Asynchronous Grid Connections Providing Fast-Frequency Response: System Integration Study

TL;DR

The paper investigates an asynchronous grid connection as a physical aggregator to deliver fast-frequency response from behind-the-meter resources. It develops a reduced-order nonlinear model, validates it with PHIL experiments, and integrates it into an IEEE 9-bus system to quantify dynamic improvements, including delayed nadirs and enhanced damping. An economic analysis in the PJM market (RegD/A framework) shows potential profitability with a 15-year horizon, driven by revenue from fast-regulation services and favorable discounting, albeit contingent on supportive tariffs and regulatory structures. The study also discusses market and regulatory barriers, emphasizing the need for standardized aggregation rules and cross-regional policy alignment to realize large-scale deployment. Overall, the work demonstrates both technical feasibility and economically favorable prospects for asynchronous-grid-based FF R services, while outlining regulatory paths and future research directions for scalability and EMT-level fidelity.

Abstract

This paper presents an integration study for a power electronic-based fast-frequency response technology, an asynchronous grid connection operating as an aggregator for behindthe-meter resources and distributed generators. Both technical feasibility and techno-economic viability studies are presented. The dynamic performance of the fast-frequency response enabled by the asynchronous grid connection is validated with Power Hardware-in-the-Loop experiments and transferred to an IEEE 9-bus system in DigSilent PowerFactory for dynamic stability analysis. We demonstrate that droop-based control enhancements to the local distributed generators could allow their aggregation to provide grid-supporting functionalities and participate in the market for ancillary services. To this end, we performed a long-term simulation embedding the system within the ancillary service market framework of PJM. The fast-frequency response regulation is subsequently used to calculate the potential revenue and project the results on a 15-year investment horizon. Finally, the techno-economic analysis concludes with recommendations for enhancements to access the full potential of distributed generators on a technical and regulatory level.

Figures (9)

• Figure 1: Conceptual visualization for the asynchronous grid introduction.
• Figure 2: model, including controller and converter average model, implemented within an RMS simulation in DigSilent Power Factory.
• Figure 3: Back-to-Back Converter in the double test bed.
• Figure 4: The green line in a) shows the low-voltage frequency of the developed model, while the blue line represents experimental benchmark acquired in the experiment. As a result of the frequency the active power flow adaptation is illustrated in b), using the same color code.
• Figure 5: Single-line diagram of the IEEE 9-bus system vijayvittalPowerSystemControl2020sauerPowerSystemDynamics2017.