UPS中三相三电平逆变器并联零序环流及其损耗研究

发布时间：2018-01-24 05:30

本文关键词： 三电平逆变器并联系统零序环流抑制空间矢量调制损耗分析　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着工业、医疗、公共服务等各行各业的快速发展，人们对于稳定可靠的高质量电源的需求越来越高。大容量、高功率密度的逆变电源并联系统的研究成为人们关注的热点。模块化的UPS并联逆变电源具有占用空间小，电能转换效率高，提高系统可靠性和冗余性，便于系统升级与扩展的特点。三电平电路因为具有电压应力小，整机效率高、输出电流纹波小等优势在高功率密度电源中有较大应用价值。本文主要针对并联系统中环流抑制问题和三电平的损耗问题进行了探究。本文研究了基于三电平逆变电路的模块化高功率密度逆变器并联系统。首先介绍了应用十分广泛的二极管钳位型三电平逆变电路的拓扑结构、工作原理及其调制方式，其中着重介绍了三电平的空间矢量法（SVPWM）调制的原理和通过叠加零序分量法的PWM载波实现方法。接下来分析了并联系统中的零序环流的产生原因，，建立了零序环流的等效电路模型，并对零序环流根据其成因进行了分类。然后针对不同成因的零序环流，提出了相应的抑制方法。针对高频的零序环流主要基于SVPWM调制中小矢量对共模电压的作用，提出了改进的19矢量法来减小零序激励，并给出两种衍生方法进行了对比分析。本文还针对三电平电路的功率器件损耗和滤波器损耗进行了的数学建模和计算分析，将数学分析得到的损耗与利用器件参数得到的损耗对比验证了其有效性，并将三电平电路与两电平电路损耗进行对比分析，论证了三电平电路在提高系统效率方面的优势和其不足。
[Abstract]:With the rapid development of industry, medical treatment, public service and other industries, people need more and more stable and reliable high quality power supply. The research of high power density parallel inverter power supply system has become a hot topic. Modular UPS parallel inverter power supply has small space, high power conversion efficiency, improve system reliability and redundancy. The three-level circuit has low voltage stress and high efficiency. The advantages of small output current ripple have great application value in high power density power supply. This paper mainly focuses on the problems of loop suppression and three-level loss in parallel systems. In this paper, a modularized parallel system of high power density inverter based on three-level inverter is studied. Firstly, the topology of diode clamped three-level inverter is introduced. The principle of three-level space vector method (SVPWM) modulation and the realization method of PWM carrier by superposition zero-sequence component method are introduced in detail. Then, the causes of zero sequence circulation in parallel system are analyzed, the equivalent circuit model of zero sequence circulation is established, and the zero sequence circulation is classified according to its origin. According to the effect of small and medium vectors of SVPWM modulation on common mode voltage, an improved 19 vector method is proposed to reduce zero sequence excitation. Two methods of derivation are compared and analyzed. The mathematical model and calculation analysis of power device loss and filter loss of three-level circuit are also given. The comparison between the loss obtained by mathematical analysis and the loss obtained by using device parameters verifies its effectiveness. The loss of the three-level circuit and the two-level circuit are compared and analyzed, and the advantages and disadvantages of the three-level circuit in improving the system efficiency are demonstrated.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464;TN86

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