A series flywheel architecture for power levelling and mitigation of dc voltage transients in multi-terminal HVDC grids

Islam Azmy Gowaid, Ahmed Abbas Elserougi, Ayman Samy Abdel-Khalik, Ahmed Mohamed Massoud, Shehad Ahmed

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


This study proposes a new architecture of flywheel energy storage system (FESS) which can be implemented at generating unit (GU) level (e.g. wind turbine) or scaled up for application in grid-side converter (GSC) stations of a multi-terminal direct current (MTDC) system. The proposed architecture suppresses DC voltage leaps under grid faults, and performs power levelling duty at grid connection points. When implemented at GU level, the proposed FESS features a doubly-fed induction machine (DFIM) - the flywheel machine - where its six stator winding terminals are connected in series between the grid and the GSC. The flywheel converter is of partial power rating, and is connected to the DFIM rotor. When employed at an MTDC GSC station, several submodules are connected to build an FESS station. The study proposes the control concept and the general topology of the FESS station. The performance parameters of the system are tested under normal and abnormal operating conditions. Results and analyses indicate smooth dynamic operation, the economic advantage and the improved fault ride-through capability because of the proposed system.
Original languageEnglish
Pages (from-to)1951-1959
Number of pages9
JournalIET Generation, Transmission & Distribution
Issue number12
Early online date18 Dec 2014
Publication statusPublished - Dec 2014


  • HVDC power convertors
  • HVDC power transmission
  • asynchronous machines
  • flywheels
  • power grids
  • power system transients
  • power transmission faults
  • rotors
  • stators
  • DC voltage leaps
  • DC voltage transients
  • DFIM rotor
  • FESS station
  • GSC stations
  • GU level
  • MTDC system
  • doubly-fed induction machine
  • fault ride-through capability
  • flywheel converter
  • flywheel energy storage system
  • flywheel machine
  • generating unit level
  • grid connection points
  • grid faults
  • grid-side converter station
  • multiterminal HVDC grids
  • multiterminal direct current system
  • partial power rating
  • power levelling duty
  • power mitigation
  • series flywheel architecture
  • smooth dynamic operation
  • stator winding terminals


Dive into the research topics of 'A series flywheel architecture for power levelling and mitigation of dc voltage transients in multi-terminal HVDC grids'. Together they form a unique fingerprint.

Cite this