基于牛顿插值算法光伏三相桥逆变器的研究

摘要

最大功率点跟踪(MPPT)技术是光伏系统研究的核心内容,易受光照强度和温度变化的影响.主要分析了光伏发电系统中使用的三相桥逆变器的结构,构建了三相单级式LCL型并网逆变器的数学模型,从而得出P-U曲线,根据三点采样,在最大功率点两侧运用牛顿插值算法输出拟合最大功率点,提出了一种基于牛顿插值算法的最优控制方法,并利用Matlab仿真对控制算法进行了仿真和对比分析,仿真结果表明该算法效果更好.%The maximum power point tracking (MPPT) technology is the core of the photovoltaic system,which is affected by the changes of illumination intensity and temperature.The structure of the three-phase bridge inverter used in the photovoltaic power system is analyzed,and the mathematical model of three-phase singlestage LCL inverter is constructed,thus the P-U curve is obtained.According to the three sampling points,Newton interpolation algorithm is used to output the fitted maximum power point on both sides of the maximum power point.An optimal control method based on Newton interpolation algorithm is put forward,which is simulated and compared by Matlab.The simulation results show that this algorithm is effective.