Impact of Geomagnetic Induced Current Neutral Blocking Devices on Distance Relays in Sub-transmission Networks with IBR

Conference · Mon Dec 01 00:00:00 EST 2025

DOI:https://doi.org/10.1109/NAPS66256.2025.11272304· OSTI ID:3020899

Patel, Trupal R ^[1]; Piesciorovsky, Emilio ^[2]; Reno, Mathew ^[1]

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1. Sandia National Laboratories (SNL)
2. ORNL

Geomagnetically induced currents (GICs) can flow through transmission lines during geomagnetic disturbances, such as solar flares or coronal mass ejections. These currents can cause problems like transformer saturation and equipment damage. The most common method of mitigating GICs involves installing GIC neutral blocking devices (NBDs) in transformer neutrals. However, the wide application of capacitive GIC blocking devices may have unintended adverse effects on other devices, such as distance protection relays. As the number of inverter-based resources being connected to the transmission and sub-transmission systems increases, the likelihood of a sub-transmission line protected by a distance relay connected to a transformer with NBDs is increasing. Therefore, distance relays fed by IBRs and transmission lines with GIC-NBDs must be studied. This paper studies the effect of GIC-NBDs on a 69kV sub-transmission line of various lengths fed by a 25 MVA IBR and synchronous source. This work focused on the behavior of the GIC-NBDs using the measured apparent phase-to-ground and phase-to-phase impedance calculated by the relay and the source impedance ratio (SIR) during various electrical faults.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 3020899
• Resource Type: Conference paper/presentation
• Conference Information: 2025 57th North American Power Symposium (NAPS) - Storrs, Connecticut, United States of America - 10/26/2025-10/28/2025
• Country of Publication: United States
• Language: English