基于输出功率预测变步长扰动观察法的光伏发电MPPT控制研究OA

This paper proposes a variable step perturbation observation method based on output power prediction to address the problems of slow convergence speed,low accuracy,and maximum power point misjudgment caused by sudden changes in solar irradiance in traditional perturbation observation method for maximum power point tracking(MPPT)control in PV power generation.By introducing solar irradiance coefficient and disturbance direction coefficient into the variable step perturbation observation method,the disturbance step size and direction can be automatically optimized,reducing the optimization time of the maximum power point and improving the optimization accuracy.Then,based on the variable step perturbation observation method,an output power prediction method is introduced.By predicting the output power between two perturbations before and after,the direction of the perturbation during sudden changes in solar irradiance is adjusted to eliminate misjudgment of the maximum power point and avoid the failure of optimizing the maximum power point of PV power generation under sudden changes in solar irradiance.Firstly,the output characteristics of PV modules are introduced,and then the MPPT control algorithm for PV string is designed.Finally,the proposed method is validated through simulation and physical testing.The research results show that:1)Under different static solar irradiance,the optimization accuracy and convergence speed(i.e.optimization time)of the variable step perturbation observation method based on output power prediction are superior to traditional perturbation observation method.2)Under dynamic solar irradiance,when the solar irradiance suddenly changes,the variable step perturbation observation method based on output power prediction can quickly and smoothly locate the maximum power point of the PV string in a short period of time,avoiding the phenomenon of misjudgment of the maximum power point due to changes in the target value.