Maximum power harvesting from a PV system using an improved two-stage MPPT scheme based on incremental conductance algorithm and integral controller

This article deals with a novel strategy called two-stage incremental conductance (INC) algorithm for maximum power point tracking (MPPT) for photovoltaic (PV) systems. This method is proposed to tackle the shortcomings of classical incremental conductance (INC) method such as oscillations, imperfect MPPT, slow tracking of MPP, etc. These demerits stem from the use of a one-stage INC algorithm with a fixed duty cycle step size, which cannot provide the optimal duty cycle especially under changing weather conditions (temperature and irradiance) and resistive load. The first stage of the proposed approach is used for providing the reference voltage using the INC algorithm; and the second one is an integrator controller tuned by Routh's criterion used to ensure the stability of the voltage closed loop control. Simulation and numerical results in different cases confirm the superiority of the proposed two-stage INC algorithm over the classical one based on one stage, with an efficiency of more than 93.75%.