Large-Scale Inverter Integration in Bulk Power Grids Using Heterogeneous Grid-Forming Control Strategies

To facilitate the decarbonization of power grids, conventional synchronous generation is gradually being replaced by inverter-based resources (IBRs). Inverters with grid-forming (GFM) control are expected to play a key role in ensuring stable operations within an IBR-rich grid. Hence, the accurate representation of inverter dynamics in realistic, large-scale transmission network models is crucial for the veracity of dynamic stability and contingency analysis studies conducted by system operators. However, the development of scalable frameworks for modeling real bulk power grids with high GFM inverter integration has not yet been thoroughly explored. To address this gap, this work develops an automation framework for creating bulk power grid models with varying IBR penetration levels, significantly reducing the time and effort required in a manual process. Two types of GFM inverter models, droop-controlled and virtual synchronous machine (VSM)-controlled inverters, are considered. Various penetration level scenarios, ranging from 24% to 100%, are modeled using the full representation of the US Western Interconnection. Simulation results show that both droop-controlled and VSM-controlled inverters can provide effective grid support in response to various disturbances.