递推最小二乘估计在光伏系统MPPT中的应用研究

Research on the Application of Recursive Least Squares Estimate in Photovoltaic System Maximum Power Point Tracking

提出一种扰动观察法和递推最小二乘估计相结合的光伏系统MPPT控制策略。采用较大步长的扰动观察法定位最大功率点的电压范围,在该电压范围内转换为小步长电压,以每步对应的采样电流作为被估量,采用递推最小二乘估计对该电流值进行滤波以削弱量测误差,提高了跟踪精度;通过机动检测判断电流是否状态突变,解决了扰动观察法存在的误判问题。仿真结果验证了所提策略的正确性、有效性。

In this paper, a new photovoltaic system MPPT control strategy is proposed by combining the perturbation＆observation method and the recursive least squares estimation. The maximum power point voltage range is posted by perturbation＆observation method with the larger step length. Converted to a small step voltage in the voltage range, the sampling current of the small step voltage is measured, the measurement error of the current value is weak-ened by the recursive least squares estimation, and the current state mutation is detected by maneuver detection. The strategy improves the tracking accuracy, and is to solve the problem of misjudgment in the perturbation＆observation method. The correctness and effectiveness of the strategy are verified by simulation.