Abstract
The stability analysis of the adaptive variable step size MPPT algorithms is extremely depending on the value of the scaling factor (N), which typically adjusts the input signal to a proper magnitude prior to determine the proceeding step size. This paper proposes a new small signal analysis of the variable step size incremental resistance INR MPPT algorithm used in photovoltaic PV battery charging systems. The contributions in this paper are: first, setting up the overall small signal model of the PV system. Second, designing the appropriate value of the scaling factor (N), that ensures a satisfactory dynamic response and an accurately steady state performance without any oscillations. The simulation and experimental results indicate the feasibility and the improved functionality of the tracking system.