Power quality enhancement by power electronic generation interface under non-ideal voltage conditions

Distributed generation (DG) interfaced to the grid through power electronic (PE) interface can be used to provide reactive power for voltage stability in a power system they are part of. Furthermore, they can be used to minimize the harmonic issues caused by the PE non-linear loads present at the distribution level. This article investigates the possibility of using a generation side PE interface for shunt active filtering in addition to supply the active power demand to the consumers under non-ideal source voltage conditions. Reference signal generation techniques for shunt compensator are based on instantaneous reactive power (IRP) p-q theory and the theory of current´ s physical components (CPC), in rotating synchronous reference frame (SRF). Converter control is based on vector control method. IRP p-q theory based reference signal generation technique uses filters to extract the desired current components. CPC utilizes frequency domain methods to compute the current references Simulation results show that the generation interface performs shunt active filtering very efficiently. However, it is observed that the source current distortion is further increased due to the reduction of fundamental current component in the source current when generation interface supplies the active power to the power network.