Patents by Inventor Kazuaki Yuuki

Kazuaki Yuuki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100327689
    Abstract: A permanent-magnet-type rotating electrical machine capable of realizing variable-speed operation in a wide range from low speed to high speed at high output and improving, in a wide operating range, efficiency, reliability, and productivity. The rotating electrical machine includes a first permanent magnet whose product of coercive force and magnetizing direction thickness is small and a second permanent magnet whose product of coercive force and magnetizing direction thickness is large, to form a magnetic pole. The product of coercive force and magnetizing direction thickness of the first permanent magnet is equal to or larger than the product of magnetic field strength and magnetizing direction thickness of the second permanent magnet at a no-load operating point. At the magnetic pole, a magnetic field created by a current of an armature coil magnetizes the first permanent magnet, irreversibly changing a flux amount of the first permanent magnet.
    Type: Application
    Filed: February 16, 2009
    Publication date: December 30, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuto Sakai, Kazuaki Yuuki
  • Publication number: 20100332065
    Abstract: According to one embodiment, there is provided an electric-vehicle driving apparatus which consumes regenerative energy by a brake resistor and can decrease harmonic components generated by a brake-chopper switching circuit. Plural brake-chopper switching circuits are provided in parallel for each inverter. Harmonic components generated by the brake-chopper switching circuits are decreased by changing phases or frequencies of triangular carrier waves of the switching circuits, relatively to each other.
    Type: Application
    Filed: September 7, 2010
    Publication date: December 30, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Min Lin, Manabu Matsuoka, Akira Miyazaki, Kazuaki Yuuki
  • Publication number: 20100327787
    Abstract: The present invention provides a permanent-magnet-type rotating electrical machine capable of realizing variable-speed operation in a wide range from low speed to high speed at high output and improving, in a wide operating range, efficiency, reliability, and productivity. A narrow magnetic path 11 is formed in a rotor core 2 of a rotor 1 at an inter-pole yoke that magnetically connects adjacent pole core portions 7 to each other, so that the narrow magnetic path is magnetically saturated with flux of a magnetic field created by a predetermined magnetizing current passed to an armature coil 21. Each of first permanent magnets 3 at each of the pole core portions 7 is magnetized with a magnetic field created by a magnetizing current passed to the armature coil 21, to irreversibly change the flux amount of the first permanent magnet.
    Type: Application
    Filed: February 16, 2009
    Publication date: December 30, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazuto Sakai, Kazuaki Yuuki
  • Publication number: 20100201294
    Abstract: A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor 1; an inverter as a magnetization unit which supplies a magnetization current for controlling a magnetic flux of the variable magnet; and a boosting unit boosting an input DC voltage to a predetermined target value to output it to the inverter. The variable magnetic flux motor drive system makes it possible to achieve size reduction and high efficiency, while securing a voltage required for supplying a magnetization current when controlling the magnetic flux of the variable magnet.
    Type: Application
    Filed: September 16, 2008
    Publication date: August 12, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
  • Publication number: 20100060223
    Abstract: A permanent magnet rotating electrical machine capable of conducting a variable speed operation at high output in a wide range from low speed to high speed and improving efficiency and reliability in a wide operating range. Two kinds of permanent magnets having different shapes or different magnetic characteristics are embedded in a rotor core, to form a magnetic pole. The permanent magnets arranged at the magnetic pole include a permanent magnet whose product of coercive force and thickness along a magnetizing direction is small and the permanent magnet whose product of coercive force and thickness along the magnetizing direction is large. A magnetic field created by passing a current to an armature coil for a short time is used to irreversibly magnetize the permanent magnet whose product of coercive force and thickness along magnetizing direction is small, thereby changing a total linkage flux amount, and a positive d-axis current is passed when torque is large.
    Type: Application
    Filed: December 7, 2007
    Publication date: March 11, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazuto Sakai, Kazuaki Yuuki
  • Publication number: 20090261774
    Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.
    Type: Application
    Filed: July 24, 2007
    Publication date: October 22, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
  • Patent number: 7443126
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: October 28, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Patent number: 7439703
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: October 21, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Publication number: 20080179999
    Abstract: A motor drive system 10-1 for a railway vehicle is capable of reducing the weight of wiring, electromagnetic noise, and manufacturing cost. The motor drive system includes an inverter 11. The inverter is configured to control a motor 13-1 and is divided into at least two separate inverter units that are arranged integrally with the motor.
    Type: Application
    Filed: December 18, 2007
    Publication date: July 31, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yosuke NAKAZAWA, Shinichi Noda, Kazuaki Yuuki, Kazuaki Fukuda
  • Publication number: 20080150470
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Application
    Filed: June 7, 2007
    Publication date: June 26, 2008
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Publication number: 20080011185
    Abstract: To provide an electric rolling stock driving apparatus allowing for an enhanced reliability of rolling stock system, a main motor 14 for driving an electric rolling stock, a VVVF inverter 13 for driving the main motor, and a brake controller 12 for controlling braking forces of wheels 16 are provided within a driving truck 9, allowing for an improvement in reliability of a rolling stock system that otherwise might have deficiencies such as an increased rolling stock manufacture term or an increased trouble restoration time by a complicated implementation of wiring due to an arrangement according to a relevant art in which, for driving a rolling stock, associated apparatuses are separately mounted to a car body and a truck.
    Type: Application
    Filed: June 7, 2007
    Publication date: January 17, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuaki Yuuki, Yosuke Nakazawa, Masato Hashimoto, Shinichi Noda, Kenzo Tonoki, Taihei Koyama, Atsuhiko Nishio, Masaki Miyairi
  • Patent number: 7312594
    Abstract: A control system for a synchronous machine including a converter for converting DC voltage to AC voltage or AC voltage to DC voltage. The synchronous machine is driven by the converter. The control system further includes a magnetic pole position presuming device for performing a presuming operation to presume a magnetic pole position of the synchronous machine based on high-frequency components of a voltage applied to the synchronous machine and a current flowing into the synchronous machine, and a control device for controlling the converter based on the magnetic pole position presumed by the magnetic pole position presuming device. The control device controls the converter so as to contain significant high-frequency components in the voltage or the current used in the presuming operation when a mean voltage or a mean current output from the converter is spatially in a region close to a straight line containing starting and ending points of non-zero voltage vector output from the converter.
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: December 25, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki, Katsumi Maekawa, Shouji Onda
  • Publication number: 20070236166
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Application
    Filed: June 7, 2007
    Publication date: October 11, 2007
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Patent number: 7253583
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: August 7, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Publication number: 20060202481
    Abstract: A controller for a synchronous machine includes: a power converter; a synchronous machine driven by the power converter; a PWM modulation section for controlling the synchronous machine; a current detection section which detects a current conducted to the synchronous machine; a voltage detection section which detects a voltage applied to the synchronous machine; a current variation operation section which operates a current variation during a time interval between timings synchronized with detection sampling in the current detection section; a voltage integration operation section which operates a voltage integration value during a time interval between the same timings as the timings in the current variation operation section; a current variation operation section for a time interval in which all sets are included, defining, as one set, the current variation and the voltage integration value, and operating a current variation during the time interval in which all the sets are included; a voltage integration
    Type: Application
    Filed: February 17, 2006
    Publication date: September 14, 2006
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki
  • Publication number: 20060097686
    Abstract: A control system for a synchronous machine including a converter for converting DC voltage to AC voltage or AC voltage to DC voltage. The synchronous machine is driven by the converter. The control system further includes a magnetic pole position presuming device for performing a presuming operation to presume a magnetic pole position of the synchronous machine based on high-frequency components of a voltage applied to the synchronous machine and a current flowing into the synchronous machine, and a control device for controlling the converter based on the magnetic pole position presumed by the magnetic pole position presuming device. The control device controls the converter so as to contain significant high-frequency components in the voltage or the current used in the presuming operation when a mean voltage or a mean current output from the converter is spatially in a region close to a straight line containing starting and ending points of non-zero voltage vector output from the converter.
    Type: Application
    Filed: October 27, 2005
    Publication date: May 11, 2006
    Inventors: Kazuya Yasui, Kazuaki Yuuki, Kentaro Suzuki, Katsumi Maekawa, Shouji Onda