Aggregate Grid-Forming Control of Distributed Energy Resources

This article presents an aggregate grid-forming control for heterogeneous distributed energy resources (DERs). The proposed control achieves a desired, aggregated grid-forming response by coordinating power contributions among multiple different DERs. Unlike existing aggregate control strategies that are typically objective-specific or topology-specific, this article proposes a generic, flexible, and modular control design. The design supports four basic module types, i.e., AC- or DC-coupling and AC- or DC-output topological arrangements, adequately accommodating diverse DER integration scenarios, e.g., AC, DC, AC/DC hybrid microgrids, hybrid energy storage systems, or hybrid renewable power plants. The grid-forming control design is systematically developed by aggregating DER dynamics and disaggregating control objectives for the four basic modules, then extended to modular configurations through a top-down approach. The grid-forming performance is comprehensively validated through simulation and experiments. This modular control design provides scalable and standardizable grid interfaces, enabling effective aggregation of heterogeneous DERs to jointly achieve grid-forming dynamic response.