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US3730638A
Expired / Lapsed
US
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Speed governor
Assignee: Hitachi Ltd
•
Filing: 1971-12-16
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Granted: 1973-05-01
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Expires: 1991-12-16
Abstract
Abstract A speed governor system for a hydraulic or pumper turbine being fed water from a penstock for controlling the output of the turbine under varying load conditions. When the load of a generator coupled to the turbine is abruptly cut off, the governor system closes the guide vane assembly to limit the flow of water to the turbine at a speed in accordance with an estimated water pressure rise in the penstock. The water pressure rise is estimated from the operational turbine factors including rotational frequency of the turbine runner, the acceleration thereof, the water head and the position of the guide vane assembly. The governor system acts to prevent a dangerous level of water pressure rise.
Inventors
- 👤 T Kuwabara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:52
CPC Classifications
F; F03; F03B; F03B15/00; F03B15/02; F03B15/04; F03B15/06; Y; Y02; Y02E; Y02E10/00; Y02E10/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
A speed governor system for controlling the operation of a turbine fed water from a penstock in which the turbine is subjected to varying load conditions, the system comprising means for detecting the rotational frequency of the turbine runner, means for adjusting the output of the turbine in accordance with the detected rotational frequency of the runner, means for continuously estimating the degree of rise of water pressure in the penstock caused by an abrupt decline of the turbine load, and means for controlling said turbine output adjusting means in accordance with the estimated degree of the pressure rise.
Claim 2
Dependent Claim
99 words
A speed governor system for controlling the operation of a turbine fed water from a penstock in which the turbine is subjected to varying load conditions, the system comprising means for detecting the rotational frequency of the turbine runner, means for adjusting the output of the turbine in accordance with the detected rotational frequency of the runner, means for continuously estimating the degree of rise of water pressure in the penstock caused by an abrupt decline of the turbine load, and means for controlling said turbine output adjusting means in accordance with the estimated degree of the pressure rise.
Claim 3
Dependent Claim
65 words
A speed governor system according to claim 1, wherein said estimating means estimates the degree of water pressure rise in the penstock in accordance with the value and amount of variation of signals representative of turbine operAtional factors fed thereto, said factors including rotational frequency N of the runner, acceleration of the runner dN/dt water head H, and guide vane opening of the turbine Y.
Claim 4
Dependent Claim
118 words
A speed governor system according to claim 1, wherein said turbine output adjusting means comprises a pressure-distributing valve responsive to the output of said runner rotational frequency detecting means, a servo motor controlled by said pressure-distributing valve, and a guide vane assembly controlled by said servo motor for adjusting the positioning of the guide vane assembly in accordance with a desired water flow rate into the runner, said pressure-distributing valve being controlled by said controlling means in accordance with the degree of water pressure rise estimated by said water pressure estimating means, the opening and closing of the guide vane assembly being controlled at a speed in accordance with the range of movement of the guide vane assembly.
Claim 5
Dependent Claim
34 words
A speed governor system according to claim 3, wherein said servo motor is actuated for controlling the immediate closing of the guide vane assembly in response to an abrupt decline of the turbine load.
Claim 6
Dependent Claim
43 words
A speed governor system according to claim 3, wherein said servo motor is responsive to an abrupt decline in the turbine load for first controlling the opening of the guide vane assembly and then for controlling the closing of the guide vane assembly.
Claim 7
Dependent Claim
85 words
A speed governor system according to claim 1, wherein said controlling means comprises a movable valve means including at least one coil means movable in response to the output of said estimating means, at least one movable stop arm responsive to said at least one movable coil means for displacement to a position in accordance with the output of said estimating means, and feedback means for feeding back to said movable valve means a signal corresponding to the amount of movement of said stop arm.
Claim 8
Dependent Claim
47 words
A speed governor system according to claim 6, wherein said turbine output adjusting means includes a pressure-distributing valve for controlling a servo motor, the range of control of the servo motor by said pressure distributing valve being limited in accordance with the position of said stop arm.
Claim 9
Dependent Claim
64 words
A speed governor system according to claim 2, including means for limiting the output of said estimating means, said limiting means including means responsive to at least one predetermined value of each of the turbine operational factors relating to water pressure rise for operating in a stepped manner in accordance with the value of the operational factors with respect to the predetermined value therefor.
Claim 10
Dependent Claim
39 words
A speed governor system according to claim 8, wherein said limiting means is provided with first and second predetermined values for the acceleration of the turbine runner and one predetermined value for each of the other turbine operational factors.
Claim 11
Dependent Claim
76 words
A speed governor system according to claim 1, wherein said turbine output adjusting means includes a pressure-distributing valve, said turbine output adjusting means being responsive to said rotational frequency detecting means for providing an electrical output signal, and limiting means responsive to the output of said water pressure rise estimating means and the output of said turbine output adjusting means for limiting the output signal of said turbine output adjusting means for controlling said pressure-distributing valve.
Claim 12
Dependent Claim
35 words
A speed governor system according to claim 6, wherein said movable valve means includes two movable coils, each coil having a stop arm associated therewith for limiting the control range of said pressure distributing valve.
References Cited (Backward Citations)
US3339567A
Cited
US3275293A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |