同步磁阻电机转子结构优化设计

同步磁阻电机(SynRM)具有效率高、成本低、结构简单等优点,但其存在转矩脉动大等问题,会影响电机的平稳运行。为了降低SynRM的转矩脉动,需要对转子结构进行优化。以一台22 kW四极的SynRM为例,采用田口法对不同电流负载下的SynRM转子结构进行优化。确定SynRM的转子拓扑,探究SynRM转子结构的关键参数对转矩性能的影响,初步确定转子关键参数的范围。利用田口法对不同电流负载下的电机进行试验分析,得到最优转子结构参数组合,利用有限元仿真验证优化结果。为了增强转子的机械强度,在转子结构中添加径向磁桥,探究径向磁桥对电机转矩性能的影响。     

Direct Torque and Flux Control of a Four-Switch Three-Phase Inverter-Fed Synchronous Reluctance Motor Drives

This paper presents an application of direct torque and flux control (DTFC) for a four-switch three-phase inverter (FSTPI)-fed synchronous reluctance motor (SynRM) in which the saturation and iron losses' effects are involved in the machine control modeling. The DTFC switching technique for the SynRM fed by FSTPI in low-power and low-cost applications is implemented by imitating the six-switch three-phase inverter (SSTPI). By considering equal effective vectors depicted in SSTPI, the αβ stationary reference frame is represented by using six sectors. Similarly, the voltage space vector formation is constructed in FSTPI. Accordingly the SynRM performance under DTFC is precisely analyzed by considering the saturation and iron losses' effects. The DTFC behavior based on SSTPI- and FSTPI-fed SynRM is evaluated using Simulink benchmark. At different operating conditions, further simulation and experimental results of DTFC based on FSTPI dynamically confirm the effectiveness of the proposed control application on the SynRM.     

多层磁障转子同步磁阻电机设计研究

针对复杂的多层磁障同步磁阻电机（SynRM）,在定、转子快速设计方面进行研究。以1台3 kW、4极电机为例,对比不同绕组形式下SynRM的性能。为降低转矩脉动,提出典型C型磁障转子的简化模型。研究各参数对电机输出转矩和转矩脉动的影响,并借助多目标优化算法进一步优化磁障参数,为同类电机的设计分析提供参考。     

Vector control of a synchronous reluctance motor includingsaturation and iron loss

The application of vector control to a conventional synchronous reluctance motor (VCSynRM) is presented with emphasis on the effects of saturation and iron losses. It is shown experimentally that these parasitic effects can significantly influence the performance of a VCSynRM. A synchronous reference frame steady state model of SynRM including saturation and iron losses is developed. The behavior of a vector-controlled SynRM is analyzed based on the model. It is observed that saturation and iron losses can have a significant effect on the performance of a VCSynRM. To verify the validity of the model for vector control, a digital signal processor (DSP) based vector controller was built for a 7.5 hp SynRM to experimentally evaluate performance. Experimental results concerning optimal torque/ampere and optimal efficiency operation are shown to be in general agreement with the predictions of the model     

一种同步磁阻电机凸极比的解析计算方法

凸极比是影响同步磁阻电机功率因数和转矩性能的关键参数,本文提出了一种基于等效磁路法的同步磁阻电机交直轴电感和凸极比分析计算方法,可以分析转子磁障结构改变对凸极比和电机性能的影响,快速进行同步磁阻电机的转子结构优化设计。为验证磁路法的可靠性和准确性,论文采用有限元法对一台30 kW同步磁阻电机进行了仿真分析,计算电机在不同转子磁障层数、不同磁障宽度、不同径向磁桥数量时的交直轴电感值、凸极比和输出转矩,并与磁路法得出的结论进行了对比。     

Evaluation of third harmonic component effects in five-phasesynchronous reluctance motor drive using time-stepping finite-elementmethod

Interaction of the third harmonic magnetic field with the third harmonic current in a five-phase synchronous reluctance motor (SynRM) can produce additional torque. However, it is still not clear about the SynRM power factor and its impact on the associated power converter because of the third harmonic components. Using time-stepping finite-element method, a mathematical model of the SynRM, which allows any desired harmonic component in computation, is presented. Performance of the five-phase SynRM with two rotor structures has been computed. The study finds that contribution of the third harmonic current to the output torque depends on the rotor structures. It is also shown that the required terminal voltage to regulate the desired current waveform is substantially increased, a result not reported before     

Position-controlled synchronous reluctance motor without rotationaltransducer

This paper presents a position sensorless control scheme of a synchronous reluctance motor (SynRM) combining a high-frequency current injection method in the low-speed region and the flux estimation method based on the stator voltages in the high-speed region. The rotor has inherent saliency, and its angle can be estimated from d-axis stator current injection and the appropriate signal demodulation in a low-speed region. In the high-speed region, the rotor can be estimated by the stator flux from the voltage information. The scheme gives a robust and dynamic estimation of the rotor angle, independent of the operating conditions, including speed and load conditions. Experimental results of closed-loop speed and position control with a 3.75 kW axially laminated SynRM are given to verify the proposed scheme     

A comparative performance analysis of induction and synchronous reluctant motors in an adjustable-speed electric drive

This article is concerned with comparative analysis of the energy performance of induction motors (IM) and synchronous reluctance motors (SynRM) in an adjustable electric drive. A feasibility study of an economically viable adjustable electric drive with a SynRM of improved design that is free from electric losses in rotor winding and corresponds to the highest energy-efficiency classes (IE3 and IE4 according to GOST (State Standard) R 54413-2011) is carried out. Results of the comparative analysis of operating and power characteristics of the IM and SynRM with the same stator design are presented in respect to pumps using various principles of control. It is shown that the advantage in the SynRM efficiency is achieved to the fullest extent when the electric angle between the current vector and the axis of the maximum rotor magnetic conductivity is constant. The calculations are performed on the basis of the ac-motor equivalent circuit. A calculation of equivalent circuit parameters for motors of a certain power is performed on the basis of nominal data on the IM being considered. At the same time, the SynRM parameters are calculated from the ratio of inductance parameters for a particular rotor design according to the literature. It is concluded that the SynRM efficiency can be significantly higher than that of the IM of the same power in the entire range of electric-drive speed regulation.     

Thermal analysis of induction and synchronous reluctance motors

In this paper, the thermal behavior of two induction motors (2.2 and 4 kW, four poles) and two synchronous reluctance motors [(SynRMs) transverse-laminated] are investigated and compared. Both motor types use the same stator but have different rotors. Using a lumped-parameter simulation program, a thermal analysis has been also carried out, and the obtained results have been compared with the experimental ones. A direct comparison of the thermal behavior of the two motor types has thus been made for constant load and constant average copper temperature conditions. Inasmuch as the SynRM has negligible rotor losses compared with the induction motor, it is capable of a larger rated torque, from 10% to more than 20%, depending on the relative size of end connections and motor length.     

稀土和铁氧体混用永磁辅助同步磁阻电机（英文）

永磁辅助同步磁阻电机在宽转速范围内的高效率优点,使其成为高性能调速驱动应用的重要方案。虽然永磁体仅用于辅助目的,但其特性仍然对电机产生重要影响。例如,稀土永磁体辅助的同步磁阻电机面临着成本高、供应链波动大的问题,而铁氧体辅助的同步磁阻电机面临永磁体磁性能较差、易退磁等问题。本文在综合考虑稀土和铁氧体特性差异的基础上,提出了一种新型混合永磁辅助同步磁阻电机。通过在靠近转子外围的磁障中放置少量稀土永磁体,可显著提高电机的抗退磁能力。分析结果表明,稀土与铁氧体的体积比例在略高于5%时,即可在抗退磁能力、单位转矩的成本等因素之间取得很好的平衡。本文设计了一台稀土体积占比为5.5%的混用永磁辅助同步磁阻电机样机,并与两台已有的常规电机（分别是铁氧体辅助和稀土辅助）进行了对比研究。有限元分析和实验结果表明：在三台电机电磁性能基本相同的前提下,混用永磁辅助电机的抗退磁能力显著高于铁氧体辅助电机,而成本明显低于稀土辅助电机。     

电力系统综合负荷模型简化方案及辨识参数集选取

负荷是电力系统的重要组成部分,建立合理的负荷模型对电力系统安全稳定分析和实时监控具有重要意义。目前综合负荷模型被广泛采用,但完整描述其动态特性需要十余个参数,在线辨识全部参数几乎不可能。文中从综合负荷模型状态方程入手,在保证暂态响应近似相等的准则下提出一种综合负荷模型简化方法,并在此基础上分析不同的参数对负荷动态特性的影响以及参数之间的相关关系,最终选取了感应电动机比例、电动机暂态电抗、电动机稳态滑差以及电动机转子时间常数组成辨识参数集,并通过仿真验证了相关结论。     

同步磁阻电机最优电流角控制

对于同步磁阻电机在运行过程中受到磁路饱和与电压极限的影响,本文提出了最优电流角控制策略。采用Ansoft软件对电机内部磁场进行有限元仿真,对dq轴电感的耦合与饱和现象进行拟合,并利用拟合结果得到最优电流角随负载转矩变化的轨迹,以实现同步磁阻电机最大转矩电流比(MTPA)控制;同时考虑电压、电流极限对电机运行的影响,使电机在高速运行时可以实现空载到满载的稳定运行。通过建立考虑磁路饱和的同步磁阻电机数学模型进行仿真验证,而实验结果也说明了该方案的可行性与有效性。     

一种采用取向硅钢片的新型同步磁阻电机

同步磁阻电机（SynRM）结构简单、稳定可靠,但转矩和功率因数偏低,在过载运行下转子导磁桥和定子齿等磁通流经关键位置的硅钢片会逐渐饱和,使得电机发热增多,输出转矩降低。本文提出一种新型同步磁阻电机(NSynRM),通过在电机转子导磁桥表面增加使用取向硅钢片以及在定子齿部替换使用取向硅钢片来解决原电机中磁密饱和带来的问题。同原电机中的硅钢片相比,取向硅钢片在轧制方向具有高磁导率和高饱和磁密的特点,因此在新型同步磁阻电机中使取向硅钢片轧制方向沿着直轴磁场流通方向,能够使磁通沿着取向硅钢片顺利流通,增加电机的抗饱和能力。计算结果表明,新型同步磁阻电机在过载运行条件下,具有更大的转矩和功率因数,能有效降低电枢绕组温升,提高能量利用率。电机的电磁性能计算通过有限元软件完成。     

六相永磁直线同步电机电磁特性分析及数学模型建立

为深入研究新型永磁直线同步电机(PMLSM)的性能,实现电机结构设计与控制优化,对其电磁特性及数学模型的建立展开了研究。针对暂态时间、饱和特性及不对称性等电磁特性进行分析,然后建立了abc坐标系和dq0坐标系下电机数学模型,由此阐述电机电磁耦合关系,继而建立了等效电路,并对瞬态工作特性进行计算。最后,通过电压测试值和瞬态推力有限元值与解析计算值进行对比,其结果吻合度较高,验证了数学模型的正确性。     

用于电磁弹射的容错型初级永磁直线电机特性

提出一种应用于电磁弹射的新型双边容错型初级永磁型直线电机,该种电机具有次级结构简单的特点。首先,本文给出了电机的结构和工作原理。其次,在采用二维有限元对电机的静态推力特性分析基础之上,通过能量法对电机推力公式进行了推导分析,并且对电机的容错特性进行了分析。然后,采用瞬态有限元对电机在正常和断路故障下的推力变化进行了仿真分析,并对电磁弹射过程电机运行情况进行了仿真分析。最后,通过一个同比例缩小的小尺寸同类电机进行了实验研究,验证了电机的推力特性和容错性能。仿真和实验结果显示该电机具有高的推力密度、较小的推力波动和简单的控制策略,在电磁弹射系统应用中具有很好的前景。     

马达负荷模型对华东电网暂态稳定性的影响分析

以华东电网为研究对象,采用中国电力科学研究院推荐的马达模型和参数,仿真比较了马达负荷模型的动态特性,分析了马达负荷模型对电网暂态稳定仿真结果的影响及原因,认为在电力系统暂态稳定仿真中,送端电网采用马达负荷模型有利于提高稳定水平。     

基于ANSYS的矩形压电振子瞬态特性分析

主要研究了矩形复合压电振子的瞬态特性,借助ANSYS分析软件,对该瞬态动力学特性进行仿真,提取节点数据并结合理论进行分析,可以得到超声波电动机的瞬态特性指标,进而预估超声波电动机的机械性能。     

同步电动机的动态和瞬态稳定极限

利用同步电动机的状态方程,研究了同步电动机在突加负载时的动态过程,经过多次迭代,分别得出了动态稳定极限和“首次摆动”瞬态稳定极限,并与由瞬态功角特性和等面积法则得到的瞬态稳定极限进行了比较,另外,还研究机组转动惯量对动态稳定极限和突加负载时动态过程的影响,最后得出了一些有用的结论。     

感应电动机负荷暂态模型的参数填补方法及典型参数分析

电力系统中存在大量参数各异的感应电动机负荷,为研究其类型及相关参数的分布特征,以文献调研获得的224台电动机负荷模型参数为基础,以电动机模型在暂态仿真中的差异为依据,进行了深入分析。首先,针对调研所得模型参数中机械转矩系数和初始滑差大量缺失的问题,分别通过K最近邻填补方法、负载率或临界滑差予以填补;其次,针对不同电动机暂态响应的差异,以仿真所得的电动机暂态功率曲线为聚类依据,采用K均值算法,获得了7类暂态特征各异的电动机,并分析了7类电动机的参数分布特征。所得的7类典型参数值补充了IEEE和国家电网有限公司推荐的电动机参数集,为感应电动机负荷模型的典型参数取值提供了参考依据。     

空载起动运行三相感应电动机突加负载及其瞬间断电时的动态仿真

首先利用三相感应电动机的运动方程,推导出它的状态方程,并结合实际电机参数利用Matlab语言对空载起动运行的三相感应电动机突加负载及瞬间断电时的动态过程进行了仿真。仿真结果符合三相感应电机的动态过程的特性。