基于matlab的逆变器控制策略研究,基于Matlab的三电平逆变器控制

毕业论文关键词：三电平逆变器，电压空间矢量脉宽调制，Matlab/Simulink

Abstract: Three-level inverter has been used in the field of high voltage and large capacity of AC speed regulation widely. This paper introduces the working principle of two-level inverter, the basic principle of voltage space vector modulation technology. Then, the working principle and control strategy of three-level inverter is analyzed, topological structure based on three-level inverter. Three-level inverter voltage space vector plane is simplified to two-level inverter voltage space vector plane by a new type of voltage space vector pulse width modulation algorithm. It reduces calculation greatly and can make full use of the full-blown two-level inverter controlling method to analyze and control, and it is easier to be programmed as well. At the same time, the DC capacitor voltage imbalance is solved by detecting the DC capacitor voltage, changing the small vector time to suppress the fluctuation of neutral point potential. Finally, the control system of three-level inverter is built based on the Matlab/Simulink software. The simulation results show that the control algorithm has the advantages of sinusoidal output voltage nearly, neutral point potential balancing, and reduces the switching loss greatly.

Keywords: three-level inverter，SVPWM，Matlab/Simulink

目    录

1  引言4

1.1  电力电子器件的发展4

1.2  多电平逆变器技术的发展4

1.3  三电平逆变器控制策略简述5

2  逆变器SVPWM技术6

2.1  电压空间矢量定义6

2.2  两电平逆变器的SVPWM算法7

3  三电平逆变器简化SVPWM控制方略15

3.1  三电平逆变器的拓扑结构15

3.2  简化的SVPWM控制算法16

3.3  中点电位平衡控制17

4  仿真与分析20

结论 22

参考文献 23

致谢 24

1  引言

1.1  电力电子器件的发展

器件和变换技术随着电力电子技术的发展已经历过以下四个阶段 ：

(1)最早出现的开关器件是晶闸管(SRC)、门极可关断晶闸管(GTO)。SRC被称为半控型器件。其特点是：当需要关断时，添加一些辅助器件或者一些相应的电路才能关断这些半控型器件，同时其本身还可以实现无源逆变。相对来说，GTO能够自行关断，不足的是，驱动自行关断的电路比较复杂，而且功率大。总的来说二者的工作电流都很大，一般常用于一些容量较大的变频器。 基于Matlab的三电平逆变器控制:http://www.lwfree.com/zidonghua/lunwen_62188.html