【作者】 王晓东；

【导师】 李岚；

【作者基本信息】 太原理工大学 ， 电气工程及其自动化， 2012， 硕士

【摘要】 能源危机和日益严峻的环境污染已经深深困扰了人类前进的步伐,成为了最迫切需要解决的世界性问题。风能、太阳能、生物能等新型的清洁能源因其无可比拟的优势而逐渐受到各国的共同关注,太阳能发电被公认是一种最具有潜力的新型替代能源。可以预料,在不久的将来,太阳能很快将会在基础型能源供应中占有相当重要的地位。太阳能发电技术就是通过光电效应由光伏电池板将太阳光转换成为电能的技术,而太阳能光伏并网发电系统则是需要将太阳能转换成为符合大电网并入要求的交流电,然后接入大电网实现并网发电运行。目前太阳能光伏并网发电系统的关键技术主要包括太阳能电池板效率、最大功率追踪和并网逆变几个方面,而并网逆变技术则是整个系统的核心技术。由于目前国内研究比较热门的为两级式光伏并网发电系统结构,因此本文针对该结构类型系统的后级并网逆变部分进行了如下研究：首先,对当前国内外太阳能光伏发电的发展形势进行了论述,指出了我国研究光伏并网发电技术的意义和优势,介绍了光伏并网发电系统的类型和并网发电技术指标。建立了两级式光伏并网发电系统的并网逆变器在不同坐标系下的数学模型,然后对基于电网电压空间矢量定向的并网控制策略进行了详细的推导与分析,为后续的并网控制实验提供了理论依据。比较了几种电网电压定向的实现方法,并确定采用基于电网电压过零点检测的硬件定向方案。介绍了光伏并网发电系统最大功率输出的能量关系以及并网电流的指令获取。在对逆变器开关管的脉冲宽度调制上采用了SVPWM调制技术,给出了在DSP控制器上实现软件方法SVPWM调制的具体步骤。在实验系统的设计方面,搭建了两级式光伏并网发电系统的后级并网逆变的硬件实验平台。介绍了以TMS320F2812为控制器的硬件平台构成,包括对主功率模块、驱动电路、保护电路及过零点检测电路的设计原理分析。按照系统控制策略实现算法设计编写了软件程序系统的主程序、中断子程序以及各个功能子模块程序,为实验平台调试提供了硬件和软件支持。在所设计的系统实验平台上进行了软、硬件系统调试,完成了独立系统实验和部分并网实验,采集了实验波形。通过对实验结果的分析可以看到,本文所采用的控制策略及程序编写是正确的,硬件系统能够可靠运行,为后续的进一步实验奠定了坚实基础。更多还原

【Abstract】 Energy crisis and the increasingly serious problem of environmental pollution have perplexed the pace of human progress, and have became the most serious and urgent global problem. The new kinds of clean energy such as wind energy, solar energy, bio-energy and so on are widely focused because of their incomparable advantages. Solar energy has been recognized as the most potential type of substituted energy, we may expect, in the near future, solar energy will hold an important position in the basic energy supplies.Solar energy generation technology is based on photoelectric effect, by the PV panels, sunlight is converted into electricity. Solar photovoltaic power generation system convert solar energy to AC electricity that meets the grid requirements, and access to the large grid realize grid-connected operation. Recently, the key techniques of solar photovoltaic power generation system mainly include several aspects:efficiency of solar panels, maximum power point tracking and the control of grid-connected inverter. Grid-connected inverter technology is the core of the whole system. Nowadays, popular research in our country is two-stage PV grid-connected power generation system. In this paper, grid-connected inverter of this structure system is researched as follows:Firstly, The development of current situation about solar photovoltaic power generation at home and abroad is discussed, The significance and advantage of China’s photovoltaic power generation technology are pointed out, types of grid-connected PV systems and the grid-connected technology standard are introduced. Secondly, the mathematical model of grid-connected inverter of two-stage PV grid-connected power generation system in different coordinates is established. Control strategy of grid-connecting based on the grid voltage space vector is extracted and analyzed detailed, provided theoretical support for the following grid-connecting control experiments. Several grid voltage orientation methods are compared, and then the hardware method that is based on the grid voltage zero crossing detection is used. The maximum power output and the obtaining method of the reference current in grid-connected PV system are introduced. Finally, SVPWM modulation technology is used in pulse width modulation of the inverter, the concrete steps of software method of SVPWM modulation in the DSP controller is given.In the experimental design, hardware experimental platform of the grid-connected inverter system is built, the compositions of hardware platform based on TMS320F2812includes power module, driving circuit, protection circuit and zero-crossing detection circuit, and design principles are introduced. Main program, interrupt subroutine, various sub-module programs are prepared according to control strategy algorithm. Better hardware and software support are provided for the following experiments.In this paper, software and hardware system have debugged on the designed experimental platform. Completed the independent experiments and some grid-connecting experiments, collected the waveforms of experiments. Through analysis the experimental results we can see, control strategies and procedures that used in the paper are right, hardware system can work reliably, these laid a foundation for the further experiments.更多还原