
【中文摘要】永磁同步电机以其结构简单、效率高、调速范围宽等优点,广泛应用于机械加工、航空航天和电力牵引等领域,而直接转矩控制是继矢量控制技术之后发展起来的一种新型高性能的交流调速技术,因此,永磁同步电机的直接转矩控制系统成为研究的热点。本文以研究永磁同步电机直接转矩控制系统为,具有重要的理论和实际意义。本文结合大量的文献资料,介绍了永磁同步电机的结构以及其直接转矩控制的研究现状与方向。从空间矢量原理出发,介绍了调速系统中常涉及到的三种坐标系以及它们之间的变换理论,推导了永磁同步电机在各种坐标系下的数学模型。深入分析了直接转矩控制的基本思想,对基于Bang-Bang滞环控制的传统方式进行了研究,分析了空间电压矢量对定子磁链和电磁转矩的影响。针对传统控制方式存在的缺限,本文将空间矢量脉宽调制技术引入永磁同步电机的直接转矩控制系统中,以解决传统直接转矩控制方式中磁链、转矩脉动大的问题,给出了定子磁链和电磁转矩协制的改进算法。借助Matlab/Simulink工具对永磁同步电机的传统直接转矩控制系统和基于SVPWM的直接转矩控制系统各子环节进行建模设计,建立了基于两种控制策略的仿真模型。得到了与理论分析相一致的实验结果:改进后系统具有良好的动、静态性能,减少了转矩和磁链的脉动。
【英文摘要】Permanent magnet synchronous machine with its simple structure, high efficiency, wide speed range, are widely applied in many fields, such as machining operation, aerospace, electric traction etc., and direct torque control is a new type of high-performance AC driving system after vector control technique, as a result, the research of direct torque control of permanent magnet synchronous machine has become a focus. Therefore, this thesis take studies of the direct torque control system of permanent magnet synchronous machine as a goal; it has important theoretical and practical significance.After consulted many literatures, the thesis introduced the structure of permanent magnet synchronous machine, and then analyzed the status and trend of permanent magnet synchronous machine’s direct torque control system. Based on space vector principle, the three kinds of coordinate systems as well as the transformation of them which usually used in motor’s speed control system are introduced, then, the mathematic models on different coordinate systems are derived. After that, the theory of DTC is studied deeply and traditional control system based on Bang-Bang mode is researched. The effects of space voltage vectors towards to stator flux and electromagnetic torque are also analyzed. Due to existent disadvantages of traditional DTC mode, Space Vector Pulse Width Modulation is brought into PMSM DTC system in order to resolve the problems such as remarkable fluctuations of flux and torque. Moreover, the improved algorithm is given for the harmonious control of stator flux and electromagenic torque.With Matlab/Simulink the subsystems of traditional DTC system and SVPWM DTC system for PMSM are modeled and designed. Then the simulation models of the above two control strategies are also established. Simulation research is conducted and the experimental results are corresponding with theory analysis:the improved system has good dynamic and static performance, less flux and torque ripple.
【关键词】永磁同步电机 直接转矩控制 空间矢量脉宽调制 Matlab/Simulink
【英文关键词】Permanent magnet synchronous machine Direct torque control SVPWM Matlab/Simulink
【目录】永磁同步电机直接转矩控制系统的研究摘要6-7Abstract7第1章 绪论10-151.1 课题研究的背景与意义10-111.2 永磁同步电机的特点及其应用的发展11-131.3 永磁同步电机直接转矩控制的发展和研究现状13-141.4 论文的主要工作14-15第2章 永磁同步电机的结构及数学模型分析15-272.1 永磁同步电机的结构简介15-172.2 空间矢量原理介绍17-182.3 坐标变换18-222.3.1 三相静止坐标系与两相静止坐标系之间的变换18-202.3.2 三相静止坐标系与两相旋转坐标系之间的变换20-212.3.3 两相静止坐标系与两相旋转坐标系之间的变换21-222.4 永磁同步电机的数学模型22-262.4.1 电机在三相静止坐标系中的数学模型23-242.4.2 电机在两相旋转坐标系中的数学模型24-252.4.3 电机在两相静止坐标系中的数学模型252.4.4 电机在磁场旋转坐标系中的数学模型25-262.5 本章小结26-27第3章 永磁同步电机直接转矩控制系统的原理及实现27-473.1 永磁同步电机直接转矩控制的基本思想273.2 传统永磁同步电机直接转矩控制系统27-373.2.1 逆变器和空间电压矢量28-293.2.2 定子磁链的估算与滞环控制29-343.2.3 电磁转矩的估算与滞环控制34-353.2.4 开关表35-363.2.5 传统控制系统存在的问题36-373.3 基于SVPWM的永磁同步电机直接转矩控制系统37-453.3.1 空间矢量脉宽调制(SVPWM)原理介绍38-393.3.2 基于SVPWM的永磁同步电机直接转矩控制系统39-403.3.3 空间矢量脉宽调制技术的实现40-453.4 传统与SVPWM直接转矩控制比较45-463.5 本章小结46-47第4章 永磁同步电机直接转矩控制系统的仿真研究47-614.1 MATLAB/simulink简介47-484.2 传统永磁同步电机直接转矩控制系统仿真48-534.2.1 永磁同步电机的模块48-494.2.2 定子电流从三相到两相的变换单元494.2.3 定子电压分量获取模块49-504.2.4 定子磁链、电磁转矩及定子磁链位置角的估算模块50-514.2.5 定子磁链区域号的判断模块51-524.2.6 开关表及逆变器驱动信号模块52-534.3 基于SVPWM的永磁同步电机直接转矩控制系统仿真53-5.3.1 参考电压矢量U_s生成模块54-554.3.2 SVPWM仿真实现的模块55-5.4 仿真结果的比较分析56-604.5 本章小结60-61结论61-62致谢62-63参考文献63-67攻读硕士学位期间发表的论文67
