Coordinated Dynamic Operating Envelopes for Unlocking Additional Flexibility at Grid Edge

TL;DR

This paper introduces a convex, geometry-aware framework for constructing dynamic operating envelopes that enhance grid flexibility while ensuring network safety, fairness, and robustness to forecast uncertainties.

Contribution

It presents a novel partial coordination approach using polytopal and hyperrectangular flexibility sets, improving flexibility and fairness in distribution grids.

Findings

Expanding flexibility by approximately 25% with 30% coordinated customers.

Framework maintains network limits and fairness constraints.

Robust formulation effectively handles forecast uncertainties.

Abstract

Dynamic operating envelopes (DOEs) provide a systematic framework to integrate the flexibility of distribution grid resources while safeguarding network limits such as line ratings and voltage bounds. However, the flexibility derived from individual DOEs is often restricted and conservative, especially when some resources can coordinate via communication with an aggregator. This paper presents a convex, geometry-aware framework for constructing DOE for distribution grid customers under partial coordination, with coordinated customers modeled through polytopal flexibility sets and non-coordinated customers through hyperrectangles. The framework additionally incorporates fairness constraints for export and import headroom allocated to the customers within the DOE design. To account for forecast uncertainty in inelastic injections, the DOE design is extended to a robust formulation for bounded uncertainty sets. Case studies on the European Low Voltage Test Feeder indicate that the proposed DOE construction expands total harnessed flexibility, while being consistent with network limits, export/import fairness constraints and is robust to forecast uncertainty. Specifically, coordinating 30% of customers increased the achievable aggregate active-power injection range by approximately 25% relative to the non-coordinated baseline.