Patent US3928975A successfully refreshed from Google Patents.
US3928975A
Expired / Lapsed
US
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Electrical system for electrohydraulic emergency trip system
Assignee: Westinghouse Electric Corp
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Filing: 1974-06-06
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Granted: 1975-12-30
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Expires: 1994-06-06
Abstract
Abstract An electrohydraulic emergency trip system for a turbine power plant to close rapidly the steam inlet valves to the turbine is disclosed. The hydraulic portion of the system for decreasing the trip fluid pressure to the steam inlet valves is governed by a first and second electrically operable trip valve means, both of which are operated to trip the turbine. Each of the trip valve means is controlled by an independent voltage source. A contingency detection means, which operates in response to a trip contingency, is energized by a third voltage source that is generated by one or both of the first and second voltage sources. The system provides for ground fault detection upon testing for a trip contingency.
Inventors
- 👤 Andrew S Braytenbah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:12
CPC Classifications
F; F01; F01D; F01D21/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
314 words
An electrohydraulic emergency trip system for a turbine power plant to close rapidly the steam inlet valves to the turbine in response to a predetermined contingency, comprising: a plurality of steam inlet valves, an operating mechanism for each steam inlet valve operative to close its associated valve in response to a predtermined decrease of fluid pressure in communication with such operating mechanism, an hydraulic trip system in communication with the valve operating mechanism, a first and a second electrically operable trip valve means operatively connected in the hydraulic trip system to decrease the fluid pressure in response to the operation of both the first and second trip valve means, a first and second electrically operable contingency detection means, first and second independent voltage sources, first circuit means connected to both the first and second voltage sources to generate a third voltage output in response to the generated voltage from either one or both of the first and second voltage sources, second circuit means including the first and second contingency detection means and the third voltage output to operate both the first and second contingency detection means in response to the opening and closing of the second circuit means, third circuit means including the first contingency detection means and the first voltage source to operate the first trip valve means in response to the operation of the first contingency detection means, fourth circuit means including the second contingency detection means and the second voltage source to operate the second trip valve means in response to the operation of the second contingency detection means, said third and fourth circuit means each being effective to operate their respective first and second trip valve means to an open position in response to a loss of the respectively connected first and second independent voltage sources, and means to operate the third circuit means in response to a predetermined contingency.
Claim 2
Dependent Claim
314 words
An electrohydraulic emergency trip system for a turbine power plant to close rapidly the steam inlet valves to the turbine in response to a predetermined contingency, comprising: a plurality of steam inlet valves, an operating mechanism for each steam inlet valve operative to close its associated valve in response to a predtermined decrease of fluid pressure in communication with such operating mechanism, an hydraulic trip system in communication with the valve operating mechanism, a first and a second electrically operable trip valve means operatively connected in the hydraulic trip system to decrease the fluid pressure in response to the operation of both the first and second trip valve means, a first and second electrically operable contingency detection means, first and second independent voltage sources, first circuit means connected to both the first and second voltage sources to generate a third voltage output in response to the generated voltage from either one or both of the first and second voltage sources, second circuit means including the first and second contingency detection means and the third voltage output to operate both the first and second contingency detection means in response to the opening and closing of the second circuit means, third circuit means including the first contingency detection means and the first voltage source to operate the first trip valve means in response to the operation of the first contingency detection means, fourth circuit means including the second contingency detection means and the second voltage source to operate the second trip valve means in response to the operation of the second contingency detection means, said third and fourth circuit means each being effective to operate their respective first and second trip valve means to an open position in response to a loss of the respectively connected first and second independent voltage sources, and means to operate the third circuit means in response to a predetermined contingency.
Claim 3
Dependent Claim
18 words
A system according to claim 1 wherein the first and second voltage sources each generate an alternating voltage.
Claim 4
Dependent Claim
17 words
A system according to claim 1 wherein the first circuit means generates a direct current output voltage.
Claim 5
Dependent Claim
99 words
A system according to claim 3 wherein the second circuit means is a direct current circuit having an ungrounded positive and an ungrounded negative bus, and further comprises a first relay winding electrically connected between the positive bus and ground, a second relay winding electrically connected between the negative bus and ground, each saiD relay being energized normally between its respectively connected bus and ground at times only when its respectively connected bus is ungrounded, and means responsive to the deenergization of one of the first and second relay windings to indicate a grounding of its respectively connected bus.
Claim 6
Dependent Claim
93 words
A system according to claim 4 wherein the second circuit means includes a resistor connected at one end to the positive bus for each contingency detecting means, each contingency detecting means includes a winding connected between the other end of the resistor and the negative bus, and a normally open switching means electrically connected at the other end of the resistor and the negative bus, whereby a ground fault occurring in the second circuit means between the resistor and the winding deenergizes the second relay winding upon the closure of the sensing means.
Claim 7
Dependent Claim
117 words
An electrohydraulic emergency trip system for a turbine power plant that includes an hydraulic system with at least two electrically operable valve means connected to close the steam inlet valves to the turbine in response to a predetermined contingency, comprising, an independnet voltage source connected to operate each of the electrically operable valve means, circuit means connected to at least two of the independent voltage sources operatively energized in response to the presence of a voltage from any one of the connected voltage sources, and electrically operable contingency detection means govern by the voltage in said circuit means to govern each independent voltage source to operate said electrically operable valve means in response to a predetermined contingency.
Claim 8
Dependent Claim
117 words
An electrohydraulic emergency trip system for a turbine power plant that includes an hydraulic system with at least two electrically operable valve means connected to close the steam inlet valves to the turbine in response to a predetermined contingency, comprising, an independnet voltage source connected to operate each of the electrically operable valve means, circuit means connected to at least two of the independent voltage sources operatively energized in response to the presence of a voltage from any one of the connected voltage sources, and electrically operable contingency detection means govern by the voltage in said circuit means to govern each independent voltage source to operate said electrically operable valve means in response to a predetermined contingency.
Claim 9
Dependent Claim
52 words
A system according to claim 6 wherein the electrically operable valve means are normally energized by the respective independent voltage sources, the contingency detection means are normally energized by said circuit means, and the contingency detection means is deenergized in response to the predetermined contingency to deenergize the electrically operable valve means.
Claim 10
Dependent Claim
94 words
A system according to claim 6 wherein said circuit means is ungrounded and the contingency detection means is governed by the presence of a voltage across buses of opposite polarity, further comprising, a first resistance means connected between one of the buses and ground operative in response to the grounding of said one bus, a second resistance means connected between the other of the buses and ground operative in response to the grounding of the other bus, and means responsive to the operation of one of the resistance means to indicate a ground fault.
Claim 11
Dependent Claim
16 words
A system according to claim 8 wherein said circuit means is energized by a DC voltage.
Claim 12
Dependent Claim
42 words
A system according to claim 8, further comprising normally open contact sensing means connected between one bus of the circuit means and each contingency detection means, whereby one of said resistance means is operated upon the closing of the contact sensing means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |