双级式单相光伏并网系统的研究

发布时间：2018-05-23 22:10

本文选题：最大功率点跟踪 + DC-DC变换器　；参考：《东北大学》2012年硕士论文

【摘要】：随着全球对能源需求的不断增长,传统能源迅速消耗引发的能源危机和环境污染问题已不容忽视,可再生能源开发和利用受到了普遍重视。其中,太阳能以其资源丰富、可再生、清洁无害等优点而备受青睐。近年来,太阳能发电技术的不断进步使得光伏电站逐渐具备大规模发电的能力,而光伏并网发电将成为太阳能利用的一个重要途径。因此,对光伏并网系统的研究与设计是具有实际意义的。本文主要以单相并网系统为研究对象,从并网系统的拓扑结构、参数的选择、最大功率点跟踪以及单相并网与有源滤波相结合的控制策略等方面对光伏并网系统作了详细的分析和研究。首先,利用MATLAB/Simulink仿真软件对光伏电池板的数学模型进行仿真分析,了解太阳能电池板的输出特性,分析太阳能电池板在光照和温度变化时对输出特性的影响,为最大功率点跟踪(MPPT)提供可行性的理论基础。在此基础上,研究了几种常用的最大功率点跟踪方法,并通过对这些方法的对比,对传统跟踪法进行了改进,减小了在寻优过程中出现误判断的概率。其次,针对小功率单相并网系统的特点,采用了体积小,成本低,易于控制的DC-DC升压电路和全桥式DC-AC逆变电路双极式主电路拓扑结构。通过理论分析和计算,对主电路中元器件进行了参数选择和硬件电路设计。此外,本文采用SPWM双闭环跟踪控制方式,结合电网电压前馈控制方案,实现并网电流与电网电压同步；同时用电压外环保证了母线电压的稳定。由于传统PI调节无法实现无差跟踪,作者采用ZPR(准比例谐振调节控制器)对系统进行改进,并通过MATLAB/Simulink仿真,验证了该控制策略的有效性。
[Abstract]:With the increasing of global energy demand, the energy crisis and environmental pollution caused by the rapid consumption of traditional energy can not be ignored, and the development and utilization of renewable energy have been paid more and more attention. Among them, solar energy is favored for its rich resources, renewable, clean and harmless. In recent years, with the continuous progress of solar power generation technology, photovoltaic power plants gradually have the capacity of large-scale power generation, and grid-connected photovoltaic power generation will become an important way to use solar energy. Therefore, the research and design of photovoltaic grid-connected system is of practical significance. This paper mainly takes single-phase grid-connected system as the research object, from the topology structure of grid-connected system, the choice of parameters, The photovoltaic grid-connected system is analyzed and studied in detail from the aspects of maximum power point tracking and the control strategy of the combination of single-phase grid-connected and active filter. First of all, the mathematical model of photovoltaic panel is simulated and analyzed by using MATLAB/Simulink simulation software to understand the output characteristics of solar panel, and analyze the influence of solar panel on the output characteristics when the light and temperature change. It provides a theoretical basis for the feasibility of maximum power point tracking (MPPT). On this basis, several commonly used maximum power point tracking methods are studied, and through the comparison of these methods, the traditional tracking method is improved to reduce the probability of misjudgment in the process of optimization. Secondly, according to the characteristics of single-phase grid-connected system with small power, DC-DC boost circuit with small volume, low cost and easy control, and bipolar main circuit topology of full-bridge DC-AC inverter circuit are adopted. Through theoretical analysis and calculation, the parameters of the main circuit and the hardware circuit design are selected. In addition, this paper adopts SPWM double closed-loop tracking control method, combined with the feedforward control scheme of grid voltage, to realize the synchronization of grid-connected current and grid voltage, and proves the stability of busbar voltage by using environmental protection outside voltage. Because the traditional Pi regulation can not realize the difference free tracking, the author uses ZPR (quasi-proportional resonance regulator) to improve the system, and verifies the effectiveness of the control strategy by MATLAB/Simulink simulation.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TM615

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