US4751438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brushless DC motor control
Assignee: Sundstrand Corp
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Filing: 1985-12-18
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Granted: 1988-06-14
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Expires: 2005-12-18
Abstract
Abstract Unlike brush-type DC motors, a brushless permanent magnet DC motor has an impedance which is resistive at low rotational speeds and becomes increasingly inductive at higher speeds. Consequently, a control for a brushless permanent magnet DC motor must control both supply voltage and commutation angle in order to maximize motor performance. The simultaneous control of both supply voltage and commutation angle is difficult to achieve and requires complex circuitry. The present invention overcomes this problem by providing first means for developing a motor performance command signal representing a desired motor operational characteristics, second means for developing a motor feedback signal representing an actual motor operational characteristic, and means coupled to the first and second developing means for deriving the commutation angle command signal and the voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic.
Inventors
- 👤 Albert L. Markunas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:45
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/06
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
138 words
A control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor; second means for developing a motor feedback signal representing an actual motor operational characteristic; and means coupled to the first and second means for deriving the commutation angle command signal and the voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic, wherein the deriving means includes means implementing first and second bivariate functions for deriving the commutation angle signal and voltage command signal, respectively.
Claim 2
Dependent Claim
138 words
A control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor; second means for developing a motor feedback signal representing an actual motor operational characteristic; and means coupled to the first and second means for deriving the commutation angle command signal and the voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic, wherein the deriving means includes means implementing first and second bivariate functions for deriving the commutation angle signal and voltage command signal, respectively.
Claim 3
Dependent Claim
65 words
The control of claim 1, wherein the first bivariate function is represented by a first series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the communtation angle command, and the second bivariate function is represented by a second series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the voltage command signal.
Claim 4
Dependent Claim
166 words
A control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor; second means for developing a motor feedback signal representing an actual motor operational characteristic; means coupled to the first and second means for deriving the commutation angle command signal and the voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic; third means for developing a signal representing a predicted performance characteristic of the motor; fourth means for developing a signal representing an actual motor performance characteristic; and means coupled to the third and fourth means for modifying the commutation angle command signal and the voltage command signal to further improve motor performance.
Claim 5
Dependent Claim
166 words
A control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor; second means for developing a motor feedback signal representing an actual motor operational characteristic; means coupled to the first and second means for deriving the commutation angle command signal and the voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic; third means for developing a signal representing a predicted performance characteristic of the motor; fourth means for developing a signal representing an actual motor performance characteristic; and means coupled to the third and fourth means for modifying the commutation angle command signal and the voltage command signal to further improve motor performance.
Claim 6
Dependent Claim
166 words
A control for a brushless DC motor driven by a voltage source inverter, the motor including a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor to drive a load, comprising: first means for developing an input command signal representing a desired operational characteristic of the load; second means for developing a load feedback signal representing an actual operational characteristic of the load; third means for developing a motor feedback signal representing an actual motor operational characteristic; fourth means coupled to the first, second and third means for developing therefrom a motor performance command signal representing a desired operational characteristic of the motor; and means coupled to the third and fourth means for deriving the commutation angle command signal and voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic.
Claim 7
Dependent Claim
166 words
A control for a brushless DC motor driven by a voltage source inverter, the motor including a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor to drive a load, comprising: first means for developing an input command signal representing a desired operational characteristic of the load; second means for developing a load feedback signal representing an actual operational characteristic of the load; third means for developing a motor feedback signal representing an actual motor operational characteristic; fourth means coupled to the first, second and third means for developing therefrom a motor performance command signal representing a desired operational characteristic of the motor; and means coupled to the third and fourth means for deriving the commutation angle command signal and voltage command signal from the motor performance command signal and the motor feedback signal so that the motor operates with the desired operational characteristic.
Claim 8
Dependent Claim
24 words
The control of claim 4, wherein the deriving means includes means for storing a mathematical model of the operation of the brushless DC motor.
Claim 9
Dependent Claim
30 words
The control of claim 4, wherein the deriving means includes means implementing first and second bivariate functions for deriving the commutation angle command signal and the voltage command signal, respectively.
Claim 10
Dependent Claim
64 words
The control of claim 6, wherein the first bivariate function is represented by a first series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the commutation angle command, and the second bivariate function is represented by a second series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the voltage command.
Claim 11
Dependent Claim
53 words
The control of claim 4, further comprising fifth means for developing a predicted performance characteristic of the motor, sixth means for developing an actual motor performance characteristic, and means coupled to the fifth and sixth means for modifying the commutation angle command signal and the voltage command signal to further improve motor performance.
Claim 12
Dependent Claim
138 words
In a control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, the improvement comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor and second means for developing a motor feedback signal representing an actual motor operational characteristic; and a function generator coupled to the first and second means, the function generator including means for storing a mathematical model of the operation of the motor, wherein the storing means is responsive to the first and second means and includes means implementing first and second bivariate functions for deriving the commutation angle command signal and the voltage command signal, respectively.
Claim 13
Dependent Claim
138 words
In a control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, the improvement comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor and second means for developing a motor feedback signal representing an actual motor operational characteristic; and a function generator coupled to the first and second means, the function generator including means for storing a mathematical model of the operation of the motor, wherein the storing means is responsive to the first and second means and includes means implementing first and second bivariate functions for deriving the commutation angle command signal and the voltage command signal, respectively.
Claim 14
Dependent Claim
63 words
The improvement of claim 9, wherein the first bivariate function is represented by a first series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the commutation angle, and the second bivariate function is represented by a second series of mathematical curves representing the relationship between the motor performance command, the motor feedback and the voltage command.
Claim 15
Dependent Claim
180 words
In a control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, the improvement comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor and second means for developing a motor feedback signal representing an actual motor operational characteristic; a function generator coupled to the first and second means, the function generator including means for storing a mathematical model of the operation of the motor, whereby the function generator is responsive to the first and second means and derives the commutation angle command signal and the voltage command signal; and third means for developing a signal representing a predicted performance characteristic of the motor, fourth means for developing a signal representing an actual motor performance characteristic, and means coupled to the third and fourth means for modifying the commutation angle command signal and the voltage command signal to further improve motor performance.
Claim 16
Dependent Claim
180 words
In a control for a brushless DC motor that includes a permanent magnet rotor and a stator having stator coils which are energized in accordance with a commutation angle command signal and a voltage command signal for imparting rotation to the rotor, the improvement comprising: first means for developing a motor performance command signal representing a desired operational characteristic of the motor and second means for developing a motor feedback signal representing an actual motor operational characteristic; a function generator coupled to the first and second means, the function generator including means for storing a mathematical model of the operation of the motor, whereby the function generator is responsive to the first and second means and derives the commutation angle command signal and the voltage command signal; and third means for developing a signal representing a predicted performance characteristic of the motor, fourth means for developing a signal representing an actual motor performance characteristic, and means coupled to the third and fourth means for modifying the commutation angle command signal and the voltage command signal to further improve motor performance.
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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) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |