基于模糊控制和功率预测的变步长扰动观察法在光伏发电系统MPPT控制中的应用

A MPPT Control for Photovoltaic Power System Based on the Fuzzy Control and Variable Step Length Disturbance Observation Method of Power Prediction

光伏系统的输出功率随外界环境条件和负载的变化而变化,为了充分提高光伏系统的效率,需要对系统的最大功率进行跟踪控制;简述了光伏发电系统传统的固定步长扰动观察法在最大功率点跟踪控制时的跟踪速度与精度之间矛盾以及可能出现误判的原因,分析了基于功率预测方法避免误判的原理,提出了一种模糊控制与功率预测相结合的变占空比步长扰动方法;通过Matlab建模、仿真和比对,验证了这种方法在跟踪速度、稳定性和最大输出功率等方面均有良好的表现。

the output power of photovoltaic system along with the change of external environment condition and the load change, in order to fully improve the efficiency of the photovoltaic system, to the maximum power tracking control of the system [9]. The article briefly pres ents the photovohaic power generation systems of the traditional fixed--step length perturbation observation method in the maximum power point tracking control of conflict between the tracking speed and precision and the reason for the possible misjudgment, analyzes the principles of power prediction method to avoid misjudgment, this paper proposes a fuzzy control is combined with the power to predict the variable duty cycle step perturbation method. Through Matlab modeling, simulation and comparison, this method was verified in the tracking speed, sta- bility and maximum output power, etc, all have good performance.