一种新型YASA电机冷却系统的优化设计

围绕着提高电机的功率密度,提出了一种新型直接冷却式轴向磁通分块铁心无磁轭(YASA)电机,根据传热学及流体力学理论对其热和流体耦合场进行了分析,并对该电机的冷却系统进行了优化设计.建立了传统背部冷却式YASA电机与直接冷却式YASA电机的三维CFD模型,并通过采用有限元法(FEM)求解了两种电机的稳态三维温度场与冷却系...     

磁通切换永磁电机等效模型与控制策略分析

针对传统转子永磁型电机散热困难导致永磁体发生不可逆退磁、限制电机出力、减少功率密度等问题,提出了一种定子永磁型磁通切换永磁(FSPM)电机,并对该电机结构特点与等效模型进行了分析,比较了定子磁场定向控制(SFOC)、直接转矩控制(DTC)及基于空间矢量调制的直接转矩控制(SVM-DTC)三种控制方法在FSPM电机上的应用效果.运用dSPACE的实验平台,对基于SFOC的FSPM电机驱动系统进行了实验研究.仿真与实验结果表明,采用SFOC的FSPM电机转矩脉动小、电流正弦度好以及低速性能优越,更适合于低速驱动领域的应用.     

电机控制集成电路的发展

论述了专用集成电路(ASIC)在电机控制中的应用,并对专用微控制器(MCU)和数字信号处理器(DSP)在电机中的应用作了预测。     

深度学习理论及其在电机故障诊断中的研究现状与展望

电机已经被广泛应用到人们生产生活的各个领域中,电机的故障不但会对电机本身会造成损害,甚至会引发经济损失、人员伤亡等各种问题。因此,将及时且高效的故障诊断技术应用于电机有着重要意义。相比较传统故障诊断技术而言,深度学习因其更强大更复杂的数据表达能力,已被应用于电机故障诊断领域,并取得了一定的研究成果。因此,介绍了深度置信网络(DBN)、自编码网络(AE)、卷积神经网络(CNN)和循环神经网络(RNN)这四类经典的深度学习模型,并总结了这四类模型在电机故障诊断中的应用。最后对深度学习在电机故障诊断领域中所面临的问题和挑战进行了总结和展望。     

基于裂比的非晶合金永磁电机设计技术

非晶合金材料电磁性能优异,应用于电机领域能显著降低电机铁心损耗,提高电机效率。针对非晶合金材料的特点,基于永磁电机基本设计理论,推导了非晶合金电机铜耗与铁心损耗的解析表达式。基于非晶合金永磁电机损耗的解析表达式对非晶合金永磁电机裂比(定子内外径之比)、磁密比值(气隙磁密与铁心磁密之比)的设计进行了研究,得出了非晶合金永磁电机裂比、磁密比值的设计规律。在对非晶合金永磁电机设计规律研究的基础上完成了一台非晶合金永磁电机的设计并进行了试验。所做的研究对非晶合金电机的设计及优化具有一定的参考价值。     

三相异步电动机杂散损耗对温升的影响

温升是电机的一项重要性能指标,它关系到电机的使用寿命。对如何降低电机温升,各厂作了大量的试验研究工作。除了寻求能耐更高温度的新型绝缘材料外,归纳起来不外二方面,即加强电机的通风冷却(更好地散热)和减少电机损耗(更少地发热)。对封闭式电机来讲属于前者的有:选择定子铁     

风扇大小对电机温升影响试验小结

在电机热耗(定、转子铜耗、铁耗以及附加损耗)及散热面积相同的情况下(例如对同一台电机),缩小风扇尺寸,会使电机温升上升。但是,由于风扇尺寸的缩小,使电机的风摩耗下降,提高了电机的效率,从而降低了电机的热耗,改善了电机的温升。因此,对一个具体规格,缩小风扇尺寸,对电     

电动车用开关磁阻电机设计与优化方法

根据电动车的性能要求,提出了一种电动车用开关磁阻电机(SRM)设计、优化方法。首先对电机进行了预设计,随后用Ansoft软件校验了电机性能。对电机主要结构参数进行了分析和优化,得到最优结果。     

PLC和变频器在电渣重熔炉改造中的应用

简要介绍了电渣重熔炉原理。对新电机的选择(主要是快速电机、自动升降电机、支臂旋转电机),以及可编程逻辑控制器(PLC)和变频器的选型进行了介绍。针对电渣重熔炉工作特点,叙述了两个重要控制过程(自动升降控制、支臂旋转控制)的设计思路和原理,并对试生产中发现的几个问题进行了阐述。     

轴向磁场磁通切换永磁电机单位功率因数控制

轴向磁场磁通切换永磁(AFFSPM)电机是一种定子永磁型双凸极电机,它结合了磁通切换电机与永磁电机的优点,且轴向长度短,转子结构简单,功率密度高,非常适合用于电动汽车与风力发电系统。本文推导了AFFSPM电机的数学模型,建立了AFFSPM电机驱动系统。针对AFFSPM电机id=0控制和最大转矩电流比(MTPA)控制策略存在功率因数降低的问题,本文以提高功率因数为目标,采用一种单位功率因数控制策略对AFFSPM电机进行了研究。仿真与实验结果表明,单位功率因数控制策略基本能够将AFFSPM电机功率因数调节到所需范围。     

一种小容量异步电机有功损耗的快速估算方法

三相异步电机空载有功损耗是异步电机比较重要的性能指标之一。在三相异步电机运行效率分析的基础上,提出了三相异步电机空载有功损耗的估算方法,并分析了其在不同异步电机空载视在功率中的占比,对开展异步电机相关的工作具有一定的现实指导意义。     

磁悬浮无轴承电动机发展、应用和前景

综述了磁悬浮无轴承电动机起源及发展历史，介绍了磁悬浮无轴承电动机的基本原理，详细论述了磁悬浮无轴承电动机在半导体工业、化工工业及生物工程等领域的应用特点和意义，展望了我国研究和应用磁悬浮无轴承电动机前景。     

Effects of Magnetic Saturation on the Performance of Thyristor Commutatorless Motors

The ratings and the other constants of motors are designed within a magnetically saturated region. Studies of motors, however, have dealt with and have been limited to the problems in a linear region for the sake of simplicity. A basic study of the operating performance of commutatorless motors in the magnetically saturated region is presented here. The magnetic saturation is evaluated in terms of the permeance of a magnetic circuit. Digital simulation based on this basic study reveals the effects of the magnetic saturation on the static characteristics of the commutatorless motors. The theory established in this paper for the analysis of the effects of the magnetic saturation can successfully be applied to other kinds of motors as well as to commutatorless motors.     

Selection and Application of Multispeed Motors

Multispeed induction motors can be used as pump or fan drives in certain petroleum and chemical industry applications to accommodate variable operating conditions. Use of multispeed motors in these cases can reduce equipment or energy costs. Applications for multispeed motors may not be considered during the project design stage because of the relatively limited use of these motors in the industry. The available types of multispeed motors and the potential cost savings associated with their use are reviewed.     

Effects of momentary voltage dips on the operation of induction andsynchronous motors

Simplified stability calculations of induction and synchronous motors on voltage dips are presented. The voltage dip withstand characteristics of induction and synchronous motors rated at the same horsepower and driving the same inertial loads are calculated. The motor characteristics influencing stability are: the type of motor selected (synchronous or induction); the pull-out torque of synchronous motors and the breakdown torque of induction motors; a constant excitation controller or an excitation boost on voltage dips for the synchronous motors; load and motor inertia; and load characteristics. Synchronous motors are not suitable for fast autoclosing or bus transfer, although these can be autoresynchronized. Transient torques and current surges must be considered when induction motors are connected for fast bus transfer. Due to varying power systems, motors and load characteristics, and much interaction between these, an analysis of avoiding a shutdown on voltage dips has to be performed on a case-by-case basis. This may include a computer-based study. The stiffness of the power system in relation to motor loads, the probable type of faults and fault clearance times, and motor protection and controls are some other concerns requiring an analysis in this context     

Ultrasonic motors: Their models, drives, controls and applications

In the last decades piezoelectrically driven ultrasonic motors have become alternative actuators to the conventional electromagnetic motors especially for precise and accurate servo positioning applications. Different types of ultrasonic motors have been constructed and manufactured. Several drive systems have been designed, implemented and proposed for these motors. A variety of control techniques have been applied to them. The research given in this study covers bases of the ultrasonic motors. Theoretical background, modeling, drive systems, control techniques and applications of the ultrasonic motors have been introduced. Firstly, the general overview has been given. Then, modeling studies focused on performance estimation and analysis of ultrasonic motors have been examined. Afterwards, drive systems and control techniques of ultrasonic motors have been investigated. Furthermore, an example drive and control system has been presented. This drive system has been designed as to be controlled digitally. In addition, the important industrial and research applications of these motors have been included. The presented study has been arranged as a review of ultrasonic motors. The important points of specifications, models, drive systems and control methods of the ultrasonic motors have been emphasized.     

Proper application of motors operated on adjustable frequencycontrol

Most high-efficiency motors can withstand the rigors of adjustable speed drive (ASD) operation. However, there are significant differences between applications of motors operated on sinewave power and motors operated on adjustable frequency controls (AFCs). This is an ongoing subject, rapidly changing due to advances in the technology of the AFCs. Subsequently, many of the older problems associated with the application of motors on AFCs have been solved, while at the same time, new problems were introduced. In many cases, high-efficiency, low-voltage motors can be applied on AFCs with no or little modification. In order to do this successfully, however, basic motor operating principles and the affect of applying a motor on an AFC need to be understood. The proper application of a motor for use on an ASD is dependent on an understanding of: thermal motor limitation-from AFC harmonics and reduced-speed operation at constant load (i.e., constant torque); and upper-speed limitation (beyond base speed)-constant power electrical limitation and mechanical upper-speed limitation. This article targets the application of motors not specifically designed for AFC operation. Generally, NEMA motors (i.e., motors up to the 440 frame) are more apt to be indiscriminately applied on AFCs than above-NEMA (ANEMA) motors (i.e., motors larger than the NEMA frame sizes). The concepts/guidelines presented here are equally applicable to both NEMA and ANEMA motors     

感应电动机动态特性与电压骤降的相互影响

基于不对称电压骤降推导了感应电动机电磁和机械回路方程,并结合电压骤降过程,分析了感应电动机动态特性和电压骤降的相互影响。运用电力系统计算机辅助设计和电磁暂态模拟程序软件（power systemcomputer aided design and electric magnetic transient in DC system,PSCAD/EMTDC）建立仿真模型来计算感应电动机的动态特性对电压骤降波形、电压骤降幅值和持续时间等特征参数的影响,以及不对称和对称电压骤降对感应电动机的母线电流、转速和电磁转矩等特性的影响。仿真结果表明感应电动机动态特性与电压骤降之间是一种动态的关系：感应电动机的动态特性会使电压骤降波形发生畸变,造成电压骤降幅值和持续时间等特征参数发生变化,而电压骤降也会造成感应电动机母线电流、转速和电磁转矩等特性发生变化。     

两个不同结构六相永磁同步电机串联驱动系统

由于多相电机较以前传统的三相电机优点明显,因此越来越受到关注.其优点之一就是多台多相电机可以进行串联,并且串联的多台电机由一台电压源型逆变器供电,减少了逆变器支路数量,使设备的体积大大减小.系统由一台对称六相永磁同步电机(PMSM)和一台夹角为0°的六相PMSM组成,两台电机的定子绕组按照一定的方式联接,运用矢量控制技术使两电机解耦,两电机实现独立控制.从电机的结构入手,分析两电机原理及串联规则,并建立两电机串联的数学模型,最后确定串联驱动系统的动态解耦性.     

与直流电动机同类型的自控式同步电动机

自控式电动机专指有直流励磁磁极的一种电机.从动态转速的观点,审视同步电动机和直流电动机的两种不同构建模式,它们的区别在于是否允许转子角速度相对于电枢磁动势角速度有所变动,以及由此呈现的不同基本特征.指出自控式的交流电动机是具有箝位效应的直流电动机的新发展.从交流电枢的视角探讨直流电动机原理有助于为工程实践提供有益的启示.