Pole Slipping in Droop-Based Grid-Forming Inverters
AbstractIntegration of grid-forming inverter-based resources (GFM-IBRs) is considered as a viable solution to address the challenges associated with the dynamics of power systems with high penetration levels of inverter-based resources. Yet, various aspects of dynamic behaviour of grid-forming inverters during disturbances have remained unknown. This paper for the first time introduces the concept of pole slipping in GFM-IBRs. The differences between stable and unstable pole slipping are highlighted. The determining factors for the occurrence of stable and unstable pole slipping in grid forming inverters and equipment-level implications of pole slipping are identified and studied. Afterwards, a solution is proposed to mitigate stable and unstable pole slipping in grid-forming inverters. The validity of the proposed concept of pole slipping in GFM-IBRs and the proposed solution is tested and verified through extensive timedomain simulations.