Patent US3858183A successfully refreshed from Google Patents.
Patent US3611082A successfully refreshed from Google Patents.
US3611082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable speed electric motor system having stator and rotor windings energized in opposite phase sequence with alternating current corresponding in angular velocity to one-half the angular velocity of the rotor
Assignee: Wisconsin Alumni Research Foundation
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Filing: 1969-12-15
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Granted: 1971-10-05
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Expires: 1989-12-15
Abstract
Abstract The motor system utilizes a conventional wound rotor induction motor but achieves operating characteristics similar to those of a series field direct current motor. Both the stator coils and the rotor coils of the motor are supplied with alternating current power from a variable frequency power supply. However, the phase sequence of the rotor coils is reversed with respect to that of the stator coils. The voltage phase and the frequency of the power delivered to the motor are determined by a shaft position transducer coupled to the motor shaft. The adjustment of the transducer determines the torque angle between the alternating voltage phase and the position of the shaft. This torque angle is maintained constant at all speeds. The speed of the motor can be varied by varying the voltage of the alternating current supplied to the motor. A tachometer governor arrangement can be used to hold the speed constant. The shaft position transducer may utilize rotary variable capacitors supplied with a carrier signal, or magnetodiodes positioned adjacent to a rotary magnet.
Inventors
- 👤 Norbert L Schmitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:08
CPC Classifications
H; H02; H02P; H02P21/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
204 words
An electrical drive system, comprising a plural-phase double armature induction motor having a stator with a wound stator armature and a rotor with a wound rotor armature, said stator armature having a set of plural-phase stator windings, said rotor armature having a set of plural-phase rotor windings, a variable frequency power supply, means for connecting said stator and rotor windings to said variable frequency power supply for energizing said stator windings with one phase sequence while energizing said rotor windings with the opposite sequence of phase rotation, the energization of said stator windings thereby producing a stator magnetic field rotating in one direction relative to said stator, the energization of said rotor windings thereby produCing a rotor magnetic field rotating in the opposite direction relative to said rotor, and a transducer having a rotatable element connected to said rotor, said transducer having means operable by said rotatable element for producing a control signal at one-half the angular velocity of said rotor, said transducer having control means responsive to said control signal and connected to said power supply to cause said power supply to generate alternating current power corresponding in angular velocity and phase to one-half the angular velocity and phase position of said rotor.
Claim 2
Dependent Claim
204 words
An electrical drive system, comprising a plural-phase double armature induction motor having a stator with a wound stator armature and a rotor with a wound rotor armature, said stator armature having a set of plural-phase stator windings, said rotor armature having a set of plural-phase rotor windings, a variable frequency power supply, means for connecting said stator and rotor windings to said variable frequency power supply for energizing said stator windings with one phase sequence while energizing said rotor windings with the opposite sequence of phase rotation, the energization of said stator windings thereby producing a stator magnetic field rotating in one direction relative to said stator, the energization of said rotor windings thereby produCing a rotor magnetic field rotating in the opposite direction relative to said rotor, and a transducer having a rotatable element connected to said rotor, said transducer having means operable by said rotatable element for producing a control signal at one-half the angular velocity of said rotor, said transducer having control means responsive to said control signal and connected to said power supply to cause said power supply to generate alternating current power corresponding in angular velocity and phase to one-half the angular velocity and phase position of said rotor.
Claim 3
Dependent Claim
29 words
A system according to claim 1, in which said transducer is constructed to provide an adjustable torque angle between the energizing power and the rotary position of said rotor.
Claim 4
Dependent Claim
37 words
A system according to claim 1, in which said control means of said transducer comprises a source of carrier signal, and a rotary capacitor operable by the rotor and connected between said source and said power supply.
Claim 5
Dependent Claim
37 words
A system according to claim 1, in which said control means of said transducer comprises a rotatable magnet connected to said rotor, and at least one magneto-responsive element adjacent said magnet and connected to said power supply.
Claim 6
Dependent Claim
14 words
A system according to claim 4, in which said magneto-responsive element comprises a magnetodiode.
Claim 7
Dependent Claim
23 words
A system according to claim 5, in which said magnetodiode has a resistance which is variable in response to a varying magnetic field.
Claim 8
Dependent Claim
35 words
A system according to claim 1, in which said power supply comprises a cycloconverter operable by alternating current power of a fixed frequency and capable of producing an alternating current output at a variable frequency.
Claim 9
Dependent Claim
24 words
A system according to claim 7, in which said cycloconverter comprises solid-state devices having control elements connected to said control means of said transducer.
Claim 10
Dependent Claim
24 words
A system according to claim 7, in which said cycloconverter comprises controlled rectifiers having control elements connected to said control means of said transducer.
Claim 11
Dependent Claim
26 words
A system according to claim 1, in which said power supply comprises an inverter operative to convert direct current power to variable frequency alternating current power.
Claim 12
Dependent Claim
24 words
A system according to claim 1, including speed control means connected to said power supply for varying the voltage output of said power supply.
Claim 13
Dependent Claim
27 words
A system according to claim 11, including a tachometer operable by said rotor and connected to said speed control means to regulate the speed of said rotor.
Claim 14
Dependent Claim
29 words
A system according to claim 1, including means for varying the output phase angle of said transducer to change the phase angle of the output from said power supply.
Claim 15
Dependent Claim
40 words
A system according to claim 1, in which said transducer comprises a rotor and a stator, said system comprising means for adjusting the angular position of said transducer stator so as to vary the output phase angle of said transducer.
Claim 16
Dependent Claim
32 words
A system according to claim 1, including a phase shifter for changing the phase angle of said signal so as to vary the phase angle of the output from said power supply.
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 |