Fast variable step-size maximum power point tracking method for photovoltaic systems

Maximum power point tracking (MPPT) is a key technology in high efficient Photovoltaic (PV) systems. Against the contradiction between the tracking speed and tracking accuracy of the MPPT in the PV systems, this paper presents a self-adaptive step-size MPPT method. First, PV modeling is built under different sunlight intensity and temperatures. Then, by discussing the due features of a self-adaptive step-size function, a new variable step-size function is built based on the logarithm form. Through modeling in Matlab/Simulink and experiment, both results show that the proposed method can improve the MPPT response in both tracking speed and accuracy steadily compared with other published results. (C) 2015 AIP Publishing LLC.