Abstract:
This paper presents a control strategy for a grid interface system fed by a PV source. A two stage topology with boost converter followed by a three phase VSI (voltage source Inverter) is employed for the grid interface. The proposed control strategy is capable of injecting harmonic free current to the grid even when the grid voltage is highly distorted. Also it is ensured maximum power is extracted from the PV and injected to the grid. The design of the magnetics used in the grid interface is also presented. The proposed control scheme is validated for injecting real power to the grid from a PV source by simulation in MATLAB SIMULINK environment. The results show that the proposed control scheme is an attractive solution for grid interface of DG sources like PV, fuel cells and wind driven PMSG.

Keywords: Photo-voltaic array, Three phase inverter, PLL, Hysteresis controller, d-q reference frame