Utilization of a series resonant DC link for a DC motor drive

A high-frequency series resonant DC link converter is utilized as a DC motor drive. This system generates a resonant current in a series link, and switching is done at zero current instants, reducing switching losses to a minimum value. A pulse density modulation (PDM) strategy, utilizing a current rectangular loop and an external motor speed feedback loop, controls the resonant converter. A sinusoidal input fundamental current and nearly unity input power factor can be observed in different load conditions. The overall characteristics of the system, including such variables as maximum power, input current, start up, and transient responses, are presented by digital simulation and were verified on an actual prototype system     

直流无刷电机中齿槽转矩的能量分析

齿槽转矩是齿槽类无刷永磁电机的固有指标,在定子绕组断电状态下,由永磁体的永磁场与定子铁芯的齿槽结构相互作用形成电磁力,进而在圆周方向产生周期性的固定转矩。本文从能量守恒的角度出发,根据齿槽转矩的产生机理推导出齿槽转矩与电磁结构的公式关系,以3对极和6对极两款直流无刷电机为例,利用二维有限元法分析了齿槽转矩在圆周方向的能量分布,研究表明,相同槽数的电机在一个周期内符合能量守恒定律,极对数的不同会造成齿槽转矩不同,通过选择合理的方法能够有效的利用齿槽转矩达到电机断电制动的效果。     

新型无刷直流电机结构设计与性能分析

针对物联网通讯技术对微纳卫星提出的高性能、低成本的需求,提出了一种新型双圈磁钢无刷直流电机结构动量轮,介绍了其结构和工作原理。采用有限元法对气隙磁密进行仿真分析,结果表明,双圈构型电机气隙磁密和有效气隙磁密平均值均优于传统方案,气隙平顶宽度从传统方案的90°拓宽到120°,有效的提升了力矩输出性能。通过对无控制器状态下两种电机转速特性分析,验证双圈构型电机具有更优的动态和抗干扰性能;基于该结构设计了转速闭环PID控制系统并进行仿真分析,结果表明双圈构型电机在空载状态及突加负载两种情况下,电机达到稳定转速的时间和达到稳定转矩的时间均优于传统结构电机,且新型结构电机的脉动幅值降低约46.5%,可实现电机的高精度稳速控制。     

直流电机噪声分析与降噪对策

分析了生产过程中产生噪声的主要因素及对策。     

直流电机接线错误分析与接线要点

直流电机安全运行是发电厂机组安全运行的最后一道保障.基于对直流系统绝缘监测装置原理的分析,国华宁电2B小机直流润滑油泵电机启动时直流母线发"母线异常"报警故障,是由电机接线错误引起的.直流电机线端标识混乱,电机制造厂还是沿用1965年版的标准.介绍并励电机正转接线的2条回路和反转接线的2条回路.     

Fuzzy-logic-based speed control of a shunt DC motor

The fundamental equations governing the operation of a DC motor are straightforward and are well presented in most undergraduate curricula, usually in a required energy conversion or electrical machinery class at the junior level. The physical implications of the equations regarding device behavior, and the need for speed control, are easily understood. Furthermore, students can readily develop a mental picture of the physical motor and its response. Speed control of a DC motor represents an ideal application for introducing the concepts of fuzzy logic. Once the fundamentals of fuzzy logic have been presented to the students, their application to the speed control problem can be easily demonstrated. The paper shows how a commercially available fuzzy logic development kit can be applied to the theoretical development of a fuzzy controller for motor speed, which represents a very practical class of engineering problems     

无刷直流电动机直接驱动系统动态特性分析

在推导了转子表面安装永磁体无刷直流电动机的数学模型的基础上,介绍了一种以集成数字信号处理器ＡＤＭＣ３３１为核心全数字矢量控制无刷直流电动机直接驱动系统。着重分析了电流参考信号超前角,系统参数和驱动方式对无刷直流电动机系统动态性能的影响。     

基于小波分析校正网络的直流电机调速研究

直流电机在生产实践中有着交流电机无法替代的广泛应用。为提高直流电机的调速精度和转速稳定性,利用小波包分析技术,提取电流、电压和转速的小波系数中所包含的丰富的时频信息,判别故障,修正转速,本文设计了带调速检测和校正网络直流电机调速器;并和常规调速器的性能进行了对比实验。经过实验和生产实践验证,该控制系统具有较好的稳态性能与瞬态性能,较高的精度高和可靠性。     

Optimum design of a long-stroke thin linear DC motor

Computers have been more widely used in recent years. Researchers are now able to analyze a magnetic field using the finite element method. A motor can be designed more effectively and rationally. It is important to understand design space. Design space means the limit of the thrust or design variables within constraints. Within these limited dimensions, a linear dc motor (LDM) for a pen recorder is designed. This LDM is very thin with long strokes. It is described as follows: (1) the thickness of the permanent magnet and the length of the gap are selected as the design variables in the magnetic circuit of the LDM; (2) the effective magnetic flux density of LDMs using the 3-D finite element method is compared; (3) the design space of thin LDM with long strokes is clarified. The LDM measurement value (thrust constant) was increased at 0.60 N/A from the first LDM. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (4): 84–93, 1997     

The effect of interbar currents in a permanent split capacitor motor

This paper demonstrates how the techniques of generalized harmonic analysis may be applied to a permanent split capacitor (PSC) motor, allowing for the effects of interbar currents. The analysis is verified using an extensive set of experimental measurements made on a 2.5-hp two-pole motor, which show excellent agreement with calculation, provided an appropriate interbar current flow model is adopted.     

超低温条件下直流电机启动性能的研究与分析

在极寒气候条件下,电机受到风机负载及内部润滑油等阻力矩的影响,启动性能急剧下降,极易导致启动失败.这是制约空调器在低温条件下正常运行的难题.通过对电机启动瞬间轴系的受力情况进行分析,分别从提高电机启动力矩和降低阻力矩两个方面进行了详细论述.由此得出:通过提高直流电机的启动电流和采用新型耐低温的润滑油及电机轴承两种方案均可解决低温条件下电机的启动问题,并通过实验证明了解决方案的有效性.     

高性能直流调速系统中变流装置的比较分析

提出一种基于开关线性复合功率变换技术供电的直流调速系统 ,并将其与Buck电路供电系统作了比较 ,说明该系统具有良好的静动态指标和负载鲁棒性     

逆变器驱动电机系统中的耦合电流

针对由于逆变器驱动电机系统中的PWM电压具有高频和高dv／dt的特性,在电机内部产生共模耦合效应,并产生共模耦合电流流过电机内部的寄生电容这一特点,通过建立的分布参数电路模型和等效的集总参数电路模型,研究了电机内部高频情况下的共模耦合效应,分析了共模耦合电流的基本特性,给出了共模耦合电流的计算方法,对三相系统中的耦合电流进行了试验研究,并讨论了耦合电流对系统性能的影响。结果表明,耦合电流伴随电压的跳变而产生。呈双频振荡,引起电压和电流的畸变,并将引起电机绕组的过电压。     

基于逻辑斯蒂映射的电机混沌反控制

为了提高工业搅拌的搅拌效率,本文以应用在工业搅拌实验中的永磁直流电机为例,提出了一种基于逻辑斯蒂(Logistic)映射的混沌反控制方法,通过转速反馈,诱导电机进入混沌运行.计算机仿真表明,在这种控制下的工业搅拌装置,可以有效地提高搅拌效率,降低搅拌时间等.同时,本文分析了混沌搅拌中的混沌特性,为进一步的实际应用打下了理论基础.     

用于直流电机驱动的控制算法设计

以ARM微控制器为控制核心,IR2104驱动的MOSFET全桥驱动电路和霍尔摇杆为平台,构建了大功率直流有刷电机的控制系统。结合脉宽调制技术的应用,设计了一套有效可行的电机控制算法。实验结果表明,系统控制起来简捷易行,算法设计上安全灵活人性化,并具有小角度大半径转弯、大角度小半径转弯和原地零半径转弯的性能。可直接应用于电动轮椅、电动车等领域。     

电压暂降下直流电机驱动动态特性仿真研究

电压暂降是目前电能质量问题中最严重也是最受关注的问题,特别是对工业应用场合中广泛使用的可调速驱动设备.首先对电压暂降问题作了简要介绍;针对直流调速系统应用广泛但易受电压暂降影响的特点,在Matlab 2007的Simulink 模块中,对工业生产中大量采用的无刷直流电机驱动进行了建模,并对不同电压暂降条件下的动态特性进行了仿真分析和比较.最后提出了解决电压暂降问题的主要途径.     

电压暂降下直流电机驱动动态特性仿真研究

电压暂降是目前电能质量问题中最严重也是最受关注的问题,特别是对工业应用场合中广泛使用的可调速驱动设备。首先对电压暂降问题作了简要介绍;针对直流调速系统应用广泛但易受电压暂降影响的特点,在Matlab 2007的Sialulink模块中,对工业生产中大量采用的无刷直流电机驱动进行了建模,并对不同电压暂降条件下的动态特性进行了仿真分析和比较。最后提出了解决电压暂降问题的主要途径。     

PM brushless DC motor drive with a new power-converter topology

With the growing potential for widespread use of permanent magnet brushless DC motor (PMBDC) drives in many low-cost applications, such as HVAC, refrigerators, and freezers in houses and small-velocity servos in process industries, it has become important to minimize the cost. One obvious place for cost reduction is in the cost of the inverter and its associated controller. With that perspective, a novel application of the converter topology for the PMBDC known as “C dump” in switched reluctance motor drives is proposed in this paper. The advantages and disadvantages of this topology vis-a-vis the conventional three-phase H-bridge converter, are highlighted from the points of view of economy in switches, volt-ampere rating, associated controller cost, and packaging. Design considerations for the PMBDC are derived for use with the proposed converter topology. The operational and design characteristics of this converter-driven PMBDC drive are derived for four-quadrant performance. Guidelines for the design of the proposed topology are derived, and presented in the paper. Experimental results from a laboratory prototype are presented to validate the feasibility of the proposed PMBDC drive system