The impact of post-fault active power recovery ramp rates of wind turbines on transient stability in Great Britain

The predominant North-South active power flows across the border between Scotland and England are currently limited by stability considerations. As the penetration of variable-speed wind power plants in Great Britain grows, it is imperative that stability limits, operational flexibility, efficiency and system security are not unnecessarily eroded as a result. The study reported in this paper illustrates the impacts on critical fault clearing times and power transfer limits through this North-South corridor in the presence of increasing levels of wind power plants on the GB transmission system. By focussing on the behaviour of a representative reduced test system following a three-phase fault occurring on one of the two double-circuits of the B6 boundary, the impacts on transient stability margins are qualitatively identified. By altering the immediate post-fault active power recovery ramp-rate of the wind power plants, the transient stability performance of the grid with additional wind power can be significantly improved. The outputs of the project are intended to provide a basis for further detailed studies on a more realistic network model.