Pluse Width Modulation Or Chopping Patents (Class 318/811)
  • Patent number: 8456122
    Abstract: A control circuit includes a current sensing circuit, an analog digital converter (ADC), an amplifying circuit, a processor, and a switching circuit. The current sensing circuit senses current supplied to an electronic device by a power supply and outputs a first voltage signal. The amplifying circuit amplifies the first voltage signal output from the current sensing circuit to a second voltage signal. The ADC converts the second voltage signal to a digital signal. The processor outputs pulse width modulation (PWM) signals according to the digital signal. The switching circuit receives the PWM signals to control a fan of the electronic device according to the PWM signals.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: June 4, 2013
    Assignee: Hon Hai Precision Industry Co., Ltd.
    Inventor: Ming-Chih Hsieh
  • Patent number: 8432116
    Abstract: In a torque motor driving device for wire cut electrical discharge machines, a voltage waveform rectified by a full-wave rectifying circuit, not using a high-capacitance electrolytic capacitor, is applied as an AC voltage to a single-phase torque motor by a bridge circuit including semiconductor switches. A PWM signal whose duty is adjusted so that the current flowing through the torque motor matches an instructed value is generated and the generated PWM signal is used for the operation of the bridge circuit.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: April 30, 2013
    Assignee: Fanuc Corporation
    Inventors: Tomoyuki Furuta, Akiyoshi Kawahara, Masao Murai
  • Patent number: 8421397
    Abstract: A system for controlling operation of a motor drive during fast start-up of an induction motor is disclosed. The system includes an AC motor drive having a PWM inverter and a control system to generate a command signal to cause the PWM inverter to control an output of the AC motor drive. The control system includes a start-up modulator that is selectively operable during start-up acceleration of the AC motor, the start-up modulator programmed to determine a motor current applied to the AC motor and a voltage of a DC bus, generate a first frequency offset that causes a frequency reference of the command signal to be decreased when the motor current is greater than a reference current threshold, and generate a second frequency offset that causes the frequency reference of the command signal to be increased when the DC bus voltage is greater than a reference voltage threshold.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: April 16, 2013
    Assignee: Eaton Corporation
    Inventors: Anbo Yu, Lei Zhang, Kevin Lee
  • Patent number: 8421394
    Abstract: The invention relates to a method for current measurement in an in particular multiphase electrical system, in which an electrical load is energized as desired by at least one circuit element and a control unit produces drive signals which act on the at least one circuit element in order to achieve the desired energization of the load. The invention provides that clock patterns of the drive signals are associated with measurement windows for current measurement, in particular for measuring phase currents, and clock patterns are temporally offset in order to obtain measurement windows with a sufficient temporal length. A minimum temporal shift is the sum of a minimum dead time of the circuit element, a minimum settling time of the measuring amplifier circuit, and a minimum sampling time of the analogue-to-digital converter. The invention furthermore provides that the clock patterns are selected taking into consideration a phase selection for the current measurement.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: April 16, 2013
    Assignee: Robert Bosch GmbH
    Inventors: Gilles Schmitt, Sven Finke, Jochen Kurfiss
  • Patent number: 8411804
    Abstract: A digital PWM demodulator includes a first set of delay cells to receive a PWM signal and to propagate the PWM signal in a forward direction for a first interval. Delayed signals obtained at the end of the first interval are propagated in the reverse direction through the delay cells for a second interval. A logic zero feeds into the last cell at the start of the second interval. The output of a last cell in the delay cells at the end of the second interval is indicative of a data value modulated on the PWM signal. The digital PWM demodulator includes a second set of delay cells designed to operate identical to the first set of delay cells. The first set of delay cells and the second set of delay cells in conjunction with additional digital circuitry demodulate alternate periods of the PWM signal.
    Type: Grant
    Filed: February 21, 2011
    Date of Patent: April 2, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Subburaj, Anant Shankar Kamath, Jayawardan Janardhanan
  • Patent number: 8405342
    Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: March 26, 2013
    Assignee: Asmo Co., Ltd.
    Inventors: Yoji Yamada, Shinji Santo, Seiya Yokoyama, Yoko Tateishi, Yoshiaki Takemoto, Shigemasa Kato
  • Patent number: 8401770
    Abstract: A method to permit a start time of a heat engine of a vehicle to be controlled. The heat engine is mechanically coupled to a polyphase rotary electrical machine connected to an on-board electrical network. The method is of the type consisting of carrying out pre-fluxing by establishing an excitation current in the inductor for a predetermined pre-fluxing time (Tpref) before the phase currents are established. In accordance with the method, the predetermined pre-fluxing time (Tpref) is a function of the voltage (Vbat+X) of the on-board electrical network. Typically, the predetermined pre-fluxing time (Tpref) is increased when the voltage (Vbat+X) of the on-board electrical network reduces within a nominal voltage range (V 1, V2).
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: March 19, 2013
    Assignee: Valeo Equipements Electriques Moteur
    Inventor: Oussama Rouis
  • Patent number: 8395338
    Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: March 12, 2013
    Assignee: DENSO CORPORATION
    Inventors: Masahiro Kuroda, Hiroshi Taki, Nobumasa Ueda
  • Patent number: 8384338
    Abstract: A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: February 26, 2013
    Assignee: Eaton Corporation
    Inventors: Bin Lu, Thomas G. Habetler, Pinjia Zhang
  • Patent number: 8384335
    Abstract: A motor driving apparatus comprises: an AC/DC converter which converts AC voltage supplied from an AC power source into DC voltage through PWM switching control of a power switching device; and a DC/AC converter which converts the DC voltage into variable-frequency AC voltage for driving a motor in a controlled manner. The AC/DC converter includes: a control unit which generates, based on an error between the DC voltage and a DC voltage command value, a PWM signal for the PWM switching control of the power switching device; and a frequency/gain varying unit which sets the frequency of the PWM signal to be generated by the control unit and a control gain in the control unit higher than their normal levels during a period in which a load in the DC/AC converter varies.
    Type: Grant
    Filed: August 12, 2011
    Date of Patent: February 26, 2013
    Assignee: FANUC Corporation
    Inventors: Wataru Kuroki, Takashi Harada, Shinichi Horikoshi, Yasusuke Iwashita
  • Patent number: 8378601
    Abstract: A control apparatus for a permanent magnet synchronous motor capable of performing highly accurate torque control not only during low-speed operation and medium-speed operation but also during high-speed operation without increasing a burden on a product CPU irrespective of whether the permanent magnet synchronous motor is an SPM motor or an IPM motor. The control apparatus includes a torque correction circuit that generate a torque correction command from a current phase of current correction commands on a d-axis and a q-axis and a torque command and supplies the torque correction command to a d/q-axis current command generator instead of the torque command.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: February 19, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masaya Harakawa, Keita Horii, Atsuo Haishi
  • Patent number: 8362732
    Abstract: A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized negative sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: January 29, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Mohammad N. Anwar, S. M. N. Hasan, Khwaja M. Rahman, Silva Hiti, Steven E. Schulz, Sean E. Gleason
  • Patent number: 8362759
    Abstract: A phase current prediction method is disclosed. The phase current prediction method predicts current representative of a PWM period using a motor model which receives current measured through a single current sensor as an input, instead of the measured current, and determines the predicted current to be phase current.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: January 29, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jung Ik Ha, Jong Ho Kim, Ho Sun Yoo, Hyung Sun You, Jang Hwan Kim
  • Patent number: 8362735
    Abstract: A device for improving efficiency of an induction motor that soft-starts the motor by applying a voltage to the motor that is substantially less than the rated voltage then gradually increasing the voltage while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the voltage to the motor is increased/decreased by measuring the phase angle between the voltage and the current to the motor and increasing the voltage when the phase angle is less than a minimum phase angle (determined during soft-start) and decreasing the voltage when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: January 29, 2013
    Assignee: Protective Energy Economizer Technology
    Inventor: Mario M. Marcoccia
  • Patent number: 8362630
    Abstract: A method for controlling a self-piloted alternator-starter for starting or restarting the thermal engine of an automobile. The alternator-starter includes a rotor rotating in a stator, and a belt for transmitting the torque of the alternator-starter rotor to the crankshaft of the thermal engine. The method includes a first preflux step during which the rotor winding is excited by a preflux electric current, and a second starting step during which the stator windings are excited. The preflux step lasts from 10 to 100 ms so that the transmission belt is tensioned below a degradation tension at the start of the second starting step.
    Type: Grant
    Filed: November 4, 2008
    Date of Patent: January 29, 2013
    Assignee: Valeo Equipements Electriques Moteur
    Inventors: Paul Armiroli, Oussama Rouis, Julien Quincerot
  • Patent number: 8348020
    Abstract: An elevator control device includes a vector controller that calculates a voltage command required for driving an elevator cage, a carrier frequency switch circuit that outputs a carrier frequency signal, and a power converter that performs PWM control based on the voltage command and the carrier frequency signal, generates an AC power and supplies the AC power to an AC motor. The carrier frequency switch circuit changes the carrier frequency signal when a torque command for driving the AC motor reaches a torque limit value. Thus, it is possible to continuously operate an elevator without causing damage to a switching element of the power converter.
    Type: Grant
    Filed: September 8, 2010
    Date of Patent: January 8, 2013
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Hiroaki Ohya, Masashiro Tanaka, Yoichi Yamamoto
  • Publication number: 20130002187
    Abstract: This disclosure relates to a variable speed drive for driving a single phase motor. The variable speed drive generates enhanced motor voltages including harmonic components configured to reduce torque pulsations.
    Type: Application
    Filed: March 11, 2011
    Publication date: January 3, 2013
    Applicant: FRANKLIN ELECTRIC COMPANY, INC.
    Inventors: James H. Spreen, Jonathan D. Northup
  • Patent number: 8344684
    Abstract: The circuit structured to drive a motor is provided. The circuit includes: a division signal generator that generates a division signal dividing each of a high level period and a low level period of a binary position signal representing a relative position of a magnetic coil to a permanent magnet into a preset number of multiple divisions; a pulse width setter that sets a pulse width for PWM control corresponding to each of the multiple divisions represented by the division signal; and a PWM signal generator that performs PWM control with the set pulse width, thereby generating a PWM signal as a driving signal for driving the motor.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: January 1, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kesatoshi Takeuchi
  • Patent number: 8339094
    Abstract: Methods, system and apparatus are provided for overmodulation of a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided to optimize voltage command signals that control a five-phase inverter module to increase output voltages generated by the five-phase inverter module.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: December 25, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Milun Perisic, Silva Hiti, Gabriel Gallegos-Lopez
  • Patent number: 8339077
    Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: December 25, 2012
    Assignee: Microchip Technology Incorporated
    Inventor: Ward R. Brown
  • Patent number: 8339093
    Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.
    Type: Grant
    Filed: November 17, 2009
    Date of Patent: December 25, 2012
    Assignee: Eaton Corporation
    Inventors: Bin Lu, Charles John Luebke, Joseph Charles Zuercher, John Charles Merrison, Thomas M. Ruchti
  • Patent number: 8314577
    Abstract: An energy converter includes magnetic coils of N phases (N is an integer of 3 or more), and a PWM drive circuit for driving the magnetic coils of N phases, wherein the magnetic coil of each phase can be independently controlled by the PWM drive circuit.
    Type: Grant
    Filed: April 25, 2012
    Date of Patent: November 20, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Kesatoshi Takeuchi, Kazuyoshi Nakamura
  • Patent number: 8310188
    Abstract: An H-bridge circuit is connected to a coil of the vibration motor that is to be driven. A comparator receives Hall signals indicating position information of a rotor of the vibration motor, and converts to an FG signal. A pulse width modulator generates a pulse-modulated pulse signal specifying energization time of the coil of the vibration motor. The pulse width modulator, in a first mode, after commencing start-up of the vibration motor, sets a duty ratio of the pulse signal to 100%, and after that, switches the duty ratio to a predetermined value in accordance with rotational frequency of the motor. In a second mode, the duty ratio of the pulse signal continues to be set to 100%. In a third mode, frequency and the duty ratio of the pulse signal are set based on a control signal of a pulse form inputted from outside. The control signal is used also in switching mode.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: November 13, 2012
    Assignee: Rohm Co., Ltd.
    Inventor: Tatsuji Nakai
  • Patent number: 8310194
    Abstract: A load drive device for driving an inductive load by PWM controlling a switching element includes synchronization control unit, a synchronization signal input terminal, and a synchronization signal output terminal. The synchronization control unit outputs the PWM signal to the switching element. The synchronization control unit receives a synchronization signal through the input terminal from an exterior. The synchronization control unit outputs the synchronization signal through the output terminal to an exterior. When the synchronization control unit does not receive the synchronization signal, the synchronization control unit outputs the synchronization signal such that a first switching period of the PWM signal is prevented from overlapping with a second switching period of a PWM signal of an external device. When the synchronization control unit receives the synchronization signal, the synchronization control unit generates the PWM signal based on the synchronization signal.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: November 13, 2012
    Assignee: DENSO CORPORATION
    Inventors: Masatoshi Yokai, Satoshi Yoshimura, Kouji Nakamura, Masao Yamada
  • Patent number: 8310184
    Abstract: The PWM control circuit includes a polarity determination unit, a full wave rectification unit, an adjustment unit that generates an adjusted waveform signal by adjusting waveform of the full wave rectification signal, and a carrier signal generating unit that generates a fixed frequency carrier signal. The PWM control circuit further includes a comparator that generates an original PWM signal by comparing the adjusted waveform signal and the carrier signal, and a PWM waveform shaping unit that generates a first PWM signal for the positive polarity section and a second PWM signal for the negative polarity section, by shaping the original PWM signal according to the polarity signal.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: November 13, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Kesatoshi Takeuchi
  • Patent number: 8310178
    Abstract: A motor control apparatus for controlling a DC motor includes a detection unit configured to detect an angular speed of the DC motor, and a control unit configured to, when the DC motor is accelerated, increase a control value that controls a driving of the DC motor at a constant rate from a first control value corresponding to an angular speed lower than a target angular speed up to a second control value corresponding to an angular speed higher than the target angular speed, and switch the control value that controls the driving of the DC motor to a control value corresponding to the target angular speed in response to the detection result of the detection unit reaching the target angular speed.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: November 13, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoritsugu Maeda
  • 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: 8288984
    Abstract: For the present invention, under various running speeds statuses, the voltage supplied to the DC brushless motor is relatively increased or decreased on the basis of the internal setting of the motor drive control device according to the increased or decreased rotational output speed, so as to prevent the shortcoming of too much variation of the input impedance caused by the inductive reactance of the winding accordingly changed when the speed of the DC brushless motor is changed, specifically, to prevent the shortcoming of unable producing required torque resulting from the increased inductive reactance caused by increasing the rotational speed which makes the current value become too low when input by the original working voltage.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: October 16, 2012
    Inventor: Tai-Her Yang
  • Patent number: 8281886
    Abstract: An electric motor control device includes an inverter that supplies an output of a primary-side DC power supply to an electric motor to control driving of the electric motor; a converter that includes a voltage increasing power supply device that increases a voltage of the primary-side DC power supply to supply the inverter with the increased voltage as a secondary voltage, and a regenerative power supply device that reversely supplies regenerative power from the inverter to the primary-side DC power supply; a secondary-side target voltage determination unit; a converter control unit; and an electric motor control unit.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: October 9, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Subrata Saha, Takashi Yoshida, Daisuke Ogino, Jin Izawa, Yoshinori Oono
  • Patent number: 8283882
    Abstract: Analog control of the pulse width used to control the speed of a voice coil motor may be implemented using a “constant-current-charging-capacitor” configuration where the time needed to charge the capacitor is directly related to how far the actual motor speed is from the target speed. The BEMF voltage, indicative of motor speed, is sampled, and then stored in a storage capacitor, which is allowed to charge/discharge to a target voltage level. The time required to charge/discharge the capacitor to the target voltage is directly proportional to the difference between the BEMF voltage and the target voltage, and may be used directly as the pulse width (i.e., the charging time) in the PWM velocity control system. To avoid larger capacitors, a pulse multiplier circuit can be added, allowing charging/discharging the sampled voltage to the target voltage to be repeated by a number, N, of times.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: October 9, 2012
    Assignee: Marvell International Ltd.
    Inventors: Jye Sheng Hong, Siew Yong Chui
  • Publication number: 20120249046
    Abstract: In an aspect, in general, a method for pulse width modulation control of a multiple phase drive includes identifying a set of at least one phase from the plurality of phases for the drive as eligible for clamping to one of a plurality of extreme power supply voltages, selecting a phase from the set of eligible phases having a largest magnitude driving current of the set of eligible phases, determining a first offset signal as a difference between a control signal level for the selected phase and an extreme control signal level corresponding to one of the plurality of extreme power supply voltages, limiting a rate of change of the first offset signal to form a second offset signal, and determining a modified control signal for each of the phases for the drive including forming for each of a plurality of the phases a combination of the second offset signal and a control signal level for the phase to determine the modified control signal for the phase.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 4, 2012
    Applicant: Bose Corporation
    Inventors: Manoel Soares, Michael Nussbaum
  • Patent number: 8278855
    Abstract: In configuring a power conversion device to drive an alternating-current motor for an electric vehicle, the device is configured in a small size, light weight, and at a low cost, while avoiding size increase of a cooler. A current-command generating unit provided in a controller to control the alternating-current motor is adjusted not to increase a loss of an inverter in a state that the inverter as a main circuit within the power conversion device is outputting a maximum voltage that can be generated at an output voltage of a direct-current power source and when a torque command is reduced, and outputs a current command to cause the alternating-current motor to generate a torque based on the torque command.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: October 2, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventor: Hidetoshi Kitanaka
  • Patent number: 8278854
    Abstract: A control device has a unit for selecting each of controlled voltages outputted from an inverter to a generator, a unit for judging a polarity of a current flowing through the generator, a unit for predicting a current of the generator from each selected voltage to be outputted from the inverter in the succeeding period, while performing the prediction based on the current polarity each time the selected voltage differs from the voltage already outputted from the inverter in the present period, a unit for determining one voltage corresponding to one predicted current nearest to an instructed current among the predicted currents, and a unit for controlling the generator by controlling the inverter to change the voltage already outputted from the inverter to the determined voltage and to apply the determined voltage to the generator in the succeeding period.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: October 2, 2012
    Assignee: Denso Corporation
    Inventor: Akihiro Imura
  • Patent number: 8278865
    Abstract: A control device that controls a plurality of inverters respectively provided corresponding to a plurality of alternating-current electric motors so as to control the plurality of alternating-current electric motors by current feedback. The control device comprises a carrier frequency setting unit that individually selects and sets one of a plurality of carrier frequencies, each of which is a frequency of a carrier for generating switching control signals for the inverter based on a pulse width modulation method, for each of the plurality of inverters, and a switching timing table that specifies a switching timing serving as a permissible timing of switching to a different carrier frequency pair from each of a plurality of carrier frequency pairs each of which is composed of a combination of the carrier frequencies set for each of the plurality of inverters.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: October 2, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Arinori Shimada, Mitsuru Nakamura, Subrata Saha, Ken Iwatsuki
  • Patent number: 8274250
    Abstract: A method for controlling a direct current (DC) brushless motor, and a control circuit thereof are provided. The DC brushless motor is sensorless. In response to a digital output signal that is applied to drive the direct current brushless motor, detection of a back electromotive force (BEMF) is ceased in a predetermined time interval, so as to avoid detecting erroneous BEMF and keep normal operation of the direct current brushless motor.
    Type: Grant
    Filed: September 10, 2008
    Date of Patent: September 25, 2012
    Assignee: Feeling Technology Corp.
    Inventors: Hsuan-Chuan Chen, Wen-Jung Su
  • Patent number: 8269442
    Abstract: A brushless D.C. motor includes having a rotor and a plurality of stator windings that define a stator field when driven by a bridge circuit, where a microprocessor drives the bridge circuit using a pulse-width modulation logic. The brushless D.C. motor is driven by triggering a commutation of the stator field; voltage induced by rotating the rotor in a non-energized stator winding is monitored to determine whether the voltage reaches, exceeds or is below a threshold voltage. A delay time between triggering the commutation of the stator field and the voltage reaching, exceeding or being below the threshold voltage is determined; and using the determined delay time a triggering time point for a next commutation of the stator field.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: September 18, 2012
    Assignee: Micronas GmbH
    Inventors: Hans Spirk, Gualtiero Bagnuoli
  • Patent number: 8264188
    Abstract: Systems and methods relating to a boosting rectifier and feeder motor drive circuit are provided. The circuit may be used to produce a regulated DC supply voltage from a variable input AC line voltage, chop the DC supply voltage and deliver a pulse width modulated motor voltage to a wire feed motor in the wire drive assembly. One embodiment relates to elimination of undesirable wire feeder inconsistencies due to motor loading conditions, distance between the primary power source and the wire feeder, and so forth. In certain embodiments, the circuit may contain power factor correction circuitry, which may reduce the size of circuit components due to increased efficiency. Current paths through the circuit during the positive and negative half cycles of the AC input voltage are provided. Exemplary controller logic that may be used to control the operation of the boosting rectifier and feeder motor drive circuit is provided.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: September 11, 2012
    Assignee: Illinois Tool Works Inc.
    Inventor: Brian James Veik
  • Patent number: 8264181
    Abstract: In a control of an AC motor that uses a PWM control and a rectangular-wave control, when switching is conducted from the rectangular-wave control to the PWM control, a current command generated in a current command generation unit is corrected so as to smooth the variations in a time axis direction on the basis of a target torque command value by taking the final current state in the rectangular-wave control immediately prior to switching as an initial value, thereby generating a current command after the correction. An inverter is current feedback-controlled based on the current command after the correction. As a result, the continuity from the current state immediately prior to switching of the rectangular-wave control can be ensured for the current command in the PWM control.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: September 11, 2012
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Toshifumi Yamakawa, Kenji Yamada, Yutaka Kuromatsu
  • Patent number: 8258739
    Abstract: A power converter includes: a determination section which, prior to an actual operation, determines presence/absence of a common mode filter connected to a line for supplying power to a motor, switching elements being driven with a predetermined PWM on/off drive signal corresponding to a carrier frequency prior to the actual operation; and a PWM control method changing/setting section which, during the actual operation, changes and sets a PWM control method in accordance with a result of the determination of the presence/absence of the common mode filter.
    Type: Grant
    Filed: December 26, 2011
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Tsuyoshi Higuchi, Kenji Yamada
  • Patent number: 8258734
    Abstract: An energy converter includes magnetic coils of N phases (N is an integer of 3 or more), and a PWM drive circuit for driving the magnetic coils of N phases, wherein the magnetic coil of each phase can be independently controlled by the PWM drive circuit.
    Type: Grant
    Filed: February 8, 2010
    Date of Patent: September 4, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Kesatoshi Takeuchi, Kazuyoshi Nakamura
  • Patent number: 8253366
    Abstract: A device for diagnosing signal status of a driven object includes an insulation transformer, a signal generating device, a current measuring device, a feedback device, and a voltage measuring device. The insulation transformer has an intermediate tap at a midpoint of its primary winding. The signal generating device generates periodically vibrating voltage and includes a rectangular wave pulse voltage and alternating voltage. The current measuring device is connected to the intermediate tap of the primary winding to measure a current. The feedback device converts the current flowing from the intermediate tap of the primary side to a voltage corresponding to the drive voltage and feeds back the converted voltage to the input drive voltage signal. The voltage measuring device measures the voltage added with the feedback voltage. Diagnosis of the signal state is performed based on measurement results of the current measuring device and voltage measuring device.
    Type: Grant
    Filed: January 9, 2009
    Date of Patent: August 28, 2012
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventor: Hideaki Emoto
  • Patent number: 8253360
    Abstract: A vector controlled motor drive system is provided that includes a test vector and duty cycle generator module designed to receive a set of three-phase voltage command signals and designed to generate a set of pulse width modulated (PWM) waveforms. The set of PWM waveforms comprise: a first modified switching vector signal for a first motor phase that comprises at least two test pulses over three consecutive PWM cycles. The first modified switching vector signal has a first amplitude value that changes between a high amplitude value and a low amplitude value during the three consecutive PWM cycles. A number of transitions by the first modified switching vector signal between the low amplitude value and the high amplitude value over the three consecutive PWM cycles is greater than six and less than twelve.
    Type: Grant
    Filed: July 15, 2009
    Date of Patent: August 28, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Yo Chan Son, Nitinkumar R. Patel
  • Patent number: 8248013
    Abstract: A fan device with improved speed control module includes a stator, a rotor, and a speed control module. The stator has a driving unit outputting currents for the stator to generate alternative magnetic fields and thus turn the rotor. The speed control module includes a control unit and a speed adjusting circuit, with the control unit generating a control command for the driving unit and further outputting a state signal for the speed adjusting circuit to control whether a PWM signal enters the control circuit or not.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: August 21, 2012
    Assignee: Sunonwealth Electric Machine Industry Co, Ltd.
    Inventors: Alex Horng, Chun-Yuan Huang, Chung-Ken Cheng, Nguyen Nguyen, Susheela Narasimhan
  • Patent number: 8242731
    Abstract: Embodiments of the present method and system permit an effective method for determining the optimum selection of pulse width modulation polarity and type including determining machine parameters, inputting the machine parameters into a predicted duty cycle module, determining the optimum polarity of the pulse width modulation for a predicted duty cycle based on a pulse width modulation generation algorithm, and determining the optimum type of the pulse width modulation for a predicted duty cycle based on the pulse width modulation generation algorithm.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: August 14, 2012
    Assignee: Aerovironment, Inc.
    Inventor: Zaher Abdallah Daboussi
  • Patent number: 8237393
    Abstract: A system is used to measure a fan rotational speed. The system includes a main controller, a first socket coupled to the linear fan, a second socket connected to the main controller, and an optical fiber amplifier connected to the main controller. A PWM (pulse width module) fan is coupled to the second socket, the PWM fan sends a first rotational speed signal, which represent a rotation speed of the PWM fan, to the main controller via the second socket. The optical fiber amplifier is capable of radiating light on fan blades of the linear fan, and sensing light reflected by the fan blades to count a rotational speed of the linear fan, and generating a second rotational speed signal which represents a rotational speed of the linear fan. The optical fiber amplifier sends the second rotational speed signal to the main controller.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: August 7, 2012
    Assignees: Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd., Hon Hai Precision Industry Co., Ltd.
    Inventors: Ling-Yu Xie, Kun-Lung Wu, Sheng-Chung Huang, San-Yong Yang, Xin-Ping Zhang, Jing Liu
  • Patent number: 8237392
    Abstract: An angle calculation portion of a motor control apparatus determines an angle ? of a rotor, and an angular velocity calculation portion determines an angular velocity ?e of the rotor. A command current calculation portion determines command currents id* and iq* on dq axes, based on a steering torque T and a vehicle speed S. An open-loop control portion determines command voltages vd and vq on the dq axes based on the command currents id* and iq* and the angular velocity ?e, according to circuit equations of a motor. A dq-axis/three-phase conversion portion converts the command voltages vd and vq to command voltages of three phases. A three-phase voltage correction portion corrects the command voltage so that an actual time average value of a voltage applied to each phase is equal to a time average value of a voltage that is to be applied to the phase if the voltage is not decreased, in order to compensate for a decrease in the applied voltage.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: August 7, 2012
    Assignee: JTEKT Corporation
    Inventors: Takeshi Ueda, Shigeki Nagase
  • Publication number: 20120187894
    Abstract: A power converter includes: a determination section which, prior to an actual operation, determines presence/absence of a common mode filter connected to a line for supplying power to a motor, switching elements being driven with a predetermined PWM on/off drive signal corresponding to a carrier frequency prior to the actual operation; and a PWM control method changing/setting section which, during the actual operation, changes and sets a PWM control method in accordance with a result of the determination of the presence/absence of the common mode filter.
    Type: Application
    Filed: December 26, 2011
    Publication date: July 26, 2012
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventors: Tsuyoshi Higuchi, Kenji Yamada
  • Patent number: 8228012
    Abstract: A controller of a multi-phase electric motor has a drive section having an upper arm switching element and a lower arm switching element for driving the multi-phase electric motor, a single current detection section for detecting a current value of the multi-phase electric motor, a pulse width modulation signal generation section for generating plural pulse width modulation of each phase within one control period based on the current value detected by the current detection section and a carrier signal, and a phase movement section for moving the pulse width modulation signal of a predetermined phase generated by the pulse width modulation signal generation section by gradually changing a movement amount of the phase in one control period, and outputting the resultant pulse width modulation signal to the drive section.
    Type: Grant
    Filed: November 24, 2008
    Date of Patent: July 24, 2012
    Assignee: OMRON Corporation
    Inventors: Masamitsu Hamasaki, Shinichi Kuratani, Takenobu Nakamura
  • Patent number: 8222842
    Abstract: A rotating electromechanical machine has a rotor having at least one current-carrying winding and at least one rotor-mounted sensor configured to sense a machine property or parameter during machine operation. Rotor-mounted circuitry dynamically modifies at least one property of the current-carrying winding during machine operation in response to the sensed machine property or parameter.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: July 17, 2012
    Inventors: Roderick A. Hyde, Jordin T. Kare, Lowell L. Wood, Jr.
  • Patent number: 8222857
    Abstract: In a controlling device for a permanent magnet synchronous motor, an asynchronous pulse mode is switched to a synchronous pulse mode in a situation where a modulation factor has become equal to or larger than a first set value or in a situation where an inverter output frequency has become equal to or higher than a second set value. The synchronous pulse mode is switched to the asynchronous pulse mode in a situation where the modulation factor has become smaller than the first set value, and also, the inverter output frequency has become lower than the second set value. By setting the second set value so that the number of pulses included in a half cycle of an output voltage fundamental wave of the inverter is equal to or larger than a predetermined value, it is possible to inhibit current oscillations and torque ripples from occurring in the motor.
    Type: Grant
    Filed: September 25, 2007
    Date of Patent: July 17, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventor: Hidetoshi Kitanaka