无位置传感器无刷直流电机的控制系统研究

本文主要介绍了一种无位置传感器无刷直流电机控制系统的硬件结构和软件系统,分析了无刷直流电机转子位置检测方法。该系统以PLC为核心监测转速的变化,采用3段式起动方法,并利用PLC串口和上位机进行通信。     

TMS320F240视域下无位置传感器无刷直流电机控制系统研究

该文主要对无位置传感器无刷直流电机的基于DSP的控制系统进行研究.采用无刷直流电机的端电压过零检测方法提取转子位置信号.利用DSP快速运算的优越性来处理反电动势的干扰信号,通过对电机启动的预定位方法的介绍,从而对电机系统中电流控制的双环闭系统进行了构建,对于电机的软硬件双方面都能够进行较好的控制.     

基于DSP的无刷直流电机无位置传感器控制的实现

在传统的无刷直流电机控制系统中,由于大多采用位置传感器来获取电机转子位置信号,导致电机体积增加,控制线路变得复杂,因而限制了无刷电机在恶劣环境中的使用。为了改善位置传感器使用带来的弊端,本文设计并制作了一个基于美国德州仪器公司(TI)的数字信号处理(DSP)芯片TMS320LF2407A为主控制芯片的无位置传感器的无刷直流电机控制系统。采用虚拟中性点提取电机反电动势过零点从而捕捉电机转子位置信号,电机启动采用三段式,逆变器的上桥臂使用脉宽调制(PWM)而对应的下桥臂恒定导通,电机调速采用速度-电流双闭环比例积分(PI)控制。研究结果表明,电机能够平滑稳定地启动,整个控制系统具有良好的动态和静态性能。该文的设计方法是行之有效的,具有较重要的工程实践借鉴价值。     

新型单相无刷直流电机控制方法及实现

针对无位置传感器单相无刷直流电机控制系统中的换相点时间不确定、换相转矩波动大两大问题.论文提出一种控制策略-相电流时分复用法,该方法在一个控制周期内的大部时分间里,电机绕组通入励磁电流被用来驱动电机旋转,在剩余的时间内,被用来检测电机转子的位置,通过精确控制提前关断功率开关管的时间,达到减小电机输出转矩的波动、提高电机的转速范围,明显提高单相无刷直流电动机无位置传感器运行时的性能,实验结果验证了提出方法的准确性和可行性.     

轴流式血泵无位置传感器控制的设计

介绍了一种用于人工心脏轴流式血泵无位置传感器永磁无刷直流电机闭环调速控制系统的电路设计，该设计利用自启动方式实现电机启动，当电机达到额定转速时进入闭环控制系统，利用反电势逻辑积分法，实现无刷直流电机无位置传感器控制．     

无传感器磁力轴承转子位移检测原理的研究

提出一种新型的无传感器磁悬浮轴承的控制技术,即不需要位置传感器就能检测到转子的位移信号。主要研究这种无位置传感器转子位移检测的方法。在不需要任何附加的控制器的情况下,在功放的输入端注入一高频信号,转子位置信息就通过包含高频分量的线圈电压或电流获取。这种位移检测方法的有效性在仿真结果中得到了验证。     

永磁同步电机无传感器位置检测

为了使永磁同步电机的无传感器控制技术更加可靠和实用化,针对永磁同步电机低速段转子估计精度较低的问题,提出基于高频信号注入的永磁同步电机无传感器位置检测法。该方法利用永磁同步电机的凸极效应来辨识转子位置,即通过注入高频信号来检测电机的直轴高频阻抗和交轴高频阻抗,从而计算转子位置角度;再利用直流偏置法来判断转子永磁体的极性。利用有限元方法对永磁同步电机的高频阻抗与转子位置关系进行了仿真研究。对基于高频信号注入的永磁同步电机位置检测进行了实验研究,实验结果表明高频电压信号注入法有效地实现了转子位置的准确检测以及转子极性的辨别,该方法可以在永磁同步电机无传感器控制系统中应用。     

基于DSP的无刷直流电机控制系统设计

随着电力测控技术以及电子技术的飞速发展,无刷直流电机得到了广泛应用,其体积相对较小、运行效率较高、运行平稳可靠、维护十分便捷,凭借这一系列优势,无刷直流电机在工业控制领域应用及其广泛.本文主要阐述了基于DSP的无刷直流电机控制系统的设计,主要包括的硬件设计和软件设计两方面.所设计的控制系统主要采用触摸式一体机作为系统控制的上位机,选用专门为电机的数字控制所设计的DSP芯片TMS320LF2407A作为下位机,此芯片作为控制的核心部分,通过上位机与下位机的通讯配合完成无刷直流电机的整体控制.     

霍尔位置传感器在直流无刷电动机控制系统中的应用

无刷直流电动机是指具有直流电机外部特性的电子换相电动机,位置传感器电动机是其最基本的一种形式,霍尔元件传感器以其优良的特性及很小的体积在直流无刷电动机控制系统中获得广泛的应用。     

永磁电机无速度传感器仿真研究

提出一种永磁电机无速度传感器速度估算的方法。该方法专门针对低速和零速时的速度估算,基于调速系统的d轴电流调节器的输出电压包含了转子位置误差的信息。算法简单,实时性强,仿真实验验证了该方法的有效性和准确性。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.