基于软开关技术的微功率光伏逆变器

发布时间：2019-06-22 12:46

【摘要】：光伏逆变器是利用太阳能源的主要设备之一,在绿色能源越来越受到重视的当今社会,得到了迅速发展。微逆变器不同于占地面积巨大的集中式光伏电站,具有抗局部阴影能力强、可分布式安装就地并网等特点,得到了广泛关注。本文通过对微型逆变器结构进行分析,选用了新颖的Boost半桥拓扑和两极式、带隔离结构的设计方案对微型光伏并网逆变器进行设计。本文对两极式光伏并网逆变器中核心部件直流升压部分进行了较为深入的分析研究。首先,以Boost半桥电路为研究对象,分析了拓扑的工作原理。对软开关的实现进行了理论推导和仿真验证,并设计了利用漏感谐振的磁集成变压器,有效的减小了开关损耗。其次,为了提高光电转换效率,在分析比较四大常用最大功率追踪方法的基础上,提出了一种新的MPPT控制算法,在动态响应速度和稳态精度上都得到了很大的改善。然后,设计了基于无差拍的电压前馈补偿逆变控制器,保持了无差拍控制算法的良好动态性能,同时也增强了系统的鲁棒性。根据系统的整体设计方案,本文最后给出了系统中重要参数的计算,以及辅助电路、控制电路和软件的设计和选择。对拓扑和控制方式进行了仿真检验,在仿真的结果基础上,试制了直流升压部分的原理样机进行了验证试验,实验结果验证了本文所提方法的有效性和可行性。
[Abstract]:Photovoltaic inverter is one of the main equipment to use solar energy. In today's society, which has been paid more and more attention to green energy, photovoltaic inverter has been developed rapidly. Different from the centralized photovoltaic power station, which occupies a large area, the micro-inverter has the characteristics of strong anti-local shadow ability and distributed installation of local grid-connected power station, which has been widely concerned. In this paper, based on the analysis of the structure of micro inverter, a novel Boost half-bridge topology and two-pole, with isolation structure are selected to design the micro photovoltaic grid-connected inverter. In this paper, the DC boost part of the two-pole photovoltaic grid-connected inverter is analyzed and studied in detail. Firstly, taking Boost half-bridge circuit as the research object, the working principle of topology is analyzed. The realization of soft switch is theoretically deduced and verified by simulation, and a magnetic integrated transformer using leakage inductance resonance is designed, which effectively reduces the switching loss. Secondly, in order to improve the photoelectric conversion efficiency, based on the analysis and comparison of the four commonly used maximum power tracking methods, a new MPPT control algorithm is proposed, which has been greatly improved in dynamic response speed and steady-state accuracy. Then, a voltage feedforward compensation inverter controller based on deadbeat is designed, which maintains the good dynamic performance of the deadbeat control algorithm and enhances the robustness of the system. According to the overall design scheme of the system, the calculation of important parameters in the system, as well as the design and selection of auxiliary circuit, control circuit and software are given at the end of this paper. The topology and control mode are simulated and tested. On the basis of the simulation results, the prototype of DC boost part is tested, and the experimental results verify the effectiveness and feasibility of the method proposed in this paper.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464;TM615

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