Control of Grid-interfacing Inverters with IntegratedVoltage

The basic principle and detailed controlof grid-interfacing inverters supporting negative-sequence voltage correction has been presented.

The control of a gridinterfacing inverter with integrated voltage unbalance correction.
It is proposed to add an additional function to the inverter to decrease the negative-sequence voltage at the point of connection with the utility grid. Based on a symmetric sequence voltage decomposition and using an improved multi-variable filter, the grid-interfacing inverter
intentionally absorbs a small amount of negative-sequence current from the grid, thereby helping to correct the negative-sequence voltage.