带功率解耦微型光伏逆变器研究

发布时间：2018-06-14 18:46

本文选题：微型光伏逆变器 + 功率解耦　；参考：《北京交通大学》2014年硕士论文

【摘要】：摘要：随着对煤炭、天然气和石油等主要化石能源的大规模开采和使用,全球环境污染和能源问题日益突出,而太阳能是一种取之不尽、用之不竭的清洁能源,因此光伏发电应运而生,同时光伏并网逆变器也成为普遍的研究热点。近年来,为了提高逆变器的效率,降低成本,实现模块化,提出了微型光伏逆变器的概念,由于其结构简单,体积小,即插即用,易于扩展等,成为未来光伏逆变器的发展趋势之一。但是在单相光伏并网逆变器中由于输入输出瞬时功率存在差异,通常需要并联很大的电解电容来平衡这部分功率,由于电解电容寿命短,严重限制了逆变器的寿命,所以研究者提出在电路中加入功率解耦单元来处理瞬时脉动功率,从而用小容值的薄膜电容代替电解电容,提高逆变器寿命。本文从三端口电路的角度研究带功率解耦的微型光伏逆变器,其包括PV端口、AC端口、功率解耦端口三部分,并介绍构成各端口的基本单元,分析了电路的组合方式以及常见的几种拓扑；文中由一种简化的带功率解耦微型光伏逆变器入手,介绍其工作原理,并通过仿真和实验进行验证；但是由于功率解耦单元的加入,电路效率降低,同时对逆变器稳态性能产生影响,因此为了进一步研究这类拓扑的特性,本文又引入另外一种解耦电流减半的改进型带功率解耦微型光伏逆变器,详细介绍了主电路设计和损耗分析,并通过PSIM软件仿真验证其可行性,同时进行硬件电路设计,搭建一个100W的实验平台,进行实验验证。此外本文还采用三种方法对该改进型拓扑进行效率优化,最终使电路效率达到89.24%；最后,根据理论分析与实验结果对比总结该拓扑的优势,其通过改进电路结构,使解耦回路工作方式发生变化,解耦电流减半,大大提高微型光伏逆变器的稳态性能。
[Abstract]:Abstract: with the large-scale exploitation and use of major fossil energy sources such as coal, natural gas and petroleum, global environmental pollution and energy problems become increasingly prominent, and solar energy is an inexhaustible clean energy. Therefore, photovoltaic generation came into being, and photovoltaic grid-connected inverter has become a popular research hotspot. In recent years, in order to improve the efficiency of inverter, reduce the cost and realize modularization, the concept of miniature photovoltaic inverter is put forward, because of its simple structure, small size, plug and play, easy to expand, etc. It will become one of the development trends of photovoltaic inverter in the future. However, in single-phase photovoltaic grid-connected inverters, due to the difference of instantaneous power between input and output, it is usually necessary to balance this part of power with a large electrolytic capacitor in parallel. Because of the short life of electrolytic capacitance, the life of inverter is restricted seriously. So the researchers put forward to add power decoupling unit to deal with transient pulsating power, so that the electrolytic capacitance can be replaced by thin film capacitor with small capacitance, and the inverter life can be improved. In this paper, the miniature photovoltaic inverter with power decoupling is studied from the point of view of three-port circuit. It includes three parts of PV port AC port and power decoupling port, and introduces the basic unit of each port. The circuit combination mode and several common topologies are analyzed in this paper, a simplified miniature photovoltaic inverter with power decoupling is introduced, and its working principle is introduced, and verified by simulation and experiment. However, due to the addition of power decoupling unit, the circuit efficiency is reduced and the steady state performance of inverter is affected. Therefore, in order to further study the characteristics of this kind of topology, This paper also introduces another improved miniature photovoltaic inverter with power decoupling with half decoupling current. The main circuit design and loss analysis are introduced in detail. The feasibility is verified by PSIM software simulation, and the hardware circuit is designed at the same time. Build a 100 W experimental platform for experimental verification. In addition, this paper also uses three methods to optimize the efficiency of the improved topology, and finally makes the circuit efficiency up to 89.24. Finally, according to the theoretical analysis and experimental results, the advantages of the topology are summarized, and the circuit structure is improved. The working mode of decoupling circuit is changed, the decoupling current is halved, and the steady-state performance of miniature photovoltaic inverter is greatly improved.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

【参考文献】