三相无死区逆变器的研究与设计

发布时间：2018-01-10 04:14

本文关键词：三相无死区逆变器的研究与设计　出处：《南京航空航天大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着化石能源的日益枯竭和环境污染的不断加剧,风能、太阳能等新能源的开发和利用成为当务之急。而作为连接电网和以新能源为代表的分布式发电系统的纽带,并网逆变器具有广泛的应用场合。无死区逆变器从根源上解决了传统桥式逆变器桥臂直通的问题,可以避免桥式拓扑死区引入的低次谐波,有利于提高电能质量。在大功率逆变场合无死区双降压并网逆变器结构简单,二极管可以单独进行优化设计,通过合理地设计滤波器参数以及改善控制策略可以有效地提升电能质量和效率,是值得研究的内容。本文首先介绍了三相桥式逆变器死区效应的消除方法。从控制的角度上,改进控制策略,可以进行死区效应补偿。从拓扑的角度上,选择无死区拓扑,可以从根本上消除传统桥式拓扑桥臂直通的现象。以三相双降压式逆变器和Z源逆变器两种无死区拓扑为例,分析了三相双降压式逆变器的工作原理,建立了其数学模型并给出其解耦控制策略,介绍了空间矢量脉宽调制方法;分析了Z源逆变器的升压原理,研究了两种逆变器的防直通网络的设计原则。对桥式电路的死区效应进行了分析研究。分别建立有死区时间的三相桥式逆变器以及无死区的双降压式逆变器的谐波计算模型,对LCL滤波器进行了分析研究,建立了进网电流THD的开环和闭环修正计算模型。针对三相双降压拓扑桥臂输出侧电感较多、体积重量偏大的问题,桥臂侧采用耦合电感,减小体积数量,在此基础上对双降压逆变器LCL滤波器进行了参数的优化设计。最后设计完成了全数字控制的18k VA三相桥式和双降压逆变器原理样机,介绍了硬件和软件的设计,并以此样机为平台进行了并网实验,实验结果与理论和仿真分析相吻合,有效地验证了分析的正确性。
[Abstract]:With the increasing depletion of fossil energy and environmental pollution, wind energy. The development and utilization of new energy, such as solar energy, has become an urgent matter, and as a link between grid and distributed generation system represented by new energy. Grid-connected inverter has a wide range of applications. The dead-time inverter solves the problem of the bridge leg of the traditional bridge inverter from the root, and can avoid the low-order harmonic caused by the dead time of the bridge topology. It can improve the power quality. In the high-power inverter, the structure of the dual-step-down grid-connected inverter without dead zone is simple, and the diode can be optimized separately. The power quality and efficiency can be effectively improved by reasonably designing filter parameters and improving control strategy. This paper first introduces the method of eliminating dead-time effect of three-phase bridge inverter. From the point of view of control, the improved control strategy can compensate the dead-time effect. From the perspective of topology, this paper introduces the method of eliminating dead-time effect of three-phase bridge inverter. Choosing dead-time topology can fundamentally eliminate the phenomenon of the traditional bridge bridge arm through. Take two kinds of dead-time topology of three-phase dual-step-down inverter and Z-source inverter as examples. This paper analyzes the working principle of the three-phase dual-step-down inverter, establishes its mathematical model and gives its decoupling control strategy, and introduces the space vector pulse width modulation method. The boost principle of Z-source inverter is analyzed. In this paper, the design principle of two kinds of inverter is studied, and the dead-time effect of bridge circuit is analyzed. The harmonic of three-phase bridge inverter with dead time and double step-down inverter without dead time are established respectively. Wave calculation model. The LCL filter is analyzed and studied, and the open-loop and closed-loop modified calculation models of THD are established. Aiming at the problem that the output side inductance of the three-phase dual-step-down topology bridge arm is more, the volume and weight of the bridge arm are too large. The coupling inductance is used to reduce the volume of the bridge arm. On the basis of this, the parameters of LCL filter are optimized. Finally, the 18kVA three-phase bridge and dual-step-down inverter principle prototype is designed and completed. The design of hardware and software is introduced, and the experiment is carried out on the platform of the prototype. The experimental results are in agreement with the theory and simulation analysis, and the correctness of the analysis is verified effectively.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM464

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