微型逆变器拓扑结构及效率特性的研究

发布时间：2018-04-13 17:17

本文选题：微型逆变器 + 拓扑结构　；参考：《长安大学》2014年硕士论文

【摘要】：传统的光伏发电系统是将光伏面板串、并联连接后由集中式逆变器将直流电转化为交流电，这种系统由于每块电池板存在着差异性和阴影遮挡等问题而导致发电效率不高和热斑等问题，为了解决上述问题，将每块光伏面板都与一个逆变器相连接，，这样就可以对每块面板进行最大功率点跟踪控制，从而大幅度提高整体效率，这种逆变器功率等级较低，称之为微型逆变器。本文首先介绍了微型逆变器的应用特点、性能要求及几种关键技术，然后对比研究了推挽串联谐振式电压型和推挽式电流型、反激式电压型和反激式电流型，分析了它们的工作原理及各自的优缺点，并对反激式和推挽式结构在功率解耦方面进行了讨论研究，为解决上述拓扑存在的问题，提出交错反激式和双向反激式微型逆变器拓扑结构，并分析了各自的优缺点。随后对提高微型逆变器效率的方法进行了分析，具体介绍了软开关技术和SiC功率器件的应用，其中通过计算了解了软开关的工作状态，然后通过SiC功率器件和Si功率器件耗损的对比，得出了SiC器件能够提高效率的结论。最后利用Pspice仿真软件对采用交错反激式结构和双反激结构及SiC功率器替换Si器件后件进行仿真，仿真结果理论计算和实际相对。
[Abstract]:The traditional photovoltaic power generation system is to connect the PV panel string in parallel and convert DC to AC from the centralized inverter.In order to solve the above problems, each PV panel is connected to an inverter because of the difference of each panel and the problems of shadow occlusion and so on, which lead to the low efficiency and heat spot of power generation, so as to solve the above problems, each photovoltaic panel is connected to an inverter.In this way, the maximum power point tracking control can be carried out on each panel, which greatly improves the overall efficiency. This inverter has a lower power level and is called a miniature inverter.In this paper, the application characteristics, performance requirements and several key technologies of micro inverter are introduced, then the push-pull series resonant voltage mode and push-pull current mode, flyback voltage mode and flyback current mode are compared and studied.Their working principles and their advantages and disadvantages are analyzed, and the power decoupling of flyback and push-pull structures is discussed.The topology of interleaved flyback and bidirectional flyback micro inverters is proposed, and their advantages and disadvantages are analyzed.Then the method of improving the efficiency of micro inverter is analyzed. The soft switching technology and the application of SiC power device are introduced in detail.Then, by comparing the consumption of SiC power device with Si power device, it is concluded that SiC device can improve the efficiency.Finally, the interleaved flyback structure and double flyback structure and SiC power device replacing Si device are simulated by Pspice simulation software. The simulation results are compared with the actual results.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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