A Photovoltaic MPPT Control Strategy Based on Gradient Optimization and MPP Voltage Law

In this work, a maximum power point tracking (MPPT) control algorithm is developed to determine power efficiency, and to improve the transient nature of the power curve characteristics of a PV cell. Based on the analysis of existing MPPT methods, for PV systems, the relationship between MPP voltage and the open circuit voltage of PV cell under different conditions is studied; moreover, a novel MPPT control strategy which can be applied to different irradiance conditions based on a sub-domain gradient optimization principle and MPP voltage law is proposed. Simulation results show that the proposed method has advantages of fast dynamic response and a non-oscillatory steady state response under different irradiance conditions and input waveforms. For the experimental setup, an existing control method and the proposed MPPT control algorithm are.implemented on solar PV cell; it was observed that the proposed MPPT algorithm has stable steady state dynamic characteristics and a fast response speed.