Rotor Speed Or Position Responsive Patents (Class 318/823)
  • Patent number: 9211909
    Abstract: A controller and control method for a motorized vehicle such a wheelchair are provided. The motorized vehicle has at least two driven wheels driven independently by a motor arrangement, and the controller receives a number of input signals from a user input device of the motorized vehicle. The controller comprises drive control circuitry for generating control signals for controlling the driving of the driven wheels by the motor arrangement, the control signals being dependent on the input signals. Speed assist circuitry is responsive to an indication of current consumed in driving the driven wheels to detect occurrence of a loading condition. On detection of occurrence of a loading condition, the speed assist circuitry is then arranged to boost at least one of the input signals in order to boost top speed in the presence of the loading condition.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: December 15, 2015
    Inventors: Nigel Peter Sharp, Glenn Leigh Garnett
  • Patent number: 9018886
    Abstract: A motor control system (10) which includes a difference calculating part (31) which calculates a difference between a first position detection value of a moving part and a second position detection value of a driven part, a judging part (32) which judges if a moving part has engaged with the driven part when the moving part is made to move from any initial position in a first and second drive directions, a holding part (33) which holds the difference as initial difference linked with the first or second drive direction, when the moving part has engaged with the driven part, and a correction amount calculating part (34) which calculates a backlash correction amount, the correction amount calculating part using the difference based on the current positions of the moving part and the driven part and the initial difference to calculate the backlash correction amount.
    Type: Grant
    Filed: September 4, 2013
    Date of Patent: April 28, 2015
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
  • Patent number: 8947024
    Abstract: An electric motor includes an arrangement of windings provided for driving the rotor, with the windings being connected to an energy source to develop torque which drives the rotor. The electric circuits of corresponding ones of the windings each have a potential point, the voltage (UL, UG) of which is supplied to an evaluation unit via an adaptation device. The adaptation device can be operated in two switchable adaptation stages and is connected to a drive circuit that operates in dependence upon the rotational position of the rotor. The drive circuit switches the adaptation device into the first stage having a high sensitivity or into the second stage having a low sensitivity in dependence upon the rotational position of the rotor of the motor, such that the number of required analog inputs at a microprocessor in the evaluation unit can be kept low.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: February 3, 2015
    Assignee: Andreas Stihl AG & Co. KG
    Inventors: Rene Wichert, Gernot Liebhard, Rudolf Saemann
  • Patent number: 8890460
    Abstract: A servo control device includes a follow-up control unit that controls a control target that drives a mechanical system by a motor, a command function unit that has input therein a phase signal ? indicating a phase of a cyclic operation performed by the control target, and that calculates a machine motion command according to the phase signal ? by a preset first function, a second derivative unit that uses a second function obtained by second-order differentiating the first function with respect to the phase signal to calculate a value of the second function according to the phase signal as a second-order differential base signal, a correction-value computation unit that computes a first command correction value for correcting the motor motion command by using a product of a square value of the phase velocity, the second-order differential base signal, and a first constant, and a correction-value addition unit that calculates the motor motion command based on an added value of the first command correction val
    Type: Grant
    Filed: October 25, 2012
    Date of Patent: November 18, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hidetoshi Ikeda, Yoshihiro Marushita, Koji Mahara, Kiyoshi Hasegawa, Hidemasa Ogi
  • Patent number: 8766589
    Abstract: In a motor control unit, a current-carrying failure detection unit determines a first determination condition and a second determination condition. The current-carrying failure detection unit measures a duration of a state where the first determination condition is satisfied, and a duration of a state where the second determination condition is satisfied. When the first or second duration exceeds a predetermined reference period, the current-carrying failure detection unit determines that a current-carrying failure has occurred.
    Type: Grant
    Filed: April 19, 2012
    Date of Patent: July 1, 2014
    Assignee: JTEKT Corporation
    Inventors: Toshihiro Takahashi, Satoru Mikamo, Hiroshi Kawamura, Jun Hasegawa, Akihiro Tomita, Akira Nambu
  • Patent number: 8766586
    Abstract: A magnetic pole position detecting device includes a calculating unit for correcting a magnetic pole position detected by a magnetic pole position detecting unit. In this magnetic pole position detecting device, an additional phase is added to the magnetic pole position detected by the magnetic pole position detecting unit, in order to move a rotor. In relation to a movement amount before and after this movement, a movement amount detected by the magnetic pole position detecting unit is compared with a movement amount detected by an encoder. When a difference between them is larger than a predetermined threshold, a process of detecting the magnetic pole position is determined as false detection.
    Type: Grant
    Filed: April 3, 2013
    Date of Patent: July 1, 2014
    Assignee: Fanuc Corporation
    Inventors: Naoto Sonoda, Masato Aochi
  • Patent number: 8674639
    Abstract: During operation of a 3 phase BLDC motor it is driven by use of a PWM waveform applied to one of the driven phase (curve a). The other driven phase is connected thereto but no driving signal is applied (curve b). The third phase is left floating (curve c). This allows the back EMF in the third phase to be monitored for the purpose of determining rotor position by detection of zero crossing points. The rapid switching of the PWM pulses causes ringing in the back EMF signal indicated for one pulse by the ringed portions 1 of curve c. The ringing in the back EMF signal introduces inaccuracy into position calculations derived from back EMF signal measurement. In order to reduce this ringing, in the present invention, a reverse pulse is applied to the other driving coil shown (curve b) prior to a PWM on pulse. The reverse pulse has a polarity such that it drives the phase current through the linked coils in a direction opposite to that caused by the PWM on pulse.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: March 18, 2014
    Assignee: Melexis Technologies NV
    Inventors: Christian Paintz, Thomas Freitag
  • Patent number: 8664901
    Abstract: Methods, systems and apparatus are provided for estimating electrical angular speed of a permanent magnet machine based on two-phase stationary reference frame feedback stator current samples, and a dimensionless gain (K) that is computed based on a sampling time (T) and machine parameters.
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: March 4, 2014
    Assignee: GM Global Technology Operations LLC
    Inventors: Milun Perisic, Yo Chan Son, Gabriel Gallegos-Lopez, Silva Hiti
  • Patent number: 8390240
    Abstract: Systems and methods are provided for an automotive drive system using an absolute position sensor for field-oriented control of an induction motor. An automotive drive system comprises an induction motor having a rotor, and a position sensor coupled to the induction motor. The position sensor is configured to sense an absolute angular position of the rotor. A processor may be coupled to the position sensor and configured to determine a relative angular position of the rotor based on a difference between the absolute angular position and an initial angular position obtained when the induction motor is started. A controller may be coupled to the induction motor and the processor and configured to provide field-oriented control of the induction motor based on the relative angular position of the rotor.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: March 5, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Constantin C. Stancu, Silva Hiti, Robert T. Dawsey, Erik Hatch, Matthew D. Laba, Peter J. Savagian
  • Patent number: 8294411
    Abstract: A sensorless induction motor control device with a function of correcting a slip frequency wherein a slip frequency estimation unit estimates the slip frequency from at least one kind of current flowing through the motor. A voltage command value calculation unit calculates a D-phase voltage command value and a Q-phase voltage command value which are used for controlling a voltage applied to the motor using a Q-phase current command value calculated based on a difference between a speed estimation value, which is calculated using an estimation value of the slip frequency, and an externally supplied speed command value. An ideal voltage command value determination unit determines an ideal voltage command value using the speed command value and the Q-phase current command value. An actual voltage command value calculation unit calculates an actual voltage command value using the D-phase voltage command value and the Q-phase voltage command value.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: October 23, 2012
    Assignee: Fanuc Corporation
    Inventors: Tadashi Okita, Takahiro Akiyama, Tomohisa Tsutsumi
  • Patent number: 8018189
    Abstract: The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current.
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: September 13, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Satoshi Narumi, Masaaki Kato, Masaharu Hoashi, Toshiya Suzuki
  • Patent number: 7948201
    Abstract: An induction motor control device includes an inverter circuit for driving an induction motor by outputting a command voltage, a current detector for detecting an output current, a magnetic flux estimation observer for generating an estimated magnetic flux, an estimated current, and a phase command for the motor using the command voltage and the output current, a primary angular speed estimator for estimating a primary angular speed using the estimated magnetic flux, a slip compensator for calculating a slip angular frequency using the output current, a first angular speed estimator for estimating a first angular speed using the primary angular speed and the output current, a second angular speed estimator for estimating a second angular speed using the output current, the estimated magnetic flux, and the estimated current, and a resistance estimator for estimating a secondary resistance value of the motor using the first and second angular speeds.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: May 24, 2011
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventor: Masanobu Inazumi
  • Patent number: 7787970
    Abstract: A position-measuring device having integrated function testing includes a position-recording unit, a processing unit, and a control-word generator. In a positional-data request, a positional-data word is first generated in the position-recording unit and output to the processing unit. There, the position data word is processed into a position value. Subsequently, a control-data word is generated in the position-recording unit according to the specification of the control-word generator and output to the processing unit. The processing unit processes the control-data word into a control value which has a defined mathematical relationship to the position value.
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: August 31, 2010
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Erich Strasser, Elmar Mayer
  • Patent number: 7595598
    Abstract: A magnetizing motor having a permanent magnet body covering an outer circumferential surface of a rotor body, includes a speed detecting unit that detects a speed of the magnetizing motor; and a controlling unit that compares the speed detected by the speed detecting unit with a reference speed, and outputs a magnetizing control signal based on the result of the comparison.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: September 29, 2009
    Assignee: LG Electronics Inc.
    Inventors: Jang-Ho Shim, Sung-Ho Lee, Jae-Min Kim, Jae-Hak Choi, Jin-Soo Park
  • Patent number: 7518332
    Abstract: A brushless synchronous motor is provided in a simple configuration and at a low cost. The brushless synchronous motor comprises a rotor having salient magnets arranged in a circumferential direction, a stator having driving magnetic poles arranged in the circumferential direction, and an exciting coil wound around each driving magnetic pole, where the rotor is made in a non-circular profile. For example, the rotor may comprise a cylindrical body which has at least one flat surface perpendicular to one magnetic pole direction of the rotor, or a cylindrical body having an elliptic profile with a longer diameter in one magnetic pole direction of the rotor. A detector circuit is associated with each of a predetermined number of exciting coils for outputting a detection signal indicative of the impedance of the exciting coil in accordance with the distance between the driving magnetic pole and rotor, to detect a rotating angle of the rotor.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: April 14, 2009
    Assignee: Ebara Corporation
    Inventors: Toshiharu Nakazawa, Atsushi Ooyama
  • Patent number: 7362071
    Abstract: In an electric rotary excavator (construction machine) 1, when earth pressure acts on a rotary body 4 in an opposite direction to an instructed direction of a lever, a control-system changing means 150 of a rotation control device 100 increases a torque output of an electric motor 5 that drives the rotary body 4. Accordingly, the torque output can properly react against the acting earth pressure, thereby preventing the rotary body from continuing to be rotated in the opposite direction. Therefore, even when the earth pressure becomes large, the work will not be affected. In addition, when the rotary body is rotated on a slope, the rotary body can be prevented from being rotated back greatly due to the weights of the boom and the arm.
    Type: Grant
    Filed: May 13, 2005
    Date of Patent: April 22, 2008
    Assignee: Komatsu Ltd.
    Inventors: Jun Morinaga, Tadashi Kawaguchi
  • Patent number: 7330011
    Abstract: A motor driving apparatus includes an inverter circuit for converting an output of a rectifier circuit connected to a single-phase AC power supply into a driving voltage, and outputting the driving voltage to a brushless motor, and an inverter control unit for controlling the amplitude value of the voltage outputted from the inverter to the brushless motor so as to minimize a difference between a command rpm indicated by an external command signal and an actual rpm derived from an estimated phase of the rotor, wherein the command rpm is set to an rpm outside a predetermined range of rpms.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: February 12, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuo Ueda, Hideki Nakata
  • Patent number: 7282875
    Abstract: An electric motor control system includes a housing and a motor disposed within the housing. The electric motor control system also includes an actuator operatively coupled to the motor and configured to operate in response to an operation of the motor. The electric motor control system further includes a controller disposed within the housing and communicatively coupled to the motor. The electric motor control system also includes a first electric conductor communicatively coupling the motor to the controller, wherein the controller is configured to supply power to and communicate a data signal with the motor over the first electric conductor.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: October 16, 2007
    Assignee: Caterpillar Inc.
    Inventor: Robert Wayne Lindsey
  • Patent number: 7274161
    Abstract: A Motor driving apparatus adjusts activation start timing of high-side activation control signals UU, VU, WU and the low-side activation control signals UL, VL, and WL with a state determination signal SJ in an activation controller 40, in the period from starting to the time when rotor rotating speed reaches a predetermined value, sets the activation start timing earlier than in normal times to perform leading phase activation control, and in normal times when the rotor rotating speed is a predetermined value or more, controls activation start timing in efficient and optimum phase. Hence, the motor driving apparatus can carry out stable PWM sensorless starting without any starting failure such as oscillation, loss of synchronism and reverse rotation and shorten starting time.
    Type: Grant
    Filed: May 6, 2005
    Date of Patent: September 25, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideaki Mori, Shinichi Kuroshima
  • Patent number: 7245225
    Abstract: A failure monitor designed to monitor a failure in operation of a motor drive control system. The system works to drive a motor-driven member through an output shaft and includes an angular position sensor for determining an angular position of the output shaft for use in controlling the motor. The failure monitor includes a storage device retaining an output shaft stop position that is the angular position of the output shaft, as determined upon a stop of the motor. The failure monitor detect the presence of failure of the angular position sensor based on a comparison between the angular position of the output shaft, as measured upon initiation of a motor start request, with the output shaft stop position.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: July 17, 2007
    Assignee: DENSO Corporation
    Inventors: Shigeru Kamio, Yasuhiro Nakai
  • Patent number: 7190138
    Abstract: A failure monitor designed to monitor a failure in operation of a motor drive control system. The system works to drive a motor-driven member through an output shaft and an electric motor and includes an output shaft angular position sensor for determining an angular position of the output shaft and an encoder for determining an angular position of the motor for use in controlling the motor. The system works to discriminate among failures in operation of the output shaft angular position sensor and the encoder and another type of a failure using outputs of the sensors.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: March 13, 2007
    Assignee: DENSO Corporation
    Inventors: Shigeru Kamio, Yasuhiro Nakai
  • Patent number: 7170243
    Abstract: A drive method for a brushless motor and a drive control apparatus therefor, in which control parameters are calculated by revolution number control means or motor current control means in accordance with the deviation between a target value and an actual value, a manipulated variable is computed by conduction phase control means on the basis of the calculated control parameters, an advance angle magnitude is computed from the relationship between a manipulated variable and an advance angle magnitude as designed and created beforehand, on the basis of the computed manipulated variable, and the value of a conduction phase angle of a drive circuit as designed on the basis of a rotation position signal or a motor current signal is corrected using the information of the computed advance angle magnitude.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: January 30, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaishia
    Inventors: Akihiro Nakagawa, Jun Suzumura
  • Patent number: 7138772
    Abstract: The invention provides an electrically movable vehicle drivable by a simplified mode of control and a control program for driving the vehicle. A normalized value Y? representing translation motion and a normalized value X? representing turning motion are fed from a command value input unit 110 to a velocity command value calculating unit 120. The calculating unit 120 determines a translation velocity command value Vg—trg based on the normalized value Y?. The calculating unit 120 determines a turn angular velocity command value ?f—trg that will always satisfy Expression (2–4) for preventing the vehicle from falling down. The translation velocity command value Vg—trg and the turn angular velocity command value ?f—trg determined by the unit 120 are fed to a control command value calculating unit 130, which calculates control command values for left and right drive wheels. The control command values are fed to a motor control unit 140 to control motors Mr, Ml and control the drive wheels.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: November 21, 2006
    Assignee: Sanyo Electric Co. Ltd.
    Inventors: Takuya Noro, Takayoshi Akagi
  • Patent number: 7103498
    Abstract: According to the invention, in a method for determining the angular position of a rotor, a reference voltage is set in a calibration phase, such that when the rotor, rotating at a calibration speed, passes through a particular detection position, said voltage is the same as the electromotive force induced in the one winding coil. In a subsequent measuring phase the reference voltage is updated to a value (UR) which is equal to the product of the voltage value set in the calibration phase and the ratio of the instantaneous motor rotational speed to the calibration rotational speed. The angular position of the rotor (?1) at which the electromotive force corresponds to the updated reference voltage is thus identified as the detection position.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: September 5, 2006
    Assignee: Conti Temic microelectronic GmbH
    Inventor: Thomas Dorner
  • Patent number: 7067999
    Abstract: In a neutral range preset, there are set a zone for stopping and holding a rotating body only by a mechanical brake, a zone for holding the body only by performing position holding control, and a zone for simultaneously exerting both effects, i.e., the effect of the mechanical brake and the effect of the holding control. On-the-spot holding torque generated when the position holding control is performed is stored. The higher of the on-the-spot holding torque stored and accelerating torque according to an operation amount of the body at a rotation starting time is set as electric motor torque for acceleration. When performing a pressing work including pressing a bucket against an object for work, torque control is carried out according to the operation amount.
    Type: Grant
    Filed: April 28, 2003
    Date of Patent: June 27, 2006
    Assignees: Kobelco Construction Machinery Co., Ltd., Kobe Steel, Ltd.
    Inventors: Naoki Sugano, Koji Inoue, Hideaki Yoshimatsu, Mamoru Uejima
  • Patent number: 6940235
    Abstract: A drive circuit for a brushless DC motor includes a switch constructed and arranged to drive the motor with a pulse signal responsive to a control signal, and control circuitry coupled to the switch and constructed and arranged to generate the control signal responsive to rotor position information from the motor so as to synchronize the pulse signal to the rotor position. A current sensing device can be used to provide the rotor position information to the control circuitry by sensing current flowing through the motor.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: September 6, 2005
    Assignee: Analog Devices, Inc.
    Inventors: Robin Laurie Getz, David Edward Hanrahan
  • Patent number: 6731086
    Abstract: In a motor driving device that drives a motor by energizing a coil of a first phase and a coil of a second phase provided in the motor in one direction alternately, which phase to energize is switched according to a back electromotive force appearing in the coil of each phase of the motor as a rotor of the motor rotates. This circuit configuration eliminates the need for an external sensor to detect the position of the rotor, and thus helps promote cost reduction and miniaturization. Here, where no external sensor is used to detect the position of the rotor, the motor is started by first bringing the rotor to rest in a particular position and then energizing the coil of a particular phase. This permits the motor to be started always in the same rotation direction, and thus helps prevent reverse rotation of the motor.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: May 4, 2004
    Assignee: Rohm Co., Ltd.
    Inventor: Masataka Nonaka
  • Patent number: 6636012
    Abstract: A method and apparatus for generating stator and rotor resistance estimate, the method including the steps of providing high frequency injection voltage signals to a three phase motor, rotating three phase feedback current therefrom, converting the feedback currents to two phase currents that represent the high frequency component of the current vector wherein the d and q axis components are within a two phase voltage coordinate system and driving a regulator via one of the current components to generate a lag angle estimate, the lag angle estimate used to solve any of several different equations to calculate the stator and rotor resistance estimates.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: October 21, 2003
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Semyon Royak, Mark M. Harbaugh, Russel J. Kerkman
  • Patent number: 6597148
    Abstract: A method for controlling an electrical machine while it is connected to an inverter comprising phase-specific switching components generating an output voltage, an optimum switching table arranged to select a switching combination for the switching components on the basis of the stator flux and torque of the electrical machine, the method comprising steps of defining the stator current vector (is) of the electrical machine, and determining the rotation speed of the electrical machine. The method also comprises the step of defining a switching combination for the switching components on the basis of the stator current vector (is) and stator current reference vector (&psgr;s, ref) of the electrical machine when the determined rotation speed is lower than a predefined limit.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: July 22, 2003
    Assignee: ABB Oy
    Inventor: Markku Niemelä
  • Patent number: 6163137
    Abstract: A rotary induction machine in which operating characteristics of the machine are controlled by adding impedance elements to the rotor windings in which the impedance elements are stationary and connected to the rotor windings by a rotary transformer.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: December 19, 2000
    Assignee: Heller-DeJulio Corporation
    Inventors: Alan K. Wallace, James A. Oliver
  • Patent number: 5949208
    Abstract: A circuit and method for controlling a rotating or oscillating element of a DC motor, including a positional deviation correction signal generator in addition to a position sensor which detects an amount of rotation or oscillation and position of the rotating or oscillating element, a main control circuit that includes a DC motor driving circuit, and a computer which controls the main control circuit. The output signal of the positional deviation correction signal generator is controlled by the computer based upon positional deviation correction information and signals from the position sensor, so that the positional deviation correction signal generator compensates for any positional deviation of the rotating or oscillating element of the DC motor at a stopping position thereof.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: September 7, 1999
    Assignee: Kabushiki Kaisha Shinkawa
    Inventors: Kuniyuki Takahashi, Hijiri Hayashi
  • Patent number: 5457374
    Abstract: A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher speeds, the motor can be designed at maximum efficiency, and minimum weight, cost and volume.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: October 10, 1995
    Assignee: AlliedSignal Inc.
    Inventors: Brian T. Branecky, Edward L. Johnson
  • Patent number: 5410234
    Abstract: A motor drive control apparatus having an electrical power amplifier for supplying an electrical power to a motor, and a current control loop and speed control loop for controlling the drive of the motor, which includes a current feedforward component calculation section for creating voltage commands to be imposed on respective phases from current commands for the respective phases for the motor and the impedance model of the motor for carrying out a feedforward control by using the voltage commands to be imposed on the respective phases.
    Type: Grant
    Filed: January 26, 1993
    Date of Patent: April 25, 1995
    Assignee: Okuma Corporation
    Inventors: Akihito Shibata, Hisashi Kondo
  • Patent number: 5196778
    Abstract: A gain change-over switch according to the present invention serves to change over at least one of a current loop gain and a velocity loop gain to a value of the gain greater than that in other modes, in the case where a rotational-position control mode is selected as a control mode of the induction motor out of a rotational-speed control mode and a rotational-position control mode or where the rotational-position control mode is chosen and at the same time, a work mode for driving a work piece to work the same is selected, whereby an induction motor is controlled with high accuracy. Further, an exciting change-over switch according to the present invention serves to select a reinforcement exciting circuit for producing the secondary flux in the induction motor, which is greater than that produced by a weakening variable exciting circuit, only in the case where the rotational-position control mode and in the work mode are selected, thereby to control the induction motor with high accuracy.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: March 23, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takahiro Hayashida
  • Patent number: 5191273
    Abstract: This invention proposes an operating control device and method for a winding type induction machine that ensures that the harmonic components naturally present in the primary voltage of a winding type induction machine, do not correspond to the antiresonance point of the impedance characteristic of the transmission system to which the winding type induction machine is connected. Those corresponding harmonic components are eliminated from the primary winding of the winding type induction machine by applying appropriate voltage command values to a PWM controlled inverter if there is distortion of the primary voltage or if the transmission system is being changed over.
    Type: Grant
    Filed: June 23, 1992
    Date of Patent: March 2, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takeo Shimamura
  • Patent number: 5187420
    Abstract: A motor control device carries cut feedback control of a motor such that the rotational speed of the motor is equal to the command speed. A control voltage is first calculated as the sum of a first constant times the difference between the command speed and the actual rotational speed, a second constant times the actual rotational speed and a predetermined offset value. The calculated control voltage is corrected on the basis of the phase difference between the command speed and the actual rotational speed and a voltage after the correction is outputted as a motor control voltage. The rotational speed of the motor can be caused to rapidly follow the target speed by adjusting the first and second constants and the offset value whether the command speed is relatively low or high, thereby to make it possible to control the motor at a constant speed.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: February 16, 1993
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Tetsuji Kajitani, Yasumasa Matsuura, Hiroyuki Harada, Toshihiko Araki
  • Patent number: 4672291
    Abstract: This invention pertains to an electrical machine whose excitation is coordinated to the respective rpm in such a fashion that a desired characteristic of induced voltage or delivered output is produced. For that purpose at least one portion of the windings generating or controlling the working flux of the machine or a resistance wired in series before the machine is connected to a rectifier circuit, which is supplied, through a frequency-dependent impedance network, with an a.c. voltage of a frequency proportional to the machine rpm.
    Type: Grant
    Filed: May 10, 1985
    Date of Patent: June 9, 1987
    Assignee: Siemens Aktiengesellschaft
    Inventor: Heinz Rosenberg
  • Patent number: 4450395
    Abstract: Control system for driving a synchronous motor at a speed greater than a rated speed with a rotational speed detector for the rotor mounted on the motor, rotational position detector for detecting the rotational position of the field pole of the motor, an error signal generator which produces the difference between a desired speed signal and an actual rotational speed signal, and a calculating device for calculating armature current component values Id, Iq and power-factor .phi..
    Type: Grant
    Filed: June 21, 1982
    Date of Patent: May 22, 1984
    Assignees: Toshiba Kikai Kabushiki Kaisha, Toei Denki Kabushiki Kaisha
    Inventors: Akira Kawamura, Tadahiro Ono
  • Patent number: 4415846
    Abstract: A wound rotor motor apparatus includes an energy recovery circuit having a rectifier connecting the rotor circuit to a gated inverter having an input filter for return of rotor power to the three-phase power supply system. A voltage chopper circuit connects the rectifier to the recovery inverter and operates to establish and maintain a constant direct current voltage to the inverter regardless of motor speed. The voltage is greater than the line voltage and is returned at near unity power factor. The chopper circuit is dual gated thyristors. A first thyristor connects an inductor in series to the rectifier. The first thyristor is turned on at the chopper frequency and current flows through the inductor. A commutating thyrister in series with diode is connected in series with a first thyristor and a parallel and back-biasing diode.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: November 15, 1983
    Assignee: Marathon Electric
    Inventor: Shashi B. Dewan
  • Patent number: 4382217
    Abstract: A starting control circuit is provided for an alternating current motor having a run winding and a start winding and a mechanical rotational output. The motor is powered by an alternating current source. A reference oscillator produces pulses having a reference frequency. A first control circuit is provided for counting the number of reference pulses produced during a predetermined number of cycles of the alternating current source. A sensor is provided for sensing a predetermined amount of rotational movement of the mechanical rotational output of the motor and producing a sensor pulse indicative thereof. A second control circuit is provided for counting the number of reference pulses produced during the time between a predetermined number of sensor pulses and for comparing the counts on the first and second control circuits. The second control circuit assumes first and second output states dependent on the relationship between the first and second output counts.
    Type: Grant
    Filed: May 15, 1981
    Date of Patent: May 3, 1983
    Assignee: Gould Inc.
    Inventors: George W. Horner, Vern J. Alway