Assessment of the future demand for grid forming converters in an exemplary transmission system
Sustainability goals aimed at mitigating climate change have led to the phasing out of traditional synchronous generation, while increasing the integration of inverted-based resources into power systems. This has brought significant challenges to stability and reliability, traditionally ensured by s...
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| Formato: | tesis de maestría |
| Fecha de publicación: | 2025 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/443961 |
| Acesso em linha: | https://hdl.handle.net/2117/443961 |
| Access Level: | acceso abierto |
| Palavra-chave: | Electric power transmission Renewable energy sources Electric power systems -- Simulation methods Energia elèctrica -- Transmissió Energies renovables Sistemes de distribució d'energia elèctrica -- Mètodes de simulació Àrees temàtiques de la UPC::Enginyeria elèctrica |
| Resumo: | Sustainability goals aimed at mitigating climate change have led to the phasing out of traditional synchronous generation, while increasing the integration of inverted-based resources into power systems. This has brought significant challenges to stability and reliability, traditionally ensured by synchronous generators. This thesis investigates the future demand for grid-forming converters (GFM) as an enabling technology for ensuring transient frequency stability in converter-dominated systems, by using an exemplary transmission system. Dynamic models of synchronous generators, grid-following (GFL) converters, and GFMs based on virtual synchronous machine concepts were developed and tested in DIgSILENT PowerFactory, followed by testing the developed models on a 9-bus system. Subsequently, a series of case studies were conducted in the studied transmission system, covering scenarios with increasing levels of IBR penetration. Simulation outputs were processed and automated using Python to compute the rate of change of frequency (RoCoF), frequency nadir and zenith, and maximum bus angle deviations, alongside plots that deepen the analysis and identify trends and thresholds. The results were benchmarked against the theoretical RoCoF calculations, the baseline synchronous generation scenario, and the German grid code requirements for transient stability. The results demonstrate that systems dominated by GFL inverters face severe stability limitations once synchronous generation is reduced. In contrast, the integration of GFM maintains and even improves frequency and angle stability, enabling compliance with grid codes under high IBR shares. Critical thresholds were identified beyond which system stability cannot be guaranteed without the introduction of GFM operation. The thesis concludes with the assessment of the exemplary transmission system, confirming the identified share thresholds to keep frequency stability, and presents some final remarks about the limitations of IBRs and future work that should be addressed to deepen the conducted work. |
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