The energy world is changing rapidly. Methods of generation, distribution, and storage are evolving to accommodate innovations on all three of those fronts—innovations that have been inspired by societal needs for a more sustainable energy future. Evolving grid dynamics are at the center of this transformation. These dynamics are made more complex by the addition of inverter-based resources (IBRs),which are electricity sources like solar, wind, and battery that use power-electronic devices to interface with the bulk power system.

New analytical approaches are needed to adapt the power system planning methods to a new environment consisting of ultra-high penetration of IBRs. Similarly, power system controllers may have to be adapted to reflect the responsiveness of the systems as the level of system inertia changes. For example, IBRs use grid voltage signals measured at their grid connection points to manage their active and reactive power. As system inertia decreases, the angle and frequency of the voltage may change very fast, leading to a more transient behavior.

Secure and reliable power system operations are critical to a new environment consisting of increased IBR usage and fewer synchronous machines. This will require a smooth transition from the present power grid to the future power grid, with a new set of analytical methods and tools. These new analytical methods will be designed to include the new phenomenon, such as high-frequency dynamics, reduced system strength, and reduced short circuit current, that will be observed in the future grid.

This project is divided into six tasks:

• Identifying gaps in applying conventional analytics approaches used in steady-state, dynamic simulations, and short circuit analysis in a grid with ultra-high IBR penetration
• Examining current generic IBR models for steady-state and dynamic simulations
• Modeling inverter behavior accurately by collecting inverter data from utility/inverter manufacturers 
• Developing controls and interconnection requirements that allow reliable operation of large AC transmission systems with very few synchronous machines
• Developing new algorithms for short circuit calculations and protection coordination between IBRs, transmission, and loads
• Performing simulation-based case studies and sensitivity analysis