Improved power quality control strategy for distributed generation systems

Distribution Generation aims at integrating different power plants to increase the reliability and provide additional power quality benefits. Coming to the grid-connected mode, almost all the commercial single-phase inverters for DG systems inject only active power to the grid, i.e., the reference current is computed from the reference active power p* that must be generated. This paper deals with a single-phase inverter acquiring power quality features, i.e., active and reactive power generation along with current harmonics compensation. This is achieved by integrating the functions of shunt Active Power Filter (APF) to the control scheme. The control scheme employs a current reference generator with a dedicated repetitive current controller. Two phase conversion of single phase system is used in this paper for the extraction of harmonic components and also for supplying required reactive power by load. The simulation results are presented for the grid connected inverter that generates active power and compensates the reactive power and current harmonics of local loads, thus achieving complete power quality features.