Research on Maximum Power Point Tracking Based on an Improved Fuzzy-PD Dual-mode Algorithm

摘要

In this paper, an improved Fuzzy-PD control Maximum Power Point Tracking (MPPT) algorithm is proposed based on the existing Fuzzy-PI control on the basis of the output characteristics of photovoltaic cells. The traditional fuzzy control method adjusts the duty cycle of the Boost circuit according to the changes of the output power and voltage of the photovoltaic cells, thus making the photovoltaic cells work at the maximum power point. The method can quickly perceive the external environment transformation, but there is repeatedly oscillation near the maximum power point. To eliminate the oscillation a Fuzzy-PI control algorithm has been given in some papers. However, as the oscillation is one characteristic of the PID control, the oscillation problem still cannot be fundamentally solved. In this paper, an improved Fuzzy-PD control algorithm has been proposed, which can effectively eliminate the oscillation phenomenon. Simulation experiments show that this improved algorithm will make the photovoltaic cells work at the maximum power point, and can effectively eliminate the oscillation at the same time.