一种优化变步长电导增量法的MPPT控制

MPPT control of a incremental conductance method with optimized variable step size

由于光伏电池的输出特性会随着环境变化而改变,因此,合理的最大功率点跟踪(maximum power point tracking, MPPT)技术是提高光伏发电系统效率的关键.但在定步长算法中,跟踪速度和稳态精度之间存在固有矛盾,而传统变步长算法在光照变化下缺乏灵活性,起动速度慢,制约了MPPT的跟踪质量.针对此问题,提出一种优化的变步长电导增量法.该算法可根据工作点位置选取合理的跟踪比例系数,克服了传统变步长算法动态响应速度慢、精度不高的问题.在Matlab/Simulink下的仿真结果证实了该算法在变化的光照情况下的可行性.

As output characteristics of photovoltaic cells change with the change of environment,reasonable maximum power point tracking(MPPT)is a key in improving efficiency of a photovoltaic system.However,there is an inherent contradiction between tracking speed and steady-state accuracy in a fixed step algorithm.The traditional variable step algorithm lacks flexibility,and has a slow start speed,limiting tracking quality of MPPT.An improved variable step incremental conductance method is proposed to solve this problem.The algorithm can select a reasonable proportion coefficient for tracking according to different work locations to overcome problems in the traditional variable step size algorithm.Simulation with Matlab/Simulink shows feasibility of the algorithm under varying illumination conditions.