Modified p-q Theory Applied to Flexible Photovoltaic Systems at the 3-Phase 4-Wire Distribution Grids

This paper proposed corrected p-q control strategyfor achieving maximum benefits from the photovoltaic (PV)systems when installed in 3-phase 4-wire distribution grids whichhave unbalanced and distorted nature. The PV is controlled toact as a flexible photovoltaic (FPV) system by combining activepower filter functionality. The control system utilize corrected pqcontrol strategy and simple maximum power point tracking(MPPT) method to generate reference current for FPV system toinject maximum available power of PV array to grid andcompensate current unbalance, load current harmonics, loadreactive power demand and load neutral current. All of thesefunctions may be accomplished either individually orsimultaneously. With such a control, the combination of gridinterfacinginverter and the 3-phase 4-wire linear/non-linearunbalanced load at point of common coupling appears asbalanced linear load to the grid. This new control concept isdemonstrated with PSCAD/EMTDC software.

کلیدواژه ها:

active filter ، modified p-q theory ، flexible photovoltaic system