US3919609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and circuit for reducing the torque ripple of a rotating-field machine
Assignee: Siemens AG
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Filing: 1973-06-27
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Granted: 1975-11-11
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Expires: 1993-06-27
Abstract
Abstract A method and circuit for reducing torque ripple in rotating field machines in which the actual torque is sensed and the sensed value compared with a reference torque value and the difference used to correct the machine current so as to cancel the ripple.
Inventors
- 👤 Herwig Klautschek
- 👤 Dieter Kollensperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:39
CPC Classifications
H; H02; H02P; H02P23/00; H02P23/0004; H02P29/00; H02P29/50; H02P21/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
In a drive system for a rotating machine wherein the machine is coupled to a multiphase AC line through a first converter, a DC link and a second converter, said system having means for controlling the current flowing in the DC link, a method of reducing the torque ripple comprising: a. measuring the actual value of torque developed by the machine; b. establishing a predetermined reference value of torque which is to be maintained; c. comparing the measured value of torque with said predetermined reference value to develop an error signal; and d. providing said error signal as a correction term to the means for controlling current in the DC link.
Claim 2
Dependent Claim
111 words
In a drive system for a rotating machine wherein the machine is coupled to a multiphase AC line through a first converter, a DC link and a second converter, said system having means for controlling the current flowing in the DC link, a method of reducing the torque ripple comprising: a. measuring the actual value of torque developed by the machine; b. establishing a predetermined reference value of torque which is to be maintained; c. comparing the measured value of torque with said predetermined reference value to develop an error signal; and d. providing said error signal as a correction term to the means for controlling current in the DC link.
Claim 3
Dependent Claim
114 words
In a drive system for a rotating machine wherein the machine is coupled to a multiphase AC line through a first converter, a DC link and a second converter, said system having means for controlling the current flowing in the DC link apparatus for reducing the torque ripple comprising: a. means to measure the torque developed by the machine and to provide an output signal indicative thereof; b. means to develop a reference torque signal; c. means to difference said output signal and said reference signal to obtain an error signal; and d. means to provide said error signal as a correction term to the means for controlling the current in the DC link.
Claim 4
Dependent Claim
114 words
In a drive system for a rotating machine wherein the machine is coupled to a multiphase AC line through a first converter, a DC link and a second converter, said system having means for controlling the current flowing in the DC link apparatus for reducing the torque ripple comprising: a. means to measure the torque developed by the machine and to provide an output signal indicative thereof; b. means to develop a reference torque signal; c. means to difference said output signal and said reference signal to obtain an error signal; and d. means to provide said error signal as a correction term to the means for controlling the current in the DC link.
Claim 5
Dependent Claim
45 words
The invention according to claim 2 wherein said error signal is provided to a torque control and wherein said means for providing comprise means to add the output of said torque control to a reference value representing the constant current desired in the DC link.
Claim 6
Dependent Claim
30 words
The invention according to claim 3 and further including a first absolute value circuit having said output signal as an input and providing its output to said means to difference.
Claim 7
Dependent Claim
30 words
The invention according to claim 4 and further including a second absolute value circuit having said reference signal as an input and providing its output to said means to difference.
Claim 8
Dependent Claim
23 words
The invention according to claim 2 wherein said means to measure comprises a torque transducer mechanically coupled to the rotor of the machine.
Claim 9
Dependent Claim
52 words
The invention according to claim 2 wherein said means to measure comprises: a. means to sense the current being fed to the machine; b. means to sense the voltage being fed to the machine; and c. a torque computer having the outputs of said current sensing and voltage sensing means as inputs.
Claim 10
Dependent Claim
18 words
The invention according to claim 2 wherein said means to develop a reference torque signal comprises a potentiometer.
Claim 11
Dependent Claim
30 words
The invention according to claim 3 wherein there is a speed control circuit associated with the rotating-field machine and wherein said reference torque signal is obtained from the speed control.
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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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |