DC protection for a multi-terminal HVDC network including offshore wind power, featuring a reduced DC circuit breaker count

• Main Authors: Max A. Parker, Derrick Holliday, Stephen J. Finney
• Format: Article
• Language: English
• Published: Wiley 2019-04-01
• Series: The Journal of Engineering
• Subjects: wind power plants; wind turbines; offshore installations; HVDC power transmission; circuit breakers; HVDC power convertors; circuit breaker requirement; DC protection; multiterminal HVDC network; offshore wind power; reduced DC circuit breaker count; offshore wind farms; shore; North Sea; high-voltage DC transmission; currently proposed methods; DC network; DC circuit breakers; high cost
• Online Access: https://digital-library.theiet.org/content/journals/10.1049/joe.2018.8149
• ISSN: 2051-3305

Large offshore wind farms located far from shore, as are being planned or built in the North Sea, will require high-voltage DC (HVDC) transmission to shore, and multi-terminal HVDC could offer further benefits. Currently proposed methods to protect against faults in the DC network are based on extremely fast-acting DC circuit breakers located on all cable ends, leading to high cost. A method is proposed based around discharging the DC network to isolate the fault, which drastically reduces the circuit breaker requirement, while making use of the inherent current-limiting behaviour of the wind turbines. The validity of this approach is demonstrated in simulation.