光伏发电系统最大功率点跟踪控制的研究

Study on maximum power point tracking control techniques in photovoltaic system

针对扰动观察法的速度和精度在很大程度上受扰动初始值和扰动步长的影响,且在最大功率点附近存在功率振荡现象等问题,提出一种改进扰动观察法。首先当日照变化较快时,利用短路电流使输出功率能够快速跟踪在最大功率点附近,然后采用可变步长的扰动观察法使光伏电池稳定在最大功率点。通过仿真实验证明该改进方法明显缩短了最大功率点的跟踪时间,并且基本消除了功率振荡现象,提高了最大功率点跟踪控制技术。

Based on the speed and precision of the perturbation and observation method is greatly affected by the perturbed initial value and step size,and point power oscillation phenomenon occurs near the maximum power.This paper puts forward an improved perturbation and observation method.When the sunshine changes rapidly,the short circuit current can be used firstly,so that the output power can quickly track near the maximum power point,then the perturbation and observation method with variable step length is used,making the photovoltaic cell work stably in the maximum power point.The simulation results show that the improved method could shorten the time of maximum power point tracking,and almost eliminate the power oscillation phenomenon,thus improving the maximum power point tracking control technology.