非均匀地磁扰动下电压稳定性的研究

Geomagnetic disturbances (GMD) are rare events that threaten grid reliability, where the severity of the impact is highly uncertain. Notably, geomagnetically induced currents (GICs) produce an excess of reactive power loading due to transformer saturation, which has an impact on voltage stability. Interface flow limits that serve to maintain voltage stability can become obsolete during a GMD due to large reactive power deviations from the nominal operating point. This paper presents methods to determine GMD-informed voltage stability limits to assist in mitigation during extreme solar storms. In this paper, a characterization of plausible, non-uniform electric fields caused by GMDs is developed to determine new interface stability limits with respect to a base operating condition. Active power limits are discussed as a function of the scale of a given GMD, characterized by bounds on electric field magnitude, signal frequencies, and earth conductivity. The presented methods use finite modeling to define a plausible set of non-uniform electric fields that is searched with a nonlinear programming formulation leveraging continuation power flow and linear sensitivities. Case studies (20-Bus and 2000-Bus) quantify the increased severity of non-uniform electric fields compared to uniform fields with the same electric field magnitude. The proposed non-uniform electric field model is used to efficiently model and identify realistic electric fields and associated flow limits to help ensure voltages remain within a safe range during a GMD.