分段式自适应变步长爬山法在光伏系统MPPT中的应用

针对传统自适应变步长爬山法扰动步长变化稳定性差,不能同时保证良好跟踪精度与较快响应速度的问题,基于传统自适应变步长爬山法提出一种分段式自适应变步长爬山法,实现扰动步长的分阶段自动调整,再通过PWM技术将扰动步长变量转化为控制BOOST斩波电路的IGBT触发脉冲,从而实现光伏系统的最大功率跟踪。在MATLAB/SIMULINK软件中分别搭建基于传统变步长爬山法与分段式自适应变步长爬山法的模型进行仿真。通过对比表明,所提方法不仅明显缩短了对最大功率点跟踪的响应时间,使功率随时间变化更加平稳,而且对环境变化的适应性更强,控制方式更加灵活,从而改善了光伏系统的并网效率。

Application of Segmented Adaptive Variable Step Climbing Method in MPPT of Photovoltaic System

In view of the poor stability of disturbance step size in traditional adaptive variable step climbing method,good tracking accuracy and fast response speed cannot be guaranteed at the same time.In this paper,based on the traditional adaptive variable step climbing method,a segmented adaptive variable step climbing method is proposed to realize the phased automatic adjustment of disturbance step length,and then the variable of disturbance step length is converted into IGBT trigger pulse controlling BOOST chopper circuit through PWM technology,so as to realize the maximum power tracking of photovoltaic system.Models based on the traditional variable step climbing method and the segmented adaptive variable step climbing method were built respectively for simulation in MATLAB/SIMULINK software.The comparison shows that the proposed method not only significantly shortens the response time of tracking the maximum power point,makes the power change more stable with time,but also has stronger adaptability to environmental changes and has more flexible control mode,thus improving the grid-connection efficiency of photovoltaic system.