Research on Maximum Power Point Algorithm Based on Adaptive Duty Cycle

In solar photovoltaic (PV) system it has been a tendency to extract the maximum output power from the PV panel with the decrease of production price. There are many novel control algorithms to track the maximum power point. The commonly used control algorithm is based on perturbation and observation algorithm (P&O). However, the traditional P&O method has some problems between the tracking speed and the control accuracy. In this paper, the mathematic model of photovoltaic cells is studied and a modified perturbation observation method is proposed. The algorithm adjusts the duty cycle step by step according to the variation of the slope of the power voltage curve. Simulink simulation of the PV module with the buck circuit proves the superiority of the variable duty cycle perturbation method in terms of tracking speed and stability compared with the traditional perturbation observation method.