Patents by Inventor Kazuhiro Imaie

Kazuhiro Imaie 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: 20070024247
    Abstract: In a power generation apparatus equipped with an AC energization synchronous generator, when energization of a secondary winding starts to conduct connecting to the network of the AC energization synchronous generator to a network voltage, energization of the secondary winding starts at a fixed frequency and a slip frequency is calculated from a difference between a frequency of the network voltage and a resultant stator voltage frequency. Thereafter, energization starts at the calculated slip frequency and a voltage having a frequency generally coincident with the network frequency is output to the stator to incorporate the generator to the network. A phase is adjusted to make zero a phase difference when the rotation speed changes or the phases become different.
    Type: Application
    Filed: April 28, 2006
    Publication date: February 1, 2007
    Inventors: Masaya Ichinose, Motoo Futami, Shinya Oohara, Kazuhiro Imaie, Mitsugu Matsutake
  • Patent number: 7158521
    Abstract: In a synchronization system adopted in a synchronous-multisystem control apparatus comprising a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems. The synchronous-multisystem control apparatus employs a plurality of control circuits each provided for one of the systems.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: January 2, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Yuichiro Morita, Kotaro Shimamura, Yoshitaka Takahashi, Takashi Hotta, Kazuhiro Imaie, Shigeta Ueda, Akira Bando, Mitsuyasu Kido, Takeshi Takehara
  • Patent number: 7157804
    Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: January 2, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Kimura, Motoo Futami, Masaya Ichinose, Kazumasa Ide, Kazuhiro Imaie
  • Patent number: 7095133
    Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: August 22, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Kimura, Motoo Futami, Masaya Ichinose, Kazumasa Ide, Kazuhiro Imaie
  • Publication number: 20060181235
    Abstract: A motor is driven with variable frequency AC power converted from DC power, and an AC output power from the motor is converted to DC. In the conversion, an electromotive force regenerated by the motor is consumed by a plurality of resistors. When the consumption of the electromotive force is impeded in any of systems including any of the plurality of resistors, the electromotive force is consumed by the systems including the remaining resistors. Even if a system including any of the plurality of resistors fails, the electromotive force can by consumed by the other systems including the remaining resistors, thus providing a reliable rheostatic brake.
    Type: Application
    Filed: February 16, 2006
    Publication date: August 17, 2006
    Inventors: Kazuhiro Imaie, Takashi Yagyu, Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara
  • Publication number: 20060138980
    Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.
    Type: Application
    Filed: February 23, 2006
    Publication date: June 29, 2006
    Applicant: HITACHI, LTD.
    Inventors: Mamoru Kimura, Motoo Futami, Masaya Ichinose, Kazumasa Ide, Kazuhiro Imaie
  • Publication number: 20060086547
    Abstract: In an electric drive system for a vehicle, an alternator is driven by an engine to generate electric power which is used to drive a motor to generate a driving force. During a retardation of the vehicle, the motor is operated as an alternator to convert kinetic energy to electric energy which is used to retard the vehicle. A retard resistor is provided for absorbing electric energy generated during the retardation state. The retard resistor is cooled down by an AC blower.
    Type: Application
    Filed: December 9, 2005
    Publication date: April 27, 2006
    Inventors: Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
  • Publication number: 20050151504
    Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.
    Type: Application
    Filed: August 20, 2004
    Publication date: July 14, 2005
    Inventors: Mamoru Kimura, Motoo Futami, Masaya Ichinose, Kazumasa Ide, Kazuhiro Imaie
  • Publication number: 20030015876
    Abstract: A compound system of a wind power generation and an electric power energy storage constituted by a plurality of wind power generators 1a and 1b, and electric power energy storage device 5a and 5b and electric power converters 6a and 6b installed in parallel with the wind power generators is provided with a composite current detecting means 8a for the wind power generators, a voltage detecting means 9a for an electric power system 18, means 8b for detecting a current of which the electric power converters input or output, means 10a for computing output electric powers Pw and Qw of the wind power generators according to the voltage of the electric power system and the detected value of composite current of the wind power generators, means 10b for computing input or output electric powers Pc and Qc of the electric power converters according to the voltage of the electric power system and the detected value of the current of the electric power converters and a control unit 11a which generates pulse signals 16a fo
    Type: Application
    Filed: January 19, 2000
    Publication date: January 23, 2003
    Inventors: Masaya Ichinose, Motoo Futami, Shigeta Ueda, Kazuhiro Imaie, Kazuo Suzuki, Akira Maekawa
  • Publication number: 20020114356
    Abstract: In a synchronization system adopted in a synchronous-multisystem control apparatus comprising a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems.
    Type: Application
    Filed: March 18, 2002
    Publication date: August 22, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Yuichiro Morita, Kotaro Shimamura, Yoshitaka Takahashi, Takashi Hotta, Kazuhiro Imaie, Shigeta Ueda, Akira Bando, Mitsuyasu Kido, Takeshi Takehara
  • Patent number: 6389041
    Abstract: In a synchronization system adopted in a synchronous-multisystem control apparatus including a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems. The synchronous-multisystem control apparatus employs a plurality of control circuits each provided for one of the systems.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: May 14, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Yuichiro Morita, Kotaro Shimamura, Yoshitaka Takahashi, Takashi Hotta, Kazuhiro Imaie, Shigeta Ueda, Akira Bando, Mitsuyasu Kido, Takeshi Takehara