US6351094B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of switched reluctance machines
Assignee: Nidec SR Drives Ltd
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Filing: 2000-02-14
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Granted: 2002-02-26
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Expires: 2020-02-14
Abstract
Abstract A switched reluctance drive includes a reluctance machine, a controller, power switches actuated by the controller and a current transducer for monitoring the current in each phase winding. The controller employs a sensorless rotor position detection technique by injecting voltage pulses into the idle period of each phase winding in a chopping mode. Acoustic noise associated with the injected pulses is concealed by varying the frequency at which the pulses are injected according to rotor speed. In an alternative embodiment the frequency is varied pseudo-randomly.
Inventors
- 👤 Charles Edward Brandon Green
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:13
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02P; H02P25/00; H02P25/02; H02P25/08; H02P25/086; H02P25/089
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
176 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to actuate the means for injecting (a) to inject a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) to inject a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
Claim 2
Dependent Claim
176 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to actuate the means for injecting (a) to inject a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) to inject a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
Claim 3
Dependent Claim
23 words
A drive as claimed in claim 1 in which the controller is operable to vary the frequency of the pulses with rotor speed.
Claim 4
Dependent Claim
23 words
A drive as claimed in claim 2 in which the controller is operable to vary the frequency in direct proportionality to rotor speed.
Claim 5
Dependent Claim
107 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to vary the frequency of the pulses above a lower threshold of rotor speed.
Claim 6
Dependent Claim
107 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to vary the frequency of the pulses above a lower threshold of rotor speed.
Claim 7
Dependent Claim
24 words
A drive as claimed in claim 4 in which the control is operable to vary the frequency below an upper threshold of rotor speed.
Claim 8
Dependent Claim
133 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to vary the frequency of the pulses with rotor speed, further wherein the rotor is operable to vary the frequency according to the formula: Pulse frequency=A/(B−Cω) where ω is the rotor angular speed and A, B and C are constants.
Claim 9
Dependent Claim
133 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to vary the frequency of the pulses with rotor speed, further wherein the rotor is operable to vary the frequency according to the formula: Pulse frequency=A/(B−Cω) where ω is the rotor angular speed and A, B and C are constants.
Claim 10
Dependent Claim
102 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, further wherein the controller is operable to vary the frequency of the pulses pseudo-randomly.
Claim 11
Dependent Claim
102 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and means for injecting diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to actuate the means for injecting according to a variable frequency to reduce the perceived noise emitted from the drive, further wherein the controller is operable to vary the frequency of the pulses pseudo-randomly.
Claim 12
Dependent Claim
28 words
A drive as claimed in claim 7 in which the controller is operable to vary the frequency of the pulses between an upper and a lower frequency limit.
Claim 13
Dependent Claim
26 words
A drive as claimed in claim 1 in which the controller is arranged to inject a plurality of pulses into the winding during an idle period.
Claim 14
Dependent Claim
20 words
A drive as claimed in claim 1 in which the means for injecting is operable to inject a voltage pulse.
Claim 15
Independent Claim
162 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the diagnostic pulses to reduce the perceived noise emitted from the machine, including (a) injecting a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) injecting a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
Claim 16
Independent Claim
162 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the diagnostic pulses to reduce the perceived noise emitted from the machine, including (a) injecting a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) injecting a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
Claim 17
Dependent Claim
19 words
A method as claimed in claim 11 in which the frequency of the pulses is varied with rotor speed.
Claim 18
Dependent Claim
21 words
A method as claimed in claim 12 in which the frequency of the pulses is varied directly proportionally with rotor speed.
Claim 19
Independent Claim
126 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the frequency of the pulses is varied directly proportionally with rotor speed; further wherein the frequency of the pulses is varied according to the formula: Pulse frequency=A/(B−Cω) where ω is the rotor speed and A, B and C are constants.
Claim 20
Independent Claim
126 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the frequency of the pulses is varied directly proportionally with rotor speed; further wherein the frequency of the pulses is varied according to the formula: Pulse frequency=A/(B−Cω) where ω is the rotor speed and A, B and C are constants.
Claim 21
Independent Claim
99 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the pulse frequency is varied above a predetermined lower threshold of rotor speed.
Claim 22
Independent Claim
99 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the pulse frequency is varied above a predetermined lower threshold of rotor speed.
Claim 23
Dependent Claim
22 words
A method as claimed in claim 15 in which the pulse frequency is varied below a predetermined upper threshold of rotor speed.
Claim 24
Independent Claim
92 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the pulse frequency is varied pseudo-randomly.
Claim 25
Independent Claim
92 words
A method of reducing the noise emitted from a switched reluctance machine having a rotor and a stator, the method comprising: controlling output of the machine by the energization of at least one phase winding of the machine according to the position of the rotor relative to the stator; injecting diagnostic pulses into the at least one winding; determining the rotor position from an effect of the diagnostic pulses; and varying the frequency of the pulses to reduce the perceived noise emitted from the machine; wherein the pulse frequency is varied pseudo-randomly.
Claim 26
Dependent Claim
21 words
A method as claimed in claim 17 in which the pulse frequency is varied between an upper and a lower frequency.
Claim 27
Dependent Claim
22 words
A method as claimed in claim 11 in which the plurality of pulses are injected into the winding during an idle period.
Claim 28
Dependent Claim
173 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and for causing injection of diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to cause the injection of pulses according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to cause (a) injection of a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) injection of a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
Claim 29
Dependent Claim
173 words
A switched reluctance drive comprising a reluctance machine having a rotor, a stator and at least one phase winding, a controller for controlling output of the machine and for causing injection of diagnostic pulses into the at least one phase winding for rotor position detection, the controller being operable to determine the position of the rotor relative to the stator according to an effect of the diagnostic pulses and to cause the injection of pulses according to a variable frequency to reduce the perceived noise emitted from the drive, wherein the controller is operable to cause (a) injection of a first series of diagnostic pulses, the first series having a first time period between each pulse of the first series, and (b) injection of a second series of diagnostic pulses, the second series having a second time period between each pulse of the second series, the first time period being different than the second time period, the machine continuously running during and between injection of the first and second series of diagnostic pulses.
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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) | 2005-02-25 | 2005-08-27 | 2006-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-02-25 | 2009-08-27 | 2010-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-02-25 | 2013-08-27 | 2014-02-26 | $7700.00 | Window Closed / Lapsed |