Patent US3763413A successfully refreshed from Google Patents.
US3763413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flux amplifier circuits for controlling induction motors and the like
Assignee: Individual
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Filing: 1972-02-11
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Granted: 1973-10-02
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Expires: 1992-02-11
Abstract
Abstract An induction motor supplied from a source of sinusoidal alternating current is provided with stator windings and rotor windings. The primary coil of a flux amplifier is connected in circuit with one of the windings. The secondary coil of the amplifier is energized, either from the primary directly or from a separate source, with sinusoidal current at the same fundamental frequency of the current in the primary coil. Means are provided to vary the amplitude and/or phase of the secondary current in the secondary coil to effect corresponding reactance changes at the primary which in turn vary the voltage and current supplied to the motor. The primary and secondary coils are coupled by a magnetic circuit having characteristics that cause fluxes from the primary and secondary coils to be linearly combined with each other so that voltage and current at the motor is controlled without developing harmonics of the fundamental frequency.
Inventors
- 👤 J Wattenbarger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:50
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/02; H02P27/026; H02P25/00; H02P25/16; H02P25/24; H02P25/26
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
294 words
In an induction motor control circuit the combination comprising an induction motor having a stator winding and a rotor winding, a source of sinusoidal current at a fundamental frequency and flux amplifier means electrically connected in circuit with said source and said motor for adjustably controlling power flow from said source to said motor, said flux amplifier means comprising a primary coil electrically connected with one of said motor windings for conducting primary sinusoidal current at said fundamental frequency during operation of said motor to thereby develop a sinusoidal primary magnetic flux at said fundamental frequency, a secondary coil, means for causing a sinusoidal secondary current at said fundamental frequency having an amplitude parameter and a phase parameter to flow in said secondarY coil to thereby develop a corresponding sinusoidal secondary magnetic flux at said fundamental frequency having amplitude and phase parameters correlated to said amplitude and phase parameters of said secondary current, a magnetic circuit operatively coupling said two coils and conducting said primary and said secondary magnetic fluxes, said magnetic circuit having a magnetic characteristic that causes said primary and secondary magnetic fluxes to be linearly combined with each other to develop a sinusoidal resultant flux in said magnetic circuit at said fundamental frequency having an amplitude parameter and a phase parameter and adjustment means having selectable adjustment positions for adjusting at least one of said parameters of said secondary current over a selected range to thereby correspondingly adjust at least one of said resultant flux parameters so that for all adjustment positions of said adjustment means said resultant flux is maintained sinusoidal whereby reactance and voltage at said primary coil can be varied to thereby operate said motor at selected motor speeds and motor torques as determined by said adjustment means.
Claim 2
Dependent Claim
294 words
In an induction motor control circuit the combination comprising an induction motor having a stator winding and a rotor winding, a source of sinusoidal current at a fundamental frequency and flux amplifier means electrically connected in circuit with said source and said motor for adjustably controlling power flow from said source to said motor, said flux amplifier means comprising a primary coil electrically connected with one of said motor windings for conducting primary sinusoidal current at said fundamental frequency during operation of said motor to thereby develop a sinusoidal primary magnetic flux at said fundamental frequency, a secondary coil, means for causing a sinusoidal secondary current at said fundamental frequency having an amplitude parameter and a phase parameter to flow in said secondarY coil to thereby develop a corresponding sinusoidal secondary magnetic flux at said fundamental frequency having amplitude and phase parameters correlated to said amplitude and phase parameters of said secondary current, a magnetic circuit operatively coupling said two coils and conducting said primary and said secondary magnetic fluxes, said magnetic circuit having a magnetic characteristic that causes said primary and secondary magnetic fluxes to be linearly combined with each other to develop a sinusoidal resultant flux in said magnetic circuit at said fundamental frequency having an amplitude parameter and a phase parameter and adjustment means having selectable adjustment positions for adjusting at least one of said parameters of said secondary current over a selected range to thereby correspondingly adjust at least one of said resultant flux parameters so that for all adjustment positions of said adjustment means said resultant flux is maintained sinusoidal whereby reactance and voltage at said primary coil can be varied to thereby operate said motor at selected motor speeds and motor torques as determined by said adjustment means.
Claim 3
Dependent Claim
40 words
The combination of claim 1 wherein said primary coil of said flux amplifier means is electrically connected between said source and said stator winding and said primary sinusoidal current flows from said source to said motor via said primary coil.
Claim 4
Dependent Claim
23 words
The combination of claim 1 wherein said primary coil of said flux amplifier means is electrically connected in series with said rotor winding.
Claim 5
Dependent Claim
31 words
The combination of claim 1 further including means for causing series resonance of the current flow from said source to said motor at said fundamental frequency and at a predetermined speed.
Claim 6
Dependent Claim
27 words
The combination of claim 4 wherein said means for causing resonance comprises a capacitance electrically connected in series with said primary coil of said flux amplifier means.
Claim 7
Dependent Claim
38 words
The combination of claim 5 wherein said capacitance has an electrical reactance at said fundamental frequency which is equal and opposite to the equivalent electrical reactance of the motor at said fundamental frequency and at a predetermined speed.
Claim 8
Dependent Claim
26 words
The combination of claim 1 including automatic control means for automatically adjusting the position of said adjustment means as a function of a selected control parameter.
Claim 9
Dependent Claim
46 words
The combination of claim 1 wherein said motor is a plural phase motor having a respective stator winding and a respective rotor winding for each phase and a respective flux amplifier means is connected in circuit with each winding in either the stator or the rotor.
Claim 10
Dependent Claim
55 words
The combination of claim 1 wherein said adjustment means comprises solid state switch means electrically connected to said secondary coil and means for operating said solid state switch means coextensively with half cycles of said secondary current to thereby cause said secondary current to be conducted to said secondary coil in units of half cycles.
Claim 11
Dependent Claim
60 words
The combination of claim 9 wherein said solid state switch means comprises first and second solid state switches electrically connected to said secondary coil and means for operating said first solid state switch coextensively with positive half cycles of said secondary current and means for operating said second solid state switch coextensively with negative half cycles of said secondary current.
Claim 12
Dependent Claim
11 words
The combination of claim 1 wherein said magnetic circuit comprises air.
Claim 13
Dependent Claim
17 words
The combination of claim 11 wherein said two coils are closely magnetically coupled by said magnetic circuit.
Claim 14
Dependent Claim
19 words
The combination of claim 1 wherein said adjustment means comprises means for varying the amplitude of said secondary current.
Claim 15
Dependent Claim
19 words
The combination of claim 1 wherein said adjustment means comprises means for varying the phase of said secondary current.
Claim 16
Dependent Claim
22 words
The combination of claim 1 wherein said adjustment means comprises means for adjusting the amplitude and the phase of said secondary current.
Claim 17
Dependent Claim
78 words
The cOmbination of claim 1 wherein said means for causing sinusoidal current flow in said secondary coil comprises a load connected across said secondary coil to complete an electric circuit path with said secondary coil so that voltage induced in said secondary coil by said primary flux causes said secondary current to flow in said secondary coil and said load wherein said adjustment means comprises means for adjusting said current flow through said load and said secondary coil.
Claim 18
Dependent Claim
31 words
The combination of claim 16 wherein said adjustment means comprises means for adjusting the magnitude of said load to thereby adjust said current flow through said load and said secondary coil.
Claim 19
Dependent Claim
12 words
The combination of claim 17 wherein said load comprises an adjustable resistance.
Claim 20
Dependent Claim
17 words
The combination of claim 16 wherein said load comprises an autotransformer electrically connected across said secondary coil.
Claim 21
Dependent Claim
49 words
The combination of claim 1 wherein said means for causing secondary current flow comprises means for conducting a portion of said primary current into said secondary coil and wherein said adjustment means comprises means for adjusting the portion of said primary current which is conducted through said secondary coil.
Claim 22
Dependent Claim
61 words
The combination of claim 20 wherein said means for conducting a portion of said primary current into said secondary coil comprises a load connected across said secondary coil and a tap connection to said load intermediate its points of connection to said secondary coil and wherein said adjustment means comprises means for adjusting the position of said tap on said load.
Claim 23
Dependent Claim
11 words
The combination of claim 21 wherein said load comprises an autotransformer.
Claim 24
Dependent Claim
268 words
In an electric control circuit the combination of a source for supplying sinusoidal current at a fundamental frequency, a load electrically connected to said source and flux amplifier means electrically connected in circuit with said source and said load for controlling power flow from said source to said load comprising a primary coil electrically connected in circuit between said source and said load which conducts said sinusoidal current from said source to said load and which develops a sinusoidal primary magnetic flux at said fundamental frequency, a secondary coil, means for causing a sinusoidal secondary current at said fundamental frequency having an amplitude parameter and a phase parameter to flow in said secondary coil to thereby develop a sinusoidal secondary magnetic flux at said fundamental frequency having amplitude and phase parameters correlated to said amplitude and phase parameters of said secondary current, a magnetic circuit operatively coupling said two coils which conducts said primary and secondary magnetic fluxes and which has a magnetic characteristic for causing said primary and secondary magnetic fluxes to be linearly combined with each other to develop a resultant flux in said magnetic circuit which is sinusoidal at said fundamental frequency, and adjustment means having selectable adjustment positions for adjusting at least one of said parameters of said secondary current over a selected range to thereby correspondingly adjust at least one of said resultant flux parameters so that for all adjustment positions of said adjustment means said resultant flux is maintained sinusoidal whereby reactance and voltage at said primary coil can be varied to thereby control power flow from said source to said load.
Claim 25
Dependent Claim
268 words
In an electric control circuit the combination of a source for supplying sinusoidal current at a fundamental frequency, a load electrically connected to said source and flux amplifier means electrically connected in circuit with said source and said load for controlling power flow from said source to said load comprising a primary coil electrically connected in circuit between said source and said load which conducts said sinusoidal current from said source to said load and which develops a sinusoidal primary magnetic flux at said fundamental frequency, a secondary coil, means for causing a sinusoidal secondary current at said fundamental frequency having an amplitude parameter and a phase parameter to flow in said secondary coil to thereby develop a sinusoidal secondary magnetic flux at said fundamental frequency having amplitude and phase parameters correlated to said amplitude and phase parameters of said secondary current, a magnetic circuit operatively coupling said two coils which conducts said primary and secondary magnetic fluxes and which has a magnetic characteristic for causing said primary and secondary magnetic fluxes to be linearly combined with each other to develop a resultant flux in said magnetic circuit which is sinusoidal at said fundamental frequency, and adjustment means having selectable adjustment positions for adjusting at least one of said parameters of said secondary current over a selected range to thereby correspondingly adjust at least one of said resultant flux parameters so that for all adjustment positions of said adjustment means said resultant flux is maintained sinusoidal whereby reactance and voltage at said primary coil can be varied to thereby control power flow from said source to said load.
Claim 26
Dependent Claim
197 words
In combination an electric motor having a stator winding and a rotor winding, alternating current source means for supplying to said stator winding a first sinusoidal current having a predetermined fundamental frequency, and series controller means connected in circuit with one of said windings to control power transferred from said source to said motor, said controller means comprising first coil means connected in series with said one winding, second coil means, magnetic flux coupling means operatively associated with said first and said second coils to provide a common fluX path therebetween, and circuit means connected in circuit with said second coil means to provide a path for a second alternating current at said predetermined frequency through said second coil means, said flux coupling means being operable according to predetermined B-H characteristics which are substantially linear over a predetermined range of flux densities in said flux coupling means and wherein said first and said second alternating currents have amplitudes and phases correlated to each other and to said B-H characteristics so that said flux coupling means operates only on said predetermined characteristics without substantially saturating said flux coupling means in response to said first and said second currents.
Claim 27
Dependent Claim
197 words
In combination an electric motor having a stator winding and a rotor winding, alternating current source means for supplying to said stator winding a first sinusoidal current having a predetermined fundamental frequency, and series controller means connected in circuit with one of said windings to control power transferred from said source to said motor, said controller means comprising first coil means connected in series with said one winding, second coil means, magnetic flux coupling means operatively associated with said first and said second coils to provide a common fluX path therebetween, and circuit means connected in circuit with said second coil means to provide a path for a second alternating current at said predetermined frequency through said second coil means, said flux coupling means being operable according to predetermined B-H characteristics which are substantially linear over a predetermined range of flux densities in said flux coupling means and wherein said first and said second alternating currents have amplitudes and phases correlated to each other and to said B-H characteristics so that said flux coupling means operates only on said predetermined characteristics without substantially saturating said flux coupling means in response to said first and said second currents.
Claim 28
Dependent Claim
26 words
The combination set forth in claim 24 wherein said first and said second coil means are a sole means supplying flux to said flux coupling means.
Claim 29
Dependent Claim
143 words
In the method of controlling the speed of an alternating current induction motor having a rotor winding and a stator winding and wherein current flow through one of said windings at a predetermined frequency is controlled by first coil means connected in circuit therewith, second coil means, and flux coupling means magnetically coupling said first and said second coil means and being operable according to predetermined B-H characteristics which are substantially linear over a predetermined range, that improvement wherein current through said one coil means is controlled by applying to said second coil means a second sinusoidal current whose phase and amplitude are correlated to the phase and amplitude of said primary current and to said B-H characteristics to cause said flux coupling means to operate only on said predetermined linear range of said B-H characteristics without substantially saturating said flux coupling means.
Claim 30
Dependent Claim
143 words
In the method of controlling the speed of an alternating current induction motor having a rotor winding and a stator winding and wherein current flow through one of said windings at a predetermined frequency is controlled by first coil means connected in circuit therewith, second coil means, and flux coupling means magnetically coupling said first and said second coil means and being operable according to predetermined B-H characteristics which are substantially linear over a predetermined range, that improvement wherein current through said one coil means is controlled by applying to said second coil means a second sinusoidal current whose phase and amplitude are correlated to the phase and amplitude of said primary current and to said B-H characteristics to cause said flux coupling means to operate only on said predetermined linear range of said B-H characteristics without substantially saturating said flux coupling means.
Claim 31
Dependent Claim
215 words
In the method of controlling power flow from a source of sinusoidal current at a fundamental frequency to a load electrically connected to said source through flux amplifier means wherein said flux amplifier means comprises primary coil means electrically connected in circuit between said source and said load, a secondary coil, and magnetic circuit means having predetermined magnetic characteristics and magnetically coupling said primary coil means with said secondary coil means, the steps of establishing in said primary coil means a primary sinusoidal current from said source which causes a sinusoidal primary magnetic flux at said fundamental frequency to be developed in said magnetic circuit means, simultaneously establishing in said secondary coil means a secondary sinusoidal current at said fundamental frequency which causes a sinusoidal secondary magnetic flux at said fundamental frequency to be developed in said magnetic circuit means, and correlating respective phase and amplitude parameters of said primary sinusoidal current with respective phase and amplitude parameters of said secondary sinusoidal current and with said predetermined magnetic characteristics of said magnetic circuit means so as to cause said primary and secondary magnetic fluxes to be linearly combined with each other in said magnetic circuit means to thereby develop a resultant flux in said magnetic circuit means which is sinusoidal and at said fundamental frequency.
Claim 32
Dependent Claim
215 words
In the method of controlling power flow from a source of sinusoidal current at a fundamental frequency to a load electrically connected to said source through flux amplifier means wherein said flux amplifier means comprises primary coil means electrically connected in circuit between said source and said load, a secondary coil, and magnetic circuit means having predetermined magnetic characteristics and magnetically coupling said primary coil means with said secondary coil means, the steps of establishing in said primary coil means a primary sinusoidal current from said source which causes a sinusoidal primary magnetic flux at said fundamental frequency to be developed in said magnetic circuit means, simultaneously establishing in said secondary coil means a secondary sinusoidal current at said fundamental frequency which causes a sinusoidal secondary magnetic flux at said fundamental frequency to be developed in said magnetic circuit means, and correlating respective phase and amplitude parameters of said primary sinusoidal current with respective phase and amplitude parameters of said secondary sinusoidal current and with said predetermined magnetic characteristics of said magnetic circuit means so as to cause said primary and secondary magnetic fluxes to be linearly combined with each other in said magnetic circuit means to thereby develop a resultant flux in said magnetic circuit means which is sinusoidal and at said fundamental frequency.
Claim 33
Dependent Claim
54 words
The method set forth in claim 27 wherein said flux amplifier means is operated by primary sinusoidal current and secondary sinusoidal current correlated to each other and to said predetermined magnetic characteristics so that said magnetic coupling has a substantially constant permeability over an anticipated operating range of said primary and said secondary currents.
Claim 34
Dependent Claim
65 words
The method set forth in claim 27 wherein said predetermined magnetic characteristic is a B-H characteristic which is substantially linear over a predetermined range and wherein said primary sinusoidal current and said secondary sinusoidal current have phases and amplitudes correlated to each other and to said B-H characteristic such tHat said flux amplifier means operates only on said predetermined linear range of said B-H characteristic.
References Cited (Backward Citations)
US3177419A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |