Patent US3737747A successfully refreshed from Google Patents.
US3737747A
Expired / Lapsed
US
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Servomechanism including a polyphase alternating current synchronous motor
Assignee: Otis Elevator Co
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Filing: 1971-05-10
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Granted: 1973-06-05
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Expires: 1991-05-10
Abstract
Abstract A servomechanism including a polyphase alternating current synchronous motor and a variable frequency, variable magnitude voltage generating means, said generating means comprising transducing apparatus responsive to the position of the rotor of said motor as well as to a desired speed signal and an actual speed signal to generate signals signifying those components of the voltages to be applied to the stator phase windings of said motor to balance, one, the counter electromotive fore which would be produced across each phase winding at no load at the speed at which the rotor is then rotating and the resistance voltage drop produced across each phase winding by the current then flowing therein, and, two, the leakage and the synchronous reactance voltage drop produced across each phase winding by the current then flowing therein and at the speed at which the rotor is then rotating. These transducing apparatus signals for each phase, after being summed vectorially, caused signal translating apparatus of the voltage generating means to apply voltages to their respective stator phase windings to operate said motor according to said desired speed signal.
Inventors
- 👤 O Krauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:14
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/024; H02P25/03
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
165 words
A servomechanism including a polyphase alternating current synchronous motor which produces torque in accordance with applied load at any angular position of the motor rotor through its speed range from zero angular velocity to a rated synchronous velocity, said system including transducing apparatus operating in response to a signal signifying the torque it is desired that the motor produce and a signal signifying the instantaneous speed of the motor to produce at least one pair of signals associated with one of said phase windings, the magnitude of each of the signals of each of said pairs varying in accordance with the desired torque and the instantaneous speed of the rotor throughout its speed range, and a voltage generator operating in response to said pairs of signals and applying to each phase winding of the motor stator an individual stator voltage to control said motor to produce said desired torque, each of said stator voltages being produced in response to one of said pairs of signals.
Claim 2
Dependent Claim
165 words
A servomechanism including a polyphase alternating current synchronous motor which produces torque in accordance with applied load at any angular position of the motor rotor through its speed range from zero angular velocity to a rated synchronous velocity, said system including transducing apparatus operating in response to a signal signifying the torque it is desired that the motor produce and a signal signifying the instantaneous speed of the motor to produce at least one pair of signals associated with one of said phase windings, the magnitude of each of the signals of each of said pairs varying in accordance with the desired torque and the instantaneous speed of the rotor throughout its speed range, and a voltage generator operating in response to said pairs of signals and applying to each phase winding of the motor stator an individual stator voltage to control said motor to produce said desired torque, each of said stator voltages being produced in response to one of said pairs of signals.
Claim 3
Dependent Claim
50 words
A servomechanism according to claim 1, wherein said transducing apparatus operates to produce an individual pair of signals for each phase winding of said motor, and wherein the terminal voltage applied to each phase winding is produced in response to the pair of signals individual to its respective phase winding.
Claim 4
Dependent Claim
66 words
A servomechanism according to claim 2, wherein said transducing apparatus includes a summing amplifier and a multiplier, both receiving said desired torque signal and said instantaneous speed signal and operating in response to the magnitudes thereof, the summing amplifier producing a signal signifying a sum of the magnitudes of said two received signals and the multiplier producing a signal signifying a product of the two magnitudes.
Claim 5
Dependent Claim
51 words
A servomechanism according to claim 3, wherein one of the signals of each pair of signals produced by said transducing apparatus is generated in response to the output signal of said summing amplifier and the other signal of each pair is generated in response to the output signal of said multiplier.
Claim 6
Dependent Claim
136 words
A servomechanism according to claim 4, wherein said transducing apparatus comprises a rotor position transducer including a cylindrical stator yoke of magnetic material, a two pole permanent magnet rotor mounted for rotation on said yoke and producing a sinusoidal flux distribution therethrough, said two pole rotor being mechanically connected to the rotor of said motor for rotation therewith and a plurality of Hall effect elements, two such elements for each phase winding of said motor, said elements being mounted at intervals around the interior surface of said yoke so that the physical location of a different one of said elements corresponds with the physical location of the axis of a different one of the individual phase windings of a stator pole of said motor and another such element is in quadrature with each such corresponding element.
Claim 7
Dependent Claim
82 words
A servomechanism according to claim 5, wherein said two pole rotor of said rotor position transducer is geared to the rotor of said motor so that one of the poles of said transducEr rotor passes the Hall effect element in quadrature with the element corresponding to one of the phase windings of a stator pole of said motor each time one of the poles of the motor rotor passes the physical location of the axis of the corresponding stator pole phase winding.
Claim 8
Dependent Claim
94 words
A servomechanism according to claim 6, wherein each of said corresponding Hall effect elements receives the output signal of said summing amplifier and generates one of the signals of one of the pair of signals, said one signal signifying that component of the terminal voltage for its associated phase winding which balances both the counterelectromotive force which would be produced across said phase winding at no load at the speed at which the rotor is then rotating and the resistance voltage drop produced across said phase winding by the current it is then conducting.
Claim 9
Dependent Claim
83 words
A servomechanism according to claim 7, wherein each of said Hall effect elements in quadrature receives the output signal of said multiplier and generates the other of the signals of one of the pairs of signals, said other signal signifying that component of the terminal voltage for its associated phase winding which balances the leakage and synchronous reactance voltage drop produced across said phase winding by the current it is then conducting and at the speed at which the rotor is then rotating.
Claim 10
Dependent Claim
58 words
A servomechanism according to claim 8, wherein said transducing apparatus includes signal summing amplifier circuitry for each phase winding of said motor, each said signal summing amplifier circuitry receiving the signal produced by the corresponding and quadrature Hall effect elements associated with its respective phase winding and producing an output signal signifying the vector sum of said signals.
Claim 11
Dependent Claim
52 words
A servomechanism according to claim 9, including speed dictation apparatus generating a signal signifying a desired speed for said motor and a speed responsive generator generating a signal signifying the actual speed of said motor, and a summation circuit responsive to said desired and actual speed signals producing said desired torque signal.
Claim 12
Dependent Claim
221 words
A control system for a polyphase alternating current synchronous motor operable to control said motor to produce torque in response to a continuously applied load with the rotor of said motor at any angular position and at any speed from zero angular velocity to a rated running speed, said system including speed dictation apparatus generating a signal signifying a desired speed for said motor, a speed responsive generator generating a signal signifying the actual speed of said motor, a summation circuit responsive to said desired and actual speed signals and producing a desired torque signal, transducing apparatus responsive to said desired torque signal and said actual speed signal and producing a pair of signals for each of the phase windings of said motor, the magnitude of one of the signals of each pair varying in response to the sum of the magnitudes of said desired torque signal and said actual speed signal, the magnitude of the other of the signals of each pair varying in response to the product of the magnitudes of said desired torque signal and said actual speed signal, and a voltage generator applying to each phase winding of the motor stator an individual stator voltage to control said motor to produce said desired torque in response to the pair of signals associated with the respective phase winding.
Claim 13
Dependent Claim
221 words
A control system for a polyphase alternating current synchronous motor operable to control said motor to produce torque in response to a continuously applied load with the rotor of said motor at any angular position and at any speed from zero angular velocity to a rated running speed, said system including speed dictation apparatus generating a signal signifying a desired speed for said motor, a speed responsive generator generating a signal signifying the actual speed of said motor, a summation circuit responsive to said desired and actual speed signals and producing a desired torque signal, transducing apparatus responsive to said desired torque signal and said actual speed signal and producing a pair of signals for each of the phase windings of said motor, the magnitude of one of the signals of each pair varying in response to the sum of the magnitudes of said desired torque signal and said actual speed signal, the magnitude of the other of the signals of each pair varying in response to the product of the magnitudes of said desired torque signal and said actual speed signal, and a voltage generator applying to each phase winding of the motor stator an individual stator voltage to control said motor to produce said desired torque in response to the pair of signals associated with the respective phase winding.
Claim 14
Dependent Claim
124 words
A control system according to claim 11, wherein said one signal of each pair signifies that component of the terminal voltage applied to its associated phase winding which balances both the counterelectromotive force which would be produced across said phase winding at no load at the speed at which the rotor is then rotating and the resistance voltage drop produced across said phase winding by the current it is then conducting and wherein said other signal of each pair signifies that component of the terminal voltage applied to its associated phase windIng which balances the leakage and synchronous reactance voltage drop produced across said phase winding by the current it is then conducting and at the speed at which the rotor is then rotating.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |