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Virginia Tech

Synchronous Condensers and Grid-Forming Control for the Integration of Inverter-Based Resources in Weak Grids

Abstract

dc:description.abstract

Power systems with a higher share of inverter-based resources (IBR) exhibit reduced system strength and inertia, which are otherwise provided by synchronous generators (SG). This is because IBRs do not have the rotational inertia of SGs, and they do not contribute to short-circuit fault currents as much as SGs do. The lack of strength and inertia increases the risk of instability during contingencies, e.g., short-circuit faults. This dissertation investigates and proposes methodologies to enhance the stability of IBRs by leveraging synchronous condensers (SC) and grid-forming control. First, it presents an optimization model to find the optimal location and size of SCs, aiming to minimize the total cost of SCs and maintain the strength (measured by short-circuit ratio [SCR]) above a desired value at the point of connection of all IBRs. Second, it develops a robust exciter controller for SCs to maintain terminal voltage stability under large disturbances in weak grids. Third, it proposes a method to identify the most effective subset of IBRs to operate in grid-forming mode, accounting for the dynamic interactions between SGs and IBRs, to improve voltage and frequency stability. These contributions collectively support the reliable and cost-effective integration of IBRs into future power systems.

Degree

thesis:*
Name thesis:degree_name
Doctor of Philosophy
Level thesis:degree_level
doctoral
Discipline thesis:degree_discipline
Electrical Engineering
Department dc:contributor.department
Electrical Engineering
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2025

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Fouladi, Ehsan
Chair dc:contributor.committeechair
  • Mehrizi-Sani, Ali
Committee members dc:contributor.committeemember
  • Liu, Chen-Ching
  • Jin, Ming
  • De La Reelopez, Jaime
  • Southward, Steve C.

Subjects

dc:subject × 3

Rights

dc:rights
Statement dc:rights
  • In Copyright
Language dc:language.iso
en

Identifiers

dc:identifier.*
Dc Identifier Other
vt_gsexam:44796
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/138163

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Fouladi, Ehsan. Synchronous Condensers and Grid-Forming Control for the Integration of Inverter-Based Resources in Weak Grids. doctoral thesis, Virginia Tech, 2025. https://hdl.handle.net/10919/138163