基于PI控制的两电平光伏并网逆变器研究

Research on Two-Level Photovoltaic Grid Inverter Based on PI Control

目前对光伏并网逆变器的研究越来越多,建立了4KW的模型,用于光伏逆变器的研究,并且系统并网到电网,对于前面的光伏部分的对他的最大功率点追踪,经过分析对比以后采用了扰动观察,基于仿真结果分析了系统内部的机理。对系统正常情况下的PI控制进行了理论分析,对在光照条件发生变化时逆变电路输出电流变化进行了研究。仿真结果表明,系统具有相对完美的电压电流跟踪效果,功率因数能够保持在0.99以上,并且实现电压与电流频率的一致性。

At present the research on photovoltaic（pv） grid inverter is more and more.the establishment of a 4 KW three-phase two levels of photovoltaic（pv） grid power generation system model,and adopted the disturbance observation MPPT algorithm and grid voltage feed-forward double closed-loop control strategy,and the simulation research,the simulation results based on the internal mechanism of the system are analyzed.The PI control in the normal condition of the system is analyzed theoretically,and the change of output current of inverter circuit is studied in the light condition.The simulation results show that the system has a good voltage current tracking effect,and the power factor can be kept above 0.99,and the consistency between voltage and cu- rrent frequency is realized.