Protection and tripping strategy for pumped-storage unit startup in back-to-back mode

Back-to back starting is used as a backup starting system for present static stating systems and is the only pump-starting method available during the static starting system is out of work. Meanwhile, back-to-back starting plays an important role in black start of the grid. In the present paper, the procedure of back-to-back starting of pumped-storage hydraulic generating units is investigated and analyzed. The short circuit fault and loss of rotor field failure is analyzed based on the SIMULINK model. Consequently the paper proposes a protection and tripping strategy.