The partial frequency energy converter: a novel device for low-frequency offshore wind electricity transmission

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2022
Thesis identifier
  • T16289
Person Identifier (Local)
  • 201676527
Qualification Level
Qualification Name
Department, School or Faculty
  • Low frequency AC transmission has been proposed for the integration of distant offshore wind farms to offer a compromise between HVAC and HVDC. The advantages in transmission distance due to the reduced power losses over HVAC and an improved fault handling capability over HVDC suggests that there is room for this technology in the wind industry. However research and industrial trends have favoured the continued use of HVDC connections despite growing concerns over cost and reliability. HVDC connections are not without issues, and questions regarding to this technology’s robustness, cost, size and synchronisation are still left unanswered. Additionally the limited supply chain and the bespoke nature of each HVDC connection introduces a further set of unknowns to project cost. Technical problems arising from recent HVDC developments have shaken the confidence of the industry and left large risk premiums on all future deployments of the technology. This thesis looks into developing novel technology to unlock the advantages of LFAC but without the downsides associated with large power-electronic converters. This technology is called the Partial Frequency Energy Converter (PFEC) which combines the controllability of DC converters with the robustness of large electrical machines. By using a combination of modern control techniques and the manipulation of electromagnetic fields in a novel arrangement of induction machines, the PFEC exists as a fusion between old and new technology. The PFEC not only allows the integration of LFAC systems to the AC grid but it is also capable of providing inertia and stabilisation to power systems. The PFEC therefore offers a solution that is not only technologically viable, but also timely and necessary to the industry.
Advisor / supervisor
  • Campos-Gaona, David
Resource Type