Harmonic Load Flow during Geomagnetic Disturbances

The main purpose of this paper is to provide a methodology to assess the impact of harmonic load flow during Geomagnetic Disturbances (GMD). A 1-100 year GMD scenario is used to derive GIC flows across Dominion's network. The harmonic spectrum of the magnetizing current is derived based on the GIC flowing through power transformers. A harmonic load flow solution is performed to assess the Total Harmonic Distortion (THD) across the network. The modeling intricacies of a network-wide harmonic analysis are discussed. The impact on major equipment (generators, SVC/STATCOM, and capacitor banks) is analyzed. The methodology is demonstrated using a highly detailed model of Dominion Virginia Power, with more than 4000 buses and 200 harmonic injections.