为保证光伏系统在光照剧烈变化条件下仍可输出最大功率，提出一种自适应变步长电阻增量算法． 该算法可根据外界环境的变化，通过步长转换函数自动将光伏系统工作区域划分为定步长区域和变步长区域:在定步长区域，基于短路电流和最大功率点电流的近似线性关系，提出一种整定初始定步长的方法;在变步长区域，结合步长转换函数与输出功率的关系，确定变步长控制策略的速度因子，保证了算法的收敛性． 搭建光伏系统Matlab/Simulink 仿真模型和基于 DSP(TMS320F28035)控制的 5 kW 光伏系统实验平台，仿真和实验结果表明，所提算法在光照剧烈变化条件下可将光伏系统动态响应速度提高73%，并使得稳态跟踪精度达到 98． 9%．

In order to ensure that the photovoltaic system under a drastically-changing light can still output its maxi- mum power,an adaptive variable step-size incremental-resistance maximum power point (MPP) tracking (MPPT) algorithm is proposed.In the algorithm,a threshold function is adopted to automatically divide the operation area of the photovoltaic system into the fixed step-size region and the variable step-size region according to the changes of external environments.In the fixed step-size region,a method of tuning initial fixed step sizes is proposed based on the approximate linear relationship between the short-circuit current and the maximum power point current.In the variable step-size region,by drawing on the relationship between the step conversion function and the output power,a scaling factor of the variable step-size strategy is determined to ensure the convergence of the proposed al- gorithm.Finally,a Matlab/Simulink model of the photovoltaic system and a 5kW photovoltaic system controlled by DSP (TMS320F28035) are established to conduct a series of experiments.Simulation and experimental results in- dicate that the proposed algorithm can improve the dynamic response speed of the photovoltaic system under a dras- tically-changing light by 73%，and can achieve a steady-state tracking accuracy of 98. 9%.