US5545964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of switched reluctance machines
Assignee: Nidec SR Drives Ltd
•
Filing: 1995-06-07
•
Granted: 1996-08-13
•
Expires: 2015-06-07
Abstract
Abstract A control system for and method of controlling a switched reluctance generator to maintain stable control of the generator in the continuous current mode. This is achieved by sensing the load on the generator, the speed of the rotor and the position of the rotor with respect to each phase winding in order to derive switching command signals to maintain the volt-seconds applied to the winding in each phase period so as to inhibit progressive flux growth in the phase windings by actuation of the controller switches.
Inventors
- 👤 John M. Stephenson
- 👤 William F. Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:18
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/40; H02P25/00; H02P25/02; H02P25/08
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
235 words
A control system for use with a switched reluctance machine having a rotor with rotor poles, a stator with at least one set of stator poles, and at least one phase winding associated with the at least one set of stator poles, wherein rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation of the at least one phase winding's inductance defines a phase period, the control system comprising: (a) a switch arrangement operatively coupled with the switched reluctance machine; (b) a rotor signal derivation arrangement operatively coupled with the switched reluctance machine to derive a rotor signal indicative of orientation of the rotor with respect to the stator; (c) an error signal generator to produce an error signal indicative of the difference between the output from the switched reluctance machine and a demanded output; and (d) a controller operatively coupled with the switch arrangement, the rotor signal derivation arrangement and the error signal generator top generate switch arrangement turn-on and turn-off signals in response to at least one of the error signal and the rotor signal, to apply volt-seconds to the at least one phase winding such that the current in the at least one phase winding is non-zero throughout the at least one phase period and such that progressive flux growth in the at least one phase winding is stably controlled.
Claim 2
Dependent Claim
235 words
A control system for use with a switched reluctance machine having a rotor with rotor poles, a stator with at least one set of stator poles, and at least one phase winding associated with the at least one set of stator poles, wherein rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation of the at least one phase winding's inductance defines a phase period, the control system comprising: (a) a switch arrangement operatively coupled with the switched reluctance machine; (b) a rotor signal derivation arrangement operatively coupled with the switched reluctance machine to derive a rotor signal indicative of orientation of the rotor with respect to the stator; (c) an error signal generator to produce an error signal indicative of the difference between the output from the switched reluctance machine and a demanded output; and (d) a controller operatively coupled with the switch arrangement, the rotor signal derivation arrangement and the error signal generator top generate switch arrangement turn-on and turn-off signals in response to at least one of the error signal and the rotor signal, to apply volt-seconds to the at least one phase winding such that the current in the at least one phase winding is non-zero throughout the at least one phase period and such that progressive flux growth in the at least one phase winding is stably controlled.
Claim 3
Dependent Claim
16 words
The control system of claim 1 wherein the switched reluctance machine is a switched reluctance generator.
Claim 4
Dependent Claim
29 words
The control system of claim 2 wherein the error signal produced by the error signal generator indicates a difference between an actual battery voltage and a demanded battery voltage.
Claim 5
Dependent Claim
16 words
The control system of claim 1 wherein the switched reluctance machine is a switched reluctance motor.
Claim 6
Dependent Claim
31 words
The control system of claim 4 wherein the error signal produced by the error signal generator is indicative of a difference between an actual rotor speed and a demanded rotor speed.
Claim 7
Dependent Claim
23 words
The control system of claim 1 wherein the error signal generator comprises a sensor to measure the output from the switched reluctance machine.
Claim 8
Dependent Claim
26 words
The control system of claim 1 wherein the controller comprises an actuating signal generator operatively coupled with the error signal generator to produce an actuating signal.
Claim 9
Dependent Claim
27 words
The control system of claim 1 wherein the controller comprises a speed signal generator operatively coupled with the rotor signal derivation arrangement to generate a speed signal.
Claim 10
Dependent Claim
48 words
The control system of claim 8 wherein the controller comprises an actuating signal generator operatively coupled with the error signal generator to produce an actuating signal; further wherein the controller generates switch arrangement turn-on and turn-off signals as a function of the actuating signal and the speed signal.
Claim 11
Dependent Claim
17 words
The control system of claim 7 wherein the actuating signal generator comprises a proportional and integral controller.
Claim 12
Dependent Claim
23 words
The control system of claim 8 wherein the controller generates a switch arrangement turn-off signal solely as a function of the speed signal.
Claim 13
Dependent Claim
23 words
The control system of claim 7 wherein the controller generates a switch arrangement turn-on signal solely as a function of the actuating signal.
Claim 14
Dependent Claim
43 words
The control system of claim 1 wherein the controller further comprises a look-up table operatively coupled with the switch arrangement to output switch arrangement turn-on and turn-off signals in response to said at least one of the reference signal and the rotor signal.
Claim 15
Dependent Claim
15 words
The control system of claim 1 wherein the error signal generator comprises a summing element.
Claim 16
Independent Claim
167 words
A method of controlling a switched reluctance machine using a switching arrangement, the switched reluctance machine including a rotor with rotor poles, a stator defining at least one set of stator poles, and at least one phase winding associated with the at least one set of stator poles, the at least one phase winding defining at least one phase period, the method comprising: (a) deriving a rotor signal indicative of orientation of the rotor with respect to the stator; (b) producing an error signal indicative of the difference between the output from the switched reluctance machine and a demanded output; (c) producing switch arrangement turn-on and turn-off signals in response to at least one of the error signal and the rotor signal to apply volt-seconds to the at least one phase winding such that current in the at least one phase winding is non-zero throughout the at least one phase period and such that progressive flux growth in the at least one phase winding is stably controlled.
Claim 17
Independent Claim
167 words
A method of controlling a switched reluctance machine using a switching arrangement, the switched reluctance machine including a rotor with rotor poles, a stator defining at least one set of stator poles, and at least one phase winding associated with the at least one set of stator poles, the at least one phase winding defining at least one phase period, the method comprising: (a) deriving a rotor signal indicative of orientation of the rotor with respect to the stator; (b) producing an error signal indicative of the difference between the output from the switched reluctance machine and a demanded output; (c) producing switch arrangement turn-on and turn-off signals in response to at least one of the error signal and the rotor signal to apply volt-seconds to the at least one phase winding such that current in the at least one phase winding is non-zero throughout the at least one phase period and such that progressive flux growth in the at least one phase winding is stably controlled.
Claim 18
Dependent Claim
29 words
The method of claim 15, wherein the error signal producing step includes producing a signal indicative of a difference between an actual battery voltage and a demanded battery voltage.
Claim 19
Dependent Claim
29 words
The method of claim 15, wherein the error signal producing step includes producing a signal indicative of a difference between an actual rotor speed and a demanded rotor speed.
Claim 20
Dependent Claim
35 words
A method of claim 15, wherein the step of producing switch arrangement turn-on and turn-off signals includes producing an actuating signal based on the error signal and applying the actuating signal to a look-up table.
Claim 21
Dependent Claim
35 words
The method of claim 15, wherein the step of producing switch arrangement turn-on and turn-off signals includes producing a speed signal based on the rotor signal and applying the speed signal to a look-up table.
Claim 22
Dependent Claim
168 words
A switched reluctance drive system comprising: (a) a switched reluctance machine including a stator having a plurality of stator poles, a rotor having a plurality of rotor poles and at least one phase winding associated with at least one stator pole, wherein rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation of the at least one phase winding's inductance defines a phase period; (b) a switching arrangement operable to energize the at least one phase winding from a source of electrical power; (c) a controller arranged to provide firing signals to the switching arrangement to control the energization of the at least one phase winding, wherein the firing signals provided by the controller are such that phase current in the at least one phase winding is continuous throughout the phase period and positive volt-seconds applied to the at least one phase winding are balanced by negative volt-seconds applied to the at least one phase winding.
Claim 23
Dependent Claim
168 words
A switched reluctance drive system comprising: (a) a switched reluctance machine including a stator having a plurality of stator poles, a rotor having a plurality of rotor poles and at least one phase winding associated with at least one stator pole, wherein rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation of the at least one phase winding's inductance defines a phase period; (b) a switching arrangement operable to energize the at least one phase winding from a source of electrical power; (c) a controller arranged to provide firing signals to the switching arrangement to control the energization of the at least one phase winding, wherein the firing signals provided by the controller are such that phase current in the at least one phase winding is continuous throughout the phase period and positive volt-seconds applied to the at least one phase winding are balanced by negative volt-seconds applied to the at least one phase winding.
Claim 24
Dependent Claim
73 words
The switched reluctance system of claim 20 wherein the rotor has a first angular position and a second angular position and wherein the controller provides firing signals to operate the switching arrangement to energize the at least one phase winding from the source of electrical power when the rotor reaches the first angular position and to initiate de-energization of the at least one phase winding when the rotor reaches the second angular position.
Claim 25
Dependent Claim
21 words
The switched reluctance system of claim 21 wherein the second angular position is independent of the rotational speed of the rotor.
Claim 26
Dependent Claim
22 words
The switched reluctance system of claim 21 wherein the second angular position is retarded as the rotational speed of the rotor increases.
Claim 27
Dependent Claim
42 words
The switched reluctance system of claim 21 wherein the controller receives an actuating signal indicative of a desired output of the switched reluctance machine and wherein the controller adjusts at least the first angular position as a function of the actuating signal.
Claim 28
Dependent Claim
51 words
The switched reluctance system of claim 24 wherein the controller operates the switched reluctance machine as a motor, wherein the actuating signal corresponds to a desired speed output and wherein the controller adjusts the first angular position such that the first angular position is retarded as the desired torque output increases.
Claim 29
Dependent Claim
78 words
The switched reluctance system of claim 25 further comprising: (a) a speed detection circuit providing a rotor speed signal representative of the rotational speed of the rotor; and (b) a comparator for comparing the rotor speed signal with a speed demand signal representative of the desired speed and providing a speed error signal that is proportional to a difference between the rotor speed signal and the speed demand signal, wherein the actuating signal comprises the speed error signal.
Claim 30
Dependent Claim
30 words
The switched reluctance system of claim 27 wherein the speed error signal is applied to a P+I controller and wherein the output of the P+I controller is the actuating signal.
Claim 31
Dependent Claim
58 words
The switched reluctance system of claim 24 wherein the controller operates the switched reluctance machine as a generator providing electrical power, wherein the actuating signal corresponds to a desired electric voltage output and wherein the controller adjusts at least the first angular position such that the first angular position is retarded as the desired electric voltage output increases.
Claim 32
Dependent Claim
93 words
The switched reluctance system of claim 28 wherein the electric power output of the generator is provided to a battery and wherein the system further comprises: (a) a voltage detection circuit providing a battery voltage signal representative of the battery voltage; and (b) a comparator for comparing the battery voltage signal with a voltage demand signal representative of the desired battery voltage and providing a voltage error signal that is proportional to a difference between the battery voltage signal and the voltage demand signal wherein the actuating signal comprises the voltage error signal.
Claim 33
Dependent Claim
30 words
The switched reluctance system of claim 29 wherein the voltage error signal is applied to a P+I controller and wherein the output of the P+I controller is the actuating signal.
Claim 34
Dependent Claim
156 words
The switched reluctance system of claim 24 wherein the controller comprises: (a) a rotor position detector providing rotor position signals representative of the angular position of the rotor relative to the stator; (b) a speed detector providing a speed signal representative of the angular speed of the rotor; (c) a control law circuit that receives the speed signal and the actuating signal and generates in response a first control signal corresponding to the first angular position and a second control signal corresponding to the second angular position; and (d) comparator circuitry that receives the rotor position signals, the first control signal and the second control signal, wherein the comparator circuitry compares the rotor position signals with the first and second control signals and generates a firing signal when the rotor position signal and the first and the second control signals indicate that the rotor is at an angular position between the first and second angular positions.
Claim 35
Dependent Claim
16 words
The switched reluctance system of claim 31 wherein the control law circuit is a programmable memory.
Claim 36
Dependent Claim
16 words
The switched reluctance system of claim 31 wherein the rotor position detector comprises a position transducer.
Claim 37
Independent Claim
139 words
A method of controlling a switched reluctance machine including a stator having a plurality of stator poles, at least one phase winding associated with at least one of the stator poles, and a rotor having rotor poles, wherein the rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation in the at least one phase winding's inductance defines a phase period, the method comprising the step of controlling energization of the at least one phase winding by a switching arrangement from a source of electrical power such that phase current in the at lease one phase winding is continuous throughout the phase period and positive volt-seconds applied to the at least one phase winding are balanced by negative volt-seconds applied to the at least one phase winding.
Claim 38
Independent Claim
139 words
A method of controlling a switched reluctance machine including a stator having a plurality of stator poles, at least one phase winding associated with at least one of the stator poles, and a rotor having rotor poles, wherein the rotation of the rotor produces cyclic variations in the inductance of the at least one phase winding, and wherein each cyclic variation in the at least one phase winding's inductance defines a phase period, the method comprising the step of controlling energization of the at least one phase winding by a switching arrangement from a source of electrical power such that phase current in the at lease one phase winding is continuous throughout the phase period and positive volt-seconds applied to the at least one phase winding are balanced by negative volt-seconds applied to the at least one phase winding.
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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) | 1999-08-13 | 2000-02-12 | 2000-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-13 | 2004-02-12 | 2004-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-13 | 2008-02-12 | 2008-08-13 | $7700.00 | Window Closed / Lapsed |