Patents by Inventor Seiji Iyasu
Seiji Iyasu 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: 10461650Abstract: In a control device applied to an insulated DC-DC converter including a transformer and drive switches connected to a input winding of the transformer, the control device operates the drive switches to control an output voltage output via the output winding to a target voltage. Furthermore, the control device includes a voltage acquiring unit acquiring the output voltage and a frequency setting unit setting a switching frequency for the drive switches based on the output voltage acquired by the voltage acquiring unit. The frequency setting unit sets, for the switching frequency, a value increasing with a value of the acquired output voltage, and sets the switching frequency such that an increase in the value of the output voltage increases a frequency increase rate corresponding to an amount of increase in the switching frequency per unit amount of increase in the output voltage.Type: GrantFiled: March 5, 2019Date of Patent: October 29, 2019Assignee: DENSO CORPORATIONInventors: Kenji Tomita, Seiji Iyasu, Yuichi Handa
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Publication number: 20190305664Abstract: In a control apparatus for a power converter, a current obtainer obtains a current flowing through an inductor as an inductor current, and a voltage obtainer obtains an alternating-current voltage. A slope compensation unit generates, based on the alternating-current voltage obtained by the voltage obtainer, a slope compensation signal having a slope that depends on the alternating-current voltage, and adds the slope compensation signal to the inductor current obtained by the current obtainer. A current controller controls on-off switching operations of a switch in a peak current mode to thereby cause the inductor current, to which the slope compensation signal has been added, to follow a sinusoidal command current that depends on the alternating-current voltage.Type: ApplicationFiled: March 29, 2019Publication date: October 3, 2019Applicant: DENSO CORPORATIONInventors: Seiji IYASU, Yuji HAYASHI, Yuichi HANDA
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Patent number: 10432100Abstract: An electric power conversion device supplies electric power of a DC power source from an input part to an output part through a power conversion circuit having a transformer and switches. The transformer has primary and secondary coils magnetically connected. The device has a choke coil, an auxiliary coil and a control part. The auxiliary coil is connected to the output part and magnetically connected to the choke coil. The auxiliary coil is wound to allow a current to flow from a negative-electrode side to a positive-electrode side of the output part when a current flows from the power source to the choke coil. The control part performs a switching control of the switches to supply electric power of the source to the output part through the auxiliary coil to prevent generation of magnetic flux in the primary coil and the current from flowing in the secondary coil.Type: GrantFiled: August 2, 2018Date of Patent: October 1, 2019Assignee: DENSO CORPORATIONInventors: Seiji Iyasu, Yuji Hayashi, Yuichi Handa
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Publication number: 20190280603Abstract: In a control device applied to an insulated DC-DC converter including a transformer and drive switches connected to a input winding of the transformer, the control device operates the drive switches to control an output voltage output via the output winding to a target voltage. Furthermore, the control device includes a voltage acquiring unit acquiring the output voltage and a frequency setting unit setting a switching frequency for the drive switches based on the output voltage acquired by the voltage acquiring unit. The frequency setting unit sets, for the switching frequency, a value increasing with a value of the acquired output voltage, and sets the switching frequency such that an increase in the value of the output voltage increases a frequency increase rate corresponding to an amount of increase in the switching frequency per unit amount of increase in the output voltage.Type: ApplicationFiled: March 5, 2019Publication date: September 12, 2019Applicant: DENSO CORPORATIONInventors: Kenji TOMITA, Seiji IYASU, Yuichi HANDA
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Patent number: 10374517Abstract: An apparatus for controlling a power converter includes a first converter configured to convert an AC voltage into a DC voltage by operations of an input side switch, a DC link capacitor charged with the DC voltage from the first converter, and a second converter configured to step down the DC voltage across the DC link capacitor by operations of one or more output side switches. In the apparatus, a lower limit calculator calculates a lower limit of the DC voltage across the DC link capacitor based on an output voltage of the second converter, a turns ratio of a transformer of the second converter, and a ratio of a turn-on period to one switching period for the one or more output side switches. A switch controller operates the input side switch to control the voltage across the DC link capacitor to a command voltage higher than the lower limit.Type: GrantFiled: November 9, 2018Date of Patent: August 6, 2019Assignees: SOKEN, INC., DENSO CORPORATIONInventors: Kenji Tomita, Seiji Iyasu, Yuichi Handa
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Publication number: 20190229645Abstract: In an apparatus for controlling a DC-AC converter including a reactor and a plurality of drive switches and configured to convert DC power supplied via input terminals into AC power and supply the AC power to an AC power source connected to output terminals. In the apparatus, a current corrector is configured to set a current correction value including a harmonic component for a frequency component of a supply voltage of the AC power source that has minima at zero crossings where the supply voltage is zero and superimpose the current correction value on a sinusoidal commanded current generated based on the supply voltage of the AC power source, thereby generating a commanded current after correction. A current controller is configured to operate the drive switches using peak current mode control to control the reactor current to the commanded current after correction.Type: ApplicationFiled: January 22, 2019Publication date: July 25, 2019Applicant: DENSO CORPORATIONInventors: Seiji IYASU, Yuji HAYASHI, Yuichi HANDA
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Publication number: 20190157974Abstract: A control apparatus performs peak current mode control in which a drive switch is turned off when output of a comparator is inverted during an on-operation period determined by a basic signal. The comparator inverts the output when a reactor current increases to a command current. The control apparatus determines that a switching frequency of the drive switch is required to be switched when the output of the comparator is detected to have not become inverted during the single switching period while the peak current mode control is being performed. The control apparatus sets the switching frequency to a first frequency when the switching determining unit determines that the switching frequency is not required to be switched, and switches the switching frequency from the first frequency to a second frequency lower than the first frequency when the switching determining unit determines that the switching frequency is required to be switched.Type: ApplicationFiled: November 15, 2018Publication date: May 23, 2019Applicants: SOKEN, INC., DENSO CORPORATIONInventors: Kenji TOMITA, Seiji IYASU, Yuichi HANDA
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Publication number: 20190149055Abstract: An apparatus for controlling a power converter includes a first converter configured to convert an AC voltage into a DC voltage by operations of an input side switch, a DC link capacitor charged with the DC voltage from the first converter, and a second converter configured to step down the DC voltage across the DC link capacitor by operations of one or more output side switches. In the apparatus, a lower limit calculator calculates a lower limit of the DC voltage across the DC link capacitor based on an output voltage of the second converter, a turns ratio of a transformer of the second converter, and a ratio of a turn-on period to one switching period for the one or more output side switches. A switch controller operates the input side switch to control the voltage across the DC link capacitor to a command voltage higher than the lower limit.Type: ApplicationFiled: November 9, 2018Publication date: May 16, 2019Applicants: SOKEN, INC., DENSO CORPORATIONInventors: Kenji TOMITA, Seiji IYASU, Yuichi HANDA
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Publication number: 20190123661Abstract: An electric power conversion device has an electric power converter and a control device. The control device adjusts an output voltage of the electric power converter to approach a first current flowing a first drive switch to an instruction current during a first period in which an input voltage supplied from an AC power source has a positive polarity, and adjusts the output voltage of the electric power converter to approach a second current flowing a second drive switch to the instruction current during a second period in which the input voltage supplied from the AC power source has a negative polarity. The control device operates a switch arranged in a second current sensor during the first period, and operates a switch arranged in a first current sensor during the second period.Type: ApplicationFiled: September 26, 2018Publication date: April 25, 2019Applicant: Denso CorporationInventors: Seiji Iyasu, Yuji Hayashi, Yuichi Handa
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Patent number: 10256719Abstract: A power supply device includes a transformer, a primary semiconductor component, a secondary semiconductor component, a choke coil and a circuit board. Electronic components which include the transformer, the primary semiconductor component, the secondary semiconductor component, and the choke coil, are stacked in pairs, in a normal direction of a board. One pair forms a first stacked body and another pair to forms a second stacked body. A circuit board is interposed between the one pair of electronic components which forms the first stacked body, and also between the other pair of electronic components which forms the second stacked body.Type: GrantFiled: November 16, 2016Date of Patent: April 9, 2019Assignee: DENSO CORPORATIONInventors: Keiichi Ando, Yuichi Handa, Kimikazu Nakamura, Kaoru Koketsu, Yuki Yamada, Seiji Iyasu, Shuji Kurauchi
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Patent number: 10232735Abstract: A control device for a power supply system includes a pre-charge unit, the power supply system having a main electric storage device, a smooth capacitor, a step-up circuit, an open-close switch, a voltage source and a regulation element. The regulation element regulates a current flowing from the smooth capacitor toward the open-close switch. The voltage source is connected to a connection portion between the open-close switch and the step-up circuit, and outputs an output voltage higher than a voltage of the main electric storage device before the open-close switch is shifted from a disconnection state to a connection state. The pre-charge unit executes a pre-charge of the smooth capacitor by supplying electric power from the voltage source to the smooth capacitor before the open-close switch is shifted from the disconnection state to the connection state.Type: GrantFiled: October 13, 2016Date of Patent: March 19, 2019Assignees: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kaoru Koketsu, Yuichi Handa, Seiji Iyasu, Takashi Nozawa
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Patent number: 10224826Abstract: A control unit capable of accurately calculating a magnetization bias of a transformer is provided, thereby appropriately reducing the magnetization bias. The control unit acquires first and second currents that flow through a transformer during a period where either first or second switches individually turn ON. The control unit predicts an amount of magnetization bias in either positive side or negative side of the excitation current that flows through the transformer. The control unit reduces the magnetization bias of the transformer based on the predicted amount of magnetization bias.Type: GrantFiled: May 23, 2018Date of Patent: March 5, 2019Assignees: SOKEN, INC., DENSO CORPORATIONInventors: Seiji Iyasu, Yuji Hayashi, Yuichi Handa
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Publication number: 20190068070Abstract: An electric power conversion device supplies electric power of a DC power source from an input part to an output part through a power conversion circuit having a transformer and switches. The transformer has primary and secondary coils magnetically connected. The device has a choke coil, an auxiliary coil and a control part. The auxiliary coil is connected to the output part and magnetically connected to the choke coil. The auxiliary coil is wound to allow a current to flow from a negative-electrode side to a positive-electrode side of the output part when a current flows from the power source to the choke coil. The control part performs a switching control of the switches to supply electric power of the source to the output part through the auxiliary coil to prevent generation of magnetic flux in the primary coil and the current from flowing in the secondary coil.Type: ApplicationFiled: August 2, 2018Publication date: February 28, 2019Applicant: DENSO CORPORATIONInventors: Seiji IYASU, Yuji HAYASHI, Yuichi HANDA
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Publication number: 20180367031Abstract: A power supply device includes a transformer, a primary semiconductor component, a secondary semiconductor component, a choke coil and a circuit board. Electronic components which include the transformer, the primary semiconductor component, the secondary semiconductor component, and the choke coil, are stacked in pairs, in a normal direction of a board. One pair forms a first stacked body and another pair to forms a second stacked body. A circuit board is interposed between the one pair of electronic components which forms the first stacked body, and also between the other pair of electronic components which forms the second stacked body.Type: ApplicationFiled: November 16, 2016Publication date: December 20, 2018Applicant: DENSO CORPORATIONInventors: Keiichi ANDO, Yuichi HANDA, Kimikazu NAKAMURA, Kaoru KOKETSU, Yuki YAMADA, Seiji IYASU, Shuji KURAUCHI
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Publication number: 20180342942Abstract: A control unit capable of accurately calculating a magnetization bias of a transformer is provided, thereby appropriately reducing the magnetization bias. The control unit acquires first and second currents that flow through a transformer during a period where either first or second switches individually turn ON. The control unit predicts an amount of magnetization bias in either positive side or negative side of the excitation current that flows through the transformer. The control unit reduces the magnetization bias of the transformer based on the predicted amount of magnetization bias.Type: ApplicationFiled: May 23, 2018Publication date: November 29, 2018Applicants: SOKEN, INC., DENSO CORPORATIONInventors: Seiji IYASU, Yuji HAYASHI, Yuichi HANDA
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Patent number: 10075059Abstract: A current detection apparatus is provided which detects a current flowing through a detection part in an electrical circuit. The current detection apparatus includes a first coil connected in series with the detection part, a second coil magnetically coupled with the first coil, a full-wave rectifier circuit connected to both ends of the second coil, a switching element having a first end connected to a positive electrode side output part of the full-wave rectifier circuit and a second end connected to a first resistor, and a second resistor that forms a closed circuit with the second coil regardless of an open or closed state of the switching element.Type: GrantFiled: November 17, 2017Date of Patent: September 11, 2018Assignee: DENSO CORPORATIONInventors: Seiji Iyasu, Yuji Hayashi, Kimikazu Nakamura, Yuichi Handa
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Patent number: 10050513Abstract: A control apparatus is provided which controls a power converter including a first circuit including first-side switching elements, and a second circuit including second-side switching elements and a choke coil. The control apparatus includes a current obtainment unit which obtains a value of current flowing through the choke coil, and a control unit which, when power is supplied from the second circuit to the first circuit, keeps a first-side switching element ON during a predetermined time period, before turning off at least one second-side switching element in an on state, the first-side switching element generating a reverse current in the second-side switching element to be turned off. The control unit performs control of keeping the first-side switching element ON during the predetermined time period and control of turning off the second-side switching element, on condition that the obtained value of the current is more than a predetermined command value.Type: GrantFiled: November 17, 2017Date of Patent: August 14, 2018Assignee: DENSO CORPORATIONInventors: Seiji Iyasu, Yuji Hayashi, Kimikazu Nakamura, Yuichi Handa
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Publication number: 20180138803Abstract: A current detection apparatus is provided which detects a current flowing through a detection part in an electrical circuit. The current detection apparatus includes a first coil connected in series with the detection part, a second coil magnetically coupled with the first coil, a full-wave rectifier circuit connected to both ends of the second coil, a switching element having a first end connected to a positive electrode side output part of the full-wave rectifier circuit and a second end connected to a first resistor, and a second resistor that forms a closed circuit with the second coil regardless of an open or closed state of the switching element.Type: ApplicationFiled: November 17, 2017Publication date: May 17, 2018Applicant: DENSO CORPORATIONInventors: Seiji IYASU, Yuji HAYASHI, Kimikazu NAKAMURA, Yuichi HANDA
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Publication number: 20180138802Abstract: A control apparatus is provided which controls a power converter including a first circuit including first-side switching elements, and a second circuit including second-side switching elements and a choke coil. The control apparatus includes a current obtainment unit which obtains a value of current flowing through the choke coil, and a control unit which, when power is supplied from the second circuit to the first circuit, keeps a first-side switching element ON during a predetermined time period, before turning off at least one second-side switching element in an on state, the first-side switching element generating a reverse current in the second-side switching element to be turned off. The control unit performs control of keeping the first-side switching element ON during the predetermined time period and control of turning off the second-side switching element, on condition that the obtained value of the current is more than a predetermined command value.Type: ApplicationFiled: November 17, 2017Publication date: May 17, 2018Applicant: DENSO CORPORATIONInventors: Seiji Iyasu, Yuji Hayashi, Kimikazu Nakamura, Yuichi Handa
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Patent number: 9899928Abstract: A power conversion apparatus includes a power conversion circuit, a choke coil, an auxiliary coil, and a rectifier element. The choke coil is disposed between the power conversion circuit and an input side direct current power source. The auxiliary coil is magnetically coupled to the choke coil and is connected in parallel with an output side circuit. The auxiliary coil is wound in a direction so that an excitation current flows from a negative electrode to a positive electrode of the output side circuit when an excitation current flows from a positive electrode to a negative electrode of the direct current power source through the choke coil. The rectifier element is series connection with the auxiliary coil, and cuts off power supply from the direct current power source to the output side circuit through the auxiliary coil and power supply from the output side circuit to the input side.Type: GrantFiled: July 28, 2016Date of Patent: February 20, 2018Assignee: DENSO CORPORATIONInventors: Yuuichi Handa, Seiji Iyasu, Kimikazu Nakamura