Patent US5949204A successfully refreshed from Google Patents.
US5949204A
Expired / Lapsed
US
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Method and apparatus for driving a brushless DC motor without rotor position sensors
Assignee: Honeywell International Inc
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Filing: 1998-05-08
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Granted: 1999-09-07
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Expires: 2018-05-08
Abstract
Abstract In a brushless dc motor, commutation is performed without the use of rotor position sensors. A voltage across a non-conducting winding of the motor is measured, a voltage across a conducting winding of the motor is computed, an emf Park vector is computed from the voltages, an imaginary component of a rotated emf Park vector is extracted, and the imaginary component is processed to determine when to perform the commutation from one winding to the next sequential winding.
Inventors
- 👤 Colin Huggett
- 👤 Gabor P. Kalman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:00
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14; H02P6/16; H02P6/18; H02P6/182
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
70 words
A method of operating a brushless dc motor, the motor including a plurality of motor windings, the method comprising the steps of: determining a back emf voltage across a non-conducting winding of the motor; determining a voltage across a conducting winding of the motor; determining an emf Park vector from the determined voltages; extracting a component from the determined voltages; and processing the component to determine when to perform commutation.
Claim 2
Independent Claim
70 words
A method of operating a brushless dc motor, the motor including a plurality of motor windings, the method comprising the steps of: determining a back emf voltage across a non-conducting winding of the motor; determining a voltage across a conducting winding of the motor; determining an emf Park vector from the determined voltages; extracting a component from the determined voltages; and processing the component to determine when to perform commutation.
Claim 3
Dependent Claim
27 words
The method of claim 1, the motor including terminals for the windings, wherein the back emf voltage is determined by measuring the back emf at the terminals.
Claim 4
Dependent Claim
75 words
The method of claim 1, power for the motor being supplied on a dc link, motor speed being controlled by a pulse width modulated control signal, wherein the voltage across the conducting winding is determined by measuring a voltage on the dc link; determining an average duty cycle of the control signal; and computing the voltage across the conducting winding as a product of the voltage on the dc link and the average duty cycle.
Claim 5
Dependent Claim
14 words
The method of claim 1, wherein the component is processed during the non-conduction interval.
Claim 6
Dependent Claim
29 words
The method of claim 1, wherein the component is extracted by: rotating the emf Park vector by a fixed angle; and determining an imaginary component of the rotated vector.
Claim 7
Dependent Claim
18 words
The method of claim 5, wherein the emf Park vector is rotated backwards by one-half a sector angle.
Claim 8
Dependent Claim
16 words
The method of claim 1, wherein a commutation point occurs when the imaginary component changes polarity.
Claim 9
Dependent Claim
29 words
The method of claim 7, wherein the imaginary component is compared to zero, whereby the commutation point occurs when the imaginary component of the rotated vector passes through zero.
Claim 10
Independent Claim
152 words
A system comprising: a brushless dc motor including a rotor and a plurality of windings, a back emf being induced in the windings when the rotor is rotated relative to the windings; an inverter including high and low switches for the windings; commutation logic for providing a sequence of gating commands that, when supplied in the sequence, cause the switches to selectively energize the windings to create a motor torque that causes the rotor to rotate; first means for measuring a back emf voltage across a non-conducting winding of the motor; second means for computing a voltage across a conducting winding of the motor; third means for extracting a component from the determined voltages; fourth means for processing the component to cause the commutation logic to supply the gating commands in the sequence,; and wherein the third means extracts the component by determining an imaginary component of a rotated emf Park vector.
Claim 11
Independent Claim
152 words
A system comprising: a brushless dc motor including a rotor and a plurality of windings, a back emf being induced in the windings when the rotor is rotated relative to the windings; an inverter including high and low switches for the windings; commutation logic for providing a sequence of gating commands that, when supplied in the sequence, cause the switches to selectively energize the windings to create a motor torque that causes the rotor to rotate; first means for measuring a back emf voltage across a non-conducting winding of the motor; second means for computing a voltage across a conducting winding of the motor; third means for extracting a component from the determined voltages; fourth means for processing the component to cause the commutation logic to supply the gating commands in the sequence,; and wherein the third means extracts the component by determining an imaginary component of a rotated emf Park vector.
Claim 12
Dependent Claim
24 words
The system of claim 9, the motor including terminals for the windings, wherein the first means measures the back emf voltage at the terminals.
Claim 13
Dependent Claim
60 words
The system of claim 9, further comprising a dc link for supplying power to the motor; a speed control for generating a pulse width modulated control signal; and a filter for filtering the control signal; wherein the second means computes the voltage across the conducting winding as a product of voltage on the dc link and the filtered control signal.
Claim 14
Dependent Claim
17 words
The system of claim 9, wherein the fourth means processes the imaginary component during a non-conduction interval.
Claim 15
Dependent Claim
36 words
The system of claim 9, wherein the emf Park vector is rotated backwards by one-half a sector angle, and wherein a commutation point occurs when the imaginary component of the rotated emf Park vector changes polarity.
Claim 16
Dependent Claim
122 words
A circuit for controlling an inverter coupled to a brushless dc motor, the motor including a plurality of motor windings, a back emf being induced in the windings when the rotor is rotated relative to the windings, the inverter including high and low switches for the windings, the circuit comprising: commutation logic for providing a sequence of gating commands that, when supplied in the sequence, cause the switches to selectively energize the windings to create a motor torque that causes the rotor to rotate; means for determining a Park vector of the motor; means for extracting a component of a rotated Park vector; and means for processing the component to cause the commutation logic to supply the gating commands in the sequence.
Claim 17
Dependent Claim
122 words
A circuit for controlling an inverter coupled to a brushless dc motor, the motor including a plurality of motor windings, a back emf being induced in the windings when the rotor is rotated relative to the windings, the inverter including high and low switches for the windings, the circuit comprising: commutation logic for providing a sequence of gating commands that, when supplied in the sequence, cause the switches to selectively energize the windings to create a motor torque that causes the rotor to rotate; means for determining a Park vector of the motor; means for extracting a component of a rotated Park vector; and means for processing the component to cause the commutation logic to supply the gating commands in the sequence.
Claim 18
Dependent Claim
41 words
The circuit of claim 14, wherein the means for extracting the component includes means for determining voltages across conducting and nonconducting windings of the motor, and means for deriving a component of a rotated emf Park vector from the measured voltages.
Claim 19
Dependent Claim
27 words
The circuit of claim 15, wherein the motor includes terminals for the windings, and wherein back emf voltage of the non-conducting winding is measured at the terminals.
Claim 20
Dependent Claim
59 words
The circuit of claim 15, a dc link for supplying power to the motor; the circuit further comprising means for providing a pulse width modulated control signal; means for determining average duty cycle of the control signal; wherein voltage across the conducting winding is determined as a product of voltage on the dc link and the average duty cycle.
Claim 21
Dependent Claim
33 words
The circuit of claim 15, wherein an imaginary component of the rotated vector is extracted; and wherein a commutation point occurs when the imaginary component of the rotated emf Park vector changes polarity.
Claim 22
Dependent Claim
15 words
The circuit of claim 18, wherein the imaginary component is processed during a non-conduction interval.
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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) | 2002-09-06 | 2003-03-08 | 2003-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-06 | 2007-03-08 | 2007-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-06 | 2011-03-08 | 2011-09-07 | $7700.00 | Window Closed / Lapsed |