Hysteresis Or Reluctance Motor Systems Patents (Class 318/701)
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Patent number: 7511444Abstract: A motor control apparatus controls a motor that drives an output shaft through a rotation transmission system. The difference between a newly established output shaft target rotation angle and a detected output shaft rotation angle is obtained, a target rotation angle for the motor is derived based on that difference, and the motor is driven accordingly. When it is determined, based on the detected output shaft rotation angle, that motor rotation has at least proceeded to a point whereby backlash in the transmission system is nullified, the target motor rotation angle is updated based on the current value of the aforementioned difference.Type: GrantFiled: January 7, 2005Date of Patent: March 31, 2009Assignee: DENSO CorporationInventors: Yasuhiro Nakai, Shigeru Kamio
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Patent number: 7508156Abstract: A controller and a motor assembly having a controller. The controller includes a first switch assembly in a series configuration with the motor, where the first switch assembly has a first transistor, a second switch assembly in a parallel configuration with the motor, where the second switch assembly has a second transistor, and a control circuit electrically connected to the first transistor and to the second transistor to control the first switch assembly and the second switch assembly to provide a chopped voltage to a motor.Type: GrantFiled: August 31, 2006Date of Patent: March 24, 2009Assignee: A. O. Smith CorporationInventor: William Louis Mehlhorn
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Publication number: 20090066173Abstract: To enable control the number of revolutions of a wheel with a new structure different from an induction motor and adjust the maximum torque rapidly and accurately. A linear drive travel system includes a metal wheel 20 having a drum rotor and a stator 30 arranged inside the metal wheel 20. The stator 30 includes a plurality of rows of electromagnets 32 arranged in the direction of rotation axis, each row being formed of a plurality of electromagnets 32 arranged along the circumference around a rotary shaft 40. A drum rotor includes a plurality of arc-shaped rotor cores 23 arranged along the circumference around the rotary shaft 40. Control means (control system 80) performs control by allowing electromagnets 32 in some rows to be a magnetization coil of the rotor core and by allowing the electromagnets 32 in other rows to be a rotation coil of the drum motor.Type: ApplicationFiled: March 12, 2007Publication date: March 12, 2009Inventors: Sachio Takahashi, Kazuo Fuda
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Publication number: 20090045768Abstract: An improved single-switch control circuit for use in a multi-phase switched reluctance machine is provided. The control circuit includes at least first and second phase windings, a switch, a capacitor, and a diode. The capacitor may have a polarity opposite that of a power source in the control circuit. The first winding may be connected in series with the switch and connected in parallel with a circuit block comprising the second winding. The second winding may be connected in parallel with the capacitor and in series with the diode. In operation, the switch may be used to redirect current from the first winding to the second winding. The capacitor can become charged by the redirected current until it eventually stores enough energy to essentially discontinue current flow in the first winding. Then, the capacitor can discharge its stored energy as a current through the second winding. In this manner, substantially all of the energy from the first winding can be transferred to the second winding.Type: ApplicationFiled: December 5, 2007Publication date: February 19, 2009Inventor: Krishnan Ramu
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Patent number: 7492117Abstract: The present invention provides a variable reluctance actuator system and method that can be adapted for simultaneous rotation and translation of a moving element by applying a normal-direction magnetic flux on the moving element. In a beneficial example arrangement, the moving element includes a swing arm that carries a cutting tool at a set radius from an axis of rotation so as to produce a rotary fast tool servo that provides a tool motion in a direction substantially parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. An actuator rotates a swing arm such that a cutting tool moves toward and away from a mounted rotating workpiece in a controlled manner in order to machine the workpiece. Position sensors provide rotation and displacement information for a swing arm to a control system.Type: GrantFiled: July 20, 2006Date of Patent: February 17, 2009Assignee: Lawrence Livermore National Security, LLCInventors: Richard C. Montesanti, David L. Trumper, James L. Kirtley, Jr.
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Patent number: 7489100Abstract: The present invention provides an electro-mechanical energy exchange system with a variable speed synchronous reluctance motor-generator having an all-metal rotor. A bi-directional AC-to-DC electric power converter interconnects the motor-generator with a DC bus. First and second hybrid controllers provide current regulation for the motor-generator and voltage regulation for the DC bus. Use of both feedback and feedforward control elements provides a controller particularly suited for operating high speed devices.Type: GrantFiled: December 21, 2006Date of Patent: February 10, 2009Inventors: Heath F. Hofmann, Claude Khalizadeh
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Publication number: 20090026997Abstract: A control apparatus for a motor (in FIG.Type: ApplicationFiled: July 25, 2008Publication date: January 29, 2009Applicant: Okuma CorporationInventor: Akiyoshi Satake
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Publication number: 20090021089Abstract: A motor and a control unit therefor comprise: salient rotor poles and salient stator poles, which are arranged along circumferences of phases A, B and C with an even interval therebetween; magnetic paths for passing magnetic fluxes, the paths permitting the magnetic fluxes passing through the salient rotor and stator poles of each phase to return to the rotor side; and substantially looped windings arranged between the salient stator poles of individual phases and the magnetic paths for passing magnetic fluxes, wherein currents are supplied to the windings in synchronization with the rotational position of the rotor to thereby output torque. Since the structures of the stator, the rotor and the windings are simple, productivity is enhanced, whereby high quality, small size and low cost can be realized.Type: ApplicationFiled: May 16, 2006Publication date: January 22, 2009Applicant: DENSO CORPORATIONInventor: Masayuki Nashiki
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Publication number: 20080297097Abstract: A motor driver system and its control methods are discussed. Even when a command magnetic flux decreases as a motor operates in a field weakening region, a current angle can be maintained always below a limit value, thereby obtaining the stability of the motor control.Type: ApplicationFiled: November 16, 2007Publication date: December 4, 2008Applicant: LG Electronics Inc.Inventors: Kyung Hoon LEE, June Hee Won, Gil Su Lee, Jun Ho Ahn, Jae Yoon Oh
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Publication number: 20080284368Abstract: Disclosed is an apparatus and method for driving a 2-phase SRM capable of individually performing an initial driving by an initializing sensor and a normal driving by a driving sensor, and capable of controlling a rotation speed of the SRM by delaying a phase signal by a half period and then generating a pulse width modulation signal based on the period. The apparatus comprises: a driving sensor which detects a position of a rotor thus to generate a driving sensor signal based on a result of the detection; a microprocessor which generates a 1-phase signal and a 2-phase signal based on a rising time and a falling time of the driving sensor signal at the time of a normal driving; an oscillator which generates first and second pulse width modulation signals delayed by a preset time; and a multiplying unit which multiplies the 1-phase and 2-phase signals with the first and second pulse width modulation signals, and generates 1-phase and 2-phase driving signals based on a result of the multiplication.Type: ApplicationFiled: October 25, 2006Publication date: November 20, 2008Applicant: LG ELECTRONICS INC.Inventors: Sang-Young Kim, Yong-Won Choi
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Publication number: 20080272721Abstract: A brushless electrical machine has at least one phase winding which produces magnetic flux in the machine. A controller controls the flux in the machine with reference to a demanded flux and a stabilisation signal which, in combination, enable the controller to operate in a stable manner in the presence of disturbances in the inputs or parameters of the controller. The controller is able to operate with either a hardware rotor position detector or with a sensorless position algorithm.Type: ApplicationFiled: April 10, 2008Publication date: November 6, 2008Applicant: Switched Reluctance Drives LimitedInventors: Peter Richard Mayes, Michael James Turner
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Patent number: 7443125Abstract: A power conversion apparatus for converting power from an alternating source to dc includes an input stage for receiving power from the alternating source, which includes an input filter, a rectifier for rectifying the alternating signal, a capacitor for storing energy from the rectified signal, and an output for outputting power from the rectifying means and the capacitor to the pulsed load. The pulsed load has at least one switched winding which receives power from the output, and wherein the capacitor is configured such that the voltage across the capacitor falls below 15% of the nominal peak rectified voltage of the source during each cycle of the alternating source. A converter of this kind provides benefits in that the current drawn from the ac supply falls within limits imposed by regulations and is simpler and cheaper than known converters of a similar power rating.Type: GrantFiled: December 10, 2003Date of Patent: October 28, 2008Assignee: Dyson Technology LimitedInventors: Andrew Charlton Clothier, Stephen Greetham, Mark Henry Haywood, Nigel James Leighton, Neil William Phillips
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Patent number: 7439702Abstract: A chiller system includes a switched reluctance motor for powering the compressor of the chiller system. A variable speed drive with a boost converter provides a boosted voltage to the switched reluctance motor. The switched reluctance motor and the compressor may be disposed within the same hermetic enclosure and driven by a common drive shaft. Cooling for both the variable speed drive and the switched reluctance motor is provided from condenser water in the condenser water circuit, or from an intermediate liquid cooled by water from the condenser circuit to increase system efficiency. Windage losses are reduced by barriers introduced within the motor, and by maintaining a reduced pressure in the switched reluctance motor.Type: GrantFiled: November 15, 2005Date of Patent: October 21, 2008Assignee: York International CorporationInventors: Stephen Harold Smith, Harold Robert Schnetzka, Ivan Jadric
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Patent number: 7432677Abstract: Method and apparatus for controlling a brushless dc motor, such as the type used in a data storage device to rotate data storage media. A sequence of drive pulses is applied to rotate the motor. The sequence is switched from first to second motor commutation states at a time determined in relation to changes in elapsed time between successive pulses in the sequence. Each drive pulse has a duration established in relation to an inductance of the motor, and is separated from adjacent pulses by an intermediate delay of predetermined value. A peak elapsed time interval between successive pulses is identified, and the next commutation state is switched in at a selected time after the peak time interval. The sequence preferably accelerates the motor from rest to an intermediate velocity, after which back electromotive force (bemf) commutation is used to accelerate the motor to a final operational velocity.Type: GrantFiled: December 16, 2004Date of Patent: October 7, 2008Assignee: Seagate Technology LLCInventors: Jeffrey A. Heydt, James W. DuLaney, Jr., David R. Street, Nicholas Swezey, Stuart Kevin Francis
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Patent number: 7429840Abstract: An electrical machine having stator (30) and rotor (31) is disclosed. The motor has field windings (F) and armature windings (A) energized by a suitable power electronic controller (401). A controller (400) sends signals to the power electronic controller (401) to control the armature current to control operation of the machine. When the machine is operating as a motor, the armature windings (A) will be supplied with electrical current from the power electronic controller by the application of applied voltage in synchronism with the rotation of the rotor (31). A mutually induced first electrical signal dependent on rotational position of the rotor will be induced within the field windings (F). This will create a superimposed gradient in the field current delivered by the power electronic controller (401).Type: GrantFiled: September 12, 2003Date of Patent: September 30, 2008Assignees: Black & Decker Inc., University of LeicesterInventors: Charles Pollock, Helen Geraldine Phyllis Pollock
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Publication number: 20080211447Abstract: Motion control using electromagnetic forces. The control of motion in unpowered apparatus and an apparatus driven by electric motors and/or other prime movers utilizes electromagnetic force/torque for control of motion. One objective is to extend the domain of electric motor speed control, traditionally characterized by electronic techniques, to small apparatus such as bubble vibration toys, paper dispensers, toothbrushes and other appliances.Type: ApplicationFiled: December 19, 2007Publication date: September 4, 2008Inventor: Gorur Narayana Srinivasa Prasanna
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Patent number: 7408318Abstract: A motor drive unit is adapted to detect a motor lock-up condition (in which an electric motor is accidentally locked during driving) based on the fact that motor drive current increases in that event. Then, a capacitor for generating a voltage signal is charged with an arbitrarily adjustable charging current to overcome the motor lock-up. To do this, an IC is formed to incorporate therein such components as a first discharging circuit for discharging the electric charge of the capacitor and a hysteresis-type comparison circuit for comparing the charging current with a threshold level to thereby adjust the charging current suitable for the motor used. Such a versatile IC as described above enables adjustment of the motor startup trial period for individual motors having different characteristics.Type: GrantFiled: April 5, 2005Date of Patent: August 5, 2008Assignee: Rohm Co., Ltd.Inventor: Masahiro Nakamura
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Publication number: 20080157703Abstract: The present invention provides an electro-mechanical energy exchange system with a variable speed synchronous reluctance motor-generator having an all-metal rotor. A bi-directional AC-to-DC electric power converter interconnects the motor-generator with a DC bus. First and second hybrid controllers provide current regulation for the motor-generator and voltage regulation for the DC bus. Use of both feedback and feedforward control elements provides a controller particularly suited for operating high speed devices.Type: ApplicationFiled: December 27, 2006Publication date: July 3, 2008Inventor: Claude Michael Kalev
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Publication number: 20080157706Abstract: The invention concerns a method for controlling a vehicle driving assembly which consists in applying to a variable reluctance machine (6) a conduction angle setpoint value (??p), in regulating said conduction angle setpoint value (?p) using an additional angle conduction (??p) determined on the basis of a torque control measurement delivered by the driving assembly.Type: ApplicationFiled: November 24, 2005Publication date: July 3, 2008Applicant: RENAULT s.a.s.Inventor: Serge Loudot
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Patent number: 7394229Abstract: A Switched Reluctance (SR) generator having improved efficiency at low and high speed is disclosed. The SR generator includes a step-up converter for controlling an excitation voltage of an excitation capacitor capable of providing a phase winding with an excitation current. Therefore, the SR generator can control the excitation current, and can provide a phase winding with a sufficient excitation current, thereby improving efficiency. The step-up converter is arranged between a battery capable of storing generated power and the excitation capacitor, boosts a voltage of the battery, and provides the excitation capacitor with the boosted voltage. Therefore, the SR generator does not include an additional power-supply unit for a boosting function, resulting in simplification of an overall structure and reduction of a production cost.Type: GrantFiled: December 8, 2005Date of Patent: July 1, 2008Assignee: LG Electronics Inc.Inventors: Jun-young Lim, Yong-won Choi
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Publication number: 20080150469Abstract: The present invention provides an electro-mechanical energy exchange system with a variable speed synchronous reluctance motor-generator having an all-metal rotor. A bi-directional AC-to-DC electric power converter interconnects the motor-generator with a DC bus. First and second hybrid controllers provide current regulation for the motor-generator and voltage regulation for the DC bus. Use of both feedback and feedforward control elements provides a controller particularly suited for operating high speed devices.Type: ApplicationFiled: December 21, 2006Publication date: June 26, 2008Inventors: Heath F. Hofmann, Claude Khalizadeh
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Patent number: 7391180Abstract: A pulse width modulation (PWM) control circuit for a multimode electrical machine and a multimode electrical machine equipped with such a control circuit, including a configuration circuit that detects the operation mode of the electrical machine and produces a pulse width modulation to control a reversible current inverter circuit such that the electrical machine operates optimally in torque in engine modes and in current generator modes. The invention applies to vehicle alternators and starters.Type: GrantFiled: June 1, 2004Date of Patent: June 24, 2008Assignee: Valeo Equipements Electrique MoteurInventors: Paul Armiroli, Cédric Plasse
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Patent number: 7388345Abstract: An electrical machine is controlled with a combination of a physical rotor position transducer and a software position detection algorithm. The physical transducer has a reduced number of sensors, so that it will only give accurate information at high speeds. The software algorithm is executed by a low-cost processor which cannot provide sufficient information at high speeds. The controller blends the information from the two position detectors to produce an economic drive which operates over a large speed range.Type: GrantFiled: September 15, 2006Date of Patent: June 17, 2008Assignee: Switched Reluctance Drives LimitedInventor: Michael Leo McClelland
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Publication number: 20080129243Abstract: A control method for a motor that rotates based on flux linkages to a winding member of the motor when the winding member is energized by a drive current is provided. The method includes storing magnetic-state information indicative of a relationship between each of a plurality of predetermined operating points of the drive current and a magnetic-state parameter associated with the flux linkages. The method includes obtaining at least one of command information associated with an operating state of the motor and detection information associated with the operating state of the motor. The method includes referencing the magnetic-state information with the use of the obtained at least one of the command information and detection information to obtain a value of the magnetic-state parameter based on a result of the reference. The method includes controlling an output of the motor based on the obtained value of the magnetic-state parameter.Type: ApplicationFiled: November 29, 2007Publication date: June 5, 2008Applicant: DENSO CORPORATIONInventor: Masayuki Nashiki
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Publication number: 20080129244Abstract: The windings of a switched reluctance machine are supplied from a converter which is capable of providing bipolar energisation. The energisation pattern supplied to the windings is dependent on the number of stator and rotor poles in the machine and is selected to produce unipolar energisation in the rotor poles. This in turn reduces the losses in the rotor which would otherwise result from bipolar energisation. The machine may also be operated to provide energisation patterns which are adapted to provide optimum performance in different parts of its operating speed range.Type: ApplicationFiled: November 28, 2007Publication date: June 5, 2008Applicant: Switched Reluctance Drives LimitedInventor: Steven Paul Randall
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Patent number: 7372232Abstract: A power converter for a switched reluctance motor (SRM) or a permanent magnet brushless direct current (do) motor (PMBDCM) may include a front-end boost partial circuit for connecting with a first phase winding of the motor to form a front-end boost circuit and a back-end boost partial circuit for connecting with a second phase winding of the motor to form a back-end boost circuit. The front-end boost partial circuit generates a first step-up voltage in cooperation with the inductance provided by the first phase winding. The back-end boost partial circuit generates a second step-up voltage in cooperation with the inductance provided by the second phase winding.Type: GrantFiled: November 24, 2004Date of Patent: May 13, 2008Assignee: Virginia Tech Intellectual Properties, Inc.Inventor: Krishnan Ramu
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Patent number: 7365505Abstract: An apparatus for controlling a rotational motion of a motor is disclosed which includes: a signal generator generating a rotational state signal indicative of a rotational state of the motor; and a controller producing a control signal for controlling the rotational motion of the motor, based on the rotational state signal generated by the signal generator, to thereby control the motor based on the produced control signal. The controller produces the control signal during a start up of the motor, such that the produced control signal is not affected by a noise component which is incorporated into the rotational state signal during the start up of the motor.Type: GrantFiled: June 23, 2006Date of Patent: April 29, 2008Assignee: Brother Kogyo Kabushiki KaishaInventor: Hisanori Okamoto
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Patent number: 7348754Abstract: An apparatus has (a) a first component having one or more electromagnetic elements and (b) a second component having one or more electromagnetic elements and movably coupled to the first component. The second component moves with respect to the first component in a cyclical manner. The one or more electromagnetic elements of the first component interacts with the one or more electromagnetic elements of the second component during each of one or more cycles of motion of the second component with respect to the first component such that, when a constant force profile is applied to move the second component with respect to the first component, the speed of motion increases and decreases one or more times during each cycle of motion due to different levels of electromagnetic interaction between the electromagnetic elements within each cycle of motion.Type: GrantFiled: April 2, 2004Date of Patent: March 25, 2008Inventor: Gorur Narayana Srinivasa Prasanna
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Publication number: 20080054838Abstract: A method of actuating a movable object in a first degree of freedom includes a) providing a first motor assembly including one or more motors of a first type and a second motor assembly including one or more motors of a second type, each of the first and second motor assembles being configured to move the movable object in the first degree of freedom, b) feeding the first motor assembly with a feed-forward signal of a feed-forward unit on the basis of a feed-forward reference signal, and c) feeding the second motor assembly with a control signal of a position control unit on the basis of a position control reference signal.Type: ApplicationFiled: August 29, 2006Publication date: March 6, 2008Applicant: ASML NETHERLANDS B.V.Inventors: Hans Butler, Franciscus Adrianus Gerardus Klaassen
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Publication number: 20080042611Abstract: A self-excited, switched reluctance generator obtains excitation energy from a capacitor bank via an excitation bus during normal operation. During a short-circuit or load fault, one or more phases of the generator provide power to the excitation bus while the remaining phases send current to a faulted positive bus. The system does not require an external battery or power source for excitation energy. The system is capable of resuming normal operation after the load bus fault.Type: ApplicationFiled: August 17, 2006Publication date: February 21, 2008Inventor: Piyush Tandon
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Patent number: 7323839Abstract: A direct current motor controlling method includes a mean for transforming a duty signal to computed value by a microprocessor unit. The microprocessor unit computes the computed value and then produces a target value by executing a dichotomy method, a rotation method and a transformed function, capable of reducing executing time and executing load of the microprocessor unit and saving memory space. The microprocessor unit sends a frequency signal to a driving circuit unit according to the target value. The driving circuit unit receives the frequency signal and then provides a driving voltage to a power switch. The power switch provides a voltage to a direct current motor or not according to the driving voltage for controlling output performance of the direct current motor.Type: GrantFiled: September 5, 2006Date of Patent: January 29, 2008Assignee: Cheng Uei Precision Industry Co., Ltd.Inventor: Lung-Chieh Chen
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Patent number: 7312595Abstract: Presence/absence of a failure in a feedback control system of a motor is monitored. When a failure is detected in the feedback control system, the motor is driven by switching to an open-loop control. During the open-loop control, the motor is rotated by sequentially switching the motor current supply phase without feeding back encoder count information. The position count is incremented or decremented every time the current supply phase is switched. When the position count has reached a target count, it is determined that the rotor has reached a target position, whereupon the open-loop control is finished.Type: GrantFiled: May 30, 2003Date of Patent: December 25, 2007Assignee: Denso CorporationInventors: Shigeru Kamio, Kenichi Fujiki
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Publication number: 20070278984Abstract: A 2-phase switched reluctance device topology includes a switched reluctance device having first and second phase coils. Each of the first and second phase coils has a first terminal and a second terminal. The first terminal of each of the first and second phase coils is electrically coupled between two switching elements of a first pair of switching elements. The second terminal of the first phase coil is electrically coupled between two switching elements of a second pair of switching elements. The second terminal of the second phase coil is electrically coupled between two switching elements of a third pair of switching elements. Each switching element includes a first electrode, a second electrode, and a control electrode, wherein the control electrode is communicatively coupled to a switch controller that operates the switching element. Each switching element also includes a diode communicatively coupling the first electrode to the second electrode.Type: ApplicationFiled: May 31, 2006Publication date: December 6, 2007Inventors: Rodwan Tarek Adra, Michael Aaron Caruthers
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Patent number: 7288915Abstract: An electrical machine is controlled without using a physical rotor position detector. When more than one phase is used simultaneously to produce sufficient torque for the application, the increased leakage flux and the reduced permeability of parts of the magnetic circuit distort the information gleaned from diagnostic pulses. By storing sets of characterizing data appropriate to the number of phases in use, the control system is able to determine the rotor position more accurately.Type: GrantFiled: December 29, 2004Date of Patent: October 30, 2007Assignee: Switched Reluctance Drives LimitedInventors: Rosemary Anne Norman, Michael Leo McClelland
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Patent number: 7282885Abstract: In a device for controlling an electric motor, especially in motor vehicles, for setting a setting element, moved by the electric motor, as a function of the deviation of an actual setting from a nominal setting of the setting element, by means of a controller, which contains a microprocessor that carries out a hardware initialization routine at least in one step and a software initialization routine optionally in a second step, once the controller has been switched on, before the actual setting of the setting element can be determined in the controller, the microprocessor is constructed in such a manner that it short-circuits the electric motor independently of the actual setting of the setting element, directly after the hardware initialization routine, by generating a defined switching state of its outputs, associated with the control of the electric motor.Type: GrantFiled: August 25, 2006Date of Patent: October 16, 2007Assignee: Bayerische Motoren Werke AktiengesellschaftInventor: Stefan Krimmer
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Patent number: 7279863Abstract: Disclosed is a method and apparatus for detecting an excitation position of an SRM by comparison of detected currents. The method includes detecting a current by applying a first test voltage to each phase of the SRM, detecting a current by applying a second test voltage to each phase, determining an operation state of the SRM based on a deviation between the currents detected in any one of the phases, determining the operation state of the SRM as a rotation state if the deviation value exceeds a predetermined value, and applying a third test voltage to a phase excited just prior to a current excited phase to detect the current and turning on a phase to be next excited if the detected current value is more than a first reference value, and turning off the phase excited just prior to the presently excited phase if the detected current value is more than a second reference value. The phase excitation position is accurately detected according to the rotating speed without using a position sensor.Type: GrantFiled: January 17, 2006Date of Patent: October 9, 2007Assignee: SR Technologies, Inc.Inventors: Jin-Woo Ahn, Dong-Hee Lee, Tae-Hyoung Kim
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Patent number: 7276830Abstract: A motor (1) has a stator (2) and a rotor (10) mounted for rotation in the stator. A commutating salient pole (11) of the stator as a winding (7), and a field-producing salient pole (12) has a winding (8). The rotor has at least two salient poles (10a, b). An outer back-iron (13) magnetically joins bases of said stator poles. An inner back-iron (14) extends from the field pole around the rotor to such an extent that a substantial amount of the magnetic field in the rotor between its poles is short-circuited by the inner back-iron, at least for a part of its rotation. An electrical circuit powers the windings to drivingly rotate the rotor.Type: GrantFiled: June 11, 2002Date of Patent: October 2, 2007Inventor: Paul Lefley
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Publication number: 20070216251Abstract: A motor includes a stator which generates a rotating magnetic field, and a rotor. The rotor includes a plurality of permanent magnets and a hysteresis band disposed on an outer periphery of the rotor.Type: ApplicationFiled: January 26, 2007Publication date: September 20, 2007Applicant: LG ELECTRONICS INC.Inventors: Jang-Ho SHIM, Seong-Ho LEE, Jae-Min KIM, Jae-Hak CHOI, Jin-Soo PARK
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Patent number: 7271564Abstract: A power converter for a switched reluctance motor or a permanent magnet brushless direct current (dc) motor may include first and second partial circuits for forming multiple conduction circuits in cooperation with first and second phase windings of the motor. The controller also includes a switch operable to open and close a first conduction circuit, which includes the first phase winding, and to regulate energization of the first and second phase windings of the motor through opening and closing the first conduction circuit. Control of the switch provides four-quadrant operation of the motor through regulated energization of the first and second phase windings.Type: GrantFiled: November 24, 2004Date of Patent: September 18, 2007Assignee: Virginia Tech Intellectual Properties, Inc.Inventor: Krishnan Ramu
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Patent number: 7271556Abstract: A discrete rotor position estimation method for a synchronized reluctance motor is provided. A d.c.-link voltage Vdc and a phase current Iph are sensed. A flux-linkage ?ph of an active phase is calculated from the sensed d.c.-link voltage Vdc and the sensed phase current Iph. The calculated flux-linkage ?ph is compared with a reference flux-linkage ?r. The reference flux-linkage ?r corresponds to a reference angle ?r which lies between angles corresponding to aligned rotor position and non-aligned rotor position in the synchronized reluctance motor. An estimated rotor position ?cal is obtained only once when the calculated flux-linkage ?ph is greater than the reference flux-linkage ?r.Type: GrantFiled: November 28, 2002Date of Patent: September 18, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Taro Kishibe, Subrata Saha, Hiroshi Murakami, Kazushige Narazaki
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Patent number: 7265513Abstract: A variable reluctance electric power system which comprises an alternator and a motor having a rotor with longitudinal lobes and no windings, commutators, slip rings, magnets, or laminations. The alternator and the motor have stators which have conventional windings and laminations and a rotor which is polarized using a static field winding which surrounds but does not touch the rotor. The alternator and the motor may be coupled with current from the alternator driving the motor and solid state power devices controlling the frequency of the current to insure that the current from the alternator is always synchronized with the motor rotor.Type: GrantFiled: January 4, 2006Date of Patent: September 4, 2007Inventors: William Hughes, Lance Gilmore, Duane Joseph Steichen
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Patent number: 7250738Abstract: A nonlinear hysteresis control system for controlling an actuator with nonlinear hysteresis effect is disclosed. An improved extended hysteresis effect profile further stores the displacement when a applied voltage of the actuator is from 0 voltage to a specific voltage and back to that specific voltage. Therefore, the system can be used under the condition of not very slow motion of the actuator.Type: GrantFiled: July 12, 2006Date of Patent: July 31, 2007Assignee: Chung-Yuan Christian UniversityInventors: Yung Ting, Hou-Ching Cha, Chun-Chung Lee
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Patent number: 7235947Abstract: A desired q-axis current is determined based on a desired torque, and a desired d-axis current is determined based on the rotating speed of a synchronous motor when the terminal voltage of the synchronous motor coincides with a predetermined maximum permissible voltage to weaken a magnetic field created by the synchronous motor equivalently and to prevent the drop of the output torque of the synchronous motor. The desired d-axis current is determined based on the desired torque and the rotating speed. Therefore, the desired d-axis current can be reduced when a high torque is not necessary and undesired increase of the desired d-axis current can be prevented. Thus the synchronous motor operates efficiently, heat generation of the synchronous motor is prevented and power factor is improved.Type: GrantFiled: November 22, 2005Date of Patent: June 26, 2007Assignee: Kawasaki Jukogyo Kabushiki KaishaInventors: Hideki Tanaka, Shinji Kajihara, Tsuyoshi Maehara, Tetsuya Kubota
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Patent number: 7233873Abstract: An electrical machine has a rotor position transducer which provides output signals to a control system. The output signals contain errors due to component shortcomings and manufacturing imperfections. A method is disclosed which is able to determine the errors in the signals by successively running the machine with a series of assumed errors in the rpt signals and building up a set of test results. These results are subsequently compared with each other so as to determine the optimum value of corrections to the control system of the machine. The correction may be stored in the control system and used to improve the accuracy of the transducer output signals, thus improving the output of the machine.Type: GrantFiled: July 21, 2005Date of Patent: June 19, 2007Assignee: Switched Reluctance Drives LimitedInventors: Peter Mark Moriarty, Michael Paul Tankard
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Patent number: 7233124Abstract: A motor drive inverter control apparatus includes a rectifier circuit for rectifying an AC power supply, an inverter circuit driven by an output from the rectifier circuit, a motor driven by an output from the inverter circuit, a first capacitor coupled in parallel to the output of the rectifier circuit, and a second capacitor coupled in parallel to the first capacitor via a diode. The second capacitor has capacitance not less than three times that of the first capacitor. Although the second capacitor shows a ripple content not less than 90% during practical use, it well absorbs regenerative energy produced by the motor. As a result, elements of the apparatus can be prevented from degrading caused by an over-voltage, and the apparatus can be downsized and reduced its cost.Type: GrantFiled: November 16, 2004Date of Patent: June 19, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshinori Takeoka, Koji Hamaoka
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Patent number: 7221116Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.Type: GrantFiled: October 25, 2005Date of Patent: May 22, 2007Assignees: Denso Corporation, Toyota Jidosha Kabushiki KaishaInventors: Yasuhiro Nakai, Shigeru Kamio, Kenichi Fujiki, Sumiko Amamiya, Keijiro Ohshima, Yasushi Kobiki, Yuji Inoue
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Patent number: 7211985Abstract: On a training device, in particular for developing human muscles, having a torque-generating unit which comprises an electric motor and a reduction gearing, and whose output interacts with at least one training element offered to the exercising person, an electric motor is designed as a three phase AC motor. Associated with the latter is a frequency converter for adjusting the frequency and amperage of the three phase current supplied to the electric motor. A control unit is provided upstream of the frequency converter. An angle-of-rotation sensor is associated with the motor whose measured signal is supplied to both the frequency converter and the control unit. The frequency converter is fed by the control unit with a setpoint value of the torque to be generated by the motor which setpoint value receives the measured signal from the angle-of-rotation sensor. The frequency converter adjusts the frequency and the amperage of the motor current using the principle of field-oriented control.Type: GrantFiled: July 8, 2005Date of Patent: May 1, 2007Inventor: Dieter Miehlich
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Patent number: 7208895Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to inputs of demanded torque, rotor position and/or speed. Control methods include calculating a scaled torque demand from the received torque demand to obtain substantially constant torque over a range of motor speeds, calculating an optimal dr-axis injection current using a cost function and a starting method that switches from speed control mode to torque control mode at a predetermined rotor speed or at predetermined start-up timing intervals.Type: GrantFiled: December 2, 2005Date of Patent: April 24, 2007Assignee: Emerson Electric Co.Inventors: Joseph G. Marcinkiewicz, Prakash B. Shahi, Michael I. Henderson
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Patent number: 7208907Abstract: A system and method of restarting a switched reluctance motor after a cycling of power provided to the motor is provided that includes receiving at the motor a power-off signal followed by a power-on signal, determining a rotational speed of a rotor, and energizing a stator only when the rotational speed of the rotor is determined to be less than a threshold speed.Type: GrantFiled: October 21, 2004Date of Patent: April 24, 2007Assignee: Shop Vac CorporationInventors: Neil N. Norell, James M. Robitaille, Mark E. Baer
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Patent number: 7208906Abstract: A switched reluctance drive is supplied from a power source. The phases of the machine are controlled by a current controller which uses an excitation strategy to minimize the supply current drawn for a particular output. The strategy alternates the excitation between two phases for a given time until the rotor moves to a desired position. A method of starting a switched reluctance motor having a stator with at least two phases, a moveable part, and a position transducer includes determining from transducer output a plurality of phases that are available to produce force in a desired direction, energizing a first phase of the available phases for a predetermined time period that is independent of the transducer output, and energizing a second phase of the available phases after energization of the first phase is initiated.Type: GrantFiled: April 30, 2004Date of Patent: April 24, 2007Assignee: Switched Reluctance Drives LimitedInventors: Michael James Turner, Paul Andrew Sykes