Variable step size MPPT algorithm for photo voltaic array using zeta converter - A comparative analysis

Maximum power point tracking (MPPT) techniques are implemented in photovoltaic (PV) systems to maximize the PV array output power where the latter depends on solar irradiance and temperature. In this paper a typical PV module is modeled mathematically and the PV characteristic curves are dissected under varying temperature and irradiation conditions. The model is then used to compare three popular MPPT techniques namely perturb and observe (P&O) method, incremental conductance (IC) method and the modified P&O method on basis of their dynamic behavior and response to step changes in irradiation levels. The paper further discusses the dynamic simulation model for a Zeta converter in discontinuous current mode (DCM) for step changes in input voltage by Generalized Switch Averaging technique and small signal analysis. The systems are modeled and simulated in a user friendly MATLAB/Simulink environment.