一种基于全局最优MPPT算法的研究

Research on a New Algorithm Based on Global Optimal MPPT

针对光伏阵列出现多个局部功率峰值时,传统的MPPT算法导致系统工作在某个局部最大功率点的问题,提出一种新的基于局部扫描法与P&O相结合的全局最优MPPT算法,该方法在系统启动后先采用固定大步长进行全局扫描来找到全局最大功率点,当系统运行在全局最大功率点附近时,然后采用变步长P&O算法变步长扫描来找到精确的最大功率点。基于Matlab/Simulink的仿真模型,对全局最优MPPT算法进行了仿真验证;并搭建一个功率为6 k W的实验平台验证当系统出现多个峰值时的效果。仿真和实验结果验证了所提出的全局最优MPPT算法在光伏阵列出现多峰值时具有很好的MPPT效果。

For photovoltaic array with multiple local power peaks,the traditional MPPT algorithm leads to systemwork in a local maximum power points,an global optimal MPPT algorithm was proposed based on local scan methodcombined Perturb Observe. Global scan was to find the global maximum power point with fixed step after systemstarted by this method. The variable step PO algorithm was used to scan for finding the exact maximum power pointwhen system was running at the global maximum power point nearby. The global optimal MPPT algorithm wassimulated based on Matlab/Simulink model. A 6 k W power was built to verify the system′s effect when the system hadseveral peaks. The results of simulation and experiment show that the proposed global optimal MPPT algorithm hasgood MPPT effect for PV array with multiple local power peaks.