【作者】 雷家宁；

【导师】 粟时平；

【作者基本信息】 长沙理工大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 随着能源短缺与环境污染问题的日益突出,太阳能作为一种非常重要的可再生能源受到了广泛的关注。光伏并网发电是太阳能大规模开发利用的必然趋势,并网逆变器作为光伏列阵与电网连接的关键设备,对其进行研究具有重要的理论与实际意义。论文首先分析了国内外光伏发电的发展状况,光伏并网发电系统的主要并网方式,以及光伏发电并网逆变器的研究现状和发展趋势。论文深入分析了光伏并网发电系统的拓扑结构及其相关控制策略,在此基础上重点研究了光伏并网发电系统主电路的拓扑结构,光伏阵列最大功率点跟踪(MPPT)控制和并网逆变器输出控制,深入探讨了光伏阵列MPPT控制的扰动观察法控制技术和并网逆变器输出控制的滑模控制技术,提出了光伏并网发电系统主电路的两级拓扑结构、光伏阵列扰动观察法控制的变步长改进方法以及并网逆变器滑模控制的指数趋近律改进方法。论文在进行详细的理论研究的基础上,设计了的25kWp光伏并网发电系统。在系统设计中,主电路的可控元件采用了性能优越的IGBT器件,控制电路采用了性能先进的浮点DSP微控制器芯片,先进的IGBT器件和浮点DSP芯片以及光伏阵列改进扰动观察法、并网逆变器改进滑模控制方法的使用为研制出高效光伏并网发电系统提供了坚实的技术和物质基础。然后,论文为了验证所研究理论方法的正确性,使用MATLAB/Simulink进行了光伏并网发电系统仿真,并给出了详细的仿真模型和仿真结果。仿真结果证明所研究的改进扰动观察法能够很好地实现光伏列阵的MPPT控制,改进型滑模控制方法能够很好地实现并网逆变器输出的快速、稳定和高精度控制。论文通过对光伏并网发电系统所涉及的理论和实现技术进行了系统性研究,在光伏阵列MPPT控制和并网逆变器输出控制等领域提出了新的有效的理论方法与实现技术,较好地解决了光伏并网发电系统的理论和技术瓶颈,为促进光伏并网发电的发展提供了很好的理论与技术支持。更多还原

【Abstract】 With the problems of energy shortage and environmental pollution have become more and more prominent, solar energy, as one kind of important renewable energy, receives widespread attention. Grid-connected photovoltaic system is the inevitable trend of large-scale use of solar energy. Grid-connected inverter is the main equipment between PV array and grid, so studies of its main circuit topology and control strategy have important practical significance.First of all, a survey is made on the development of photovoltaic power generation at home and abroad, as well as the major ways of connection between photovoltaic power generation and grid. Research state of output current control of grid-connected inverter is also summarized.Secondly, the paper analyses the topology structure and control strategy of grid-connected photovoltaic power system. In the thesis, the principle of the system is analyzed, maximum power point tracking (MPPT) control of photovoltaic arrays and output control of grid-connected inverter are also studied. After in-depth studies of perturbation and observation method and sliding mode control, which respectively implement MPPT control of photovoltaic arrays and real-time output control of grid-connected inverter, provements are made to them. For the perturbation and observation method, variable step size is adopted. For the sliding mode control, its index reaching law is improved.Based on the detailed theoretical studies above, the paper designs a 25kWp grid-connected photovoltaic power system. In the design, IGBT devices with better performance are used as the switch components of the main circuit, and advanced floating-point DSP is used as the chip of control circuit. These devices, along with the improved perturbation and observation method and sliding mode control method, provide a solid technology and material foundation for setting up the system.Then, to improve the correctness of the theoretical methods which are proposed above, simulations are performed by MATLAB software. Simulation results show that the improved perturbation and observation method can well implement the MPPT control of photovoltaic arrays, improved sliding mode control also can carry out the fast, stable and high precision control of grid-connected inverter.Thought studies on the theory and implementation techniques related to the grid-connected photovoltaic power system, the paper puts forward new and effective methods and its realization in the field of MPPT control of photovoltaic arrays and output control of grid-connected inverter. These work do well to solve the theoretical and technical problems of grid-connected photovoltaic power system, and provide a good theoretical support for promoting the development of photovoltaic power generation.更多还原