七电平毕业设计.doc

摘要 级联型多电平变频器输出电压谐波含量小，易于实现模块化，适用于高压大功率场合，本文主要针对七电平H 桥级联型逆变器的拓扑结构和控制方式的相关问题进行分析与研究。级联个数不同，对控制方法也有不同的要求。分别对载波层叠调制和载波移相调制方法进行了相关仿真研究。验证了两种方法的正确性，同时也对相关量的谐波进行了分析。 多电平逆变器现在主要应用于高压大功率的交流电动机的变频调速、直流输电和电能质量综合治理以及超导储能的上面，感应加热以及大功率的不间断电源(UPS)等这些领域；同时也在清洁能源的利用上面也起到了非常重要的作用，比如风力发电和太阳能发电就可以通过高压多电平逆变器来入网。在我国的国民经济高速发展的今天，这样的多电平逆变器已经应用到了各个领域，有着非常广阔的应用前景。 关键词：H桥级联；七电平；载波层叠；载波移相 Abstract Cascaded multilevel inverter output voltage harmonic content of small, easy to implement modular, suitable for high-power situations, the paper focused on the seven-level cascaded H-bridge inverter topology and control related issues analysis and research. Different cascade number of control methods have different requirements. Were stacked on the carrier modulation and carrier phase shift modulation methods related simulation. Two methods to verify the correct Resistance, but also on the amount of correlation of the harmonic analysis. Multi-level inverter is now mainly used in high-voltage power inverter AC motor, DC power transmission and power quality management and SMES above, induction heating, and uninterruptible power supply (UPS), etc. These field; while taking advantage of the above are also clean energy also plays a very important role, such as wind power and solar power can be high-pressure multi-level inverter through to the net. In the rapid development of Chinas economy today, such a multi-level inverter has been applied to various fields, has a very broad application prospects. Keywords: H-bridge cascade; seven levels; carrier disposition; carrier phase shift  目 录 摘 要 I Abstract II 1绪论 1 1.1 多电平逆变器产生背景 1 1.2多电平逆变器的研究现状 2 1.3 本文的主要内容 10 2 级联H桥工作原理 11 2.1 单个H桥工作原理 11 2.2 多个级联H桥拓扑结构的数学模型 12 2.3 单元级联型多电平逆变器的调制控制方法 14 2.4 载波SPWM的采样方式 20 3 MATLAB 的特点和优势 23 3.1 MATLAB 的组成 23 3.2 MATLA与图象处理4 3.3 MATLAB特点与优势4 4 级联H桥七电平逆变器仿真分析 26 4.1级联式多电平逆变器PWM调制技术 26 4.2 H桥单元模型 27 4.3载波发生器设置方法 4.4 调制波的设置 30 4.5七电平的级联型逆变器的仿真模型 30 4.6仿真结果分析 31 5