一种电流预测控制的自适应变步长最大功率跟踪方法

An Adaptive and Variable Step MPPT Method Based on Current Predictive Controllers

针对定步长扰动观察法存在的不足(扰动步长过小,外部条件变化较快无法快速跟踪;扰动步长过大,在最大功率点功率振荡比较大),为了提高电流快速跟踪能力,提出一种基于电流预测控制的自适应变步长最大功率跟踪方法。该方法结合自适应变步长控制器和电流预测控制器各自优点,将此方法应用于中点钳位型三相三电平光伏发电系统。建立起10 kW三相三电平光伏发电系统实验平台,并与传统最大功率跟踪方法进行对比实验。实验结果表明:所提出的最大功率跟踪方法使系统具有很好的静、动态性能。

Due to the shortage of the fixed step perturbation and observation（P＆O） method（if the perturbation step is small, it cannot fast track under a rapidly changing weather condition; and if the perturbation step is large, there will be large oscillating power around the maximum power point（MPP））. In order to improve the ability of fast current tracking, the paper proposed an adaptive variable step maximum power point tracking（MPPT） based on a current predictive controller. The new algorithm has combined the respective advantages of the adaptive variable step controller and the current predictive controller, which is applied to a neutral-point-clamped（NPC） three-phase three-level photovoltaic generation system. Comparative experimental tests for different conventional MPPT algorithms have been verified based on three-phase three-level photovoltaic generation system rated at 10 kW. The experimental results show that the proposed MPPT algorithm has good steady-sate and dynamic performance.