Patents by Inventor Takayuki Nagakura
Takayuki Nagakura 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).
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Patent number: 11728676Abstract: A power conversion device which converts electrical power generated by a distributed energy resource into electrical power corresponding to a power system is provided, comprising a communication unit which periodically receives, via communication, reception information indicating whether an accident has occurred in the power system, a disconnection unit which disconnects the distributed energy resource from the power system when the communication unit receives the reception information indicating accident occurrence, and a control unit which starts an islanding determination process for determining whether the distributed energy resource is in an islanding state by detecting a change in AC characteristics in the power system, when the communication unit does not receive the reception information for a predetermined first period.Type: GrantFiled: June 24, 2020Date of Patent: August 15, 2023Assignee: FUJI ELECTRIC CO., LTD.Inventors: Takayuki Nagakura, Songhao Yin
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Patent number: 11705731Abstract: In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.Type: GrantFiled: October 30, 2020Date of Patent: July 18, 2023Assignee: FUJI ELECTRIC CO., LTD.Inventors: Takayuki Nagakura, Songhao Yin
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Patent number: 11515711Abstract: It is desirable to improve the accuracy of voltage control in the grid interconnection device for supplying the power generated by the distributed power source to the interconnection point. Provided is a grid interconnection device for supplying power generated by a distributed power source to an interconnection point, comprising: a calculation unit for calculating voltage at the interconnection point based on output voltage of the grid interconnection device, output current of the grid interconnection device, and an impedance component between the grid interconnection device and the interconnection point; and a control unit for controlling output power from the grid interconnection device, based on voltage at the interconnection point calculated by the calculation unit.Type: GrantFiled: June 24, 2021Date of Patent: November 29, 2022Assignee: FUJI ELECTRIC CO., LTD.Inventors: Songhao Yin, Takayuki Nagakura
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Publication number: 20210320502Abstract: It is desirable to improve the accuracy of voltage control in the grid interconnection device for supplying the power generated by the distributed power source to the interconnection point. Provided is a grid interconnection device for supplying power generated by a distributed power source to an interconnection point, comprising: a calculation unit for calculating voltage at the interconnection point based on output voltage of the grid interconnection device, output current of the grid interconnection device, and an impedance component between the grid interconnection device and the interconnection point; and a control unit for controlling output power from the grid interconnection device, based on voltage at the interconnection point calculated by the calculation unit.Type: ApplicationFiled: June 24, 2021Publication date: October 14, 2021Inventors: Songhao YIN, Takayuki NAGAKURA
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Patent number: 11101659Abstract: A detection device includes a first detection unit that detects whether a power source may be in an islanding operation based on a frequency of an power supplied from a power source connected to a system, a power processing unit that changes the amount of power supplied from the power supply to the system in response to that the first detection unit detects that the power source may be in the islanding operation, a second detection unit that detects a voltage of a system with the power supply amount having been changed, and a disconnection processing unit that determines whether to disconnect a power source from a system in response to a change in a voltage of a system with the power supply amount having been changed.Type: GrantFiled: July 29, 2019Date of Patent: August 24, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventor: Takayuki Nagakura
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Publication number: 20210159702Abstract: In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.Type: ApplicationFiled: October 30, 2020Publication date: May 27, 2021Inventors: Takayuki NAGAKURA, Songhao YIN
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Patent number: 11018507Abstract: An islanding operation is detected appropriately through interconnection to the power grid which may have various characteristics. A detection apparatus is provided, which includes a frequency parameter calculation unit configured to calculate frequency parameters according to frequencies of power supplied by a power supply, a deviation parameter calculation unit configured to calculate a deviation parameter according to a frequency deviation based on the frequency parameters in a first term and the frequency parameters in a second term earlier than the first term, an islanding operation detection unit configured to detect whether the power supply is in an islanding operation based on the deviation parameter, and a time gap change unit configured to change a time gap between the first term and the second term.Type: GrantFiled: February 27, 2019Date of Patent: May 25, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventors: Takayuki Nagakura, Hideyuki Ito
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Publication number: 20210006091Abstract: A power conversion device which converts electrical power generated by a distributed energy resource into electrical power corresponding to a power system is provided, comprising a communication unit which periodically receives, via communication, reception information indicating whether an accident has occurred in the power system, a disconnection unit which disconnects the distributed energy resource from the power system when the communication unit receives the reception information indicating accident occurrence, and a control unit which starts an islanding determination process for determining whether the distributed energy resource is in an islanding state by detecting a change in AC characteristics in the power system, when the communication unit does not receive the reception information for a predetermined first period.Type: ApplicationFiled: June 24, 2020Publication date: January 7, 2021Inventors: Takayuki NAGAKURA, Songhao YIN
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Publication number: 20200091723Abstract: A detection device includes a first detection unit that detects whether a power source may be in an islanding operation based on a frequency of an power supplied from a power source connected to a system, a power processing unit that changes the amount of power supplied from the power supply to the system in response to that the first detection unit detects that the power source may be in the islanding operation, a second detection unit that detects a voltage of a system with the power supply amount having been changed, and a disconnection processing unit that determines whether to disconnect a power source from a system in response to a change in a voltage of a system with the power supply amount having been changed.Type: ApplicationFiled: July 29, 2019Publication date: March 19, 2020Inventor: Takayuki NAGAKURA
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Publication number: 20190199099Abstract: An islanding operation is detected appropriately through interconnection to the power grid which may have various characteristics. A detection apparatus is provided, which includes a frequency parameter calculation unit configured to calculate frequency parameters according to frequencies of power supplied by a power supply, a deviation parameter calculation unit configured to calculate a deviation parameter according to a frequency deviation based on the frequency parameters in a first term and the frequency parameters in a second term earlier than the first term, an islanding operation detection unit configured to detect whether the power supply is in an islanding operation based on the deviation parameter, and a time gap change unit configured to change a time gap between the first term and the second term.Type: ApplicationFiled: February 27, 2019Publication date: June 27, 2019Inventors: Takayuki NAGAKURA, Hideyuki ITO
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Patent number: 7906926Abstract: A door drive control apparatus capable of an accurate detection, without misidentifying an inverse overrun condition, and a door drive control method that improves safety. The door drive control apparatus includes a power converter that supplies power to a door drive linear motor, and operates the power converter by feedback control using a speed detection value and a speed command value of the door, and controls a speed of the door. The door drive control apparatus includes a speed trouble determiner, which outputs a door inverse direction speed trouble signal in the event that the speed command value of the door exceeds either a positive or negative first setting speed, and the speed detection value exceeds a second setting speed of a polarity opposite to that of the speed command value.Type: GrantFiled: April 2, 2008Date of Patent: March 15, 2011Assignee: Fuji Electric Systems Co., Ltd.Inventors: Takayuki Nagakura, Yoshinobu Sato, Akira Fujimori, Naoki Takeda
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Patent number: 7891139Abstract: In controlling, with recognition of their installation positions, the opening/closing driving of plural doors that are driven by respective linear motors, each door is driven closed by switching the door opening/closing drive torque to high torque if the drive speed of the door has become less than or equal to a prescribed speed. In doing so, operation instruction computing sections set high torque application periods for respective doors so that the periods of high-torque closure driving of respective doors or predetermined door groups do not overlap with each other, and issue instructions to drive the doors closed with high torque only during the high torque application periods.Type: GrantFiled: March 6, 2007Date of Patent: February 22, 2011Assignee: Fuji Electric Systems Co., Ltd.Inventor: Takayuki Nagakura
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Publication number: 20090100758Abstract: In controlling, with recognition of their installation positions, the opening/closing driving of plural doors that are driven by respective linear motors, each door is driven closed by switching the door opening/closing drive torque to high torque if the drive speed of the door has become less than or equal to a prescribed speed. In doing so, operation instruction computing sections set high torque application periods for respective doors so that the periods of high-torque closure driving of respective doors or predetermined door groups do not overlap with each other, and issue instructions to drive the doors closed with high torque only during the high torque application periods.Type: ApplicationFiled: March 6, 2007Publication date: April 23, 2009Inventor: Takayuki Nagakura
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Publication number: 20080258665Abstract: A door drive control apparatus capable of an accurate detection, without misidentifying an inverse overrun condition, and a door drive control method that improves safety. The door drive control apparatus includes a power converter that supplies power to a door drive linear motor, and operates the power converter by feedback control using a speed detection value and a speed command value of the door, and controls a speed of the door. The door drive control apparatus includes a speed trouble determiner, which outputs a door inverse direction speed trouble signal in the event that the speed command value of the door exceeds either a positive or negative first setting speed, and the speed detection value exceeds a second setting speed of a polarity opposite to that of the speed command value.Type: ApplicationFiled: April 2, 2008Publication date: October 23, 2008Applicant: FUJI ELECTRIC SYSTEMS CO., LTD.Inventors: Takayuki Nagakura, Yoshinobu Sato, Akira Fujimori, Naoki Takeda
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Patent number: 7042181Abstract: A method and system for controlling motor torque provides improved responsiveness and reliability in motor control applications. The motor control system includes a power converter, a voltage detector for detecting the converter input voltage and a control circuit for controlling the converter. The control circuit includes a torque command limit value generator and a torque command limiter for limiting a torque command value. The system may also include a torque command coefficient generator for generating a coefficient corresponding to an input current of the power converter, and a multiplier for calculating a final torque command value for the motor by multiplying together the torque command value and the torque command coefficient. The torque command limit and coefficient values may be determined from the converter input voltage, calculated or detected converter input current and calculated input impedance between a power supply and the converter.Type: GrantFiled: August 23, 2004Date of Patent: May 9, 2006Assignee: Fuji Electric Systems Co., Ltd.Inventor: Takayuki Nagakura
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Publication number: 20050077853Abstract: A method and system for controlling motor torque provides improved responsiveness and reliability in motor control applications. The motor control system includes a power converter, a voltage detector for detecting the converter input voltage and a control circuit for controlling the converter. The control circuit includes a torque command limit value generator and a torque command limiter for limiting a torque command value. The system may also include a torque command coefficient generator for generating a coefficient corresponding to an input current of the power converter, and a multiplier for calculating a final torque command value for the motor by multiplying together the torque command value and the torque command coefficient. The torque command limit and coefficient values may be determined from the converter input voltage, calculated or detected converter input current and calculated input impedance between a power supply and the converter.Type: ApplicationFiled: August 23, 2004Publication date: April 14, 2005Inventor: Takayuki Nagakura