STOPPING METHOD FOR VARIABLE SPEED REVERSIBLE PUMP-TURBINE OR PUMP

摘要

PURPOSE:To reduce the input from an electric power system at the time of parallel-off stopping the operation of pump by reducing the number of revolutions of a generator-motor and further reducing the opening of guide vanes when a pump is stopped. CONSTITUTION:When the command to stop the operation of pump is received, the performance of pump changes in accordance with the thick solid line C-D. The opening of guide vanes is gradually throttled, and at the same time the number of revolutions is gradually decreased via speed controller being a means to regulate the number of revolutions. The motor is brought into parallel-off from an electric power system at the point D where the number of revolutions is not less than the lowest number of revolutions and the opening of guide vanes is the parallel-off opening GVOd. Thus, as compared with that the pump input at the time of parallel-off was the parallel-off input Pd1 in the case of a constant speed machine, it can be reduced to the parallel-off input Pd2 in the time of parallel-off notwithstanding the same guide vane parallel-off opening GVOd.