PR Controller for a Three-phase Grid-connected Inverter in an Unbalanced System using a Time-Domain Symmetrical Components Extraction Method

Ahstract-This study describes a way for controlling the power delivered by a three-phase inverter into an unbalanced grid while also balancing the grid currents. The control system has two objectives: maintaining the unbalanced in the grid currents and injecting the grid with the desired power. The inverter reference current is derived from: 1) a component for balancing grid currents derived from the unbalanced load currents' negative/zero sequence components utilizing a time-domain symmetrical components extraction technique, and 2) a second component obtained from an inverter power command. So, the proposed method can achieve both objectives at the same time - balancing the grid currents and injecting power to the grid. The proposed method's performance has been validated by experimental results.