Modeling the impact of GIC neutral blocking devices on distance protection relay operations for transmission lines

Journal Article · Mon Dec 09 04:00:00 EST 2019 · Electric Power Systems Research

DOI:https://doi.org/10.1016/j.epsr.2019.106135· OSTI ID:1607236

Piesciorovsky, Emilio C. ^[1]; Tarditi, Alfonso G. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Geomagnetic Induced Current (GIC) blocking devices typically include a capacitor on the neutral grounding path of wye-configured transformers. This type of GIC blocking device was designed as an effective countermeasure to prevent possible damages caused on the power grid by geomagnetic storms, and by the slow-varying component of a high-altitude electromagnetic pulse (HEMP). The insertion of a capacitor in the transformer neutral impedes the establishment of GICs in lines terminated with wye-connected transformer windings. With the presence of a capacitively grounded neutral, however, it becomes important to evaluate that no adverse effects are introduced in the general grid operations. In this context, this study investigates the impact of GIC neutral blocking devices on the functionality of distance protection relays for different values of transformer neutral blocking capacitors, and at different transmission line voltages. This study was conducted with a real-time simulation platform, and the simulations were performed by introducing a phase-to-ground fault at different line locations, and by measuring the apparent impedance at the protection relay location. Finally, the results indicated that, for typical values of capacitance considered for GIC neutral blocking devices, the distance protection relay model operates properly, without requiring a modification of the relay settings.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1607236
• Journal Information: Electric Power Systems Research, Journal Name: Electric Power Systems Research Journal Issue: C Vol. 180; ISSN 0378-7796
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
apparent impedance
distance protection relay
geomagnetic induced currents
neutral blocking device
transmission line