Patent US4393345A successfully refreshed from Google Patents.
US4393345A
Expired / Lapsed
US
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Circuit for damping hunting by electric machines
Assignee: Siemens AG
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Filing: 1980-10-22
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Granted: 1983-07-12
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Expires: 2000-10-22
Abstract
Abstract A circuit for damping hunting oscillations of controlled electric machines. The circuit is provided with a measuring circuit for determining the hunting oscillations and an identifier circuit for determining the angle components of such hunting oscillations. A phase shifter circuit is provided for receiving the angle components produced by the identifier circuit and forming a hunting oscillation correction signal which is shifted in phase from the hunting oscillations by a predetermined phase angle. The hunting oscillation correction signal is conducted to a control unit of the electric machine. The invention is particularly useful in damping hunting by the rotors of voltage controlled synchronous generators.
Inventors
- 👤 Kurt Fork
- 👤 Wolfgang Kaufhold
- 👤 Wolfgang Meusel
- 👤 Hermann Waldmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:03
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/10; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/851
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
A circuit for damping hunting oscillations of a controlled electric synchronous machine of the type having a rotor and a stator, the circuit being of the type which determines the hunting oscillation and combines a phase-shifted oscillation correction signal with a control signal of the circuit, the circuit further comprising: identification circuit means for producing a first signal having a frequency which corresponds to a frequency of the hunting oscillation and a second signal having saId frequency and shifted in phase by 90° with respect to said first signal; phase shift means for forming the phase-shifted oscillation correction signal, said phase-shifted oscillation correction signal being shifted in phase with respect to said first and second signals by a selectable amount, said first and second signals being combined with one another in accordance with their respective amplitudes.
Claim 2
Dependent Claim
136 words
A circuit for damping hunting oscillations of a controlled electric synchronous machine of the type having a rotor and a stator, the circuit being of the type which determines the hunting oscillation and combines a phase-shifted oscillation correction signal with a control signal of the circuit, the circuit further comprising: identification circuit means for producing a first signal having a frequency which corresponds to a frequency of the hunting oscillation and a second signal having saId frequency and shifted in phase by 90° with respect to said first signal; phase shift means for forming the phase-shifted oscillation correction signal, said phase-shifted oscillation correction signal being shifted in phase with respect to said first and second signals by a selectable amount, said first and second signals being combined with one another in accordance with their respective amplitudes.
Claim 3
Dependent Claim
25 words
The circuit of claim 11 wherein said identification circuit means comprises a power measuring circuit for measuring electrical power related to the controlled electric machine.
Claim 4
Dependent Claim
14 words
The circuit of claim 1 wherein said measuring means comprises a rotor position transmitter.
Claim 5
Dependent Claim
22 words
The circuit of claim 1 wherein said identification circuit means comprises a vector identifier for identifying angle components of the hunting oscillations.
Claim 6
Dependent Claim
22 words
The circuit of claim 4 wherein said vector identifier further comprises means for eliminating a steady-state signal component in said first signal.
Claim 7
Dependent Claim
22 words
The circuit of claim 1 wherein said identification circuit means comprises a vector filter for identifying angle components of the hunting oscillations.
Claim 8
Dependent Claim
55 words
The circuit of claim 1 wherein said phase shift means forms said phase-shifted oscillation correction signal which is shifted in phase with respect to the hunting oscillations by a phase angle which is responsive to a selectable one of a load condition of the controlled electric synchronous machine and an analysis of the hunting oscillations.
Claim 9
Dependent Claim
53 words
The circuit of claim 1 wherein there are further provided controller means for controlling electrical conduction through the stator of the controlled electric synchronous machine; and comparator means having a first input terminal for receiving said phase-shifted oscillation correction signal, and an output terminal for conducting a fourth signal to said controller means.
Claim 10
Dependent Claim
36 words
The circuit of claim 8 wherein said comparator means is provided with a second input terminal for receiving a signal corresponding to a voltage at a network to which the controlled electric synchronous machine is connected.
Claim 11
Dependent Claim
45 words
The circuit of claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 wherein the controlled electric synchronous machine is a voltage controlled synchronous generator, said hunting oscillation correction signal being responsive to hunting oscillations of the rotor of said voltage controlled synchronous generator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-11 | 1987-01-10 | 1987-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-11 | 1991-01-10 | 1991-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-11 | 1995-01-10 | 1995-07-12 | $7700.00 | Window Closed / Lapsed |