Grid Current Based MPPT in Two Stage Photovoltaic Systems

This paper presents a grid-side current control in two stage photovoltaic (PV) systems for achieving maximum power injected into grid (MPIG). In two stage grid integrated photovoltaic systems, maximum power point tracking (MPPT) is employed to control DC-DC converter in maximizing the PV power by sensing photovoltaic parameters. In contrast, the proposed technique maximizes the power injected into the grid while operating in different insolation levels by using grid current control. The proposed method works effectively without knowing PV voltage and PV current and hence the system becomes cost effective as there is no requirement of PV-side sensors. Further, the simulation result demonstrates that the proposed grid-current based MPPT has higher penetration of power into the grid under different insolation conditions.