Stability study of variable step size incremental conductance/impedance MPPT for PV systems

This paper proposes a variable step size maximum power point tracking MPPT based on incremental conductance/impedance INC method. In order to design the appropriate variable step size scaling factor, a small signal model for the overall system equipped with the PV model and the INC algorithm has been developed. The optimal value of the variable step size scaling factor has been designed using the root locus technique. The theoretical analysis and the design principle of the proposed stability analysis have been validated using PSIM simulation, and experimentally using digital signal processor DSP.