DC Interconnection and Transmission in Offshore Wind Farms

  • Supervisors: Dr. D Ewen Macpherson, Dr. Markus Mueller (University of Edinburgh), Dr. Steve Finney (University of Strathclyde)
  • Sponsoring Company: GE Energy & Power Conversion
  • PhD Student: Tom Wood
  • This student has graduated and the project is complete.

This Project aims to develop a system model of an offshore wind farm with a focus on electrical power transmission. Most existing offshore wind farms are within 20km of the shore and use AC transmission. However, future wind farms will be further from shore. Overall, transmission by AC cable is more economic over short distances but as distance increases there is a break point above which DC cable is more cost effective.  Advances in and falling costs of power electronic devices are moving this break point down. 

The project will investigate the use of DC transmission all the way from the wind turbine tower to the onshore inverter. The multi-terminal DC grid that will be modelled may have applications to other DC, MVDC or HVDC grid designs. In particular, the challenges presented by variable and uncontrolled input power from the wind will be similar for other types of renewable generation. Additionally, voltage, current and power flow control methods can be applied to any DC grid, be it offshore, national or cross-border.