DVAC on Multi-terminal VSC-HVDC grids

A novel distributed supplementary control of MTDC grids for static and dynamic stability enhancement of AC/DC systems, aiming to minimize the interaction with the DC voltage


The solution consists in a decentralized control architecture to enhance AC transient stability while keeping the power balance of the DC grid even if converters reach their active power limits.



  • Increasing the security of the overall system (AC rotor angle and DC voltage). FR1906968 and FR1906969
  • Automatic dispatch of stations in the same synchronous grid. This feature helps to avoid power loops in the grid, therefore to avoid unnecessary losses. FR1906968
  • In case of AC asynchronous grids connected through an MTDC, the solution can help to synchronize the systems. FR1906968
  • Supplementary control references for dynamic stability enhancement of the surrounding AC grid. Power oscillation damping and Transient stability enhancement. FR1906968.
  • Supplementary power references do not interact with the DC voltage control, even when power references reach converter limits. This principle can be used for other supplementary controllers, not only the FDC and ADC. FR1906969


  • Multi-Terminal VSC-HVDC grids embedded or partially embedded in an AC grid (at least two terminals in the same synchronous grid)


  • Patent applications (FR1906969, FR1906968), Technical reports, Virtual mock-ups
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