共查询到20条相似文献,搜索用时 31 毫秒
1.
Hiroshi Osawa Makoto Hashii Naotaka Matsuda Kenji Endoh 《Electrical Engineering in Japan》1994,114(8):106-117
This paper describes low torque pulsation and high-power control of permanent magnet synchronous motor (PM motor) with distorted electromotive force (emf). The experimental model of PM motor is a 40-kW, 190 r/min, salient-pole, six-phase machine. An individual single-phase transistor inverter is connected to each phase of PM motor as a power source. By adopting full pitch and concentrated winding in the armature of the motor, the rate of flux utilization and output torque per mass can be increased. This winding causes trapezoidal distortion in the phase voltage waveform at no load. For realization of high-performance control of PM motor, the current waveform should be determined so as to minimize torque pulsation and to maximize the output torque of the motor under the rated current. This paper proposes also the method to determine the optimum current waveform. The currents and emfs are expressed as N-dimensional vectors (N: the number of phases). Due to the characteristics of the particular structure of the motor, the armature reaction is small enough to be neglected. In this case, the optimum current vector can be derived under two conditions: (1) the direction of the current vector always agrees with that of the emf vector; and (2) the scalar product of the two vectors is held constant. Supplying the optimum current vector provides no torque pulsation and the nearly maximum output torque under the rated current. This method also can derive the new optimum current corresponding to open-phase operation. The validity of the method is confirmed experimentally. The characteristics of the experimental model of PM motor also are described in this paper. 相似文献
2.
3.
4.
A dc motor drive is controlled by varying the armature current and field current. The field is a measure of flux, and the armature current times field current is a measure of torque. Various approximate means of estimating the flux and torque levels in an induction motor exist. Most of these methods are sensitive to motor parameter value changes and do not work well near zero speed. Also, the harmonics in the motor voltage and current due to the nonsinusoidal inverter waveform cause errors in the estimated torque. A practical method has been developed to measure the flux level in an induction motor in the actual operating environment. Using the flux signals and stator current, the actual electromagnetic torque can be obtained. This torque signal responds correctly to motor saturation and inverter voltage waveform harmonics. The motor can be designed to operate without the customarily required flux margin, since the flux level is accurately controlled. The control strategy for use with these feedback signals does not require the use of a tachometer. 相似文献
5.
6.
7.
用绕组函数法分析了多相永磁同步电机绕组磁势波的谐波构成,提出注入适当的谐波电流可以提高输出转矩,并且降低铁芯磁饱和。在旋转坐标系下建立了九相永磁同步电机数学模型,通过分析电磁转矩的构成,定量地分析了谐波电流在提升电磁转矩中的作用。推导出了基于最大逆变器功率约束的最优谐波注入比。最后,在simulink下搭建了九相矢量控制系统的仿真模型,对比了注入谐波前后电机输出转矩及电流波形的变化,并验证了注入谐波时电机的动态特性。仿真验证了理论方法的正确性和谐波电流注入的可行性。 相似文献
8.
This paper deals with an iterative learning approach for modulating the desired torque profile so as to obtain ripple-free torque in switched reluctance motors. Because of the highly nonlinear relation between torque, current, and rotor position for this motor, it is not possible to obtain a closed-form mathematical expression for current as a function of torque and rotor position. Thus, the current waveforms are conventionally computed by using the linear torque model of the motor, and it is well known that such a scheme results in high torque ripple. In this paper, a novel method is proposed to minimize the ripple. In this new scheme, the current is still computed using the linear torque model, but the value of the torque used for this is not the desired (specified) torque, but rather a modulated-desired torque that is obtained by repeated corrections to the desired torque from iteration to iteration. The conventional rectangular pulse profile is taken as the initial current waveform. The method requires much less a priori knowledge of the magnetic characteristics of the motor. The algorithms have been formulated for both one-phase-on and two-phase-on schemes, for a four-phase switched reluctance motor, in the light of the principles behind iterative learning. Based on the observations from the simulation results of these schemes, a modified scheme has been proposed by incorporating a suitable commutation process, often called torque sharing functions, in order to generate reasonably smooth current waveforms for the ease of tracking by the stator circuit of the motor. The performances of all the proposed schemes have been verified by computer simulation. 相似文献
9.
10.
二相四绕组小容量无刷直流电动机稳态运行的分析模型 总被引:3,自引:0,他引:3
二相四绕组小容量无刷直流电动机,由于驱动电路结构简单,运行可靠和成本低,因而运用于大批量应用的场合。首次为这类电动机系统建立了较为精确的稳态分析模型,它考虑了旋转电压的实际波形和驱动电路的实际结构及某些参数,能真实反映电机的参数对运行性能的影向,为研究。设计和优化等问题提供了基础,对电流波形和机械特性等进行仿真计算和实验校核,验证了该模型的正确性。 相似文献
11.
针对开关磁阻电机(SRM)的转矩脉动问题,提出了一种新的SRM转矩控制方案。首先应用自适应模糊神经网络(ANFIS)对SRM静态转矩逆模型和磁链模型进行离线学习,然后根据转矩分配函数对各相转矩进行分配,利用ANFIS转矩逆模型求出期望转矩下的SRM优化相电流波形。考虑到离线模型的局限性和实时运行时电机中存在的参数变化等不确定因素,通过在线监督学习的方法调整ANFIS转矩逆模型和磁链模型的参数以提高模型的准确性。基于在线调整的ANFIS磁链模型设计自适应滑模控制器调节SRM相绕组中的实际电流跟踪期望相电流波形,从而实现其高性能转矩控制。 相似文献
12.
梯形波相电流驱动下六相感应电机转矩研究 总被引:1,自引:0,他引:1
针对多相电机控制模式复杂性的特点,本文提出一种新颖的控制方式:六相感应电机梯形波相电流控制.该梯形波相电流由励磁电流和转矩电流组成,在该梯形波相电流驱动下六相定子绕组可以分为励磁绕组和转矩绕组,模拟直流电机实现励磁磁场和转矩的直接控制而不需要复杂的派克变换.本文主要通过理论分析计算、有限元分析和实验测量数据来研究梯形波相电流驱动下六相感应电机输出转矩性能,并对磁势解耦时的参数k进行了理论分析和计算.输出转矩的理论分析、有限元分析和实验结果是一致的,表明了分析模型的正确性以及该控制策略可以从真正意义上模拟直流电机的转矩输出性能. 相似文献
13.
用谐波注入抑制永磁同步电机转矩脉动 总被引:28,自引:0,他引:28
气隙磁场的畸变和逆变器的非线性特性使永磁同步电动机(permanentmagnetsynchronousmotor,PMSM)电流中含有大量高次谐波,电流波形发生畸变,导致电机电磁转矩脉动。针对这一问题,提出了一种新颖的谐波抑制算法,在建立PMSM谐波数学模型的基础上,利用注入谐波电压的方式来抵消电机运行时电机电流中的谐波分量,改善电机电流波形,抑制电机电流谐波分量和电磁转矩脉动。通过仿真及实验验证了该算法的有效性。该算法不需要增加任何硬件和离线实验测量,具有较强的灵活性和适应性。 相似文献
14.
基于梯形波相电流驱动的六相交流感应电动机性能 总被引:1,自引:0,他引:1
为了实现六相感应电动机的励磁磁场和电磁转矩直接控制,提出了梯形波相电流来驱动六相交流感应电动机,并对其性能进行研究.首先采用理论分析和有限元分析对气隙磁场和电动机的电磁转矩进行了计算.其次,利用所构建的六相电动机的实验装置对理论分析结果进行了佐证.该六相电动机控制策略的最大优点是可以实现励磁磁场和转矩电流的直接控制而不需要派克变换,另一个优点是通过六相定子分布,合成的磁场电流可以产生一个近似的方波气隙磁场,使电磁转矩的输出得到极大的提高. 相似文献
15.
16.
17.
永磁无刷直流电机负载磁场及其电磁转矩的计算 总被引:22,自引:18,他引:22
该文在考虑齿槽影响的前提下,建立了永磁无刷电机电枢反应磁场的解析计算模型,求出永磁电机相绕组的自感和互感。在对水磁无刷直流电机空载气隙磁场和空载相绕组反电动势求解的基础上,结合永磁无刷直流电机主电路的拓扑结构,构造出电机绕组的场路耦合模型,由此计算出电机相绕组电流变化波形。在考虑齿槽影响情况下,计算出永磁电机在任意时刻的电枢反应磁场和负载气隙磁场,进而计算出永磁无刷直流电机产生的瞬时电磁转矩,以便定量分析永磁无刷电机的电磁转短被动和绕组换相引起的转矩被动,为分析永磁无刷直流电机的工作特性和振动噪声提供了可靠的依据。 相似文献
18.
矢量控制永磁同步电动机低速轻载运行的研究 总被引:9,自引:2,他引:7
提出了削弱电压源型空间矢量脉宽调制逆变器死区效应的方法.给出因死区时间和开关器件开通、关断时间引起的误差电压矢量,依据误差电压矢量的表达式,采用降低载波频率和减小直流母线电压的方法削弱死区效应.分析了降低载波频率对磁链轨迹畸变和转矩脉动的影响,在低速空载情况下通过增大电机定子励磁电流分量获得连续电流波形,通过检测电流矢量角判断电流极性,对死区进行补偿.仿真并对比了不同载波频率下的转矩脉动,实验结果证明了所提出的方法能有效地降低电机转速,改善电流波形. 相似文献
19.
20.
永磁无刷直流电机转矩波动的自抗扰控制 总被引:8,自引:3,他引:8
自抗扰控制器(ADRC)是在继承经典PID不依赖于对象模型优点的基础上,通过改进经典PID固有缺陷而形成的新型控制器,性能优良且算法简单。在分析永磁无刷直流电机转矩波动研究现状的基础上,根据其自身特点以及自抗扰控制器的设计原则,提出了基于自抗扰控制器的永磁无刷直流电机转矩波动抑制方法。将电机等效为由2个非线性系统构成的串联对象,设计了2个一阶自抗扰控制器实现对电机的内外环控制,即外环控制转速并给出内环转矩参照值,内环控制转矩以抑制转矩波动,其实质是改善馈电电流波形。内环转矩子系统采用3个相同的扩张状态观测器(ESO)对三相转矩分别进行观测,进而得到电磁转矩估计值及转矩子系统的实时作用值,据此构造以逆变器直流侧电压为控制输入的转矩子系统一阶自抗扰控制器。实验结果表明,该控制方案不仅能够明显抑制电机运行中的转矩波动,而且电机具有良好的动态响应性能,控制系统具有较强的适应性和鲁棒性。 相似文献