Patent US4074174A successfully refreshed from Google Patents.
US4074174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlling apparatus for asynchronous motors with wound rotor
Assignee: Toshiba Corp
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Filing: 1976-01-28
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Granted: 1978-02-14
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Expires: 1996-01-28
Abstract
Abstract A super-synchronous Scherbius apparatus which enables wound rotor type induction motors to have a smooth speed control below and above the synchronous speed by controlling the secondary power in either the forward or backward direction through the connection of a cyclo-converter on its secondary side includes a first detecting circuit for detecting a signal corresponding to the primary voltage or the rotating magnetic field, a second detecting circuit for detecting a signal corresponding to the position of the rotor, and a calculating circuit for forming a signal corresponding to the phase of the secondary voltage in accordance with the signals of the first and second detecting circuits.
Inventors
- 👤 Katutaro Kuge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:33
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/06; H02P23/00; H02P23/08; H02P25/00; H02P25/16; H02P25/24; H02P25/26; H02P21/00; H02P21/06; H02P21/08; H02P21/09; H02P2201/00; H02P2201/13
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A controlling apparatus for a supersynchronous Scherbius apparatus to enable wound rotor type induction motors to have a smooth speed control below and above the synchronous speed comprises first detecting means for detecting a signal corresponding to the rotating magnetic field of the induction motor, second detecting means for detecting a signal corresponding to the position of the rotor, calculating means for generating a signal corresponding to the phase of the secondary voltage in accordance with the signals of the first and the second detecting means, power converting means for reversibly converting the power of a secondary winding of the induction motor to the power of an A.C. power supply, and power controlling means for controlling the power converting means in accordance with the signal of the calculating means.
Claim 2
Dependent Claim
129 words
A controlling apparatus for a supersynchronous Scherbius apparatus to enable wound rotor type induction motors to have a smooth speed control below and above the synchronous speed comprises first detecting means for detecting a signal corresponding to the rotating magnetic field of the induction motor, second detecting means for detecting a signal corresponding to the position of the rotor, calculating means for generating a signal corresponding to the phase of the secondary voltage in accordance with the signals of the first and the second detecting means, power converting means for reversibly converting the power of a secondary winding of the induction motor to the power of an A.C. power supply, and power controlling means for controlling the power converting means in accordance with the signal of the calculating means.
Claim 3
Dependent Claim
63 words
A controlling apparatus according to claim 1 further comprising speed detecting means for detecting the speed of the induction motor, secondary winding voltage detecting means for detecting a signal of the secondary winding, and means for switching the signal of the calculating circuit to the signal of the secondary winding voltage detecting means in response to an output of the speed detecting means.
Claim 4
Dependent Claim
49 words
A controlling apparatus according to claim 2 wherein the means for switching switches to the signal of the calculating means except for the starting period of the induction motor and switches to the signal of the secondary winding voltage detecting means during the starting period of the induction motor.
Claim 5
Dependent Claim
23 words
A controlling apparatus according to claim 1 wherein the power converting means comprises a plurality of thyristors and a plurality of smoothing reactors.
Claim 6
Dependent Claim
15 words
A controlling apparatus according to claim 4 wherein the power converting means comprises a cycloconverter.
Claim 7
Dependent Claim
22 words
A controlling apparatus according to claim 4 wherein the power converting means comprises two converters having a rectifying and an inverting function.
Claim 8
Dependent Claim
22 words
A controlling apparatus according to claim 1 further comprising a transformer provided between the power converting means and the A.C. power supply.
Claim 9
Dependent Claim
26 words
A controlling apparatus according to claim 1 wherein the second detecting means is a synchronous generator having the same number of poles as the induction motor.
Claim 10
Dependent Claim
26 words
A controlling apparatus according to claim 1 wherein the calculating means comprises two transformers, a fullwave rectifier, two dividers, three phase-shifters, four multipliers and three adders.
Claim 11
Dependent Claim
36 words
A controlling apparatus according to claim 2 wherein the means for switching comprises a plurality of field effect transistors, a plurality of diodes and two switching transistors having input terminals for receiving the switching control signals.
Claim 12
Dependent Claim
36 words
A controlling apparatus according to claim 1 wherein the power controlling means comprises two operational amplifiers for amplifying the speed and the current signals, a phase controlling circuit, an AND logic circuit and a driving circuit.
References Cited (Backward Citations)
US3144594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |