Oscillatory spreading and inertia in power grids

Area of Science:

• Electrical Engineering
• Complex Systems
• Network Science

Background:

• The integration of variable renewable generators (VRGs) into power systems is increasing.
• VRGs introduce new sources of power oscillations, while traditional synchronous generators (SGs) provide stabilizing responses that diminish with VRG penetration.
• This shift necessitates novel methods for rapid assessment of power system oscillatory behavior, moving beyond computationally intensive simulations.

Purpose of the Study:

• To investigate the impact of system inertia on power system oscillatory responses to VRG perturbations.
• To develop and apply a new metric for quantifying the spread and severity of oscillations.
• To establish a relationship between inertia, network structure, and oscillatory behavior.

Main Methods:

• Utilized a known localization metric to quantify the number and magnitude of network nodes responding to perturbations.
• Analyzed the effect of varying inertia values on system dynamics under representative VRG disturbances.
• Introduced a heuristic derived from the network Laplacian to characterize the transition in oscillatory response spread.

Main Results:

• A higher system inertia value was found to transition the response to node perturbations from localized to delocalized.
• The study quantified the relationship between inertia and the spread of power oscillations.
• The proposed heuristic accurately described the oscillation spread in a realistic power system test case.

Conclusions:

• System inertia is a critical parameter influencing the nature and extent of power system oscillations.
• The developed heuristic offers a computationally efficient method for predicting oscillatory behavior.
• This approach has significant potential for optimizing power system planning and operation by reducing computational demands.