Identification of umbrella constraints in DC-based security-constrained optimal power flow
Bibliographic record
Abstract
Summary form only given. The general goal of security-constrained optimal power flow (SCOPF) problems is to optimize electricity network operation while ensuring that operational and planning decisions are consistent with technical limits under both pre- and post-contingency states. The solution of SCOPF problems is challenging because of the inherent size and scope of modern grids. As empirical evidence and longstanding operator experience show, relatively few of the constraints of SCOPF problems actually serve to enclose their feasible region. Hence, all those constraints not contributing directly to set up the SCOPF feasible space are superfluous and could be discarded. In light of this observation, this paper proposes an optimization-based approach for identifying so-called umbrella constraints in SCOPF problems where the network operation is approximated by the dc power flow. Umbrella constraints are constraints which are necessary and sufficient to the description of the feasible set of an SCOPF problem. The resulting umbrella constraint discovery problem (UCD) is a convex optimization problem with a linear objective function. For SCOPF problems of practical importance, the UCD is also quite large and requires the use of a decomposition technique. In this paper, we concentrate on an SCOPF formulation for preventive security generation dispatch. We show that by removing superfluous constraints, the resulting sizes of SCOPF problems are much smaller and can be solved significantly faster.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".