基于STM32F407的单相光伏并网逆变器研究

Research of single-phase grid-connected photovoltaic inverter based on the STM32F407

逆变器是光伏并网发电系统的核心设备。其主要拓扑结构可以分为单级式和两级式,一种好的拓扑结构是保证逆变器稳定、高效率和高安全性工作的基础。采用两级式结构,前级采用单重Boost进行升压和最大功率获取,后级采用典型的单相全桥逆变,经过LCL滤波器并入电网,单相两级式光伏并网逆变系统具有最大功率点跟踪控制和逆变并网控制相互独立、互不干扰和效率高等优点。锁相采用一种新型的单相锁相环。通过理论分析确立了系统的控制规律,仿真及实验结果证明了该方案的有效性。控制芯片采用STM32F407,该芯片具有运算速率高、使用方便等优点。

Inverter is the core of grid-connected photovoltaic system.The main topology structure can be divided into single stage and two stage.A good topology is the basis of stability,high effciency,high security to ensure the inverter to work.Researched the two-stage structure,the preceding stage use single Boost to obtain the maximum power and improve voltage,the backward stage adopt the typical single-phase full bridge inverter and then adopt LCL filter incorporated into the grid.The two-stage structure has the advantage of separate control and high effciency.The maximum power point tracking and the control of the grid-connected are independent from each other which made the photovoltaic system more fexible and reliable.A new type of single phase locked loop is used.With theoretical analysis,the control method is established,results of simulation and experiment proved the effectiveness of the program.The control chip uses STM32F407,this chip has the advantages of high speed of operation and easy to use.