An efficient technique for controlling power flow in a single stage grid-connected photovoltaic system

Compared to multistage grid-connected photovoltaic systems (gcpvss), complexity in monitoring and controlling scheme in a single-stage gcpvs is much increased, as maximum power point tracking and power sharing with the grid need to be considered simultaneously in the same stage. an efficient technique for performing the aforementioned functions, simultaneously, in a single stage system, by adjustment of the voltage phasor of a voltage source inverter, is presented. active and reactive powers flow from the inverter is regulated by the adjustment of amplitude and phase angle of the inverter output voltage with respect to the grid voltage. an algorithm is also developed for automatic active and reactive powers sharing for the intended applications in the single stage gcpvss. a typical 2.8 kwp, 368 v (dc) nominal photovoltaic array based gcpvs is modeled and simulated to analyze proper load matching for different ambient and grid voltage conditions. performances, like the efficiency of the inverter and the total harmonic distortion of the inverter output voltage and current, are studied, with variations in ambient conditions and the modulation index of a sinusoidal pulse width modulation of the igbt based inverter. simulation results have been included to show the feasibility of the proposed technique.