Synchronization Stability of Hybrid Power Systems Integrated with Grid-Forming Inverters and Grid-Following Inverters

This paper investigates the synchronization stability of hybrid power systems integrated with grid-forming (GFM) inverters and grid-following (GFL) inverters. In hybrid power systems, the interactions between GFM and GFL inverters bring about challenges for the synchronization stability analysis. To address this issue, a fourth-order synchronization model considering controller interactions is established. Then, the influence of inter-actions on the stable equilibrium point (SEP) and the synchronization process is fully clarified. It is found that interactions are detrimental to the SEP of GFM inverters but beneficial to the SEP of GFL inverters. For synchronization processes, the instability and stabilization caused by controller interactions are presented, indicating the important effect on the synchronization process. In addition, suggestions for controller design to improve synchronization dynamics through controller interactions are provided. Simulation results validate these findings.