基于最优梯度的滞环比较光伏最大功率点跟踪算法

光伏电池的输出功率特性随着外界环境的改变而变化.为使光伏阵列得以高效利用,需要对光伏并网系统进行最大功率点跟踪.提出了一种滞环比较法和最优梯度法相结合的最大功率点跟踪(maximum power point tracking,MPPT)算法,它很好地克服了最大功率点跟踪过程中的振荡和误判问题.为了验证该算法的有效性,在 PSCAD/EMTDC 软件平台上搭建了三相单级式光伏并网仿真系统,对常规的定步长扰动观察法和改进算法进行了仿真对比分析.结果表明:改进后的 MPPT 算法能有效消除直流电压的扰动纹波;当外界环境突变时,系统能快速稳定在新的最大功率点.

Improved Maximum Power Point Tracking Algorithm for Photovoltaic Generation Based on Combination of Hysteresis Comparison With Optimal Gradient

The output power characteristics of photovoltaic(PV) cells vary with the variation of external environment.To utilize PV cell array high-efficiently,it is necessary to trace the maximum power point of grid-connected PV generation system.To overcome the shortcomings such as oscillation and misjudgment during the process of tracing maximum power point,an improved maximum power point tracking(MPPT) based on the combination of hysteresis comparison with optimal gradient was proposed.To verify the effectiveness of the proposed algorithm,a three-phase single-stage grid-connected PV generation system was constructed on PSCAD/ EMTDC platform to perform simulation and comparative analysis on both conventional perturbation and observation method with fixed step length and the proposed improved algorithm.Simulation and analysis results showed that the proposed improved MPPT algorithm could effective eliminate interference ripples in output DC voltage of the PV system;when external environment suddenly changed,the PV generation system could be rapidly stabilized at the new maximum power point.