三电平逆变器研究

电气工程论文编号:DQ131   论文字数:15606,页数:42

目 录
摘要…………………………………………………………………………… .……………...... II
Abstract……………………………………………………………………….……………...... III
1  前言…………………………………………………………………………………....………1
1.1  多电平逆变器产生的背景……………………………………………………....………1
1.2  多电平逆变器的分类和基本工作原理…………………………………………....……2
1.3  本论文的主要研究内容…………………………………………………………....…...5
2  两电平逆变器…………………………………………………………………….…...…….6
2.1  三相两电平逆变器结构特点……………………………………………………...…….6
2.2  三相两电平逆变器的PWM简介………………………………………………....…….6
3  钳位式三电平逆变器……………………………………………………………....………8
 3.1  二极管钳位式三电平逆变器……………………………………………………....…...8
  3.1.1  二极管钳位式三电平逆变器的基本结构和原理………………………....……8
  3.1.2  SPWM状态分析……………………………………………………..………...10
  3.1.3  二极管钳位式三电平逆变器的特点………………………………..…………11
  3.1.4  三相二极管钳位三电平逆变器…………………………………………..……11
  3.1.5  三相二极管钳位三电平逆变器的SPWM研究…………………………...…..13
 3.2  中点电位平衡的研究…………………………………………………………..……...14
  3.2.1  中点电位不平衡的原因及危害………………………………………..………15
  3.2.2  直流侧电容电压的平衡方法…………………………………………..………15
4  级联式三电平逆变器…………………………………………………………..………....17
 4.1  级联式三电平逆变器的结构与特点………………………………………..………...17
 4.2  三相级联式三电平逆变器…………………………………………………..………...20
  4.2.1  2H桥级联的PWM研究分析……………………………………...…………...22
5  逆变器的SIMULINK仿真………………………………………………..……………24
 5.1  MATLAB/SIMULINK简介…………..……………………………………….…………...24
 5.2  各逆变器仿真对比简析………………………………………………….…………...24
  5.2.1  各逆变器主电路对比…………………………………………………………..25
  5.2.2  各逆变器PWM电路图对比……………………………………………………26
  5.2.3  各逆变器输出电流和电压波形对比…………………………………..………28
  5.2.4  各三相异步电机的电流、转速和电磁转矩对比…………………........………29
 5.3  对比总结…………………………………………………………………………....…33
6  总结………………………………………………………………………………......………35
 6.1  总结………………………………………………………………………....…………35
 6.2  展望………………………………………………………………………........………35
致谢……………………………………………………………………………………….....……37
参考文献…………………………………………………………………………………......….38

摘要

 多电平逆变器中每个功率器件承受的电压较低，因此可以用低耐压的功率器件实现高压大容量逆变器。且采用多电平变换技术可以显著提高逆变器输出电压的质量指标。因此，随着功率器件的不断发展，采用多电平变换技术将成为实现高压大功率逆变器的重要途径和方法。
 本文首先对电力电子技术的发展和多电平逆变器的发展状况进行了描述。在分析两电平逆变器工作原理的基础上对三电平逆变器进行了研究，综合比较了三电平逆变电路两种典型拓扑结构的优缺点；介绍了二极管钳位型三电平逆变器和级联型三电平逆变器，分析了二极管钳位型逆变器和级联型三电平逆变器相对于传统两电平逆变器的优点，体现了课题研究的重要意义。
 最后通过MATLAB/SIMULINK的来建立仿真模型，对三电平逆变器进行仿真，对主电路、PWM信号产生电路、电流与电压采样电路、IGBT驱动及保护电路进行了分析研究。
 
关键词： 两电平逆变器、三电平逆变器、仿真、钳位式、级联式
 
Abstract
 
  In multi-level inverters, the voltage stress of each power device is relatively lower. That is suitable to realize the high voltage and large capacity inverters with the low voltage resistant power devices. And it is possible to enhance the quality of inverter’s output voltage obviously by using multi-level inverter. Therefore, with the development of power devices, the multi-level converter technology has been an effective approach for inverters to achieve high voltage and large power.
  Initially, summing up the development prospect of power electronic technology and the development status of multilevel inverter control technology. Based on the principle of two-level inverter, three-level inverter is studied on and the advantages and disadvantages of the three-level inverter’s two canonical topology structure are comprehensively compared. The three-level inverter with diode clamped is introduced, which is analysised about advantages to the two-level inverter. It embody the important significance of the subject research.
 In the end, by founding MATLAB/SIMULINK model. Analysis the main circuit、electrify cushion circuit、PWM signal generate、current and voltage sampling、IGBT drive and protect circuit.
 
Key words: Two-level inverter, Three-level inverter, Simulation, Clamped type, Cascaded