Reversible pump-turbine system
AssigneeHitachi, Ltd.
InventorsTakao Kuwabara, Masataka Harada
Life of this patent
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Abstract
A reversible pump-turbine system having a discharge adjustment device such as guide vanes, which make it possible to safely stop a pump turbine at the time of emergency shutdown in a generating mode by performing a close operation using an inlet valve even if abnormality has occurred with the guide vanes, without causing abnormal water hammer. Also, at the time of pump mode emergency shutdown, reverse rotation can be prevented even if abnormality occurs in the guide vanes, and it is possible to achieve a safe stop while reducing the loads/stresses to the reversible pump-turbine.
Claims18
A reversible pump-turbine system provided with an inlet valve and a discharge adjustment device for controlling adjustment of a discharge of a reversible pump-turbine connected to a generator-motor, comprising:
- inlet valve closure means for closing the inlet valve at a rate slower than a normal closure rate of the discharge adjustment device at the time of emergency shutdown, wherein
- the closure rate of the inlet valve is switched according to an operating mode of the reversible pump-turbine.
A reversible pump-turbine system provided with an inlet valve and a discharge adjustment device for controlling adjustment of a discharge of a reversible pump-turbine connected to a generator-motor, comprising:
- inlet valve closure means for closing the inlet valve at a rate slower than a normal closure rate of the discharge adjustment device at the time of emergency shutdown, wherein
- the closure rate of the inlet valve is switched according to an operating mode of the reversible pump-turbine;
- and further comprising:
- a low speed detector for detecting that rotation speed during pumping operation has fallen below a rated value;
- and
- closure means for closing the inlet valve at a high rate faster than the closure rate at the time of generating mode emergency shutdown, in response to a signal from the low speed detector.
A reversible pump-turbine system provided with an inlet valve and a discharge adjustment device for controlling adjustment of a discharge of a reversible pump-turbine connected to a generator-motor, comprising:
- inlet valve closure means for closing the inlet valve at a rate slower than a normal closure rate of the discharge adjustment device at the time of emergency shutdown, wherein
- the closure rate of the inlet valve is switched according to an operating mode of the reversible pump-turbine;
- and further comprising:
- a low speed detector for detecting that the rotation speed during pumping operation has fallen below a rated value,
- a failure detector for detecting that a closing operation of the discharge adjustment device has not been carried out at a specified rate;
- and
- closure means for closing the inlet valve at a fast rate faster than the rate at the time of generating mode emergency shutdown in response to operation of the low speed detector and the failure detector.
A reversible pump-turbine system provided with an inlet valve and a discharge adjustment device for controlling adjustment of a discharge of a reversible pump-turbine connected to a generator-motor, comprising:
- a controller for closing the inlet valve at a rate slower than a normal closure rate of the discharge adjustment device at the time of emergency shutdown, wherein
- the closure rate of the inlet valve is switched according to an operating mode of the reversible pump-turbine.
In a reversible pump-turbine system provided with an inlet valve and a discharge adjustment device, a method of controlling adjustment of a discharge of a reversible pump-turbine connected to a generator-motor, comprising the steps of:
- closing the inlet valve at a rate slower than a normal closure rate of the discharge adjustment device at the time of emergency shutdown, wherein
- the closure rate of the inlet valve is switched according to an operating mode of the reversible pump-turbine.
Dependencies are inferred from the claim text.