system could potentially meet the demand for high power electric drive systems, which are both rugged and energy-efficient. High phase number drives possess several advantages over conventional three-phase drives such as: reducing the amplitude and increasing the frequency of torque pulsation, reducing the rotor harmonic currents, reducing the current per phase without increasing the voltage per phase, lowering the dc link current harmonics, higher reliability and increased power in the same frame. The high phase order drive is likely to remain limited to specialized applications where high reliability is demanded such as electric/hybrid vehicles, aerospace applications, ship propulsion, and high power application where a combination of several solid state devices form one leg of the drive. The research has been underway for the last two decades to investigate the various issues related to the use of multi-phase machine as a potential alternative to the conventional three-phase machine. This paper, therefore, reviews the progress made in multi-phase induction machine drive research and development since its inception. Attempts are made to highlight the current and future issues involved for the development of multi-phase induction machine drive technology for future application. 相似文献
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表贴式多相永磁电机的永磁体形状是影响永磁电机电磁性能的一个重要因素。以一台六相永磁同步电机为例,推导了将少量3次谐波注入正弦削极的永磁体时其厚度表达式,并对偏心削极和3次谐波削极的气隙磁场密度、空载反电动势和平均输出转矩进行了仿真分析。分析计算结果表明相对于偏心削极,谐波削极能有效提高永磁电机的输出转矩,可为多相永磁电机工程设计提供参考。 相似文献
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Multi-phase ac motor drives are nowadays considered for various applications, due to numerous advantages that they offer when compared to their three-phase counterparts. In principle, control methods for multi-phase machines are the same as for three-phase machines. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, information of the rotor speed is extracted from measured stator currents and voltages at motor terminals. Vector controlled drives require estimating the magnitude and spatial orientation of the fundamental magnetic flux waves in the stator or in the rotor. Open-loop estimators and closed-loop observers are used for this purpose. They differ with respect to accuracy, robustness, and sensitivity against model parameter variations. This paper analyses operation of an open-loop and model reference adaptive system (MRAS)-based sensorless control of vector controlled five-phase induction machine with current control in the stationary reference frame. The MRAS-based sensorless operation of a three-phase induction machine is well established and the same principle is extended in this paper for an IRFOC five-phase induction machine. Performance, obtainable with hysteresis current control, is illustrated for a number of operating conditions on the basis of simulation results. Full decoupling of rotor flux control and torque control is realised. Dynamics, achievable with a five-phase vector controlled induction machine, are shown to be essentially identical to those obtainable with a three-phase induction machine. Experimental verification is also provided. 相似文献
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五相逆变器的空间矢量PWM控制 总被引:17,自引:6,他引:17
多相逆变器由于电压矢量的增加,其空间矢量PWM(SVPWM)控制同三相电机相比具有更大的灵活性,文中通过对五相逆变器电压矢量空间的分析,认为多相逆变器空间矢量PWM控制的线性调制范围及形成的电机定子磁通要优于三相电机。根据五相逆变器的结构特点,在传统的最近两矢量SVPWM(NTV-SVPWM)控制的基础上,提出了两种新的五相逆变器SVPWM控制方式:最近四矢量SVPWM(NFV-SVPWM)控制和最小开关损耗SVPWM(MSL-SVPWM)控制。推导了3种控制方式下的目标输出电压函数及波形,通过对比分析,认为:NTV-SVPWM控制含有较大的低次谐波,不适宜用于多相控制:NFV-SVPWM控制的输出谐波最小,MSL-SVPWM控制的开关损耗最小,分别适用于低调制指数和高调制指数工作区。利用MATLAB对五相同步电机调速控制系统进行了仿真研究,仿真结果验证了上述结论。 相似文献
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标量控制的感应电机高效节能运行的实现 总被引:1,自引:0,他引:1
从感应电机高效节能运行出发,依据三相感应电机的等效电路推导出电机高效率运行的供电条件,揭示了电机高效率运行时电机输出的转速和负载转矩与输入的电源电压和频率之间存在的确定关系.在此基础上,提出实现电机高效节能运行的标量控制方案,并通过与恒压频比控制方式运行效率的比较及控制系统转速调节和转矩变化过渡过程的仿真实例,验证了电机高效节能控制运行方案的可行性. 相似文献
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ABSTRACT In this paper a new technique for optimizing the power generated by a double output induction generator (DOIG) is established. The proposed control strategy ensures stable operation of the DOIG within a wide speed range without overheating the machine. The proposed scheme employed a controllable rectifier, a d. c. link, an inverter, and an isolating transformer in the rotor circuit. Variation of firing angles, overlap angle, voltages, and powers with speed are deduced. Experimental results are given. Results showed that twice the rated machine power is generated at S=-l. 相似文献