US6586903B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor position monitoring of a reluctance drive
Assignee: Nidec SR Drives Ltd
•
Filing: 2000-12-11
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Granted: 2003-07-01
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Expires: 2020-12-11
Abstract
Abstract A reluctance drive includes a stator, a phase winding (16) on the stator, a rotor (12) that is movable relative to the stator, a controller for applying a current to the phase winding (13), and a sensor for measuring the phase current in the winding (16). Aspects of the invention detect when the phase current has passed its peak, compute when the peak phase current occurred using information on when the phase current passed its peak, determine rotor position using the computed position of the peak phase current.
Inventors
- 👤 Peter Mark Moriarty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:07
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14; H02P6/16; H02P6/18; H02P25/00; H02P25/02; H02P25/08; H02P25/086; H02P25/089; H02P25/092
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
100 words
A method for sensorless determination of rotor position in a reluctance drive comprising a rotor with a plurality of rotor poles and a stator with a plurality of stator poles, the poles of one of the rotor and stator being provided with windings defining a plurality of phases, the method comprising: sampling phase current within a conduction period of a phase, detecting when the phase current within the conduction period has passed its peak, computing when the peak phase current occurred using information on when the phase current passed its peak, and determining rotor position using the computed peak current.
Claim 2
Independent Claim
100 words
A method for sensorless determination of rotor position in a reluctance drive comprising a rotor with a plurality of rotor poles and a stator with a plurality of stator poles, the poles of one of the rotor and stator being provided with windings defining a plurality of phases, the method comprising: sampling phase current within a conduction period of a phase, detecting when the phase current within the conduction period has passed its peak, computing when the peak phase current occurred using information on when the phase current passed its peak, and determining rotor position using the computed peak current.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1 , wherein detecting when the phase current passed its peak includes monitoring the rate of change of current against time.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 2 , wherein a rate at which the phase current is sampled is dependent on the speed of the rotor.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 3 , comprising: monitoring the speed of the rotor, and varying the sample rate depending on the monitored speed.
Claim 6
Dependent Claim
19 words
A method as claimed in claim 3 , wherein the sampling is done using an analog to digital converter.
Claim 7
Dependent Claim
21 words
A method as claimed in claim 1 , wherein the sampling of phase current includes using a sensor comprising a resistor.
Claim 8
Dependent Claim
49 words
A method as claimed in claim 6 , used in a drive that is supplied from a power converter that has at least one switch connected to a zero voltage line through the resistor, wherein the sampling of the current is synchronized with a switching cycle of the switch.
Claim 9
Dependent Claim
16 words
A method as claimed in claim 1 , wherein the drive is a switched reluctance drive.
Claim 10
Dependent Claim
21 words
A method as claimed in claim 1 , wherein the drive is operated in a motoring mode or a generating mode.
Claim 11
Dependent Claim
111 words
A reluctance drive with sensorless determination of rotor position, comprising: a stator, a rotor that is movable relative to the stator, a phase winding on one of the stator and rotor, the phase winding defining a phase, a controller for applying a current to the phase winding, means for measuring phase current in the winding within a conduction period of the phase, means for detecting when the phase current within the conduction period has passed its peak, means for computing when the peak phase current occurred using information on when the phase current passed its peak, and means for computing rotor position using the computed position of the peak phase current.
Claim 12
Dependent Claim
111 words
A reluctance drive with sensorless determination of rotor position, comprising: a stator, a rotor that is movable relative to the stator, a phase winding on one of the stator and rotor, the phase winding defining a phase, a controller for applying a current to the phase winding, means for measuring phase current in the winding within a conduction period of the phase, means for detecting when the phase current within the conduction period has passed its peak, means for computing when the peak phase current occurred using information on when the phase current passed its peak, and means for computing rotor position using the computed position of the peak phase current.
Claim 13
Dependent Claim
35 words
A reluctance drive as claimed in claim 10 , wherein the means for detecting when the phase current has passed its peak is operable to monitor the rate of change of phase current against time.
Claim 14
Dependent Claim
34 words
A reluctance drive as claimed in claim 11 , wherein the means for detecting when the phase current has passed its peak includes means for sampling the phase current at discrete intervals of time.
Claim 15
Dependent Claim
34 words
A reluctance drive as claimed in claim 12 , wherein at least one negative slope in the rate of change of phase current against time indicates that the current has passed its peak value.
Claim 16
Dependent Claim
26 words
A reluctance drive as claimed in claim 12 , wherein a sample rate of the means for sampling is dependent on the speed of the rotor.
Claim 17
Dependent Claim
28 words
A reluctance drive as claimed in claim 14 , comprising means for monitoring the speed of the rotor and varying the sample rate according to the monitored speed.
Claim 18
Dependent Claim
20 words
A reluctance drive as claimed in claim 12 , wherein the means for sampling is an analog to digital converter.
Claim 19
Dependent Claim
19 words
A reluctance drive as claimed in claim 10 , wherein the means for detecting is provided in a microprocessor.
Claim 20
Dependent Claim
17 words
A reluctance drive as claimed in claim 17 , wherein the microprocessor is a Microchip PIC 16C72A.
Claim 21
Dependent Claim
22 words
A reluctance drive as claimed in claim 10 , wherein the sampling of phase current includes using a sensor comprising a resistor.
Claim 22
Dependent Claim
55 words
A reluctance drive as claimed in claim 12 , wherein the drive is a switched reluctance drive that is supplied by a power converter having at least one switch connected to a zero voltage line through the resistor and the means for sampling the phase current is synchronized with a switching cycle of the switch.
Claim 23
Dependent Claim
83 words
A computer program, on a data carrier or other computer-readable medium, for sensorless determination of rotor position in a reluctance machine, the computer program having instructions for controlling sampling of phase current within a conduction period of a phase of the reluctance machine, detecting when the phase current within the conduction period has passed its peak, computing when the peak phase current occurred using information on when the phase current passed its peak and determining rotor position using the computed peak phase current.
Claim 24
Dependent Claim
83 words
A computer program, on a data carrier or other computer-readable medium, for sensorless determination of rotor position in a reluctance machine, the computer program having instructions for controlling sampling of phase current within a conduction period of a phase of the reluctance machine, detecting when the phase current within the conduction period has passed its peak, computing when the peak phase current occurred using information on when the phase current passed its peak and determining rotor position using the computed peak phase current.
Claim 25
Dependent Claim
32 words
A computer program as claimed in claim 21 , wherein detecting when the phase current passed its peak includes controlling the sampling to monitor the rate of change of current against time.
Claim 26
Dependent Claim
25 words
A computer program as claimed in claim 22 , wherein the instructions for controlling set a sample rate depending on the speed of the rotor.
Claim 27
Dependent Claim
29 words
A computer program as claimed in claim 23 , comprising instructions for noting a measured speed of the rotor and varying the sample rate depending on the measured speed.
Claim 28
Dependent Claim
60 words
A computer program as claimed in claim 24 adapted to control a drive that is supplied from a power converter having at least one switch connected to a zero voltage line through a resistive current sensor, wherein the computer program is adapted to control sampling of the current so that it is synchronized with a switching cycle of the switch.
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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) | 2006-06-30 | 2006-12-30 | 2007-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-06-30 | 2010-12-30 | 2011-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-06-30 | 2014-12-30 | 2015-07-01 | $7700.00 | Window Closed / Lapsed |