微型光伏逆变器最大功率点自动跟踪方法

Automatic Tracking Method of Micro Photovoltaic Inverter Maximum Power Points

针对现有自动跟踪方法跟踪捕获结果存在较大误差的问题,本文提出了一种微型光伏逆变器最大功率点自动跟踪方法。首先,根据不同光照强度下电荷的特性,绘制微型光伏逆变器的I-U/P-U特性曲线,计算功率输出达到最大值时的运行效率,并在最大功率点附近对其进行控制。其次,采用DCM和BCM两种工作模式实现低功率频段和高功率频段的输出。再次,通过判断光伏阵列中两侧峰值点的大小得到特性曲线之间的交点位置,并运用改进粒子群算法更新粒子位置进行飞行搜索。最后,通过动态调整粒子飞行的最优位置和历史位置,完成对全局最大功率点的追踪。实验结果表明,当光照强度改变时,实验组的微型光伏逆变器能准确跟踪捕获电池的最大输出功率点(200 W),取得了较好的跟踪效果。

In response to the problem of significant errors in the tracking and capture results of existing automatic tracking methods,this paper proposes a maximum power point automatic tracking method for micro photovoltaic inverters.Firstly,based on the characteristics of charge under different lighting intensities,draw the I-U/P-U characteristic curve of the micro photovoltaic inverter,calculate the operating efficiency when the power output reaches its maximum value,and control it near the maximum power point.Secondly,two operating modes,DCM and BCM,are used to achieve output in both low-power and high-power frequency bands.Once again,the intersection position between the characteristic curves is obtained by determining the size of the peak points on both sides of the photovoltaic array,and an improved particle swarm optimization algorithm is used to update the particle position for flight search.Finally,by dynamically adjusting the optimal and historical positions of particle flight,the tracking of the global maximum power point is completed.The experimental results show that when the light intensity changes,the micro photovoltaic inverter of the experimental group can accurately track and capture the maximum output power point of the battery(200 W),achieving good tracking effect.