Negative-sequence (NS) current sharing among different grid-forming (GFM) sources is a critical issue in islanded microgrids (MGs). Existing sharing strategies only focus on the NS current distribution among inverter-based resources (IBRs). However, existing approaches have not fully considered the NS current sharing among IBRs and SGs and are easily affected by line impedances. In this paper, a leader-follower-based approach is proposed for the NS current sharing among IBRs and SGs. The leader IBR regulates the bus NS voltage to zero to generate the total NS current references. The NS current references are shared by leader and follower IBRs. After the IBRs’ NS currents follow the references, the SGs’ NS currents can also be determined. The proposed control strategy is verified through both simulation and experimental testing on a converter-based hardware testbed.
