US3611085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preventing torque pulsation in inverter-fed polyphase
Assignee: General Electric Co
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Filing: 1970-11-05
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Granted: 1971-10-05
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Expires: 1990-11-05
Abstract
Abstract Separate sets of armature windings in a polyphase motor are individually supplied with square-wave alternating current from separate inverters. The inverter outputs are phase shifted with respect to one another and paralleling transformers are provided to average the line-to-line waveforms; or, in another embodiment, the windings are angularly displaced within the motor by an amount corresponding to the phase shift between the inverter outputs. The summing of the phase-shifted waveforms effects a cancellation of harmonic components which produce undesirable torque pulsations.
Inventors
- 👤 George M Rosenberry Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:18
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/497
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
61 words
Means for energizing a polyphase electric motor having a plurality of electrically isolated polyphase windings, comprising: a plurality of polyphase inverters, each inverter being adapted to directly supply phase displaced power to different ones of said polyphase windings; and means for inductively coupling conductors carrying current developed by corresponding phases of said polyphase inverters to absorb voltage differences between the inverters.
Claim 2
Dependent Claim
61 words
Means for energizing a polyphase electric motor having a plurality of electrically isolated polyphase windings, comprising: a plurality of polyphase inverters, each inverter being adapted to directly supply phase displaced power to different ones of said polyphase windings; and means for inductively coupling conductors carrying current developed by corresponding phases of said polyphase inverters to absorb voltage differences between the inverters.
Claim 3
Dependent Claim
40 words
Energizing means as defined in claim 1, wherein successive ones of said polyphase windings are angularly displaced with respect to the preceding winding by an angle defined by the expression 60/n where n is the number of said polyphase windings.
Claim 4
Dependent Claim
149 words
A polyphase motor system, comprising; first and second polyphase windings, each phase of each of said windings being electrically isolated from the other phases of said winding; first and second sets of inverters, each of said sets comprising one single-phase inverter for each of the phases of each of said polyphase windings, each inverter supplying power directly to a separate phase of each of said windings, one of said inverters of said second set developing altErnating current having a phase angle relative to corresponding ones of said inverters of said other set of inverters defined by the expression 60/n where n is the number of said windings; means for connecting said inverters to said windings; and means for inductively coupling connecting means which conduct current to corresponding phases of said windings for combining the waveforms of the currents supplied over said windings to absorb voltage differences between said waveforms.
Claim 5
Dependent Claim
149 words
A polyphase motor system, comprising; first and second polyphase windings, each phase of each of said windings being electrically isolated from the other phases of said winding; first and second sets of inverters, each of said sets comprising one single-phase inverter for each of the phases of each of said polyphase windings, each inverter supplying power directly to a separate phase of each of said windings, one of said inverters of said second set developing altErnating current having a phase angle relative to corresponding ones of said inverters of said other set of inverters defined by the expression 60/n where n is the number of said windings; means for connecting said inverters to said windings; and means for inductively coupling connecting means which conduct current to corresponding phases of said windings for combining the waveforms of the currents supplied over said windings to absorb voltage differences between said waveforms.
Claim 6
Dependent Claim
33 words
A polyphase motor system as defined in claim 3 wherein said plurality of polyphase windings comprise two three-phase windings, and said plurality of sets of inverters comprise two sets of three single-phase inverters.
Claim 7
Dependent Claim
106 words
A polyphase motor system, comprising: a motor having a plurality of electrically separate polyphase windings, each of said windings being disposed at an angle to others of said windings within said motor; and a plurality of inverters, each of said inverters supplying polyphase power directly to a different one of said polyphase windings, the output of each of said inverters being phase-shifted with respect to the output of each of said other inverters by an amount equivalent to the angular displacement of its respective windings, said angle and being represented by the expression 60/n where n is the number of said plurality of said polyphase windings.
Claim 8
Dependent Claim
106 words
A polyphase motor system, comprising: a motor having a plurality of electrically separate polyphase windings, each of said windings being disposed at an angle to others of said windings within said motor; and a plurality of inverters, each of said inverters supplying polyphase power directly to a different one of said polyphase windings, the output of each of said inverters being phase-shifted with respect to the output of each of said other inverters by an amount equivalent to the angular displacement of its respective windings, said angle and being represented by the expression 60/n where n is the number of said plurality of said polyphase windings.
Claim 9
Dependent Claim
26 words
The motor supply system as defined in claim 5 further including means for inductively coupling the respective phases of said inverters to absorb voltage differences therebetween.
Claim 10
Dependent Claim
88 words
A polyphase motor system, comprising: a motor having a plurality of polyphase windings, a plurality of inverters supplying polyphase power directly to a different one of said polyphase windings, the polyphase output power of each inverter being phase-shifted with respect to the output power of said other inverters by an amount equal to 60/n wherein n is the number of said plurality of polyphase windings; and means inductively coupling the conductors carrying current from each inverter to corresponding phases of said polyphase windings to absorb voltage differences therebetween.
Claim 11
Dependent Claim
88 words
A polyphase motor system, comprising: a motor having a plurality of polyphase windings, a plurality of inverters supplying polyphase power directly to a different one of said polyphase windings, the polyphase output power of each inverter being phase-shifted with respect to the output power of said other inverters by an amount equal to 60/n wherein n is the number of said plurality of polyphase windings; and means inductively coupling the conductors carrying current from each inverter to corresponding phases of said polyphase windings to absorb voltage differences therebetween.
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) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |