模糊/PID双模控制在光伏发电MPPT中应用

光伏电池输出功率随外部环境和负载的变化而变化,需采用最大功率点跟踪(MPPT)算法.根据MPPr的基本原理,采用一种基于模糊控制具有在线参数调整的自适应占空比扰动法,该方法在不干扰系统正常工作的情况下,能迅速感知外界环境变化,但输出功率在最大功率点附近振荡严重.为了充分发挥光伏电池的效能,在模糊控制的基础上引入PID控制.采用模糊/PID双模控制可有效消除光伏电池输出功率在最大功率点的振荡,减少能量损失.实验结果证明该方法能够快速、准确地跟踪光伏电池的最大功率点,避免在最大功率点的振荡,提高能量转换效率.

MPPT of photovoltaic generation system using fuzzy/PID control

The output power of photovoltaic cell varies with external environment and loads,which applies MPPT(Maximum Power Point Tracking) algorithm. According to the basic principle of MPPT, an adaptive duty - cycle disturbance method with fuzzy control and automatic on - line parameter tuning is proposed,which tracks MPP changes rapidly without disturbing photovoltaic system,while the output power oscillates seriously around MPP. PID control is thus introduced to reduce output power oscillation and energy loss. Experimental results show that,the proposed method tracks MPP exactly and quickly,greatly improving energy conversion efficiency.