单相光伏并网逆变器的拓扑设计与共模电压抑制技术研究

发布时间：2018-02-04 09:46

本文关键词： 单相逆变器光伏并网发电共模电压漏电流中点钳位电路　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：世界发展日新月异,同时,人类对能源的需求与日俱增,不同种类的能源受到世界各国学者的广泛关注,其中包括传统的化石能源、水能、核能等,但是化石能源属于非可再生能源,尽管其储量巨大,但是随着人类社会对化石这种不可再生燃料的过度贪婪,其储量也在逐年减小。所以,具有能够循环使用、不对环境造成污染等特点的新能源受到了各国的高度关注,新能源发电包括风力发电、光伏发电、潮汐能发电等等,这些发电类型不会对环境产生危害而且具有可持续发展的特点,能够持续不断的为人类提供能源的需求。其中光伏发电具有环保、使用过程中不对环境产生污染、应用价值较高而受到各国较为密切的关心。光伏发电的原理是把太阳光辐射的能量收集到光伏板上进行光生伏打的反应,在这个过程中能量被转换为直流电能,进而为人类提供各种形式的能源需求,由于在转换过程中不需要燃烧,所以较为环保。而且,太阳能的来源较为广泛,只要有充足太阳光辐射的地区,均可以进行太阳能发电。在太阳能光伏发电系统中,分为光伏板,逆变器,并网控制器等几部分,需要系统各模块的协同配合,才能提供符合要求的高质量电能,以供并网或者离网负载使用。在太阳能光伏发电系统中,光伏逆变器是将光伏板输出的直流电能转换为交流电的主要模块,逆变器具有各种各样的电路结构,它们各自有各自的特点,在这些电路拓扑中,不带隔离变压器的光伏逆变器具有其它结构不具有的特点:重量轻,占地面积小,损耗较低等等,非常适合于中等或者小功率负荷的场景。但是非隔离型光伏逆变器不具备电气隔绝的效果,会产生电路可靠性方面的问题,如共模漏电流较大,威胁人身设备的安全等,影响光伏逆变器的大规模推广,同时,在逆变器运行过程中也会由于开关误导通等原因有可能会使得一个桥臂电路上的开关均被错误打开,从而影响逆变器的安全运行。基于光伏并网逆变器漏电流以及可靠性等方面的问题,文章详细探究了非隔离型光伏并网逆变器单相拓扑结构的设计和改进,从逆变器拓扑角度考虑改善电路的共模特性并且提高电路运行的可靠性,从而减小逆变系统的整体共模漏电流水平,提高电路的可靠性和效率,最后通过仿真和实验验证了理论分析的正确性。
[Abstract]:The world is developing with each passing day, at the same time, the demand for energy is increasing day by day, different kinds of energy are widely concerned by scholars all over the world, including traditional fossil energy, water energy, nuclear energy and so on. But fossil energy is a non-renewable energy, although its reserves are huge, but with the excessive greed of the human society to fossil non-renewable fuel, its reserves are also decreasing year by year. Therefore, it has the ability to recycle. New energy sources, which do not cause pollution to the environment, are highly concerned by all countries. New energy generation includes wind power, photovoltaic power generation, tidal power generation and so on. These types of power generation are not harmful to the environment and have the characteristics of sustainable development, which can continuously provide energy for human needs. Among them, photovoltaic power generation is environmentally friendly. The principle of photovoltaic power generation is to collect the energy of solar radiation to photovoltaic panels for photovoltaic response. In this process, the energy is converted into direct current energy, which provides various forms of energy demand for human beings. Because there is no need to burn in the conversion process, it is more environmentally friendly. Moreover, the sources of solar energy are more extensive. As long as there is sufficient solar radiation, solar power generation can be carried out. In the solar photovoltaic power generation system, there are several parts, such as photovoltaic panel, inverter, grid-connected controller and so on, which need the cooperation of various modules of the system. In the solar photovoltaic system, the photovoltaic inverter is the main module to convert the direct current energy output from the photovoltaic panel to alternating current. Inverter has a variety of circuit structures, they have their own characteristics. In these circuit topologies, the photovoltaic inverter without isolation transformer has the characteristics that other structures do not have: light weight. Small area, low loss and so on, very suitable for medium or small power load scenarios. But the non-isolated photovoltaic inverter does not have the effect of electrical isolation, which will produce circuit reliability problems. Such as large common mode leakage current, threatening the safety of personal equipment, affecting the large-scale promotion of photovoltaic inverter, at the same time. During the operation of the inverter, it is possible that the switch on the bridge arm circuit will be turned on wrongly because of the misguided switch and so on. Based on the problems of leakage current and reliability of photovoltaic grid-connected inverter, this paper discusses the design and improvement of single-phase topology of non-isolated photovoltaic grid-connected inverter in detail. From the point of view of inverter topology, the common-mode characteristic of the circuit is improved and the reliability of the circuit is improved, thus reducing the level of the whole common-mode leakage current of the inverter system and improving the reliability and efficiency of the circuit. Finally, the correctness of the theoretical analysis is verified by simulation and experiment.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464;TM615

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