Lessons Learned About Transient Behaviours of Inverter-Based Resources and Identification of Best Practices for Interconnection Line Protections

Among the protection functions that have shown to be critically affected by IBRs, those used in transmission lines stand out. Various known issues are transient in nature, being related to either the IBR controls or IBR interconnection system topology/sources. Such characteristics may affect unit and non-unit line protections, including phasor- and transient-based solutions.

Given the presented context, this work shares lessons learned on the impacts of fault transient response of power systems under the influence of IBRs, identifying solutions that can help transmission line phasor- and transient-based protections to overcome issues that may be caused by Grid-Following (GFL) and Grid-Forming (GFM) IBRs. To do so, off-the-shelf solutions and literature proposals are studied and referenced, mapping features that may be promising for

IBR-interconnecting line protection. Presented studies are carried out by means of real-world records and PSCAD simulations, through which detailed GFL- and GFM-IBR models are tested, considering a typical interconnection transmission system topology. Different fault cases and control strategies are assessed to demonstrate how they impact on IBR transient behaviours and, consequently, how they affect the performance of line protections. From the obtained results, a list of good practices for phasor- and transient-based line protections applied to systems near IBRs are indicated as recommendations, adding information to previous works that already addressed the IBR influence on fault steady-state conditions.