【作者】 聂卫民；

【导师】 王辉； 肖雁鸿；

【作者基本信息】 湖南大学 ， 电力电子与电力传动， 2004， 硕士

【摘要】 三电平逆变器由于具有优良的输出特性，在许多工业领域得到了广泛的应用。论文通过查阅大量国内外参考文献对多电平逆变器的研究现状有了系统的认识，通过对参考文献的认真研究，对各种拓扑结构和各种控制策略的优点及所存在的缺陷有了深入的认识。论文深入研究了三电平逆变器的基本结构、基本原理、特性及PWM控制策略。。 论文首先详细分析了三电平逆变器的基本原理，特性发展。综合比较了多电平逆变电路三种典型拓扑结构的优缺点，在分析由独立电源钳位的“H型桥串级逆变电路”结构改进得到的基于混合单元电路的逆变电路时，本文提出了一种使用不同电压比的控制模式，并对其可行性做了分析论证。 论文对三电平逆变器的电路方程进行了深入的分析，在开关函数的基础上建立了三电平逆变器的数学模型，对三电平逆变器的开环和闭环PWM控制结构进行分析，重点分析了三电平逆变器的滞环电流PWM闭环控制策略。 论文深入地研究了三电平逆变器的基于开环的PWM调制策略，分析和提出了多电平逆变器的SPWM调制策略，同时提出了改进的空间矢量PWM算法，通过仿真，两种方法简单有效，验证了二者的正确性和可行性。并且还介绍了三电平逆变器的两种SVPWM控制策略，一是SVPWM的最优化实现控制策略，二是空间矢量PWM的简化控制算法。 最后论文还对多电平逆变器存在的中点电位漂移问题进行了讨论，并采用两种方法来实现中点电压平衡，即判别逆变器功率流向法和检测瞬时电流值方法。更多还原

【Abstract】 Three-level inverter is applied widely in the many industry fields for its excellent performance. Through referring lots of national and native conference documents, the understanding to the current researches of three level inverter are obtained , the profound comprehend to the features of the different PWM control strategies and control methods are acquiredThe paper deeply analyzes fundamental principle, performance and development of three level inverter, and compares the advantages and disadvantages of three kinds of typical multilevel circuit. Based on analyzing inverter circuits based on the hybrid cells improved by H cascade inverter circuits using the independent power and bring forward a new control pattern for Hybrid multilevel inverter which uses different voltage ratio in the hybrid cells for getting more multilevel voltages.The paper deeply analyzes the circuit equations of three levels inverter , And establishes the mathematical model of three-level inverter based on the switch function, discusses the application of various current PWM control techniques and compares the advantage and disadvantage of them , and the hysteretic band current control strategy of three level inverter is studied in detail in the paper based on close loop PWM controller.Then this paper deeply analyses PWM control strategies of three-level inverter .The paper discusses and proposes SPWM strategy and the voltage SVPWM algorithm improved, and provides the results that they are simple and effective through simulation.which indicate that they are accurate and feasible.The paper introduces SVPWM modulations of three-level inverter including optimal space vector PWM controller and simple SVPWM control arithmetic.Finally,this paper discusses the problems of neutral point control that exists in the three-level inverter, and adopts two methods to control neutral voltage balance namely judging power direction and detecting instantaneous current value.更多还原