Grid strength impedance metric : an alternative to SCR for evaluating system strength in converter dominated systems
Henderson, Callum and Egea-Alvarez, Agusti and Knueppel, Thyge and Yang, Guangya and Xu, Lie (2024) Grid strength impedance metric : an alternative to SCR for evaluating system strength in converter dominated systems. IEEE Transactions on Power Delivery, 39 (1). pp. 386-396. ISSN 0885-8977 (https://doi.org/10.1109/TPWRD.2022.3233455)
Preview |
Text.
Filename: Henderson_etal_IEEE_TOPD_2022_Grid_strength_impedance_metric_an_alternative.pdf
Accepted Author Manuscript License: Strathprints license 1.0 Download (1MB)| Preview |
Abstract
Short circuit ratio is an outdated measure of system strength in converter dominated systems as the useful behaviour of inverter-based resources is not represented. While still useful for determining fault current provision, converter connected generation contributes to short circuit level and system strength in a different way to traditional synchronous generation. Additionally, traditional measures only account for system strength at the fundamental frequency while converters possess complex interactions across a frequency range. A novel method of determining system strength across this frequency range from the network impedances is proposed in this paper. The approach known as the Grid Strength Impedance Metric, calculates the system strength independently from short circuit level. The unique contribution of grid-following and grid-forming converters is represented by including the multiple-input multiple-output converter output impedances in the calculation. Small-signal impedance models are employed, and the metric is largely concerned with short-term voltage stability, but some inferences can be made for longer timescales. The approach is validated using time domain simulations to check for any identified areas of weakness in the frequency range. The Grid Strength Impedance Metric successfully represents the useful behaviour of grid-forming converters, indicating an enhancement in voltage stiffness in locations of deployment.
ORCID iDs
Henderson, Callum, Egea-Alvarez, Agusti ORCID: https://orcid.org/0000-0003-1286-6699, Knueppel, Thyge, Yang, Guangya and Xu, Lie ORCID: https://orcid.org/0000-0001-5633-7866;-
-
Item type: Article ID code: 83669 Dates: DateEvent1 February 2024Published9 January 2023Published Online28 December 2022AcceptedSubjects: Technology > Electrical engineering. Electronics Nuclear engineering > Electrical apparatus and materials > Electric networks Department: Faculty of Engineering > Electronic and Electrical Engineering Depositing user: Pure Administrator Date deposited: 10 Jan 2023 17:02 Last modified: 12 Dec 2024 14:12 URI: https://strathprints.strath.ac.uk/id/eprint/83669