局部阴影下光伏最大功率跟踪的混沌搜索新算法

New Algorithm of Chaos Research of Photovoltaic Maximum Power Point Tracking Under Partial Shade

光伏阵列在实际运行过程中往往会遇到局部阴影,导致输出功率特性曲线呈现多峰值情况,而传统的最大功率跟踪算法因无法跳出局部最优很难寻找到真正的最大功率点。文章将混沌理论用于光伏最大功率跟踪技术,提出采用2种不同混沌机制产生的混沌变量作为随机步长进行搜索扰动,该方法增加了混沌搜索的充分性,克服了传统搜索易陷入局部最优的困境,通过变尺度操作降低了混沌搜索的盲目性,从而提高搜索效率。在Matlab环境下针对外界不同条件的变化进行仿真分析,同时与传统方法对比分析了该方法的快速性和有效性,最后通过实验验证仿真的正确性。

Photovoltaic array often encounter partial shade during the process of actual operation, thus the output power characteristic curve shows a multi-peak. While the traditional maximum power point tracking(MPPT) algorithm is unable to jump out of local optimum, so it is very difficult to find out the true maximum power point. In this paper, the chaos theory was used for photovoltaic MPPT technology. The chaotic variables were generated by two different chaotic mechanisms as random step to search. The method increased the adequacy of chaos search, and overcame the dilemma that the traditional search easily fell into local optimum. By adopting the variable scale operation to reduce the blindness of chaos searching, the search efficiency can be improved. The simulation analysis for the change of external conditions was made in the Matlab platform. The quickness and the effectiveness of the method are verified by comparing with the traditional method, and the correctness of the simulation is confirmed by the experiments finally.