光伏发电系统MPPT固定频率滑模控制

基于光伏电池的数学模型,采用Buck电路作为实现电路,以开关周期平均状态概念为基础,建立光伏发电系统的平均状态数学模型.基于滑模控制理论和光伏电池的工作特性,设计了光伏发电系统最大功率点跟踪固定频率滑模控制器,对控制器的固定频率滑模控制算法采用Lyapunov方法进行了存在性和稳定性分析.在理论分析基础上,对光伏发电系统及固定频率滑模控制器进行了数字仿真和实际物理系统实验.仿真和实验结果表明,所设计的固定频率滑模控制器抖振很小,能很好地实现光伏发电系统最大功率点跟踪,控制算法实用有效.

Fixed-frequency-sliding-mode Controller Used in Photovoltaic System MPPT

Based on the mathematical model of photovoltaics and the concept of average model, average-state mathematic modeling was done with a Buck circuit. Based on the sliding-mode theory and operating characteristic of photovoltaics, a fixed-frequency-sliding-mode (FFSM) controller was proposed for photovoltaic system MPPT with the existence and the stability proved. Through sufficient theoretical analysis, system simulations and experiments were implemented .The results of simulations and experiments show that the fixed-frequency-sliding-mode controller can achieve photovoltaic system MPPT with tiny buffeting and the control arithmetic works well.