部分遮挡条件下光伏阵列最大功率点跟踪方法

Maximum power point tracking methods of photovoltaic array under partially shaded condition

针对光伏阵列在部分阴影遮挡条件下具有多个局域最大功率点的最大功率点跟踪问题,在详细分析光伏阵列I-V特性的基础上,提出一种新颖的全局最大功率点跟踪方法。该方法根据光伏阵列最大功率点附近电压随电流的增加迅速下降的特点,先以大步长扫描方法锁定到各局域峰点附近,然后再采用P&O法以小步长跟踪该峰点,最后通过比较搜索到的各个局域峰点的功率来确定全局最大功率点。仿真和实验结果表明所提方法能够准确而迅速地跟踪到全局最大功率点,有效提高光伏阵列在部分阴影遮挡条件下的并网发电输出效率。

In order to track the real global maximum power point（GP） of the photovoltaic array which has multi-local maximum power point under partially shaded condition, a novel algorithm for tracking GP was advanced on the base of analyzing the I-V characteristics of photovoltaic array. According to the character-istics that the voltage nearby maximum power point decrease rapidly with the increase of the current, a large step scan method is applied firstly to locate the vicinity of the local maximum point and then the P＆amp;O method was applied to track the local maximum point with small step. At last, the GP was obtained by comparing the power of all local maximum point. The simulation and experiment results show that the GP can be tracked accurately and quickly with the proposed algorithm, and the grid-connected power genera-tion efficiency of the photovoltaic array can be improved Effectively under partial shadowing conditions.