Geomagnetic Disturbance: A comprehensive approach by American Electric Power to address the impacts

American Electric Power (AEP), one of the largest electric utilities in the United States, operates the nation?s largest electricity transmission system with a nearly 40,000-mi network in 11 states, connecting more than 5,000 substations, among which more than 800 are 138 kV and above. Per the recently approved North American Electric Reliability Corporation (NERC) geomagnetic disturbance (GMD) standards EOP-010-1?Geomagnetic Disturbance Operations and TPL-007?Transmission System Planned Performance During Geomagnetic Disturbances, AEP?being the owner and operator of the bulk-power system?would be required to develop GMD operating procedures and conduct initial and ongoing assessments on potential impacts of benchmark GMD events on bulk-power system equipment, especially extra-high-voltage (EHV) transformers, and the bulk-power system as a whole. Based on these assessments, it is also required to prepare a plan (if necessary) to mitigate any GMD impacts. This article describes AEP?s comprehensive approach and efforts on GMD monitoring, modeling, and mitigation to ensure reliable performance of its critical transmission network and assets.