Integration of geomagnetic disturbance modeling into the power flow: A methodology for large-scale system studies

Abstract

Abstract-This paper presents a methodology for integrated power flow modeling of the impact of geomagnetic disturbances (GMDs) on the power system voltage stability. GMDs cause quasi-dc, geomagnetically induced currents (GICs) in the transformers and transmission lines, which in turn cause saturation of the high voltage transformers, greatly increasing their reactive power consumption. GICs can be calculated using standard power flow modeling parameters such as line resistance, augmented with several GIC specific fields including substation geographic coordinates and grounding resistance, transformer configuration, and transformer coil winding resistances. When exact values are not available estimated quantities can be used. By then integrating GIC into power flow analysis, the changes in reactive power losses and bus voltages can be quantified to assess the risk of voltage instability and large-scale voltage collapse. An example calculation is provided for a North American Eastern Interconnect model.

Modeling Geomagnetically Induced Currents From Magnetometer Measurements: Spatial Scale Assessed With Reference Measurements

“…The model relating substation transformer neutral current to surface electric field is given by (Overbye et al, , ): where are the neutral currents as a function of time t ; T is the number of transformers; depends on the transformer configuration (e.g., Y or Δ connected) and resistances; S is the number of substations and L is the number of lines; depends on the topology, line resistances, and substation resistances; depends on the line lengths and orientations; and E ( t ) is the vector of time‐varying northward and eastward surface electric field components. Note that the model makes the simplifying assumption that the induced geoelectric field is uniform over the simulated power grid footprint.…”

“…The second modeling step, referred to as the engineering step, involves relating GMD‐driven surface geoelectric field to currents induced in a high‐voltage power network (Albertson et al, ; Boteler & Pirjola, ; Kappenman, ; Overbye et al, ; Pirjola, ). Such models are dependent on knowledge of power grid network topology and other system parameters such as line and substation resistances, transformer configuration, and transformer resistances.…”

North Europe power transmission system vulnerability during extreme space weather

“…Several studies assume a linear transformer behavior during GIC saturation (Dong, 2002;Overbye et al, 2012). The increase in reactive power consumption due to saturation caused by GICs is proportional to a coefficient K1 that depends on the characteristics of the transformer core design (Dong, 2002).…”

Rapid prediction of electric fields associated with geomagnetically induced currents in the presence of three‐dimensional ground structure: Projection of remote magnetic observatory data through magnetotelluric impedance tensors

“…Applied research efforts have been aimed at understanding the nature of GICs to predict and effectively mitigate them through dynamic control of the grid as an alternative to widespread hardening of transformers. GIC prediction software has been developed to model in near real time the effects within a power system of changes in the electric field at ground level due to GMDs [ Overbye et al ., ; Khosravi and Johansson , ], so that voltages within the system can be biased to lessen harmful effects. The GIC prediction problem reduces the components of the specified grid to an equivalent complex circuit, and it uses the ground electric field along the components of the grid to determine the variable intensity of current flow in response to the imposed electric field [ Pirjola , ].…”