基于分段数值逼近的自适应步长电导增量法MPPT控制仿真

SIMULATION OF AUTO-ADAPTED STEP SIZE INCREMENTAL CONDUCTANCE METHOD MPPT CONTROL BASED ON SEGMENTED NUMERICAL APPROXIMATION

根据太阳能光伏系统输出电压、输出电流的dI/dV+I/V值和系统当前输出电压与最大功率点电压差值Vmodify之间的特性关系,提出一种基于分段数值逼近的可变步长电导增量MPPT方法。采用Matlab 2009搭建太阳电池模块和带有MPPT控制的光伏系统,当光强在500W/m2和1000W/m2之间发生跳变时,对不同方法下MPPT跟踪效果进行仿真比较。结果表明,所提出的方法与传统固定步长电导增量法相比,具有追踪速度快、精度高的优势;与迭代求解变步长、智能控制变步长等较复杂的方法相比,更易于实现。

Considering the characteristic of the relation between d//dV ＋ I/V and Vmodify （the deviation between the instantaneous value of system output voltage and the value of maximum power point voltage） for PV systems, an auto-adapted step size incremental conductance MPPT method based on segmented numerical approximation was proposed . The PV system model with the solar cell block and the MPPT controller was built by using Matlab 2009. Then, the tracking effectiveness of this algorithm when the illumination intensity changed sharply between 500W/m^2 and 1000W/m^2 was emulated by using this model. The result showed that, compared with the conven- tional fixed step size method, the proposed approach can effectively improve the tracking speed and accuracy simul- taneously. As compared with other more complex methods, such as the gradient iteration solution and intelligent control method, the proposed approach is simpler and easier to implement.