US6288513B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor position detection in switched reluctance machines
Assignee: Nidec SR Drives Ltd
•
Filing: 2000-01-10
•
Granted: 2001-09-11
•
Expires: 2020-01-10
Abstract
Abstract A polyphase switched reluctance machine is controlled by a control system using sensorless position detection. A method of operating the machine at high speeds interrogates every nth phase reference point to allow sufficient time for computations of position to be carried out, where n is an integer greater than one.
Inventors
- 👤 Charles Edward Brandon Green
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:29
CPC Classifications
G; G02; G02C; G02C5/00; G02C5/12; G02C5/126; H; H02; H02P; H02P25/00; H02P25/02; H02P25/08; H02P25/086; H02P25/089
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
144 words
A method of rotor position detection for a switched reluctance machine having a rotor, a stator and a plurality of phase windings, the rotor being movable relative to the stator according to a cyclic variation of magnetic properties of each phase, the method comprising: defining a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties; sampling at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions; deriving a rotor position from the sampled characteristic(s); and advancing the rotor beyond a subsequent reference position and sampling the at least one characteristic again to allow further time for a subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
Claim 2
Independent Claim
144 words
A method of rotor position detection for a switched reluctance machine having a rotor, a stator and a plurality of phase windings, the rotor being movable relative to the stator according to a cyclic variation of magnetic properties of each phase, the method comprising: defining a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties; sampling at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions; deriving a rotor position from the sampled characteristic(s); and advancing the rotor beyond a subsequent reference position and sampling the at least one characteristic again to allow further time for a subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1 in which the advance is an integer number of reference positions.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 1 in which the at least one sampled characteristic is used to provide signals indicative of phase current and flux linkage in a corresponding phase winding.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 1 in which the at least one sampled characteristic comprises phase current and voltage applied across the corresponding winding.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 1 , including detecting rotor speed from the sampled characteristic(s).
Claim 7
Dependent Claim
59 words
A method as claimed in claim 1 , including: defining a set of speed ranges for the rotor, including a low speed range and at least a first high speed range; determining into which speed range the rotor speed falls; and advancing the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 8
Dependent Claim
27 words
A method as claimed in claim 6 in which the value of the advance beyond the subsequent reference position is a fraction of one phase inductance cycle.
Claim 9
Dependent Claim
29 words
A method as claimed in claim 7 in which the fraction is {fraction (m/n)} where n is the number of phases and m is an integer less than n.
Claim 10
Dependent Claim
37 words
A method as claimed in claim 6 in which the set of speed ranges includes a second high speed range, the value of the advance beyond the subsequent reference position being one or more phase inductance cycles.
Claim 11
Independent Claim
170 words
A method of rotor position detection for a switched reluctance machine having a rotor, a stator and a plurality of phase windings, the rotor being movable relative to the stator according to a cyclic variation of magnetic properties of each phase, the method comprising: defining a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties; sampling at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions; deriving a rotor position from the sampled characteristic(s); advancing the rotor beyond a subsequent reference position and sampling the at least one characteristic again to allow further time for a subsequent derivation of the rotor position; defining a set of speed ranges for the rotor, including a low speed range and at least a first high speed range; determining into which speed range the rotor speed falls; and advancing the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 12
Independent Claim
170 words
A method of rotor position detection for a switched reluctance machine having a rotor, a stator and a plurality of phase windings, the rotor being movable relative to the stator according to a cyclic variation of magnetic properties of each phase, the method comprising: defining a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties; sampling at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions; deriving a rotor position from the sampled characteristic(s); advancing the rotor beyond a subsequent reference position and sampling the at least one characteristic again to allow further time for a subsequent derivation of the rotor position; defining a set of speed ranges for the rotor, including a low speed range and at least a first high speed range; determining into which speed range the rotor speed falls; and advancing the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 13
Dependent Claim
27 words
A method as claimed in claim 10 in which the value of the advance beyond the subsequent reference position is a fraction of one phase inductance cycle.
Claim 14
Dependent Claim
29 words
A method as claimed in claim 11 in which the fraction is {fraction (m/n)} where n is the number of phases and m is an integer less than n.
Claim 15
Dependent Claim
37 words
A method as claimed in claim 10 in which the set of speed ranges includes a second high speed range, the value of the advance beyond the subsequent reference position being one or more phase inductance cycles.
Claim 16
Dependent Claim
149 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller having means for deriving a rotor position from at least one sampled characteristic of the machine; and means for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the means for sampling thereafter to allow further time for subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
Claim 17
Dependent Claim
149 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller having means for deriving a rotor position from at least one sampled characteristic of the machine; and means for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the means for sampling thereafter to allow further time for subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
Claim 18
Dependent Claim
21 words
A system as claimed in claim 14 including means for deriving the rotor speed from the at least one sampled characteristic.
Claim 19
Dependent Claim
53 words
A system as claimed in claim 14 including means for determining into which of a low speed range and at least a first high speed range the rotor speed falls, the controller being operable to advance the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 20
Dependent Claim
48 words
A system as claimed in claim 16 in which the means for determining is operable to allocate the determined rotor speed into a first high speed range, the controller being operable to advance the rotor beyond the subsequent reference position by a fraction of the phase inductance cycle.
Claim 21
Dependent Claim
30 words
A system as claimed in claim 17 in which the fraction is {fraction (m/n)} where n is the number of phases and m is a positive integer less than n.
Claim 22
Dependent Claim
47 words
A system as claimed in claim 16 in which the means for determining is operable to allocate the determined rotor speed into a second high speed range, the controller being operable to advance the rotor beyond the subsequent reference position by one or more phase inductance cycles.
Claim 23
Dependent Claim
171 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller having means for deriving a rotor position from at least one sampled characteristic of the machine; means for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the means for sampling thereafter to allow further time for subsequent derivation of the rotor position; and means for determining into which of a low speed range and at least a first high speed range the rotor speed falls, the controller being operable to advance the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 24
Dependent Claim
171 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller having means for deriving a rotor position from at least one sampled characteristic of the machine; means for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the means for sampling thereafter to allow further time for subsequent derivation of the rotor position; and means for determining into which of a low speed range and at least a first high speed range the rotor speed falls, the controller being operable to advance the rotor beyond the subsequent reference position if the rotor speed falls outside the low speed range.
Claim 25
Dependent Claim
48 words
A system as claimed in claim 20 in which the means for determining is operable to allocate the determined rotor speed into a first high speed range, the controller being operable to advance the rotor beyond the subsequent reference position by a fraction of the phase inductance cycle.
Claim 26
Dependent Claim
30 words
A system as claimed in claim 21 in which the fraction is {fraction (m/n)} where n is the number of phases and m is a positive integer less than n.
Claim 27
Dependent Claim
47 words
A system as claimed in claim 20 in which the means for determining is operable to allocate the determined rotor speed into a second high speed range, the controller being operable to advance the rotor beyond the subsequent reference position by one or more phase inductance cycles.
Claim 28
Dependent Claim
145 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller deriving a rotor position from at least one sampled characteristic of the machine; and a sampler for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the sampler thereafter to allow further time for subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
Claim 29
Dependent Claim
145 words
A switched reluctance machine system including: a stator having a plurality of phase windings; a rotor movable relative to the stator; and a controller programmed with a reference position of the rotor relative to the stator in each cyclic variation of the magnetic properties of each phase of the machine, the controller deriving a rotor position from at least one sampled characteristic of the machine; and a sampler for sampling the at least one characteristic of the machine at an estimate of the time of reaching one of the reference positions, the controller further being operable to advance the rotor beyond a subsequent reference position and to enable the sampler thereafter to allow further time for subsequent derivation of the rotor position; wherein said one reference position is in one phase and said subsequent reference position is in another phase of the switched reluctance machine.
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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) | 2004-09-10 | 2005-03-12 | 2005-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-10 | 2009-03-12 | 2009-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-10 | 2013-03-12 | 2013-09-11 | $7700.00 | Window Closed / Lapsed |