光伏发电系统最大功率追踪控制研究
时间:2018-05-05 21:30 来源:毕业论文 作者:毕业论文 点击:次
| 摘要能源的利用方式反映了一个国家和社会的文明程度，因此，能源问题一直都是社会发展的焦点。然而，随着经济的快速发展，人类对能源的需求量越来越大，传统能源面临着日益枯竭的困境以及大量使用化石能源所带来的严重环境问题，使得世界各国将目光转向了新能源领域。太阳能以其洁净、储量巨大、分布广泛等优点而倍受青睐，成为公认的理想能源替代形式。太阳能光伏发电作为一种有效的太阳能利用方式，得到了广泛的关注，取得了快速的发展。但是，光伏阵列的转换效率比较低、成本比较高、输出特性容易受到环境因素的影响，这些问题都制约着光伏发电的进一步推广和发展，因此，研究光伏发电系统的最大功率点追踪控制技术，对于提高光伏发电系统利用太阳能的效率，具有重要的意义。本文首先介绍光伏电池的物理原理及输出特性。因为光伏电池的工作点容易受到外界环境条件的影响，这将会导致光伏发电系统输出功率的损失，因此必须对光伏阵列进行最大功率点的追踪控制，保证其始终处于最佳工作点上。目前，常用的研究光伏阵列最大功率点追踪控制的方法有很多，主要有扰动观察法和电导增量法等。本文详细地介绍了扰动观察法，并研究了它的原理及工作过程，还对其存在的振荡问题和误判问题进行了分析；提出用一种新的变步长扰动观察法对光伏阵列进行最大功率点追踪控制，系统地介绍了其设计思路和追踪过程；然后通过 Matlab 软件进行模拟仿真，并在相同的外界环境条件下，与传统的定步长扰动观察法进行实验比较和分析；最后，实验验证了该方法在追踪最大功率点、提高系统的输出效率上是有效的。22276 毕业论文关键词 光伏阵列 最大功率点 扰动观察法 定步长 变步长 Title Maximum Power Point Tracking Control of PV Systems Abstract Energy utilization ways reflect the degree of civilization of a society, therefore, the energy problem has always been the focus of the social development. However, with the development of economic, the demand for energy is growing, the traditional energy sources dried up and the increasingly serious environmental problems, make the world turned to the new energy sector. The solar energy with its clean, widely distributed, and huge reserves, recognized as an ideal alternative energy sources. Photovoltaic solar energy, as a kind of effective way of solar energy utilization, has been rapid development. But the conversion efficiency of PV arrays is low, the cost is relatively high, the output characteristics easily affected by environmental factors, all these problems restrict the further promotion and development of photovoltaic power generation, as a result, studied PV system maximum power point tracking control for improving efficiency of PV systems has important theoretical and practical significance. This paper deeply studies and analyzes the physical principle and output characteristics of photovoltaic cells. Because the operating point of the photovoltaic cell susceptible to external environmental conditions, which will result in a loss of the photovoltaic power system, therefore the PV array must be controlled by the maximum power point tracking system, to ensure that it is always in the optimum operating point. At present, the commonly used method of PV array maximum power point tracking control hasa lot of, mainly has Perturbation and Observation method, incremental conductance method, the parasitic capacitance method and fuzzy control method, etc. This paper describes in detail the Perturbation and Observation method and study its principles and working process, but also its oscillation problems and false problems were analyzed, then paper (责任编辑：qin) |