为了解决常规能源引发的问题，新能源的开发越来越受到关注，太阳能因其独特的优势得到了人们的青睐。近几年来各国纷纷出台优惠政策推动国内太阳能产业的发展，希望能够在太阳能行业占据主导地位，这使得太阳能发电技术成为一个全球性的课题，本文研究的重点是太阳能并网技术。 首先，本文对太阳能电池的结构及其输出特性进行了分析。为了能够充分发挥太阳能电池的光电转化能力，本文采用了最大功率点追踪技术。本文按照太阳能电池的实际等效电路，在MATLAB下搭建了太阳能电池模型，并对其输出特性曲线进行了仿真。在升压电路的基础上运用扰动观察法和改进后的电导增量法分别对建模的太阳能电池板进行了最大功率追踪仿真。 其次，研究了光伏并网逆变器的类型和控制策略。从系统的动态响应和稳定性方面考虑，本文选择了电压输入电流输出的非隔离型两级式逆变器。为了使并网电流能够很好的跟踪电网电压的相位，必须要消除并网电流与指令电流之间的偏差，因此本文设计的并网逆变器采用的是改进型固定开关频率控制策略。为了缓和开关频率和开关损耗之间的矛盾，本文采用倍频式SPWM技术对逆变器进行控制。 然后，为了保证直流采样过程的准确性，本文采用了去极值求平均法的软件滤波方式。软件锁相环的应用使得系统的响应速度加快，并减少了硬件电路的设计。 最后，在MATLAB下搭建了系统的仿真模型验证了本文所设计的光伏并网发电系统的正确性，通过实验平台也做了部分硬件电路并给出了测试结果。

In order to solve the problems caused by conventional energy , new energy, especially solar energy development attracted more and more attention because of the irreplaceable advantages. In recent years, every country competes for the dominance in the solar industry, and has introduced preferential policies to promote the development of solar energy industry, which makes solar power technology become a global issue. The paper focuses on photovoltaic grid-connected system. Firstly, the structure and output characteristics of the solar cell have been analyzed. In order to give full play to the conversion efficiency of solar cells, a maximum power point tracking method has been raised. The paper has built a solar cell model in the MATLAB environment, which is equivalent with the actual circuit of the solar cells, and the output characteristic has been simulated. The MPPT(Maximum Power Point Tracking) simulation based on booster circuit has been done with the perturbation and observation method and the improved incremental conductance method. Secondly, the types and control strategy of PV grid-connected inverter are studied. Considering the dynamic response and stability of the system,the right inverter has been choose.In order to better tracking the phase of the grid voltage, the bias of the grid-connected current and the instruction current must be eliminated. Improved fixed switching frequency control strategy is used in the inverter control. In order to ease up the contradiction between the switching frequency and switching loss, the multiple frequency SPWM technology is used to control the inverter. Thirdly, the software filtering method that averaged after removing the extreme is used to improve the accuracy of the DC sampling. The application of SPLL(software phase-locked loop) can speed up the system response speed and simplify the hardware circuit. In the end, the correctness of the photovoltaic power generation system has been verified through building the simulation model of the system, and part of the hardware circuit is designed and the test results have been given.