摘要 |
In a hydroelectric facility, a vertically mounted rotatable shaft is connected to a motor-generator and carries a pump-turbine with a supplying pump disposed below and immersed in water, the supplying pump disengaging from the shaft when the pump-turbine is driving the motor-generator and engaging the shaft when the motor-generator is driving the pump-turbine and supplying pump, thereby providing a two-stage pumping mode and a single-stage generating mode. |