一种基于改进萤火虫算法的光伏MPPT控制方法
2020-08-26张鹏罗正华唐成达黄建刚
张鹏 罗正华 唐成达 黄建刚



摘 要:局部阴影条件下,光伏发电系统输出功率降低且P-U曲线存在多峰值,标准萤火虫算法易陷入局部极值且收敛后期易发生震荡现象。针对这一问题,提出一种基于模糊-萤火虫算法(FFA)的MPPT算法,利用模糊控制器自适应调整随机移动步长因子α。算法运行前期赋予较大α值,萤火虫能快速向最优值附近移动,后期快速减小α值,避免震荡现象,使算法能稳定收敛。通过在MATLAB/Simulink下对FFA算法建模、仿真,并对比了标准萤火虫算法(FA)仿真结果,实验证明萤火虫算法与模糊控制技术相结合,能快速、准确、稳定的收敛到最大功率点,实现光伏发电最大效益输出。
关键词:最大功率点跟踪;局部阴影;萤火虫算法;模糊控制
DOI:10.15938/j.jhust.2020.03.009
中图分类号: TM615
文献标志码: A
文章编号: 1007-2683(2020)03-0053-08
Abstract:Under partially shaded conditions, the power of the photovoltaic system becomes lower and the P-U characteristic curve has multiple peaks. The standard firefly algorithm will fail to work and is prone to oscillation during the final phase of convergence. To solve this problem, the MPPT algorithm based on fuzzy-firefly algorithm (FFA) is proposed, which uses fuzzy controller to adaptively adjust the factor of random moving step. In the early stage of the algorithm,the fuzzy controller output a large α so that firefly can quickly move to the vicinity of the optimal value. In the later stage of algorithm, the value of α decrease sharply to avoid oscillation, so that the algorithm can converge stably. By modeling and simulating in the MATLAB/Simulink and comparing the simulation results of FFA with the standard firefly algorithm (FA), the experiment proves that the FFA can quickly, accurately and stably converge to the MPP so that the PV system can output the maximum power.
Keywords:maximum power point tracking (MPPT); partial shading; firefly algorithm (FA); fuzzy control
0 引 言
隨着全球变暖以及能源危机的日益加重,人们对新型清洁能源的开发与利用越来越迫切。可再生能源被认为是产生清洁能源的技术选择。丰富的太阳能资源逐渐成为各国新能源开发和应用的主要选择[1]。为了获得光伏发电的最大功率输出,最大功率点跟踪(Maximum Power Point Tracking,MPPT)技术应运而生,并产生了众多成熟算法。如Buciarelli等人提出的扰动观察法(P&O)和Hussein等人提出的增量电导法(IncCond)。但上述算法均只适用于均匀光照条件下,即每个光伏板接受相同的光照强度。当周围环境出现阴影情况如光伏板表面有灰尘,树木遮挡等情况时,光伏系统输出P-U曲线会出现多个峰值,上述传统MPPT算法易陷入局部峰值而不能追踪到最大功率点,造成系统功率失配和功率浪费,甚至会影响光伏阵列的寿命[2-6]。……
