Future Grid Challenges: Case Studies on Forced Oscillations, Grid Strength, and Dynamic Modeling

With the energy transition the grid is undergoing, grid planning is more challenging than ever due to the shift of the current synchronous generation dominated grid paradigm to inverter-based resources. The energy transition will be shaped by intense load growth due to electrification of various energy sectors and thus highlights a critical need to evaluate stability of the grid, even in areas dominated with synchronous generation. This dissertation will discuss large-scale studies aimed at assessing near-term issues as well as planning for the future grid uncertainty. In particular, case studies will consider small-signal stability, grid strength, and dynamic grid modeling. Forced oscillations are used to evaluate stability impacts on a particular region within the Eastern Interconnection as well as more broadly to the entire grid. A grid strength study considering short circuit levels is used to assess the impacts as a small island grid transitions from a fossil-fuel dominated grid to entirely renewable energy. Model tuning and optimization of loads and generators through the use of high- and low-resolution measurements is explored to improve accuracy of simulations. Lastly, this work explores the application of the transfer function dynamic model reduction method for equivalizing a large area of a grid.