Patents by Inventor Ryuichi Ogawa

Ryuichi Ogawa 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).

  • Patent number: 11777428
    Abstract: A higher control unit 1 generates a command current i* based on a command value. A model predictive control unit 2 sets a plurality of assumed voltage vectors for each switching cycle of an output voltage, divides the switching cycle of the output voltage into two periods according to a ratio between a dead time and the switching cycle of the output voltage, calculates a predicted current of the assumed voltage vector for each of the two periods obtained by the two-dividing, determines an evaluation function between the assumed voltage vector and the predicted current, sets the assumed voltage vector which has highest evaluation function result, as a command voltage vector. A gate signal g for outputting a voltage expressed by the command voltage vector from the power converter is output. The power converter is driven and controlled based on the gate signal.
    Type: Grant
    Filed: July 8, 2021
    Date of Patent: October 3, 2023
    Assignee: MEIDENSHA CORPORATION
    Inventors: Ryuichi Ogawa, Masashi Takiguchi
  • Publication number: 20230246580
    Abstract: A higher control unit 1 generates a command current i* based on a command value. A model predictive control unit 2 sets a plurality of assumed voltage vectors for each switching cycle of an output voltage, divides the switching cycle of the output voltage into two periods according to a ratio between a dead time and the switching cycle of the output voltage, calculates a predicted current of the assumed voltage vector for each of the two periods obtained by the two-dividing, determines an evaluation function between the assumed voltage vector and the predicted current, sets the assumed voltage vector which has highest evaluation function result, as a command voltage vector. A gate signal g for outputting a voltage expressed by the command voltage vector from the power converter is output. The power converter is driven and controlled based on the gate signal.
    Type: Application
    Filed: July 8, 2021
    Publication date: August 3, 2023
    Applicant: MEIDENSHA CORPORATION
    Inventors: Ryuichi OGAWA, Masashi TAKIGUCHI
  • Patent number: 11601039
    Abstract: A minimum number of levels required to output a target modulation ratio is determined. Additionally, determining a total number of voltage orders to be controlled among a voltage fundamental wave and harmonics of power converter, comparing the minimum number of levels and the total number of voltage orders to be controlled, and fixing a larger one as a number of switching times in a quarter cycle for the target modulation ratio are performed. Further, when the total number is fixed, a shape of an output voltage is determined, and based on the target modulation ratio and the number of switching times in the quarter cycle, a determination of switching phases is made, in addition to a derivation of the pulse pattern for one cycle by which each output voltage level is used according to the target modulation ratio and the output voltage shape, and the phase is determined.
    Type: Grant
    Filed: March 30, 2020
    Date of Patent: March 7, 2023
    Assignee: MEIDENSHA CORPORATION
    Inventors: Ryuichi Ogawa, Masashi Takiguchi
  • Patent number: 11575331
    Abstract: For a serial multiplex inverter in which each phase includes cells connected serially, wherein each cell includes switching elements and is configured to output a level of +1 (ON), a level of zero (OFF), and a level of ?1 (ON) as output levels by operation of the switching elements, a control device includes a switching load distribution control section. This control section is configured to: store information about an ON-output duration of each of the cells and information about an OFF-output duration of each of the cells; for a shift pattern from ON to OFF in the cells, put OFF a gate signal for one of the cells whose ON-output duration is the longest of the cells; and for a shift pattern from OFF to ON in the cells, put ON a gate signal for one of the cells whose OFF-output duration is the longest of the cells.
    Type: Grant
    Filed: June 3, 2020
    Date of Patent: February 7, 2023
    Assignee: MEIDENSHA CORPORATION
    Inventors: Ryuichi Ogawa, Masashi Takiguchi
  • Patent number: 11563367
    Abstract: Ina power conversion system having a fixed pulse pattern modulation unit 2 that is configured to refer to tables storing therein pulse patterns that determine respective command voltage levels corresponding to phase information for each modulation ratio and to generate a gate signal g on the basis of a command modulation ratio d and a control phase ? and driving a power converter 3 on the basis of the gate signal g, the fixed pulse pattern modulation unit 2 is further configured to, when performing a pulse pattern transition, search for a proper post-transition table reference position and make a command voltage level follow a command voltage level of a post-transition pulse pattern. With this, the power conversion system that can perform the pulse pattern transition without current impulse and that can also be applied to a multi-level power converter having four levels or more can be provided.
    Type: Grant
    Filed: August 18, 2020
    Date of Patent: January 24, 2023
    Assignee: MEIDENSHA CORPORATION
    Inventors: Ryuichi Ogawa, Masashi Takiguchi
  • Publication number: 20220352805
    Abstract: Ina power conversion system having a fixed pulse pattern modulation unit 2 that is configured to refer to tables storing therein pulse patterns that determine respective command voltage levels corresponding to phase information for each modulation ratio and to generate a gate signal g on the basis of a command modulation ratio d and a control phase ? and driving a power converter 3 on the basis of the gate signal g, the fixed pulse pattern modulation unit 2 is further configured to, when performing a pulse pattern transition, search for a proper post-transition table reference position and make a command voltage level follow a command voltage level of a post-transition pulse pattern. With this, the power conversion system that can perform the pulse pattern transition without current impulse and that can also be applied to a multi-level power converter having four levels or more can be provided.
    Type: Application
    Filed: August 18, 2020
    Publication date: November 3, 2022
    Applicant: MEIDENSHA CORPORATION
    Inventors: Ryuichi OGAWA, Masashi TAKIGUCHI
  • Publication number: 20220337174
    Abstract: A higher-level control unit 5 generates a level command L* on the basis of a command value cmd. A switching load distribution control unit 6 stores the output period information of each cell and designates a gate signal so that: in case of a pattern by which a cell is changed from ±1 level to 0 level, the cell having the longest ±1 level period information is set to 0 level; and in case of a pattern by which a cell is changed from 0 level to ±1 level, the cell having the longest 0 level output period is set to ±1 level. This distributes the switching load of each cell in the serial multiplex inverter control device.
    Type: Application
    Filed: June 3, 2020
    Publication date: October 20, 2022
    Applicant: MEIDENSHA CORPORATION
    Inventors: Ryuichi OGAWA, Masashi TAKIGUCHI
  • Publication number: 20220320994
    Abstract: The present invention has steps of determining a minimum number of levels (L_duty) required to output a target modulation ratio (d_ref) (S2), determining the total number (N_volt) of voltage orders to be controlled among a voltage fundamental wave and harmonics of power converter (S3), comparing the minimum number of levels (L_duty) and the total number (N_volt) of voltage orders to be controlled and fixing a larger one as the number of switching times N in a quarter cycle for the target modulation ratio (S4-S6); when (N_volt) is fixed, determining shape of an output voltage (S7), and based on the target modulation ratio and the number of switching times N in the quarter cycle, determining switching phases for N times, and deriving the pulse pattern for one cycle by which each output voltage level according to the target modulation ratio, the output voltage shape and the phase is determined (S8, S9).
    Type: Application
    Filed: March 30, 2020
    Publication date: October 6, 2022
    Applicant: MEIDENSHA CORPORATION
    Inventors: Ryuichi OGAWA, Masashi TAKIGUCHI
  • Patent number: 11444525
    Abstract: An inverter system includes a level skip prevention control section. The level skip prevention control section is configured to: in response to an upward shift of an output voltage level of a first one of phases, set a counter for inhibiting upward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting downward shifting of an output voltage level of a second one of the phases other than the first phase during a predetermined duration; and in response to a downward shift of the output voltage level of the first phase, set a counter for inhibiting downward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting upward shifting of the output voltage level of the second phase during a predetermined duration.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: September 13, 2022
    Assignee: MEIDENSHA CORPORATION
    Inventors: Ryuichi Ogawa, Shizunori Hamada
  • Publication number: 20220209643
    Abstract: An inverter system includes a level skip prevention control section. The level skip prevention control section is configured to: in response to an upward shift of an output voltage level of a first one of phases, set a counter for inhibiting upward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting downward shifting of an output voltage level of a second one of the phases other than the first phase during a predetermined duration; and in response to a downward shift of the output voltage level of the first phase, set a counter for inhibiting downward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting upward shifting of the output voltage level of the second phase during a predetermined duration.
    Type: Application
    Filed: March 31, 2020
    Publication date: June 30, 2022
    Applicant: MEIDENSHA CORPORATION
    Inventors: Ryuichi OGAWA, Shizunori HAMADA
  • Patent number: 10169762
    Abstract: The determination of legal or contractual risks in datacenter migration is performed by: storing business application information which is information about management of applications and data, applicable law information at a datacenter and contract information about a contract with a datacenter; extracting first migration information, which is information regarding datacenter migration, from business application information associated with a particular application and particular data which are migration targets; extracting second migration information, which is information regarding the datacenter migration, from applicable law information associated with a migration destination datacenter; extracting third migration information, which is information regarding the datacenter migration, from contract information associated with the migration destination datacenter; and comparing the first and second migration information with the third migration information.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: January 1, 2019
    Assignee: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Patent number: 9363290
    Abstract: A system 100 stores policy information in which role identification information, resource group identification information and action information are associated with each other (101), stores user identification information and role identification information in association with each other (102), receives an access request including user identification information for identifying a user of a client device (103), generates access control information based on the policy information and transmits the generated access control information to an access target device (104), acquires address information of a transmission source of the access request (105), and generates communication filter information representing permission for communication relating to an address represented by the acquired address information and transmits the generated communication filter information to a communication filter device specified based on the policy information (106).
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: June 7, 2016
    Assignee: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Publication number: 20150348054
    Abstract: The determination of legal or contractual risks in datacenter migration is performed by: storing business application information which is information about management of applications and data, applicable law information at a datacenter and contract information about a contract with a datacenter; extracting first migration information, which is information regarding datacenter migration, from business application information associated with a particular application and particular data which are migration targets; extracting second migration information, which is information regarding the datacenter migration, from applicable law information associated with a migration destination datacenter; extracting third migration information, which is information regarding the datacenter migration, from contract information associated with the migration destination datacenter; and comparing the first and second migration information with the third migration information.
    Type: Application
    Filed: September 3, 2013
    Publication date: December 3, 2015
    Applicant: NEC CORPORATION
    Inventor: Ryuichi OGAWA
  • Patent number: 9183009
    Abstract: The present invention provides a policy update apparatus which can update a software policy appropriately corresponding to the configuration change in a resource. The policy update apparatus includes policy retrieving means which receives a resource identifier, reads out an install destination resource identifier corresponding to the resource identifier from resource management means which stores with providing a mapping between the resource identifier and the install destination resource identifier which indicates an install destination resource in which the resource identified by the resource identifier is installed, and reads out the software policy corresponding to the resource identifier and the install destination resource identifier, and policy update means which updates the software policy, correlates the updated software policy to the resource identifier and the install destination resource identifier, and stores to policy storage means.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: November 10, 2015
    Assignee: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Patent number: 8954960
    Abstract: In a net boot type thin client system, bottle necks concentrate on specific steps in a previously downloading method and an on-demand downloading method so as to hinder high-speed operation. Specifically, a previously file acquiring section for acquiring a file before the OS operates, an on-demand file acquiring section for acquiring a file while the OS operates, and a file determining section for determining whether or not a file is used in a high frequency. A high use-frequency file is downloaded before an OS operates and a low use-frequency file is downloaded while the OS operates.
    Type: Grant
    Filed: January 5, 2010
    Date of Patent: February 10, 2015
    Assignee: NEC Corporation
    Inventors: Ryuichi Ogawa, Takayuki Sasaki
  • Publication number: 20140366084
    Abstract: There is provided a management system (10) including a transmission information acquisition unit (11) that acquires transmission information indicating that resources held in a resource holding unit (31) are to be transmitted to an external data center, an extraction unit (12) that extracts a first security policy, which is a security policy applied to an application to be transmitted and is a security policy to be realized in the external data center, from a security policy holding unit (32) that holds the security policy applied to the application when the transmission information acquisition unit (11) acquires the transmission information, an acquisition unit (14) that acquires security information, which indicates a security function realizable in the external data center, from the external data center when the transmission information acquisition unit (11) acquires the transmission information, and a determination unit (13) that determines whether or not the first security policy is realizable in the ext
    Type: Application
    Filed: January 16, 2013
    Publication date: December 11, 2014
    Applicant: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Publication number: 20130290695
    Abstract: The present invention provides a policy update apparatus which can update a software policy appropriately corresponding to the configuration change in a resource. The policy update apparatus includes policy retrieving means which receives a resource identifier, reads out an install destination resource identifier corresponding to the resource identifier from resource management means which stores with providing a mapping between the resource identifier and the install destination resource identifier which indicates the resource in which the resource identified by the resource identifier is installed, and reads out the software policy corresponding to the resource identifier and the install destination resource identifier, and policy update means which updates the software policy, correlates the updated software policy to the resource identifier and the install destination resource identifier, and stores to policy storage means.
    Type: Application
    Filed: June 20, 2012
    Publication date: October 31, 2013
    Applicant: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Publication number: 20130174217
    Abstract: A system 100 stores policy information in which role identification information, resource group identification information and action information are associated with each other (101), stores user identification information and role identification information in association with each other (102), receives an access request including user identification information for identifying a user of a client device (103), generates access control information based on the policy information and transmits the generated access control information to an access target device (104), acquires address information of a transmission source of the access request (105), and generates communication filter information representing permission for communication relating to an address represented by the acquired address information and transmits the generated communication filter information to a communication filter device specified based on the policy information (106).
    Type: Application
    Filed: August 23, 2011
    Publication date: July 4, 2013
    Applicant: NEC CORPORATION
    Inventor: Ryuichi Ogawa
  • Publication number: 20110276964
    Abstract: In a net boot type thin client system, bottle necks concentrate on specific steps in a previously downloading method and an on-demand downloading method so as to hinder high-speed operation. Specifically, a previously file acquiring section for acquiring a file before the OS operates, an on-demand file acquiring section for acquiring a file while the OS operates, and a file determining section for determining whether or not a file is used in a high frequency. A high use-frequency file is downloaded before an OS operates and a low use-frequency file is downloaded while the OS operates.
    Type: Application
    Filed: January 5, 2010
    Publication date: November 10, 2011
    Inventors: Ryuichi Ogawa, Takayuki Sasaki
  • Publication number: 20080162837
    Abstract: A technique for preventing erroneous writing or erasing on a nonvolatile memory at a low cost without an external circuit when an arithmetic processing device operates erroneously.
    Type: Application
    Filed: October 27, 2005
    Publication date: July 3, 2008
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Ryuichi Ogawa