Notice bibliographique
Résumé
Power systems are part of the nationâs critical infrastructure and they support several indispensable services of our civilization such as hospitals, transportation systems, and telecommunications. Among the many requirements that power systems need to satisfy, power systems need to ensure that voltages and currents in the power grid are sinusoidal with a synchronous frequency of 50 or 60 Hz. Failure to do so would cause damage in appliances as well as in electrical industrial machinery that were developed under the assumption of sinusoidal voltages and currents with constant frequency. Furthermore, according to the North American Electric Reliability Corporation, frequency divergence of one or more of the generators that supply power to the grid, i.e., loss of synchronization, can lead to vibrations causing serious damage to the generators. As documented in the United States Department of Energy report on the August 14, 2003 blackout in Canada and the Northeast of the United States, frequency swings are the main reason for blackouts to spread across power systems. This makes the preservation of synchronization of generator frequencies one of the most important problems in power systems. This problem is also known as the transient stability problem in the power systems literature.The classical models used to study the transient stability problem implicitly assume that all the generators are rotating at angular velocities close to the synchronous frequency. This assumption is known not to hold in real power systems. A well documented example by the Department of Energy is the final stage of the August 14, 2003 blackout. This makes us question the validity of the existing tools and methods, based on classical assumptions and models, to predict and prevent the spread of blackouts.In this work, we abandon the classical models and replace them with energy-based models derived from first principles that are not subject to hard-to-justify classical assumptions. In addition to eliminate assumptions that are known not to be satisfied, we derive intuitive conditions ensuring the transient stability of power systems. Providing such conditions in theclassical framework with lossy transmission lines is a problem that has remained unsolved for more than sixty years and partial solutions under very restrictive assumptions have only recently been found. This is to be contrasted with the conditions described in this thesis that naturally handle lossy transmission lines. With the help of the insights we gained in the analysis performed in Section 4.3, we design easy-to-implement controllers that solve the transient stability problem in power systems. We also provide a novel way of performing circuit reduction, aiming to reduce the complexity of transmission grid models. Kron reduction, which is performed under steady state assumptions, is the standard circuit reduction technique used in the power systems literature. The novel circuit reduction method described in Section 3.1 shows how to perform Kron reduction for a class of electrical networks without these steady state assumptions.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,002 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,002 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».