Publication

Abstract : Maximum Power Point Tracking (MPPT) is used in Solar Photovoltaic (SPV) systems to maximize the photovoltaic array output power, irrespective of the temperature and irradiation conditions and of the load electrical characteristics. This paper proposes a mathematical model for three-phase SPV systems with MPPT control. The parametric equation of SPV cell, MPPT algorithms for tracking maximum power from the PV source, integration of PV model with the grid through a DC-DC boost converter and a three-phase PWM inverter are discussed. The detailed model is developed to perform the comparison of different algorithms in terms of switching losses, junction temperature and sink temperature of power electronics devices. The resulting system has high efficiency, lower cost and can be easily modified for different applications. Perturb and Observe (P&O) method and Incremental Conductance (INC) method with variable step size is used for MPPT, giving the basis for reference current generation and in turn effectively control the PWM inverter feeding power to the grid. The performance evaluation has been carried out for modified variable step size of the duty cycle of DC-DC boost converter for both algorithms for various outputs of the SPV array, in terms of energy injected to grid, switching losses, junction temperature and sink temperature. The results validated the effectiveness of the MPPT algorithm in increasing SPV output energy, decrease in the switching losses, junction and sink temperature. The results show that INC method is slightly better to P&O method in energy injected to the grid with lower switching losses, junction and sink temperature.