Establishing Power Transformer Capability While Under Geomagnetic Disturbances

December 2022

Geomagnetic Disturbances (GMD) is a phenomenon which is widely studied due to its impact on the operation of the electrical grid. Power transformers, which are a critical component of the electrical grid, are particularly susceptible to GMD and the resulting geomagnetically induced currents (GIC) which flow through transmission lines and transformer terminals connected to the ground. While the effects of GMD events on power transformers are generally known, advancements in modeling have improved the understanding of the susceptibility of power transformers to these effects. Establishing power transformer capability while under GMD allows asset owners to plan and reliably operate their power transformers during these events.

Technical Reports & Applicable Papers or Presentations

IEEE PES Transactions Papers

IEEE Transmission and Distribution Conference Papers

IEEE PES Conference Papers


Other Available Material
IEEE PES Webinars & General Meeting Sessions
Impact of Geomagnetically Induced Current (GIC) on Power Transformers & Power Systems IEEE-PES General Meeting Session: July 2022 Speakers: M. Olson, K. Patil, A. Commander, T. Hartmann, A. O’Malley, R. Girgis, G. Hoffman, and S. Digby The Panel Session at the 2022 IEEE PES GM Conference covered the following Topics:
  • NERC’s TPL007 Standard, its requirements, Tasks, and Timeline
  • System Modelling and Calculation of GIC Flow in Power Systems
  • GIC Transformer Fleet Assessment – Case study
  • Other Utility experiences with GIC Fleet Assessment
  • GIC Thermal Capability of Power Transformers
  • FirstEnergy’s experience with GIC System Study
  • On-Line Monitoring of GIC and its Thermal impact in Real Time
  • Overview of IEEE GMD Guide; C57.163-2016 and planned updates
IEEE PES Tutorial Sessions
Geo-magnetically Induced Current: Effects on Power Transformers and the Power System; Monitoring, and Potential Mitigation IEEE-PES Tutorial: 2012 Speaker: E. Bernabeu, D. Fugate, R. Girgis and F. Koza Geo-magnetically induced currents (GIC) flow into power transformers through the neutral. These currents can cause core saturation depending on the magnitude of the GIC and the design of the transformer. However, there is some misconception in the electric power industry today that GIC currents have caused and will cause significant damage to large and medium power transformers installed on power grids. The purpose of this tutorial is to present the true effect of GIC on power transformers and power systems, and the available methods to monitor GIC, as well as mitigating its effects. This tutorial has four parts. First, factors that influence the susceptibility of power transformers to overheating due to GIC will be explained. This will be followed by a presentation on simulating GIC flow in power systems and the impact of the resulting MVAR demands and magnetizing current harmonics on voltage stability, system protection, and other power system components. The third part of the tutorial will include an overview of GIC monitoring, typical time-scale & magnitude characteristics of GICs, the type of sensors that are required (and sensor locations relative to the monitored transformer), and the data acquisition hardware used to capture and transmit GIC information. The last part of this tutorial will deal with the work of a task force (TF) formed by NERC to study all aspects of Geomagnetic Disturbances (GMD). Finally, representatives of power utilities in North America who will be attending the tutorial will be given the opportunity to share with the attendees. VIEW MORE >