Power Collection and Distribution in Medium-Voltage DC Networks

Latest News

2015.09.08: Project application submitted to Innovationsfonden.dk

2015.09.01: CIGRÉ Working Group established. C6-31 “MVDC Grid Feasibility Study”

Research Programme Description

To reduce electrical losses and investment cost of HVDC-connected offshore wind power plants, it is proposed to let the wind farm’s internal power collection network become medium-voltage DC rather than medium-voltage AC. Such a paradigm shift entails new solutions in the entire chain from wind turbine to HVDC export cable:

  • Wind turbine DC converters (~10MW, ±50kV)
  • MVDC cables
  • MV/HV DC/DC converters (~hundreds of MW, ±50kV/±320kV)
  • MVDC distribution substation and network control & protection.

This not only requires development of new essential components that work together in a new system configuration. Therefore, we:

  • Investigate different DC network topologies for power flow control, security of supply, while establishing a foundation for equipment rating (cables, converter stations
  • Explore and demonstrate 50kV converter design using relevant power semiconductors
  • Explore and demonstrate high‐frequency converter transformer designs with low‐loss steels, suitable winding arrangement and insulation systems, leading to the construction of a prototype
  • Study methods to secure DC network stability and power quality
  • Develop insulation co‐ordination for DC networks and assure fault clearance capability
  • Promote early standardisation of the ensemble of components in DC networks and equipment functionalities based on findings
  • Develop MVDC system simulation models and simulation environment.

With the above, we aim to identify the optimal - and feasible - DC collection solution(s) in terms of configuration, equipment ratings, operational characteristics.

MVAC based offshore wind farm: One or more wind plants with substation, connected to a single HVDC offshore converter.

MVDC based offshore wind farm: plant power collection at medium-voltage DC & offshore step-up HVDC converter.


Pontoppidanstræde 101
9220 Aalborg East

Professor Philip Carne Kjær
E-mail: pck@et.aau.dk
Phone: +45 5139 3726

Professor Claus Leth Bak
E-mail: clb@et.aau.dk
Phone: +45 9940 9281

Associate Professor Filipe Miguel Faria Da Silva
E-mail: ffs@et.aau.dk
Phone: +45 9940 9280

Postdoc Yu-Hsing Chen
E-mail: yhc@et.aau.dk
Phone: +45 2295 8743

PhD Catalin Gabriel Dincan
E-mail: cgd@et.aau.dk
Phone: +45 5086 6867

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