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Patent US3820003A successfully refreshed from Google Patents.
US3820003A
Expired / Lapsed
US
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Method of controlling a pulse inverter for an induction machine
Assignee: Siemens AG
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Filing: 1972-03-13
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Granted: 1974-06-25
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Expires: 1992-03-13
Abstract
Abstract A method controls a pulse inverter for controlling the speed of induction machines such as asynchronous machines. To provide the control signals for the inverter, the point of intersection of a periodic reference curve whose frequency corresponds to the desired fundamental oscillation frequency of the output voltage of the inverter is provided with a determinable number (l to n) of DC voltage levels (al to an). The DC voltage level positions are controllable according to a desired rule or principle in dependence on a control voltage (USt) whose level depends on the desired amplitude of the fundamental oscillation.
Inventors
- 👤 H Tappeiner
- 👤 H Waldmann
- 👤 K Bayer
- 👤 M Wiebelzahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:31
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/527
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A method of controlling a pulse width modulated inverter having switch means for the control of the speed of an induction machine, said method comprising the steps of producing a predetermined number n of DC voltage levels of different magnitudes, producing a periodic reference potential having a frequency corresponding to the desired fundamental oscillation frequency of the output voltage of the pulse width modulated inverter; intersecting said periodic reference potential with the DC voltage levels to determine the pulses of the control signals for the pulse width modulated inverter; controlling the switch means of the pulse width modulated inverter in dependence upon said control signals; and controlling the positions of the DC voltage levels in accordance with a predetermined rule in dependence upon a control voltage Ust having a level which depends on the desired amplitude of the fundamental oscillaTion of the output voltage.
Claim 2
Independent Claim
144 words
A method of controlling a pulse width modulated inverter having switch means for the control of the speed of an induction machine, said method comprising the steps of producing a predetermined number n of DC voltage levels of different magnitudes, producing a periodic reference potential having a frequency corresponding to the desired fundamental oscillation frequency of the output voltage of the pulse width modulated inverter; intersecting said periodic reference potential with the DC voltage levels to determine the pulses of the control signals for the pulse width modulated inverter; controlling the switch means of the pulse width modulated inverter in dependence upon said control signals; and controlling the positions of the DC voltage levels in accordance with a predetermined rule in dependence upon a control voltage Ust having a level which depends on the desired amplitude of the fundamental oscillaTion of the output voltage.
Claim 3
Dependent Claim
18 words
The method claimed in claim 1, wherein the reference potential (r) comprises a sinusoidal curve of constant amplitude.
Claim 4
Dependent Claim
15 words
The method claimed in claim 1, wherein the reference potential (r) comprises a sawtooth curve.
Claim 5
Dependent Claim
24 words
The method claimed in claim 1, wherein the number of DC voltage levels having a magnitude greater than zero Volts is at least one.
Claim 6
Dependent Claim
33 words
The method claimed in claim 1, further comprising positioning the DC voltage levels (a1 to an) to provide a maximum fundamental frequency content and a minimum harmonic content of the inverter output voltage.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein the reference potential comprises a triangular curve.
Claim 8
Dependent Claim
13 words
The method of claim 1, wherein the reference potential comprises a trapezoidal curve.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |