[论文解读] Ramping-aware Enhanced Flexibility Aggregation of Distributed Generation with Energy Storage in Power Distribution Networks

Hyeongon Park, Molzahn, Daniel K.+1 more|arXiv (Cornell University)|Jan 21, 2026

Optimal Power Flow Distribution被引用 0

一句话总结

This paper develops a ramping-aware flexibility aggregation framework at the transmission–distribution interface, introducing a pre-ramping strategy to enlarge the aggregate flexibility envelope while guaranteeing device-level disaggregation and network feasibility, validated on an IEEE-33 bus system.

ABSTRACT

Power distribution networks are increasingly hosting controllable and flexible distributed energy resources (DERs) that, when aggregated, can provide ancillary support to transmission systems. However, existing aggregation schemes often ignore the ramping constraints of these DERs, which can render them impractical in real deployments. This work proposes a ramping-aware flexibility aggregation scheme, computed at the transmission-distribution boundary, that explicitly accounts for DER ramp limits and yields flexibility envelopes that are provably disaggregable. To further enhance the attainable flexibility region, we introduce a novel pre-ramping strategy, which proactively adjusts resource operating points to enlarge the aggregated flexibility envelope while preserving both network feasibility and disaggregation guarantees. The proposed method demonstrates a 5.2% to 19.2% improvement in flexibility relative to the baseline model, depending on system conditions. We validate the scheme on an IEEE-33 bus distribution system and provide formal proofs showing that both aggregation strategies are disaggregable for all feasible trajectories within the aggregate flexibility envelope.

研究动机与目标

• Motivate the need for distribution-system flexibility to support transmission-system operations amidst increasing DER penetration.
• Develop a ramping-aware inner-box flexibility envelope at the grid connection point that respects DER ramp limits and network constraints.
• Introduce a pre-ramping strategy to proactively reposition operating points and enlarge the aggregated flexibility envelope.
• Prove disaggregation guarantees for all trajectories within the envelope and demonstrate practical gains in an FRP market context.

提出的方法

• Formulate a ramping-aware baseline flexibility envelope at the GCP using a linear program.
• Impose resource-level constraints (generation and ESS), including explicit ramp-rates and cross-time transitions.
• Model distribution-network feasibility with LinDistFlow and enforce voltage and power-flow constraints.
• Introduce pre-ramping decision variables to pre-position resources and expand the envelope while preserving feasibility and disaggregation guarantees.
• Provide a finalized LP formulation that incorporates both baseline and pre-ramped constraints (jointly enforced).
• Validate performance on an IEEE-33 bus distribution system with case studies including envelope area comparison and FRP-market considerations.

实验结果

研究问题

• RQ1 How can ramp-rate constraints of distributed generators and energy storage be explicitly incorporated into a tractable aggregate flexibility envelope at the GCP?
• RQ2 Does introducing pre-ramping expand the achievable aggregate flexibility while preserving disaggregation guarantees and network feasibility?
• RQ3 What is the quantitative improvement in the deliverable flexibility region when using the pre-ramped enhanced model versus baseline ramping-aware models?
• RQ4 How does the approach perform under realistic FRP-market settings and with time-varying PV and load profiles?
• RQ5 Can the proposed envelopes be disaggregated to feasible schedules for individual DERs across a 24-hour horizon?

主要发现

• The ramping-aware baseline model yields a feasible aggregate envelope when enforcing explicit ramp-rate constraints, eliminating infeasible interior trajectories.
• The pre-ramped enhanced model enlarges the aggregate flexibility envelope by repositioning resources in advance, while maintaining disaggregation guarantees and network feasibility.
• Compared to a no-ramping model, the approach achieves improvements in envelope area, with gains ranging from 5.2% to 19.2% depending on ESS capacity and placement.
• Validation on IEEE-33 bus system demonstrates disaggregation feasibility for all trajectories within the proposed envelopes via Monte Carlo sampling.
• Case studies indicate that ESS capacity and strategic placement significantly influence the delivered envelope area, with notable gains when ESSs are relocated near critical network locations.
• The models are applicable in FRP market contexts, providing a grid-aware method to quantify and deliver ramping flexibility.