Control Strategies for Power Electronic Interfaces in Unbalanced Diesel Hybrid Mini-Grids with Renewable Sources and Storage
Notice bibliographique
Résumé
Traditionally, remote communities worldwide consist of autonomous power systems (mini-grids) supplied almost exclusively by diesel-engine generator sets (gensets) at relatively high costs. Integration of renewable energy sources (RESs), such as, photovoltaic (PV) and wind, can substantially reduce the cost of electricity generation and emissions in these remote communities. However, the highly variable load profile typical of mini-grids and the fluctuating characteristics of the RESs, cause frequent operation of the diesel genset at low loading condition, at low efficiency points and subject to carbon build up, which can significantly affect the maintenance costs and even the life time of the genset. Another important issue that is frequently overlooked in small (< 100 kVA) mini-grids, which usually present a low number of loads thus reducing the averaging effect, is load unbalance. Diesel gensets supplying unbalanced loads experience overheating in the synchronous generator and vibration in the shaft. For efficient operation, the genset should be operated near its full capacity and also in balanced mode. \nIn order to address the above mentioned issues, a fast and reliable multi-mode battery energy storage system (BESS) employing voltage source inverter (VSI), is proposed in this thesis. In the genset support mode, as a basic feature, it can provide minimum loading for the genset and supplement it under peak load conditions. In addition, it can also provide load balancing and reactive power compensation for the mini-grid system. Therefore, the genset operates in balanced condition and within its ideal power range. In cases when the power demand from the genset is low, due to high supply of RESs and/or low load consumption, the genset can be shut-down and the BESS forms the grid, regulating voltage and frequency of the mini-grid system in the grid forming mode. Besides, the logic for defining the operating mode of the BESS and for achieving smooth transitions between modes are also presented in this thesis. \nThe conventional approach for the control of three-phase VSI with unbalanced loads uses three-phase vector (dq) control and symmetrical components calculator which usually results in slow dynamic responses. Besides, the common power (P) vs. frequency (f) droop characteristic of the genset results in the mini-grid operating with variable frequency what further complicates the design of the controller for the VSI. Therefore, a new frequency adaptive per-phase dq-control scheme for three-wire and four-wire three-phase VSI based on the concept of fictive axis emulation is presented. It enables the control of current/voltage of each phase separately to achieve better dynamic performance in the variable frequency diesel hybrid mini-grid system. The effectiveness of the proposed techniques is demonstrated by means of simulation and experimental results.
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) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
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 ».