IMAGE LICENSED BY GRAPHIC STOCK By Qun Qiu, Jeffery A. Fleeman, and David R. Ball Geomagnetic Disturbance A comprehensive approach by American Electric Power to address the impacts. Digital Object Identifier 10.1109/MELE.2015.2480615 Date of publication: 2 December 2015 22 I E E E E l e c t r i f i cati o n M agaz ine / december 2015 MERICAN 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- A Transmission System Planned Performance 2325-5987/15©2015IEEE