两级式光伏并网逆变器混沌行为分析及其控制研究

发布时间：2018-09-19 13:12

【摘要】：太阳能光伏发电,简称太阳能光电,是利用太阳电池将太阳能直接转化为电能的发电方式,也是现阶段对太阳能进行合理利用的一种重要形式。作为最具潜力的“未来能源”,太阳能光伏技术成为各国研究的焦点。光伏并网逆变器(Photovoltaic grid-connected inverter,简写PVGCI)作为整个能量装换系统的重要组成部分,其稳定性显得格外重要。因此,研究并网逆变器中的混沌行为并同时给出有针对性的混沌保护控制策略,对电网的安全稳定运行具有十分重要的意义。本文针对两级式光伏逆变系统中的分岔、混沌行为进行了相关的分析和研究,具体工作概括如下:(1)分析了本课题的研究背景与意义,对国内外的混沌控制和电力电子变换器混沌控制研究现状进行了综述,进一步指出本课题的研究意义,给出本课题的研究目标与内容。(2)在研究PVGCI主电路拓扑构造及其工作原理的基础上,根据KVL、KCL建立PVGCI的状态方程。并对PVGCI的混沌现象进行研究和分析,确定产生混沌行为的条件和出现混沌行为时的参数阈值。(3)根据PVGCI状态方程参数较多,构造比较复杂这一特点,基于改善状态关联性理论设计混沌控制器,实现对PVGCI的混沌控制。该控制策略只改变状态变量关联系数,优点是控制量比较少,设计直接简便易于实现。(4)基于状态反馈和参数扰动方法设计控制器,通过给相关的状态变量加入状态反馈,实现了对PVGCI混沌行为的控制,同时能够使输出并网电流的频率、相位与公共电网达到同步状态。由于该控制策略属于闭环控制,受系统内部参数影响较小,在对系统进行控制的过程中具有较好的鲁棒性,不需要事先设定预期控制目标,就能够达到期望控制效果。(5)基于LaSalle不变集定理设计控制器,对PVGCI的混沌行为进行控制。该控制策略不必提前知道平衡点的位置,同时也不需要相关系统状态变量以外的任何有关被控系统的信息,系统原有的结构也不需要做出改变,就能够实现对系统的控制。根据该控制策略设计的控制器的设计简单,易于实现和控制。最后,对本文的研究进行总结并指出接下来工作主要方向。
[Abstract]:Solar photovoltaic power generation, referred to as solar photovoltaic, is the use of solar cells to directly convert solar energy into electricity generation mode, but also is an important form of reasonable use of solar energy at this stage. As the most potential "future energy", solar photovoltaic technology has become the focus of research around the world. Photovoltaic grid-connected inverter (Photovoltaic grid-connected inverter, PVGCI) as an important part of the whole energy switching system, its stability is particularly important. Therefore, it is of great significance to study the chaotic behavior of grid-connected inverter and to give the corresponding chaotic protection and control strategy for the safe and stable operation of power grid. In this paper, the bifurcation and chaotic behavior of two-stage photovoltaic inverter system are analyzed and studied. The specific work is summarized as follows: (1) the research background and significance of this subject are analyzed. The research status of chaos control and power electronic converter at home and abroad is summarized, and the significance of this research is pointed out. The research objectives and contents of this paper are given. (2) on the basis of studying the topology construction and working principle of PVGCI main circuit, the state equation of PVGCI is established according to KVL,KCL. The chaotic phenomena of PVGCI are studied and analyzed, and the conditions for the chaotic behavior and the threshold of the chaotic behavior are determined. (3) according to the characteristics of the PVGCI equation of state with more parameters, the structure is more complicated. Chaotic controller is designed based on improved state correlation theory to control chaos in PVGCI. This control strategy only changes the correlation coefficient of state variables, which has the advantages of less control quantity, simple and easy design. (4) based on the method of state feedback and parameter perturbation, the controller is designed by adding state feedback to the relevant state variables. The chaotic behavior of PVGCI is controlled, and the frequency and phase of the output grid-connected current are synchronized with the public power grid. Because the control strategy belongs to the closed-loop control and is less affected by the internal parameters of the system, it has good robustness in the process of controlling the system, and it does not need to set the expected control target in advance. The desired control effect can be achieved. (5) based on the LaSalle invariant set theorem, a controller is designed to control the chaotic behavior of PVGCI. The control strategy does not need to know the position of the equilibrium point in advance, and also does not need any information about the controlled system other than the related system state variables, and the original structure of the system does not need to be changed, so the control of the system can be realized. The controller designed according to the control strategy is simple and easy to realize and control. Finally, this paper summarizes the research and points out the main direction of the next work.
【学位授予单位】：广西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM464

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