Impedance-compensated grid synchronisation for extending the stability range of weak grids with voltage source converters

This paper demonstrates how the range of stable power transfer in weak grids with voltage source converters (VSCs) can be extended by modifying the grid synchronisation mechanism of a conventional synchronous reference frame phase locked loop (PLL). By introducing an impedance-conditioning term in t...

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Detalles Bibliográficos
Autores: Suul, Jon Are, D'Arco, Salvatore, Rodríguez Cortés, Pedro|||0000-0002-1865-0461, Molinas Cabrera, Marta
Tipo de recurso: artículo
Fecha de publicación:2016
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:2117/99088
Acceso en línea:https://hdl.handle.net/2117/99088
https://dx.doi.org/10.1049/iet-gtd.2015.0879
Access Level:acceso abierto
Palabra clave:Power electronics
synchronisation
HVDC power convertors
phase locked loops
power grids
Electrònica de potència
Àrees temàtiques de la UPC::Enginyeria elèctrica::Maquinària i aparells elèctrics
Descripción
Sumario:This paper demonstrates how the range of stable power transfer in weak grids with voltage source converters (VSCs) can be extended by modifying the grid synchronisation mechanism of a conventional synchronous reference frame phase locked loop (PLL). By introducing an impedance-conditioning term in the PLL, the VSC control system can be virtually synchronised to a stronger point in the grid to counteract the instability effects caused by high grid impedance. To verify the effectiveness of the proposed approach, the maximum static power transfer capability and the small-signal stability range of a system with a VSC HVDC terminal connected to a weak grid are calculated from an analytical model with different levels of impedance-conditioning in the PLL. Such calculations are presented for two different configurations of the VSC control system, showing how both the static power transfer capability and the small-signal stability range can be significantly improved. The validity of the stability assessment is verified by time-domain simulations in the Matlab/Simulink environment.