Power Control of a Three-phase Grid-connected Inverter using a Time-Domain Symmetrical Components Extraction Method under Unbalanced Conditions

Presented in this paper is a method to use a three-phase inverter to inject currents to balance the grid currents while supplying power to the grid. The reference currents for the inverter are determined from the negative/zero sequence components of the measured load currents using a time-domain symmetrical components extraction method. Under the existence of unbalanced conditions, the proposed method corrects the unbalanced grid currents while simultaneously supplying the commanded power to the grid. The simulation and experimental results validate the performance of this proposed method.