Abstract:
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Nowadays, the majority of the photovoltaic (PV)
power sources are connected to the public grid. One of the main
connection problems occurs when voltage sags appear in the grid
due to short circuits, lightning, etc. International standards regulate
the grid connection of PV systems, forcing the source to remain
connected during short-time grid-voltage faults. As a consequence,
during the voltage sag, the source should operate with increasing
converter currents to maintain the injection of the generated power.
This abnormal operation may result in nondesired system disconnections
due to overcurrents. This paper proposes a controller for
a PV three-phase inverter that ensuresminimum peak values in the
grid-injected currents, as compared with conventional controllers.
From the system analysis, a design method is presented in order
to set the parameters of the control scheme. Selected experimental
results are reported in order to validate the effectiveness of the
proposed control. |