A Review of the GIC Blocker Placement Problem

TL;DR

Geomagnetic disturbances pose high-impact, low-frequency risks to the bulk electric system, motivating sparse deployment of transformer neutral blocking devices. The paper delivers a comprehensive literature review of GIC blocker placement and presents a complete optimization formulation that couples full AC power-flow with a quasi-DC GIC model, implemented in open-source software. It demonstrates the computational difficulty of globally optimal blocker placement on larger networks and discusses relaxations and future work to enable scalability while highlighting the trade-off between load served and blocker deployment costs. Overall, the work provides a concrete, implementable framework for optimization-based GIC blocker placement and serves as a foundation for scalable approaches in real-world networks.

Abstract

Space weather poses a tremendous threat to power systems: geomagnetic disturbances could result in widespread disruptions and long-duration blackouts, including severe damage to system components. To mitigate their impacts, a handful of strategies exist, with the most promising being the deployment of transformer neutral blocking devices. The high cost of these devices, however, precludes their installation at all substations; this motivates the development of effective solutions for the cost-effective placement of such devices. While the current state-of-the-art in blocker placement methods is insufficient to be applied to real-sized power grids, ongoing research continues to increase the size of networks for which the placement problem remains tractable. Along these lines, the contributions of this paper are two fold: first, a comprehensive overview of the current state-of-the-art in blocker placement methods is provided; and second, a complete optimization formulation - implemented and benchmarked in an open-source software - for the blocker placement problem is presented.