Control strategy of grid-tied converter considering negative-sequence voltage of PCC under unbalanced voltages

Recently, the adoption of renewable energy power generation sources has been increasing annually. In the future power grid, it is anticipated that Inverter-Based Resources (IBR) will replace synchronous generators. When a grid fault occurs, IBR can inject compensation current into the grid relatively quickly compared to a synchronous generator. So, the emergence of new grid codes has introduced requirements for rapid current injection, but the converters' limitations on maximum current during faults present difficulties in devising effective control strategies for such current contribution. The existing grid codes only establish a linear relationship between voltage droop and grid-support current, thus failing to provide optimized voltage support. Considering the impact of unbalanced voltages on the load, need a requirement to eliminate negative-sequence components. Hence, there is a need for a control strategy that can efficiently inject compensation current by accounting for the negative sequence.