凸极转矩对内置式永磁同步电机转矩波动的影响

转矩波动是内置式永磁同步电机的主要缺点之一,而凸极转矩在转矩波动中占有一定比例。首先给出了包含凸极转矩的内置式永磁同步电机的转矩波动计算公式;其次,通过有限元法计算了内置式永磁同步电机不同转子结构情况下空载反电动势谐波畸变率(THD)与电机电磁转矩波动的关系,揭示两者不成比例;最后利用保存磁导率法和傅里叶分解法将永磁转矩与磁阻转矩进行分离并进行了对比,得出两者在电磁转矩中所占的比例,同时计算了纹波转矩和凸极转矩的波动情况,得到永磁转矩产生的纹波转矩与EMF的THD有关,而磁阻转矩产生的凸极转矩与EMF的THD无关,为降低内置式永磁同步电机转矩波动提供了理论依据。     

一种非对称混合式永磁同步电机设计与分析

针对传统内置式永磁同步电机磁阻转矩与永磁转矩不是在相同电流相位角下达到最大,不能最有效的利用磁阻转矩与永磁转矩的问题,提出了一种新型非对称转子结构永磁同步电机设计方案,电机输出转矩和减小转矩脉动。首先,一种不对称转子结构,通过使转子不对称,使磁阻转矩和永磁转矩在相近电流相位角下达到最大,从而提高输出转矩。其次,为衡量转矩利用率,引入转矩利用率因子,利用冻结磁导率法将电磁转矩分解为磁阻转矩和永磁转矩两部分,运用有限元确定表面磁极最佳偏移角θ;最后,对提出的新型非对称转子结构永磁同步电机进行电磁性能分析,在不增加材料与制造成本的情况下,电机最大输出转矩增加7.52%,转矩脉动减小39.15%。     

永磁同步电机直接转矩控制技术研究进展

直接转矩控制是永磁同步电机控制的关键技术。介绍了直接转矩控制的基本原理,较全面地总结了与直接转矩控制相关的技术与方法。围绕转矩脉动抑制和定子磁链观测等关键技术,分析和归纳了永磁同步电机直接转矩控制技术近年来的研究进展情况,指出了研究中所遇到的技术问题,给出了一种工程成功应用的直接转矩控制方法,探讨了永磁同步电机直接转矩控制技术的未来发展方向及在火炮中的应用方向。     

感应电机直接转矩控制系统仿真研究

直接转矩控制是通过转矩与磁链控制来控制电机的一种方法。本文在对感应电动机的数学模型进行分析的基础上,基于Matlab/Simulink仿真计算,设计了直接转矩控制系统的磁链计算以及磁链和转矩控制模块,构建感应电动机直接转矩控制系统仿真方案,并通过仿真结果,分析了转矩、控制器参数和磁链滞环容差变化对控制系统的影响,证明了所建模型通过磁链与转矩的计算实现了感应电机转速的直接转矩控制。     

基于无刷电机转矩减少的相数选择分析

在不同奇数相下从转矩和转矩脉动两方面对方波励磁无刷电机的性能进行了比较,得出了励磁极的极弧度与电机转矩和转矩脉动的关系,和方波励磁无刷电机的电磁转矩脉动为最小的条件,为电机相数的选择提供了依据.     

感应电机DTC转矩与磁链模糊PI自校正控制

为克服传统感应电机直接转矩控制存在低速转矩脉动和开关频率不固定等问题,设计了基于转矩与磁链模糊PI自校正控制器以降低转矩脉动。该控制器根据转矩与磁链误差和误差变化率,实时在线调整控制参数,改善转矩与磁链控制性能。在此基础上提出12个细分电压矢量DTC空间矢量调制控制方案。该方案利用细分的12个电压空间矢量合成需要的任意电压空间控制矢量。仿真与实验结果表明:该系统获得转矩与磁链更精细的控制,降低了电机低速转矩脉动,提高DTC系统的自适应能力。     

新型双段Halbach阵列轴向永磁联轴器的多目标优化

为了解决传统双段Halbach轴向永磁联轴器转矩性能较低的问题,提出一种新型双段Hal-bach轴向永磁联轴器,并以转矩性能为优化目标进行多目标优化.采用3 D有限元法对新型双段HAMC进行建模,主要分析新型阵列的每个关键参数对新型双段HAMC转矩和转矩密度的影响.通过参数分析,发现转矩和转矩密度不能同时达到最优,需要对提出的新型双段HAMC进行多目标优化,则建立转矩和转矩密度的多项式回归模型和非支配排序遗传算法Ⅱ,以获得转矩和转矩密度的极大值.优化之后的新型双段HAMC,转矩提高了5.60％,转矩密度提高了4.19％.通过气隙磁密与转矩性能分析,进一步验证了新型结构的合理性和多目标优化方法的有效性.     

基于转矩角简化的异步电动机SVM-DTC研究

为了减小基本直接转矩控制(DTC)的磁链和转矩脉动,采用空间矢量调制(SVM)与直接转矩控制相结合(SVM-DTC)的方法。从直接转矩控制的基本原理出发,分析了SVM-DTC中目标电压矢量求取的关键点,提出了基于转矩角简化的目标电压矢量的求取方法,分析了SVM-DTC实现要解决的关键问题并给出了解决方法。仿真与实验结果表明,与基本DTC相比,采用基于转矩角简化的SVM-DTC可以大大减小电机磁链和转矩脉动,有效提高异步电动机系统的动、静态性能。     

磁动势法五相永磁力矩电机转矩分析

五相永磁力矩电机由于极数与槽数相近,含有丰富的磁动势谐波,磁动势谐波会影响电机的转矩性能。为此,采用磁动势法分析电机的电磁转矩,通过磁能和虚位移原理推导出了电机电磁转矩的解析表达式,揭示了具有相同空间次数的定子和转子磁动势谐波相互作用才能产生电磁转矩的规律。通过对五相永磁力矩电机的定、转子磁动势谐波与电磁转矩关系的分析,指出与与主波转速一致的定子和转子磁动势谐波相互作用能提高五相永磁力矩电机的平均电磁转矩。利用Ansoft有限元软件仿真分析了电机在正弦波、梯形波和方波供电下的定子磁动势、转子磁动势以及转矩性能。结果表明,非正弦供电能够增加电机的电磁转矩,但也带来了转矩脉动,验证了磁动势法分析五相永磁力矩电机转矩的有效性和正确性。     

基于转矩分离的永磁辅助同步磁阻电动机转矩脉动抑制

永磁辅助同步磁阻电动机（PMaSRM）内同时存在永磁转矩和磁阻转矩。不同转矩分量的占比大小和转矩脉动大小是评价电机电磁结构设计合理性的重要指标。以一台3 kW的PMaSRM为研究对象,在考虑磁路饱和与d、q轴交叉耦合因素的影响下,采用冻结磁导率法进行了电机的转矩分离和转矩脉动分离。基于转矩分量和转矩脉动分量的分离结果,以降低负载齿槽转矩为目标,进行了电机转子结构的优化设计,为PMaSRM的设计提供了参考。     

Analysis of the dynamic performance of a variable-frequency induction motor drive using various control structures and algorithms

A comparative analysis of the dynamic characteristics of field-oriented induction motor drive control systems relying on the main magnetic flux linkage vector reference, space-vector pulse width modulation (SVPWM) of the voltage inverter output, and direct torque control (DTC) is carried out using the Matlab/Simulink program package, with the parameters of the induction motor model used being the same. A changeover from stepless vector control systems to systems using microprocessors and modern controllable frequency converters operating on the principle of relay control entails possible changes in the properties of the electric drives being controlled. In this connection, there is a need to compare the dynamic performance characteristics of an electric drive with a slave vector control system (with an idealized frequency converter), referred to as electric drive 1 (ED1), an electric drive with a DTC system (ED2), and an electric drive using direct torque control and SVPWM (ED3). Modeling has shown that the response time of the torque control loop in all the control systems considered is the same, the time delay being no more than 0.01 s. On the whole, speed control transients in all of the above systems take their course in one and the same way. The differences in flux linkage control transients between ED2 and ED3, on the one hand, and ED1, on the other hand, are due to the differences between the methods used to form the electromagnetic torque. No provision is made in the above control systems for the stabilization of the magnitude of the flux linkage vector. At low loads, the flux linkage automatically follows the load. In an ED3 with direct torque control, the calculation of the necessary instant magnitudes of the voltage vector projections and the SVPWM based formation of the voltages applied to the motor allows implementation of a fast-response control system with minimal harmonic distortions and torque pulsations. The control system coefficients are calculated beforehand. The speed controller is adjusted to the technical optimum. In the main flux linkage oriented control system, it is also desirable to use an SVPWM-based formation of the motor voltage.     

Electromechanical resources of a frequency-controlled synchronous electric drive in continuous periodic operating modes

The possibility of increasing overload capability and reducing power loss in a frequency-controlled synchronous electric drive operating in a continuous periodic mode is considered. A definition of a “continuous periodic mode” is given. A functional diagram of vector control system of synchronous electric drive is presented. The statement of a problem in the study of electric drives is formulated. A modeling method of a synchronous electric drive making it possible to recognize the maximum loads upon heating of a synchronous motor is described. Results of computer modeling of the continuous periodic operational mode of a salient pole motor with continuous and optimal regulation of armature magnetic flux are presented. The resource of synchronous motor is determined on the basis of the criterion of motor torque allowable upon heating. A comparative analysis of power loss of synchronous motor in the continuous periodic mode with continuous and optimal regulation of armature magnetic flux is carried out. The conclusion is drawn that the use of optimal regulation of armature magnetic flux in vector control systems of synchronous electric drives operating in continuous periodic mode is efficient.     

电动汽车用永磁同步电机转矩脉动抑制方法综述

在各类驱动电机中,永磁同步电机以其能量密度高,效率高、响应快等优势,广泛应用于电动汽车电驱动系统中。电机本体存在气隙磁场分布的非正弦特性、齿槽效应,逆变器存在死区时间和管压降等会引发电机的转矩脉动问题,导致电驱动系统产生大量电磁噪声。国内外学者提出了多种优化和改进措施,结合近年来国内外的研究成果,针对电机本体齿槽转矩脉动采用的斜槽法和分数槽法、针对电流谐波转矩脉动的迭代学习控制、重复控制法、附加转矩闭环控制和谐波电流注入法等,分析了各类方法的优缺点,为改善电动汽车的舒适性和电驱动系统的可靠性提供了理论参考。     

电动汽车感应电机驱动系统矢量控制的双CPU实现

为电动汽车感应电动机驱动系统设计开发了一套用双CPU来实现的矢量控制系统。通过坐标变换得到了适用于矢量控制的同步旋转坐标系下的感应电动机基本数学方程,推出了转子磁链方程和转矩方程。系统软件基于这些数学模型来实现感应电动机转子磁场定向矢量控制,并给出了软件程序流程。仿真与试验结果并表明,控制系统具有良好的动态特性和较宽的调速范围以及恒转矩区域。     

Electric drive based on double-inverter-fed induction machine with minimization of power losses

An electric drive based on a double-inverter-fed induction machine is presented. The control system of the electric drive minimizes the electromagnetic losses both at constant flux linkage in the gap and during its regulation at the optimal level. The considered variant of control permits one to significantly increase the acceptable electromagnetic torque during two-region rate regulation and to improve the energy characteristics.     

升船机电气传动系统方案的研究

针对升船机电气传动系统,提出了三种电气传动系统方案,就升船机的多电机传动速度控制和出力均衡控制进行了分析,并阐述了国内升船机传动方案应用及调试效果。     

An Effective Four-Level Voltage Switching State Algorithm for Direct Torque Controlled Open End Winding Induction Motor Drive by Using Two Two-Level Inverters

This paper introduces an effective four-level voltage switching state algorithm for direct torque controlled open end winding induction motor drive with two-two level inverters in dual mode. In the recent days, direct torque control of open end winding induction motor drive became an interesting area for researchers because it provides high dynamic performance and instantaneous control of stator flux and torque. It is more important especially in applications like propulsion and hybrid electric vehicles they require ripple free torque. The direct torque control provides high flux, torque ripple, and variable switching frequency. This paper introduces an effective voltage switching state algorithm for an open end winding induction motor drive to reduce torque and flux ripple at different frequencies of operation. The experimental results show that the proposed algorithm reduces torque and flux ripples without losing features of conventional direct torque control (DTC) algorithm and in addition it provides multi-level operation.     

无速度传感器控制矿用电力机车牵引变频调速器

基于异步电机的定子磁场定向控制模型,研制了无速度传感器控制矿用电力机车牵引变频调速器,选用高性价比的M16C系列MCU作为主控单元,采用PWM死区补偿及速度和励磁电流闭环控制,输出电流谐波小,起动力矩大,成功地用于煤矿10吨架线式矿用电机车的牵引控制。采用变频调速牵引代替了原来普遍使用的调阻电机车和直流斩波电机车,提高了生产效率,大大减小了能耗,降低了机车维修及损耗材料费用。     

直接转矩控制在开关磁阻电机中的应用

开关磁阻电机有角度位置控制、电流斩波控制和PWM控制等传统控制方式,但上述控制方式下系统转矩脉动较大,导致振动和噪声比其他调速系统严重,制约了它在某些场合中的应用.文章将直接转矩控制技术应用到开关磁阻电机中,建立了直接转矩控制的仿真模型.仿真研究表明直接转矩控制技术能够将磁链矢量幅值很好的控制在滞环带内,从而有效地控制...     

A traction electric drive for electric cars

It is advisable to use a controlled electric drive in electric drives of electric off-road vehicles due to its significant multiplicity of the supported torque (5: 1 and higher) in a low-power mode. Such overloads can be achieved, for example, in electric drives with a field-regulated reluctance machine, not only because of the capacity of the electric machines, but also due to the choice of the drive control system. Analysis of requirements for the electric drive of an electric vehicle is performed, and the influence of the control method on the specific parameters is considered. Analysis of the number of independent control actions in synchronous reluctance electric drives is provided. The possibility of increasing the overload multiplicity of the torque by abandoning the vector control in favor of structures similar to dc drive systems is shown.