双级式光伏并网发电系统及其关键环节的设计

Designing of Two Level Grid Connected PV System and the Key Links

以双级式光伏并网发电系统作为研究重点,前级采用Boost升压电路,结合最大功率点跟踪(MPPT)技术提升光伏阵列的工作效率;后级为双闭环控制的三相电压型逆变电路,利用LCL滤波器减小并网电流的谐波含量。在Matlab/Simulink中搭建仿真模型,结果表明:在改变温度和光照强度的情况下,可实现对最大功率点(MPP)的准确跟踪控制和单位功率因数并网。

The two level grid connected PV system is used as the research focus. The front level adopts Boost circuit to improve the efficiency of PV system, which is combined with the maximum power point tracking （MPPT） technology, and the second level is the inverter circuit of three-phase voltage with the double closed loop control, the reducing of the har- monic content of the grid current is put forward by LCL filter. The simulation model is built in Matlab/Simulink. The results show that the accurate tracking control of the maximum power point （MPP） and the power factor of the unit can be achieved with the change of temperature and light intensity.