Small-signal modeling of weak AC networks with a low short-circuit ratio
The modelling of weak grids in power systems is an active research topic due to the decrease in the strength of the network as a result of the integration of power electronicbased devices in the system. When the small-signal stability criterion is used to identify potential interactions and propose...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/340611 |
| Acceso en línea: | https://hdl.handle.net/2117/340611 |
| Access Level: | acceso abierto |
| Palabra clave: | Electric networks -- Mathematical models Xarxes elèctriques -- Models matemàtics Àrees temàtiques de la UPC::Enginyeria elèctrica::Distribució d’energia elèctrica |
| Sumario: | The modelling of weak grids in power systems is an active research topic due to the decrease in the strength of the network as a result of the integration of power electronicbased devices in the system. When the small-signal stability criterion is used to identify potential interactions and propose new control strategies, the common practice is to represent the grid by a simple RL-Thévenin equivalent based on a certain short-circuit ratio. However, this approach may not able to include the relevant network dynamics for the stability assessment, and thus leading to misleading results. In this work, the different representation of the main power system elements is analysed in the context of small-signal stability for the particular case of weak grids and their equivalence is assessed. It is shown that the load representation is of great relevance for assessing the system stability and that there is a certain equivalence in representing the grid by a SG-based model and by Thévenin equivalent. Nonetheless, discrepancies are apparent in the frequency and state variables of the detected instabilities in the various models, which illustrates that the assessment and mitigation of the potential issues may differ between different grid representations. |
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