Grid-Tied Three-Phase Inverter Current Control Considering Low Voltage Ride Through Capability: A Comparison between Stationary and Synchronous Reference Frames

This work presents a study and comparison of current control for three-phase grid connected voltage inverters to cope with low voltage ride through requirements. A comparison between current control loops implemented employing synchronous and stationary frames is presented and their performances are analyzed during voltage sags. Current reference generation method is discussed; under which it is possible to minimize active power oscillations during a voltage sag or inject balanced currents even in asymmetric sags. The control system developed in this work is implemented in a DSC and demonstrated operating in a 5-kW three-phase voltage inverter with an LCL filter. Experimental results are presented to validate the analyzes.