🤖 AI Summary
This work addresses the high computational cost of full power flow calculations in real-time N-1 thermal security assessment and the lack of statistical safety guarantees in existing fast linear methods under deployment shifts. The authors propose an audit-based selective verification framework that employs a lightweight proxy model to pre-screen contingencies eligible for skipping, complemented by online randomized full power flow audits. By leveraging a risk budget and confidence bounds, the method provides theoretical guarantees on the thermal violation rate of the skipped set. Notably, it achieves statistically safe, lightweight screening under arbitrary deployment shifts—relying on actual verification and online auditing rather than proxy accuracy—and is compatible with diverse controller outputs. Evaluations on three public transmission systems demonstrate that the actual violation rate consistently remains below the allocated budget, reducing full power flow computations by 29%–75% while preserving safety under deployment shifts.
📝 Abstract
Real-time N-1 contingency screening in an energy management system trades assurance against cost: verifying every credible outage with full power flow is too slow, while fast linear-sensitivity screening gives no statistical guarantee and can silently pass unsafe operating points, especially when a controller drives the system into unfamiliar regimes. This paper introduces Audited Selective Verification, a risk-budgeted screening and triage layer for any controller's output (optimization, model-predictive, or learned). A cheap surrogate proposes which outages to skip; an online audit runs full power flow on a small random sample each window; and a calibrated threshold certifies a thermal-violation-rate bound for the skipped set at a chosen budget and confidence, with a corresponding bound for the unverified trusted subset. Validity rests on real verification and the audit rather than on surrogate accuracy, so it holds under arbitrary deployment shift. It is a risk-budgeted screen, not a replacement for deterministic verification when policy requires checking every credible contingency. On three public transmission systems up to 1354 buses, the realized violation rate stays within budget, standard deterministic and calibrated screens become unsafe under shift, and the method cuts full power-flow studies by 29 to 75 percent per real-time operating point.