Collaborative Solution of Distance Protection and Dual Current Control for Outgoing Lines of Inverter-Based Resources during Line-to-Line Faults

Unlike synchronous generators (SGs), inverter-based resources (IBRs) exhibit unique fault behaviors. These fault behaviors include limited fault current amplitude, controlled fault current phase, and unsteady sequence impedance. The unique fault behaviors of IBRs, combined with the absence of zero-sequence current, can lead to the malfunction of IBR-side distance protection on outgoing lines of IBRs during nonmetallic line-to-line (LL) faults. In this paper, a collaborative solution of distance protection and dual current control is proposed to address this issue. The proposed collaborative solution includes distance protection with accurate trip regions (ATRs) and a negative-sequence impedance reconstruction (NSIR) control strategy. The distance protection with ATRs calculates the additional impedance angle and generates ATRs accordingly, while the NSIR control strategy maintains constant negative-sequence impedance angles for IBRs to coordinate with the distance protection with ATRs. The proposed collaborative solution can effectively avoid underreach and overreach of distance protection, while still maintaining consistency with IEEE Std. 2800 and modern grid codes even though the NSIR control strategy changes the fault behaviors of IBRs. The proposed collaborative solution is verified with the PSCAD/EMTDC test.