异步电机直接转矩控制中定子电阻方法研究

在直接转矩控制系统中,对定子磁链的精确估算是关键技术之一,定子电阻变化在低速下对磁链观测的影响非常大,而电机的温升是引起定子电阻变化的主要原因。本文改进了基于真实环境的随着温度变化电机定子电阻发生改变的仿真模型,并通过实验给出了满足系统平稳运行时电机定子电阻和磁链观测处定子电阻二者的关系。仿真和实验结果表明,该方法具有良好的动态和稳态性能。     

基于自适应全阶磁链观测器的直接转矩控制系统

基于模型参考自适应理论，采用自适应全阶磁链观测器观测定子磁链和辨识转速，并结合模糊控制，利用Matlab／Simulink构建了无速度传感器直接转矩控制系统。     

一种基于感应电机直接转矩控制磁链观测器的速度辨识方法

分析一种感应电机直接转矩控制中转子磁链的观测方法,并对转子磁链及磁链转差进行数学建模分析,在此基础上估算出电机转速.通过仿真结果可以看出,这种方法能够提高低速观测精度,增强系统鲁棒性,受电机参数变化影响不大,算法简单直观,便于实现.     

直接转矩控制方案中的磁链估计

将现代控制理论运用于交流永磁同步电机的直接转矩伺服系统中,以提高系统在低速时的性能.通过分析指出了定子电压积分法估计磁链时存在的不足,提出了采用定子自适应全雏观测器来估计磁链,经仿真比较表明该算法具有较好性能,从而证明了该方法的可行性.     

基于直接转矩控制无速度传感器交流调速研究

在直接转矩控制的基础上,结合定子磁场定向和转子磁场定向各自的特点,详细讨论了速度估计的算法和有关的参数计算,提出了一种简单、实用的速度估计方法,并进行了仿真研究。仿真和试验结果表明,速度估计值与实际值能很好地吻合。     

异步电机全阶自适应磁链观测

针对传统的直接转矩控制系统采用纯积分的电压模型作为磁链观测器,存在着误差积累以及直流偏移,导致电流和转矩的波动问题,提出了一种基于定子磁链的自适应全阶观测器的直接转矩控制系统。     

异步电动机直接转矩控制中定子磁链控制方法的应用研究

在异步电动机直接转矩控制理论基础上，分析了定子磁链的控制方法，提出了一种获得圆形定子磁链的处理方法，通过仿真和试验，结果证明该方法的有效性。     

异步电机直接转矩控制磁链模型切换的研究

在分析各种切换模型的基础上,针对实际应用的高低速模型切换存在的问题,提出了一种采用速度差对时间积分的模型切换方法.实验结果表明:采用上述控制策略的调速系统具有良好的静、动态性能.     

新型自适应速度观测器在异步电机直接转矩控制系统中的应用

实现高性能直接转矩控制系统的重要环节是准确地观测异步电机的定子磁链，本文将一种新型的速度自适应磁链闭环观测器，应用于直接转矩控制系统中，取代了传统的积分器，理论证明该系统是超稳定系统，仿真与实验表明，该方案对电机磁链的观测精度高，对电机参数的鲁棒性好，同时基于磁链观测器所设计的速度自适应辨识方案准确性好，收敛速度快，使系统在较低转速下仍能保持优良的性能，本系统针对1．1kW异步电机，采用数字信号处理器DSP（TMS320C32）进行了数字化实现，实时控制软件是采用C和汇编语言混合编程实现的。     

一种能消除积分漂移的电压型磁链观测器

对异步电机交流调速系统中经典的定子磁链观测方法进行了分析,为消除积分漂移误差对电压型定子磁链观测器的影响,提出了一种改进积分器算法.将坐标系定向在定子电流矢量上,在该坐标系下,定子磁链的d-q分量幅值在稳态下基本恒定,其微分信号接近于零,并且电流矢量幅值在稳态下亦接近于恒定量,由此推出了一套稳态下的定子磁链观测方法.新的磁链观测方法中不合有积分器,定子电阻摄动无影响,计算量较小,精度较高,且易于DSP实现.仿真表明,该方法可以得到较理想的磁链观测值.     

基于RS-485总线结构的气象通量观测系统

介绍了一种基于RS-485总线的气象通量观测系统,阐述了其整体结构、硬件设计以及系统软件的开发和实现。该系统具有灵活性强、适应性广、扩展性好等特点,可广泛应用于农业、林业、草原、交通、航空等气象观测。     

Design and determination of stator geometry for axial flux permanent magnet free rod rotor synchronous motor

During designing a new axial flux permanent magnet free rod rotor synchronous motor, it is important to know before hand in which phase the largest angular velocity can occur, what is the ways to reduce the power consumption, how to achieve to increase or decrease the rotation speed by changing the core geometry. Therefore, presenting these preliminary information that are necessary for the design of a free rod rotor synchronous motor to the researchers is the aim of this work. In this respect, this study presents the design and geometrical dimensions of the stator for a new synchronous motor which is an axial flux permanent magnet free rod machine with three, four, five and six phases. This type of motors are an innovative approach especially for the applications used in industrial stirrers. Each type of stator is designed such that it has an appropriate number of phases. The rotating magnetic field over the stator is established by a PIC based microcontroller feeding the interface circuit to the stator wounds. The maximum angular speeds of bar magnet rotors with four different lengths and masses are calculated theoretically and determined experimentally. In addition, the effects of the distance between the rotor and stator, the angular speed of the rotor within the limits of the operation, and the volume of the liquid to be stirred to the power applied are investigated. Furthermore, the effects of the lengths and angular speeds of the bar magnet rotors to the distance between the rotor and stator are determined. In the light of the information obtained and taking into account the power used, the most appropriate parameters and variables such as the stator geometry changing with the phase used, the length of rotor, the distance between the rotor and stator and the angular speeds of rotor are determined.     

SRM的直接瞬时转矩控制及其改进型的仿真研究

针对开关磁阻电动机的转矩脉动较大的问题,对直接瞬时转矩控制方法进行了研究,并将其与PWM控制方法相结合,进一步介绍了一种改进型的控制方法。对两种控制方法的工作原理展开分析,重点介绍了转矩差值控制环节,它是依据转子角度位置的不同,将电动机的相绕组电感分为三个区间,并通过编程实现各个区间内电动机的控制。通过Matlab/Simulink软件分别搭建了四相8/6极开关磁阻电动机的直接瞬时转矩控制和改进型直接瞬时转矩控制的仿真模型,其中,瞬时反馈转矩是由相电流、转子位置和转矩三者之间的关系表查表得到。研究结果表明,两种方法都能够对转矩脉动起到抑制作用,但相比较而言,改进型直接瞬时转矩控制方法的抑制效果更加明显。     

Theoretical analysis and experiments of axial flux pm motors with minimized cogging torque

This paper deals with analysis and experiments of an axial flux PM (AFPM) brushless dc motor with minimized cogging torque. Recently, many optimal designs for the AFPM motor have been done by finite element (FE) analysis, but such analysis is time-consuming. In this study, the equation of magnetic flux lines existing between PMs and core is assumed mathematically and the minimum cogging torque is calculated theoretically and geometrically without FE analysis. The form of equation is assumed to be a 2^nd order polynomial. The skew angle that makes the cogging torque minimized is calculated theoretically, and the value of minimum cogging torque is compared with the results obtained by FE analysis and experiments. The maximum cogging torque of a proposed AFPM motor has the smallest value approximately at a skew angle of 4° in both the theoretical and FE analysis. Compared with the non-skewed motor, the cogging torque of the skewed motor can be decreased to over 90%, which has a value of 5% of the rated torque. Two types of stator cores, with the skew angle of 0° and 4°, are analyzed, manufactured, and tested experimentally. This paper was recommended for publication in revised form by Associate Editor Hong Hee Yoo Dong Ho Kim received B.S. and M.S. degrees in Mechanical Engineering from Pusan National University in 1982 and 1984, respectively. He then received his Ph.D. degree from Yonsei University in 2007. Dr. Kim is currently a Professor at the Department of Automation and Robots at Kyonggi Institute of Technology in Gyeonggi, Korea. His research interests are in the area of production automation. Jong Hyun Choi received B.S., M.S., and Ph.D. degrees in Mechanical Engineering from Yonsei University, Seoul, Korea, in 1996, 1998, and 2006, respectively. Dr. Choi is currently a post-doctor at the School of Mechanical Engineering at Yonsei University. His research interests are in the area of electromagnetic actuators and magnetic levitation system. Chang Woo Son received a B.S. from Kyungwon University, Seoul, Korea, in 2006, and his M.S. degree from Yonsei University in 2008, all in mechanical engi-neering. He is currently a research engineer at DA Laboratory of LG Electronics in Seoul, Korea. His research interests are in the area of electromagnetic actuators. Yoon Su Baek received B.S. and M.S. degrees from Yonsei University, Seoul, Korea, in 1979 and 1981, respectively, and M.S. and Ph.D. degrees from Oregon State University in 1986 and 1990, respectively, all in mechanical engineering. He worked for Samsung Heavy Industry Ltd. as head research engineer at Mechatronics Research Center from 1990 to 1993. Dr. Baek is currently a Professor at the School of Mechanical Engineering at Yonsei University. His research interests are motion devices and robotics, especially relating to multi-D.O.F. actuators. He is also interested in magnetic brake and levitation system.     

基于进给速度修调的轮廓误差控制研究

在分析进给速度对轮廓误差影响的基础上,提出了一种基于进给速度自动修调的轮廓误差控制方法,并设计了相应的轮廓误差控制器。通过其在西门子840D数控机床上的应用,可以有效控制加工过程中的轮廓误差,从而为进一步提高工件轮廓加工精度提供了重要的方法与理论依据。     

基于LabVIEW的变转速液压调速远程测控系统

针对泵控马达变转速节流复合调速系统实验台,运用LabVIEW开发了具备远程测控功能的液压调速综合控制平台.利用该控制系统对液压实验台进行远程调速模式下的实验研究,结果表明,在远程控制条件下,复合调速具有较优良的控制特性,该方案基本满足了实际应用需求.     

一种新型高剪切均质分散机的研制

介绍了一种新型的多级多层环形梳状齿高剪切均质分散机的主要结构和工作原理,分析了均质分散的机理和主要零件的的结构特点。该分散机与传统设备相比具有分散效率高、能耗低、噪音低、易清洗等优点。     

无刷直流电机双模糊直接转矩控制系统的研究

针对无刷直流电机直接转矩控制存在传统PID速度环自适应较差和相对较大的转矩脉动等问题,对直接转矩控制系统的转矩观测等方面进行了研究,对直接转矩控制策略进行了归纳,提出了一种双模糊控制策略。在转速闭环中,以模糊自适应PID代替普通的PID控制,实现了PID参数的自适应整定。在转矩控制环中,在转矩滞环控制器的基础上,将转矩的偏差和转矩偏差的变化率模糊化,模糊控制非零矢量和零矢量的作用时间,消除了容差宽度选择对转矩脉动的影响,使转矩脉动进一步减小。研究结果表明,相比普通的直接转矩控制系统,引入双模糊控制策略的直接转矩控制系统,可进一步地减小电磁转矩脉动和提高转速的自适应调节能力,显著地改善系统的控制性能。     

一种实用的数控系统加减速控制方法

阐述步进电机速度控制原理 ,并介绍微机进行加、减速控制方法及控制软件