Multi-tasking dc-dc and dc-ac converters for dc voltage tapping and power control in highly meshed multi-terminal HVDC networks

Grain Philip Adam, Ibrahim Abdelsalam, Lie Xu, John Fletcher, Graeme Burt, Barry Williams

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9 Citations (Scopus)
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this paper extends a recently proposed dc auto-transformer to a true multi-port converter that can function simultaneously as dc auto-transformer and a dc/ac converter for dc voltage matching and tapping, and power control in highly meshed multi-terminal dc grids. The presented multi-port converter can generate multiple adjustable dc voltages from a fixed or variable input dc voltage, or from an active ac grid. Theoretical discussions and simulations indicate that when the proposed multi-port converter is used as a hybrid dc and ac hub to manage congestions and resolve loop flow issues in a highly meshed multi-terminal dc network, large dc power can be fed to the lower dc terminal, without exposing the switching devices of the lower sub-converter to excessive current stress. Its increased control flexibility and response to dc faults at high and low dc terminals are validated using simulations and experiments.
Original languageEnglish
Number of pages20
JournalIET Power Electronics
Early online date11 Aug 2017
Publication statusE-pub ahead of print - 11 Aug 2017


  • modular multilevel converter
  • multi-terminal dc grids
  • multi-port converter
  • high-voltage direct current transmission systems

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