基于改进的扰动观察光伏发电MPPT控制方法的仿真研究

Simulation research on MPPT control method for photovoltaic system based on improved perturbation and observation method

为改进传统扰动观察法跟踪速度慢、稳定性差的问题,提出一种改进的扰动观察法。在光伏发电系统到达最大功率前,通过扰动步长与功率差成正比的方式进行扰动,当功率差大于所选阈值E时选择大步长快速到达最大功率点附近,当功率差小于阈值E时采用小步长进行跟踪扰动。利用Matlab/Simulink搭建光伏发电系统的最大功率点跟踪模型。仿真实验表明:到达最大功率点所需时间从传统扰动观察法的0.045s减少到0.03s左右。达到最大功率点后,震荡也比传统扰动观察法明显减小,避免过多的能量损失。

Aiming at the low efficiency and poor stability of traditional PO,an improved PO was developed.Before the PV system reached maximum power,thedisturbance was conducted through the proportional way of perturbation step length and power difference.The method of long step to reach the maximum power point quickly was chose when the power difference was greater than the selected threshold E.On the contrary,when the power difference was smaller than E,the method of small steps to track was used.The MPPT model of the photovoltaic system was established with Matlab/Simulink software.Compared with traditional PO,the time required to reach the maximum power point decreased from 0.045 sto about 0.03 s.After reaching the maximum power point,the shock was significantly reduced,avoiding excessive energy loss.