基于改进扰动观察法的光伏系统MPPT算法

MPPT algorithm of photovoltaic system based on improved perturbation and observation method

针对传统扰动观察法存在最大功率点附近扰动与跟踪速度之间矛盾的问题,提出了一种改进的变步长扰动观察法的光伏系统MPPT算法,设计了遗传算法优化的模糊控制器。该算法采用恒电压启动,以Fibonacci数列为变步长,以输出最大功率点附近电压为模糊控制器的参考输入,通过改进的自适应遗传算法优化模糊控制的隶属函数,避免种群陷入局部最优或过早收敛。建立了光伏系统的仿真模型,经Matlab仿真分析,在局部阴影或光强度突变的情况下,能够准确跟踪最大功率。

For the problem of a contradiction between the disturbance near MPP and the tracking speed in traditional P＆O,an improved variable step P＆O of PV system MPPT algorithm was proposed and a FLC of GA optimization was designed.The al-gorithm started with a constant voltage,Fibonacci numbers were regarded as variable steps and output voltage near MPP as an input reference of FLC.Through membership function of FLC optimized by improved adaptive GA,it avoided the population into local optimum or premature convergence.A model of PV system was established.Through Matlab simulation analysis,the pro-posed algorithm could track MPP quickly and accurately under the shadow.