基于FPGA的同步电机数字调速控制系统
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目 录
摘要
ABSTRACT
第一章 绪 论...............................................................................................................1
§1.1 交流电机调速的现状和发展······················································ 1
§1.2 直接转矩控制的发展趋势及研究热点·········································· 4
§1.3 国内外现状··········································································· 5
§1.4 主要研究内容········································································ 5
第二章 同步电机.............................................................................................................7
§2.1 同步电机的基本结构和工作原理················································ 7
§2.1.1 同步电机的基本结构...........................................................................7
§2.1.2 同步电机的工作原理...........................................................................8
§2.2 同步电机模型········································································ 8
§2.2.1 电磁关系...............................................................................................9
§2.2.2 阻尼绕组补偿的励磁电流控制.........................................................11
§2.3 小结··················································································· 13
第三章 励磁同步电机直接转矩控制系统设计...........................................................14
§3.1 直接转矩控制系统的总体设计··················································14
§3.1.1 设计思想.............................................................................................14
§3.1.2 直接转矩控制系统的总体结构.........................................................14
§3.2 直接转矩控制系统的结构························································15
§3.2.1 逆变器.................................................................................................15
§3.2.2 坐标变换.............................................................................................17
§3.2.3 磁链和转矩计算.................................................................................18
§3.2.4 转矩比较器.........................................................................................20
§3.2.5 定子磁链的调节和其空间位置的确定.............................................21
§3.3 小结··················································································· 24
第四章 励磁同步电机直接转矩控制系统的仿真.......................................................25
§4.1 MATLAB 简介······································································25
§4.2 动态仿真工具 SIMULINK······················································· 25
§4.3 励磁同步电机直接转矩控制系统仿真结构图······························· 26
§4.4 仿真实验及结果····································································27
§4.5 小结··················································································· 31
第五章 基于 FPGA 的同步电机调速系统.................................................................. 32
§5.1 FPGA 设计···········································································32
§5.1.1 FPGA 简介......................................................................................... 32
§5.1.2 FPGA 的原理与结构......................................................................... 33
§5.1.3 FPGA 选型......................................................................................... 33
§5.1.4 FPGA 的存储电路......................................................................................... 35
§5.1.5 FPGA 的配置电路............................................................................. 37
§5.1.6 FPGA 的时钟电路............................................................................. 40
§5.1.7 FPGA 的复位电路......................................................................................... 40
§5.1.8 电源电路.............................................................................................41
§5.2 FPGA 硬件设计···································································· 42
§5.3 FPGA 功能仿真和时序仿真····················································· 42
§5.3.1 功能仿真.............................................................................................42
§5.3.2 时序仿真.............................................................................................43
§5.3.3 实验波形...............................................................................................1
§5.4 系统总体设计······································································· 46
§5.4.1 系统主电路设计.................................................................................47
§5.4.2 智能功率模块 IPM............................................................................ 48
§5.4.3 光电隔离电路.....................................................................................50
§5.4.4 相电流的检测和采样.........................................................................51
§5.4.5 电机转速检测.....................................................................................52
§5.5 实验结果与分析····································································54
§5.6 小结··················································································· 56
第六章 总结...................................................................................................................57
附录.................................................................................................................................58
参考文献.........................................................................................................................65
在读期间公开发表的论文和承担科研项目及取得成果.............................................67
致 谢.............................................................................................................................68
摘 要
直接转矩控制技术是 20 世纪 70 年代提出的,是继矢量变换控制技术之后,
且与之并行发展的一种新型高性能的交流传动控制技术。与矢量控制技术相比,
它具有更多的优越性,如它具有新颖的控制思想、简洁的系统结构和优良的静动
态性能等。
本文首先介绍了交流电机调速的现状和发展,并引出了直接转矩控制技术的
概念、特点及其发展趋势。在研究同步电机的基本结构和工作原理的基础上,建
立了励磁凸极同步电机的数学模型,分析了其电磁关系,并提出了阻尼绕组补偿
的励磁电流控制思想,增强了系统的稳定性。
然后依据直接转矩控制系统的设计思想,设计了一套具有高动态性能的直接
转矩控制系统,并对系统的结构进行了详细地分析和研究,利用 MATLAB 软件中
的SIMULINK 工具对励磁同步电机直接转矩控制系统进行了建模、仿真。
基于可编程逻辑器件 FPGA,利用 QuartusII7.2 仿真软件,采用直接转矩控制
的思想,构建了控制电路的算法模块图,并进行了功能仿真和时序仿真。最后搭
建了同步电机调速的硬件系统并进行了实验研究,实验结果表明该系统稳定可靠,
具有良好的特性。
关键词:直接转矩控制 电机调速 同步电机 FPGA
ABSTRACT
Direct Torque Control (DTC) was proposed in 1970s.It is a second high
performance AC motor control method after the vector control and is developing in
parallel with it.It has more advantages than the vector control technology. For example,
it has novel control ideas, simple system structures and excellent static and dynamic
properties.
This paper describes the status and development of AC motor speed control and
introduces the concepts, characteristics and development trends of direct torque control
techniques. Based on the research of basic structure and working principle of
synchronous motor, the mathematical model of electrically excited salient-pole
synchronous motor is eatablished and its electromagnetic relation is analyzed. The
control idea of excitation current which is compensated by damper windings is
proposed.It enhances the stability of the system.
Based on the idea of direct torque control system, a high dynamic performance of
direct torque control system is designed. And the structure of the system is analyzed and
studied detaily. Based on the simulink environment of the MATLAB software, The
direct torque control system of electrically excited synchronous motor is modeled and
simulated.
Based on programmable logic device(FPGA),the simulation software of
QuartusII7.2 and the idea of direct torque control,the control circuit block diagrams of
the algorithm are constructed and the functional simulation and timing simulation are
carried out. At last,The hardware system of the synchronous motor speed is built and an
experimental study is carried out.The experimental results show that the system is stable
and reliable and it has good performance.
Key words :direct torque control, motor speed control, synchronous
motor, FPGA
第一章 绪论
1
第一章 绪 论
§1.1 交流电机调速的现状和发展
调速系统可以分为交流调速系统和直流调速系统。直流调速系统采用转速负
反馈、电流负反馈和前馈的控制手段,可以获得高精度、快响应、宽范围的转速
调节和转矩控制特性。但是,直流调速系统结构复杂,本身结构上没有机械换相
器和电刷,维护麻烦,不能用于有易燃、易爆及腐蚀性气体场合,且容量受限制。
19 世纪 80 年代以前,直流传动是唯一的电气传动方式。1885 年交流鼠笼型
异步电机问世以后,由于它克服了直流电机的许多缺点,交流鼠笼型异步电机获
得了广泛的应用,但其也有转速不易改变的缺点,限制了它的广泛应用。
改变异步电机的转速通常可以通过四种方式来实现:
.降压调速。
.绕线转子电机串极调速。
.变极对数调速。
.变频调速。
随着现代电力电子技术的发展,以及处理器技术的飞跃,变频调速已占据了
领导地位。在成本、性能及容量上,变频调速技术都有了较大的进步,并且发展
出了一些性能优良的调速技术,如矢量控制技术和直接转矩控制技术,如表 1-1
所示。
表1-1 各种电气传动方案的调速性能比较
调速方案
调速范围
调速
精度
低速
特性
响应
速度
直流电动机
宽(1:5000)
高
好
慢
交流
电动
机
VVVF
窄(1:10)
低
差
较慢
矢量控制
较宽(1:20~200)
较高
较好
(连续)
较快
直接转矩控
制
较窄(1:15~100)
较高
较差
(脉动)
快
交流伺服控制
很宽(1:10000~100000)
很高
很好
很快
矢量控制技术于 1971 年由德国学者 F.Blaschke 提出。所谓矢量控制,是将交
流电机等效为直流电机来控制,通过坐标变换来实现电机定子电流励磁分量和转
矩分量的解耦,然后分别进行控制,获得类似直流电机的优良性能。矢量控制技
术的关键是磁场的定向,一般可以通过直接法和间接法来实现磁场的定向。直接
基于 FPGA 的同步电机数字调速控制系统
2
法是在电机内部埋设磁通传感器,这种方法使电机结构复杂化,因而广泛应用的
是间接法。间接法的思路是测量电机的定子电压、定子电流及转速等容易测量的
量,通过解方程得到电机磁链。这种方法便于实现,但是牵涉到电机参数,易受
电机参数变化的影响,后来,又发展出了参数的在线识别来弥补它的不足。
直接转矩控制技术于 1985 年由德国学者 Depenbrock 提出,直接转矩控制的德
文缩写是 DSR(Direckten Selbtregelung),意译为直接自调整控制,英文缩写为
DSC(Direct Self Control)或DTC(Direct Torque Control)。它在定子坐标系下对电机
进行控制,只需知道定子电阻,通过简单的计算,定向定子磁场,利用电压对磁
场的控制来实现力矩控制。这种控制方式结构简单,在很大程度上克服了矢量控
制中由定子坐标变换引起的计算量大、控制结构复杂、系统性能受电机参数影响
较大等缺点,而且系统的动静态性能指标都十分优越,是一种良好的交流调速方
案。因此,直接转矩控制理论一问世便受到广泛关注,目前国内外围绕直接转矩
控制的研究更是十分活跃。
直接转矩控制系统是建立在定子坐标系下,通过磁链和转矩的直接控制来实
现系统的高动态性能。
与交流电机的矢量控制方式相比,直接转矩控制主要有以下的几个特点[1]:
(1)直接转矩控制是直接在定子坐标系下,利用空间矢量的概念来分析电机的
数学模型,控制电机的磁链和转矩。因此省掉了矢量控制中坐标变换等复杂的运
算,信号处理工作简单,易于实现实时控制。
(2)直接转矩控制磁场定向采用的是定子磁链,而定子磁链的观测模型要比转
子磁链的观测模型简单得多,而且受电机参数变化的影响较小。
概括的说,直接转矩控制就是利用空间矢量的分析方法,直接在定子坐标系
下计算和控制交流电机的转矩,采用定子磁场定向,借助于离散的两点式调节
(Bang-Bang 控制)产生 PWM 信号,直接对逆变器的开关状态进行最佳控制,以获
得高动态性能的转矩响应。
直接转矩控制主要有两种形式:一种由 M.Depenbrock 提出的直接转矩控制,
其中定子磁链是依照正六边形轨迹运动的。由于正六边形的六条边分别与六个非
零电压空间矢量对应,直接通过六个非零电压空间矢量实现磁链轨迹控制。与其
他控制方式相比,这种控制方式结构简单,在输出同样的频率时器件开关次数最
少,开关损耗也小,因此在器件的开关频率不是要求太高的大功率场合下,得到
了广泛应用。
由于在这种方法中定子磁链轨迹是依照正六边形轨迹运动的,电压、电流的
波形畸变都比较严重,低速时转矩脉动也比较大,因此在一定程度上限制了直接
摘要:
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目录摘要ABSTRACT第一章绪论...............................................................................................................1§1.1交流电机调速的现状和发展······················································1§1.2直接转矩控制的发展趋势及研究热点··········································4§1.3国内外现状····························...
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作者:陈辉
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时间:2024-11-19