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US4733340A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for stabilizing turbine-generator shaft torsional oscillations

Assignee: Toshiba Corp
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Filing: 1987-03-03
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Granted: 1988-03-22
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Expires: 2007-03-03
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Abstract

Abstract An apparatus for stabilizing turbine generator shaft torsional oscillations including: a current detector for detecting ac current of a turbine generator used in combination with a dc power-transmission system, a filter to which an output of said current detector is delivered, the filter comprising a first bandpass filter for detecting a sub synchronous component (f l -f m ) and a second bandpass filter for detecting a super synchronous component (f l +f m ) where a fundamental freuency of the generator is represented by f l and a natural frequency of the mechanical shaft system of the generator is represented by f m , a calculation circuit for applying conversion of at least one of d and q axis to respective outputs from the first and second bandpass filters using a generator phase θ G to take out at least one of Δi d and Δi q of the sub and super synchronous components, a third bandpass filter to which an output from the calculation circuit is fed, the third bandpass filter for taking out a stabilization signal therefrom, and a circuit for controlling a converter for delivering an output of the generator to the dc power-transmission system on the basis of the stabilization signal.

Inventors

  • 👤 Akira Mase
  • 👤 Atsushi Kurita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 16:55
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/10; H02J; H02J3/00; H02J3/001; H02J3/0014; H02J3/00142; H02J3/36; H02M; H02M1/00; H02M1/12; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/443; H02M5/45; H02P29/00; H02P29/50

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 209 words
An apparatus for stabilizing turbine generator shaft torsional oscillations including: (a) a current detector for detecting ac current of a turbine generator used in combination with a dc power-transmission system; (b) a filter to which an output of said current detector is delivered, said filter comprising a first bandpass filter for detecting a sub synchronous component (f 1 -f m ) and a second bandpass filter for detecting a super synchronous component (f 1 -f m ) where fundamental frequency of said generator is represented by f 1 and a natural frequency of the mechanical shaft system of said generator is represented by f m ; (c) a calculation circuit for applying conversion of at least one of d and q axis to respective outputs from said first and second bandpass filters using a generator phase θ G to take out at least one of Δi d and Δi q of the sub and super synchornous components; (d) a third bandpass filter to which an output from said calculation circuit is fed, said third bandpass filter for taking out a stabilization signal therefrom, and a circuit for controlling a converter for delivering an output of said generator to said dc power-transmission system on the basis of said stabilization signal.
Claim 2
Independent Claim 209 words
An apparatus for stabilizing turbine generator shaft torsional oscillations including: (a) a current detector for detecting ac current of a turbine generator used in combination with a dc power-transmission system; (b) a filter to which an output of said current detector is delivered, said filter comprising a first bandpass filter for detecting a sub synchronous component (f 1 -f m ) and a second bandpass filter for detecting a super synchronous component (f 1 -f m ) where fundamental frequency of said generator is represented by f 1 and a natural frequency of the mechanical shaft system of said generator is represented by f m ; (c) a calculation circuit for applying conversion of at least one of d and q axis to respective outputs from said first and second bandpass filters using a generator phase θ G to take out at least one of Δi d and Δi q of the sub and super synchornous components; (d) a third bandpass filter to which an output from said calculation circuit is fed, said third bandpass filter for taking out a stabilization signal therefrom, and a circuit for controlling a converter for delivering an output of said generator to said dc power-transmission system on the basis of said stabilization signal.
Claim 3
Dependent Claim 39 words
An apparatus as set forth in claim 1, wherein there is provided means for detecting said generator phase θ G from a synchronizing circuit in said circuit for controlling said converter as a synchronous phase output θ op .
Claim 4
Dependent Claim 43 words
An apparatus as set forth in claim 2, further comprises a fourth bandpass filter for taking out said natural frequency f m from said synchronous phase error change Δθ ep , an output from said fourth bandpass filter being delivered to said converter.

References Cited (Backward Citations)

US3883792A Cited
US4551780A Cited
US4377780A Cited
US4331882A Cited
JPS57186978A Cited
EP0174520A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-22 1991-09-21 1992-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-22 1995-09-21 1996-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-22 1999-09-21 2000-03-22 $7700.00 Window Closed / Lapsed

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