US4409535A
Expired / Lapsed
US
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Gated asynchronous carrier modulation
Assignee: Siemens Energy and Automation Inc
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Filing: 1982-03-18
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Granted: 1983-10-11
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Expires: 2002-03-18
Abstract
Abstract A motor pulse width modulation control technique employing gated asynchronous carrier modulation including establishing a repetitive modulation signal along with the generation of a carrier frequency signal at a frequency greater than the frequency of the modulation signal. The carrier frequency signal is gated at a gating rate less than the frequency of the carrier frequency signal so as to provide the gated carrier frequency signal. Means are provided for modulating the gated carrier frequency signal by the aforementioned repetitive modulation signal so as to provide cyclic pulse width modulation drive signal for motor control.
Inventors
- 👤 Mark R. Hickman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:36
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/527; H02M7/529
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
141 words
Motor pulse width modulation control apparatus comprising; means for establishing a repetitive modulation signal, means for generating a carrier frequency signal at a frequency greater than the frequency of the modulation signal, means for gating the carrier frequency signal at a gating rate less than the frequency of the carrier frequency signal so as to provide a gated carrier frequency signal, and means for modulating the gated carrier frequency signal by the repetitive modulation signal so as to provide a cyclic pulse width modulation drive signal for motor control, said means for gating the carrier frequency signal comprising means for generating, on an asynchronous basis to the modulation signal, a resetting of the carrier frequency signal whereby the carrier frequency is restarted a number of times every modulation cycle, said carrier frequency being restarted from a fixed amplitude at each gating.
Claim 2
Dependent Claim
141 words
Motor pulse width modulation control apparatus comprising; means for establishing a repetitive modulation signal, means for generating a carrier frequency signal at a frequency greater than the frequency of the modulation signal, means for gating the carrier frequency signal at a gating rate less than the frequency of the carrier frequency signal so as to provide a gated carrier frequency signal, and means for modulating the gated carrier frequency signal by the repetitive modulation signal so as to provide a cyclic pulse width modulation drive signal for motor control, said means for gating the carrier frequency signal comprising means for generating, on an asynchronous basis to the modulation signal, a resetting of the carrier frequency signal whereby the carrier frequency is restarted a number of times every modulation cycle, said carrier frequency being restarted from a fixed amplitude at each gating.
Claim 3
Dependent Claim
26 words
Motor control apparatus as set forth in claim 1 wherein said means for generating a carrier frequency comprises a carrier frequency oscillator that is voltage controlled.
Claim 4
Dependent Claim
27 words
Motor control apparatus as set forth in claim 1 wherein said means for generating a carrier comprises a waveform generator which runs asynchronously to the modulation frequency.
Claim 5
Dependent Claim
18 words
Motor control apparatus as set forth in claim 3 wherein said waveform generator comprises a triangular waveform generator.
Claim 6
Dependent Claim
18 words
Motor control apparatus as set forth in claim 3 wherein said waveform generator comprises a ramp waveform generator.
Claim 7
Dependent Claim
32 words
Motor control apparatus as set forth in claim 1 wherein the frequency of the gating signal is at a rate of at least twice the number of phases times the modulation frequency.
Claim 8
Dependent Claim
30 words
Motor control apparatus as set forth in claim 1 wherein the modulation signal is three phase and the gating signal is at a frequency of six times the modulation frequency.
Claim 9
Dependent Claim
22 words
Motor control apparatus as set forth in claim 1 wherein said means for establishing a modulation signal comprises a trapezoidal waveform generator.
Claim 10
Dependent Claim
24 words
Motor control apparatus as set forth in claim 8 wherein said trapezoidal waveform generator comprises ramp-up circuit means, ramp-down circuit means and multiplexer means.
Claim 11
Independent Claim
103 words
A method of motor pulse width modulation control comprising the steps of; establishing a repetitive modulation signal, generating a carrier frequency signal at a frequency greater than the frequency of the modulation signal, gating the carrier frequency signal asynchronously to the modulation signal at a gating rate less than the frequency of the carrier frequency signal with the carrier frequency being restarted from a fixed amplitude at each gating and a number of times every modulation cycle, and modulating the gated carrier frequency signal by the repetitive modulation signal so as to provide a cyclic pulse width modulation drive signal for motor control.
Claim 12
Independent Claim
103 words
A method of motor pulse width modulation control comprising the steps of; establishing a repetitive modulation signal, generating a carrier frequency signal at a frequency greater than the frequency of the modulation signal, gating the carrier frequency signal asynchronously to the modulation signal at a gating rate less than the frequency of the carrier frequency signal with the carrier frequency being restarted from a fixed amplitude at each gating and a number of times every modulation cycle, and modulating the gated carrier frequency signal by the repetitive modulation signal so as to provide a cyclic pulse width modulation drive signal for motor control.
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |