用于光伏并网发电系统的级联准Z源逆变器研究
发布时间：2018-07-15 13:13
【摘要】：摘要：由传统化石能源发电带来的能源危机和环境污染问题迫在眉睫,可再生能源发电的出现缓和了人类的燃眉之急,其中最具发展潜力的光伏发电备受关注,而逆变器作为整个光伏系统的核心部件一直是学术界研究的焦点。针对光伏并网发电系统中光伏电池利用率低、并网电流谐波含量高等问题,改进逆变器拓扑是行之有效的解决办法。在已有的逆变器拓扑中,级联准Z源逆变器拓扑具有优越的性能,它结合了级联多电平输出和准Z源直通升压的优点,能提高光伏并网系统的发电效率和并网电能的质量。 论文以级联准Z源逆变器为研究对象,并将其应用于光伏并网发电系统,在分析了基于级联准Z源逆变器的光伏并网发电系统的结构以及工作机理后,根据电路结构以及控制目标提出了适用于该系统的主从控制策略。为实现系统的可靠稳定高效运行,整个控制系统采用了多个闭环控制,包括光伏电池电压输入环、直流母线电压环和并网电流环,分别实现光伏电池板的最大功率点跟踪、各级联单元母线电压的均衡和单位功率因素并网,且在分析了各个闭环控制原理的基础上对各控制环的调节器参数进行了设计。另外,对载波移相调制(C PS-SPWM)方法进行了改进,提出了针对于级联准Z源逆变器拓扑的改进型载波移相调制,使得逆变器输出多电平波形从而提高并网电能质量。 论文在MATLAB/SIMULINK环境下搭建了基于级联准Z源逆变器的光伏并网发电系统仿真模型,并对不同仿真条件下的仿真结果进行对比分析,结果证明了论文的理论分析以及所提控制策略的正确性与有效性。图86幅,表5个,参考文献68篇。
[Abstract]:Abstract: the energy crisis and environmental pollution caused by traditional fossil energy power generation are imminent. The emergence of renewable energy power generation has alleviated the urgent needs of human beings, among which photovoltaic power generation, which has the most potential development, has attracted much attention. The inverter as the core component of the whole photovoltaic system has been the focus of academic research. To solve the problems of low utilization rate of photovoltaic cells and high harmonic content of grid-connected current in photovoltaic grid-connected generation system, improving inverter topology is an effective solution. Among the existing inverter topologies, the cascaded quasi-Z-source inverter topology has excellent performance. It combines the advantages of cascaded multilevel output and quasi-Z-source direct-pass boost, and can improve the efficiency of photovoltaic grid-connected system and the quality of grid-connected power. This paper takes the cascaded quasi-Z source inverter as the research object and applies it to the photovoltaic grid-connected generation system. After analyzing the structure and working mechanism of the photovoltaic grid-connected generation system based on the cascaded quasi-Z-source inverter. According to the circuit structure and the control target, the master-slave control strategy suitable for the system is proposed. In order to realize the reliable, stable and efficient operation of the system, the whole control system adopts several closed-loop controls, including the PV cell voltage input loop, the DC bus voltage loop and the grid-connected current loop, respectively to realize the maximum power point tracking of the photovoltaic panel. The voltage equalization and the unit power factor are connected to the grid. Based on the analysis of each closed-loop control principle, the regulator parameters of each control loop are designed. In addition, the carrier phase shift modulation (CPS-SPWM) method is improved, and an improved carrier phase shift modulation for cascaded quasi-Z-source inverter topology is proposed, which makes the inverter output multilevel waveform and improve the power quality of grid-connected power. In this paper, the simulation model of photovoltaic grid-connected generation system based on cascaded quasi-Z-source inverter is built in MATLAB / Simulink environment, and the simulation results under different simulation conditions are compared and analyzed. The results show that the theoretical analysis and the proposed control strategy are correct and effective. There are 86 pictures, 5 tables and 68 references.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464
本文编号：2124187
[Abstract]:Abstract: the energy crisis and environmental pollution caused by traditional fossil energy power generation are imminent. The emergence of renewable energy power generation has alleviated the urgent needs of human beings, among which photovoltaic power generation, which has the most potential development, has attracted much attention. The inverter as the core component of the whole photovoltaic system has been the focus of academic research. To solve the problems of low utilization rate of photovoltaic cells and high harmonic content of grid-connected current in photovoltaic grid-connected generation system, improving inverter topology is an effective solution. Among the existing inverter topologies, the cascaded quasi-Z-source inverter topology has excellent performance. It combines the advantages of cascaded multilevel output and quasi-Z-source direct-pass boost, and can improve the efficiency of photovoltaic grid-connected system and the quality of grid-connected power. This paper takes the cascaded quasi-Z source inverter as the research object and applies it to the photovoltaic grid-connected generation system. After analyzing the structure and working mechanism of the photovoltaic grid-connected generation system based on the cascaded quasi-Z-source inverter. According to the circuit structure and the control target, the master-slave control strategy suitable for the system is proposed. In order to realize the reliable, stable and efficient operation of the system, the whole control system adopts several closed-loop controls, including the PV cell voltage input loop, the DC bus voltage loop and the grid-connected current loop, respectively to realize the maximum power point tracking of the photovoltaic panel. The voltage equalization and the unit power factor are connected to the grid. Based on the analysis of each closed-loop control principle, the regulator parameters of each control loop are designed. In addition, the carrier phase shift modulation (CPS-SPWM) method is improved, and an improved carrier phase shift modulation for cascaded quasi-Z-source inverter topology is proposed, which makes the inverter output multilevel waveform and improve the power quality of grid-connected power. In this paper, the simulation model of photovoltaic grid-connected generation system based on cascaded quasi-Z-source inverter is built in MATLAB / Simulink environment, and the simulation results under different simulation conditions are compared and analyzed. The results show that the theoretical analysis and the proposed control strategy are correct and effective. There are 86 pictures, 5 tables and 68 references.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464
【参考文献】
相关博士学位论文 前1条
1 赵清林;准单级高频链逆变电源控制及并网技术研究[D];燕山大学;2006年
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