单相光伏发电的并网控制研究--毕业论文.docVIP

【摘 要】 能源是国家经济发展以及人类赖以生存和发展的重要物质基础，在当今能源紧缺的时代背景下，太阳能光伏发电的研究具有非常重要的战略意义。随着电力电子技术的不断发展，建立大规模的光伏并网发电系统将会是太阳能利用的主要方式。基于此背景，本课题研究了单相光伏并网发电系统，对该系统中的光伏电池最大功率点跟踪(MPPT)、并网逆变作了分析与研究。 首先对单相光伏并网发电系统的几种不同结构进行了比较，确定了单相光伏并网系统的拓扑结构。 其次从光伏电池的等效模型出发，建立其数学模型。利用 Matlab/Simulink 建立光伏电池模型，仿真分析了光照强度的改变及温度的改变对其输出特性的影响。 然后分析比较了几种常规的最大功率跟踪（MPPT）方法，并采用扰动观察法通过控制Boost电路占空比实现光伏电池的最大功率跟踪控制。仿真表明模型对外界环境变化具有较好的适应性和良好的动态性能。 最后通过并网电流控制方式的分析和比较，研究实现了光伏发电并网运行控制策略的仿真模型，确定了控制器参数。建立了电网电压前馈补偿的SPWM电流跟踪控制模型，仿真验证了模型能够实现单位功率因数并网。 关键词：光伏发电；最大功率点跟踪；Boost变换器；逆变 【Abstract】 Energy is an important material foundation of the national economic development and human survival and development. In todays energy shortage under the background of the times, the solar photovoltaic research has very important strategy sense. The establishment of large-scale gird-connected PV systems will be the main way of using solar energy with the continuous development of power electronics technology. The single phase photovoltaic grid-connected generation system is researched in the paper. The system makes a profound analysis and research of photovoltaic maximum power point tracking (MPPT) and grid-connected inverter. Firstly, the topology of the system in the paper is determined by analyzing several different structures of the single-phase grid-connected PV systems. Secondly, the mathematical models of solar cell are established through the equivalent model of solar cell. MATLAB/Simulink is used to study the output characteristics of photovoltaic array under the conditions of the changes of light intensity and temperature and partial shadow. Thirdly, several conventional maximum power point tracking (MPPT) methods are analyzed and compared. Perturbation and Observation method (PO) is used to control the boost converter to realize the PV Maximum Power Point tracking (MPPT). The results of simulation show that the method has good adaptability according to external environmental changing and good dynamic performance. Finally, the simulat