基于新型H6拓扑的市电互补光储变流器及其控制策略研究

发布时间：2018-02-13 23:16

本文关键词： 光伏发电市电互补变流器漏电流 H6拓扑　出处：《安徽大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,由于新能源产业的发展和世界各国政策的支持,光伏发电得到了快速的发展。光伏发电由于清洁无污染、建设成本低、获取便捷等优点,已被广泛应用于分布式发电系统中。目前,一些偏远山区的电网接入仍不稳定,时常出现电网断电或者异常的情况,不仅对当地的居民生活造成不便,还会造成电气设备的损坏。本文设计了一种基于新型H6拓扑的市电互补光储变流器,不仅避免了电网断电或异常导致的电气设备无法使用或损坏的问题,而且消除了共模电压的脉动从而有效抑制了漏电流。基于新型H6拓扑的市电互补光储变流器采用两级式非隔离结构,前级采用两路并联的Buck变换器,实现直流侧光伏电池的降压充电功能以及光伏最大功率点跟踪控制;后级采用Buck/Boost变换器和新型H6拓扑,完成系统的整流和逆变功能。基于提出的新型H6拓扑提出了对应的调制策略,该调制策略改变了拓扑的续流电流路径,使得续流电流只经过MOS管,不经过通态损耗较大的体二极管,从而减小了器件的通态损耗和完全消除了二极管的反向恢复损耗,提高了变流器的工作效率。本文首先对新型市电互补光储变流器的控制策略进行了分析和比较,并对系统的各个部分进行设计,包括DC/DC、DC/AC及滤波部分等。系统采用TMS320F28335芯片进行软件控制,包括MPPT控制、蓄电池充电控制、直流母线稳压控制及逆变器整流逆变控制等。基于本文的理论研究,研制了一套5kVA市电互补光储变流器实验样机,并进行了各项性能指标的测试。实验结果表明,采用本文的系统设计和控制策略能够有效地抑制漏电流,并且系统的工作效率也大幅提高。
[Abstract]:In recent years, photovoltaic power generation has been developing rapidly because of the development of new energy industry and the support of policies around the world. Photovoltaic power generation has the advantages of clean and pollution-free, low construction cost, convenient access and so on. It has been widely used in distributed power generation systems. At present, access to power grids in some remote mountainous areas is still unstable, and power grids are often cut off or abnormal, causing inconvenience not only to the lives of local residents, but also to local residents. In this paper, a new H6 topology based complementary optical storage converter is designed, which can not only avoid the problem that the electrical equipment can not be used or damaged due to the power failure or abnormal power loss. Moreover, the pulse of common-mode voltage is eliminated and the leakage current is effectively suppressed. Based on the new H6 topology, the complementary optical storage converter adopts a two-stage non-isolated structure, and the front stage uses a two-channel parallel Buck converter. The DC side photovoltaic cell has the function of voltage down charging and the tracking control of photovoltaic maximum power point. The rear stage adopts Buck/Boost converter and a new H6 topology. Based on the proposed new H6 topology, the corresponding modulation strategy is proposed. The modulation strategy changes the current path of the topology and makes the current only pass through the MOS tube. The on-state loss of the device is reduced and the reverse recovery loss of the diode is completely eliminated without passing through the bulk diode with high on-state loss. In this paper, the control strategy of the new complementary optical storage converter is analyzed and compared, and each part of the system is designed. The system uses TMS320F28335 chip for software control, including MPPT control, battery charging control, DC bus voltage control and inverter rectifier inverter control. An experimental prototype of 5kVA complementary optical storage converter is developed, and various performance indexes are tested. The experimental results show that the leakage current can be effectively suppressed by the system design and control strategy in this paper. And the work efficiency of the system is also greatly improved.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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