Full-size variable speed pumped storage unit has such advantages as fast adjustable power

fast response speed

Independent decoupling of active and reactive power and can provide multiple services such as peak load regulation

frequency regulation

reactive voltage support and demand response for the operation of power grid and is presently one of the main technical development directions of pumped storage technology. However

the maximum current of full-size variable speed pumped storage unit shall not exceed the overload capacity of the converter at any time due to the limitation of the current flow capacity of the converter. The demand for active and reactive power is different during fault and fault recovery period with the power grid side. In this paper

several active and reactive current distribution strategies of variable speed pumped storage unit are compared. And it is proposed that the reactive current priority control strategy of variable speed pumping unit can meet the reactive voltage demand of weak power grid during fault and fault recovery. Finally

the correctness of this strategy is verified through the simulation analysis of variable speed pumped storage unit in actual power grid.