Protection Devices for MVDC Offshore Wind Integration

Project Description:

This Research Project is part of the Aura CDT’s research for optimisation and reliability of wind turbine systems and components Cluster.

The potential for integration of Offshore Wind energy through the use of Medium Voltage DC (MVDC) connections opens up new challenges in addition to the often discussed possibilities. Traditional protection devices for the distribution grid are deisgned for AC power, whereas MVDC systems require a complete paradigm shift in approach.

Recent developments in high voltage power transistors frealised from wide bandgao semiconductors, such as silicon carbide, have opened up the possibility to control systems operating beyond 10 kV with a single device. This leads to the possibility of realising passive and active protection functionality that can protect the wind turbine and collection network from fault conditions, including lightning strike and short circuit fault. The project will utilise a range of high performance silicon carbide components to demonstrate high reliability operation of MVDC networks for offshore energy systems.

To date, protection has been demonstrated at low voltage levels (<1 kV) and for low power levels. This project intends to demonstrate a step change in capability supported by access to novel transistors and optimisation of the switching and thermal characteristics of the devices. Protection of DC circuits is a rapidly evolving field of research that supports a wide range of applications from electric aircraft to the creation of microgrids for the decarbonisation of remote communities in addition to offshore wind energy systems. Current technology solutions absed on solid state breakers do not offer the capability to actively control the energy flow in these high voltage MVDC systems, resulting in a loss of control at the system and reduced system availability when fault conditions occur.