双向光伏微型逆变器的研究

发布时间：2018-11-07 19:35

【摘要】：鉴于我国面临严峻的能源局面以及传统能源发电方式给生产生活和生态环境带来负面影响,国家积极推进新能源发电。光伏微型逆变器由于具备稳定可靠、配置灵活、高效清洁等优点而备受人们关注。增加蓄电池模块的微型逆变器有效减小了天气因素对逆变器工作可靠性的影响,提高了光伏电池板的能量利用率。本文以此为切入点,对光伏微型逆变器展开了研究。第一,对单纯并离网模式的微型逆变器(本文简称传统微型逆变器)的工作模式进行分析。首先对反激电路进行数学建模,并在并网模式下引入了最大功率跟踪(Maximum Power Point Tracking,MPPT)技术。为了实现无差跟踪并网正弦电流,本文引入了自适应谐振控制器。然后在并离网模式下,分别对电网部分和负载部分的控制器进行设计,并通过仿真对控制效果进行验证。第二,为了解决微型逆变器存在光伏板能量利用率低的问题,本文对在传统微型逆变器的基础上增设蓄电池模块进行了着重介绍。设计了一种双向DC/DC电路,并对单向反激电路、逆变电路等拓扑进行改进,新型的双向反激电路、双向DC-AC电路使得能量能在微逆电路和蓄电池电路中双向传递。搭建升压斩波电路和降压斩波电路的数学模型,并对改进后的微型逆变器在不同光照情况下的工作模式进行分析,然后在并离网模式下,对蓄电池部分的控制器分别进行设计,并在仿真中对四种工作模式的控制效果进行验证。第三,由于微型逆变器的输出功率只有几百瓦,为提高系统效率,需尽可能降低系统的硬件损耗,因此本文对主功率板各元器件的参数进行了严格设计。在分析硬件元器件工作特性的同时,对电路各部分的损耗进行数学建模,采用控制变量法。当系统工作频率或输入功率发生变化时,比较系统在不同反激电路拓扑下产生的损耗,并搭建实验平台,对系统效率进行测验,选择最优工作拓扑。第四,搭建250W光伏微型逆变器物理实验平台,对新型工作模式下的控制方法及输出波形进行验证。
[Abstract]:In view of the severe energy situation in China and the negative impact of traditional energy generation on production, living and ecological environment, the country actively promotes new energy generation. Photovoltaic miniature inverters have attracted much attention because of their advantages such as stability, reliability, flexible configuration, high efficiency and cleanliness. Increasing the miniature inverter of battery module can effectively reduce the influence of weather factors on the reliability of the inverter and improve the energy utilization ratio of photovoltaic panels. In this paper, the photovoltaic miniature inverter is studied. Firstly, the working mode of simple parallel-off-grid miniature inverter (traditional miniature inverter) is analyzed. Firstly, the mathematical model of flyback circuit is established, and the maximum power tracking (Maximum Power Point Tracking,MPPT) technique is introduced in grid-connected mode. In order to realize the sinusoidal current without difference tracking, an adaptive resonant controller is introduced in this paper. Then the controller of the power system and the load part are designed in parallel and off-grid mode, and the control effect is verified by simulation. Secondly, in order to solve the problem of low energy utilization of photovoltaic panels in miniature inverters, this paper mainly introduces the addition of battery modules on the basis of traditional miniature inverters. A bidirectional DC/DC circuit is designed, and the topology of unidirectional flyback circuit and inverter circuit is improved. The new bi-directional flyback circuit and bidirectional DC-AC circuit make the energy can be transferred bidirectionally in micro-inverse circuit and battery circuit. The mathematical models of the boost chopper circuit and the step-down chopper circuit are built, and the operation modes of the improved miniature inverter under different illumination conditions are analyzed. Then, the controller of the battery part is designed separately in the parallel off-grid mode. The control effect of the four working modes is verified in the simulation. Thirdly, because the output power of the miniature inverter is only several hundred watts, in order to improve the system efficiency, the hardware loss of the system should be reduced as much as possible, so the parameters of each component of the main power board are strictly designed in this paper. At the same time, the loss of each part of the circuit is modeled by the control variable method. When the operating frequency or input power of the system changes, the losses of the system under different flyback circuit topologies are compared, and an experimental platform is built to test the system efficiency and select the optimal working topology. Fourthly, the physical experiment platform of 250 W photovoltaic miniature inverter is built to verify the control method and output waveform in the new mode.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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