Patents by Inventor Morimitsu Sekimoto
Morimitsu Sekimoto 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: 11705843Abstract: A direct power conversion device includes a control unit. tb=1/|fdc?n×fL|. fdc is a frequency twice as high as a frequency of an AC power supply, fL is a frequency of periodic load fluctuations, and n is a positive integer that maximizes tb. In a half period of power supply during a period of tb, the half period including a timing at which peaks of a fundamental wave of load torque and an absolute value of a power supply voltage substantially coincide with each other, the control unit being configured to control the switching elements so that two or more local maximum points appear in the half period of power supply, in a waveform obtained by combining a second harmonic, a fourth harmonic, and a sixth harmonic of a power supply frequency contained in a waveform of an absolute value of a motor current vector.Type: GrantFiled: September 10, 2021Date of Patent: July 18, 2023Assignee: Daikin Industries, Ltd.Inventors: Daisuke Ueki, Nobuo Hayashi, Takurou Ogawa, Morimitsu Sekimoto
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Publication number: 20210408953Abstract: A direct power conversion device includes a control unit. tb=1/|fdc?n×fL|. fdc is a frequency twice as high as a frequency of an AC power supply, fL is a frequency of periodic load fluctuations, and n is a positive integer that maximizes tb. In a half period of power supply during a period of tb, the half period including a timing at which peaks of a fundamental wave of load torque and an absolute value of a power supply voltage substantially coincide with each other, the control unit being configured to control the switching elements so that two or more local maximum points appear in the half period of power supply, in a waveform obtained by combining a second harmonic, a fourth harmonic, and a sixth harmonic of a power supply frequency contained in a waveform of an absolute value of a motor current vector.Type: ApplicationFiled: September 10, 2021Publication date: December 30, 2021Inventors: Daisuke UEKI, Nobuo HAYASHI, Takurou OGAWA, Morimitsu SEKIMOTO
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Patent number: 10951152Abstract: In order to suppress vibration with a motor a load torque of which periodically fluctuates, an output torque of the motor is controlled to be periodically changed. In this case, in order to increase a vibration suppressing component by a direct power conversion apparatus, at least one of first control and second control is performed. In the first control, an output torque having a waveform including a fundamental frequency component of the load torque a fundamental frequency of which is a frequency in accordance with a fluctuation period of the load torque and at least one of a fourth harmonic and a sixth harmonic of a power source frequency of an AC power source is generated. In the second control, the output torque having a waveform including at least one of a second harmonic and a third harmonic of the fundamental frequency of the load torque and a second harmonic of the power source frequency of the AC power source is generated.Type: GrantFiled: September 15, 2020Date of Patent: March 16, 2021Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Nobuo Hayashi, Takurou Ogawa, Daisuke Ueki, Morimitsu Sekimoto
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Patent number: 10931207Abstract: An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.Type: GrantFiled: June 25, 2018Date of Patent: February 23, 2021Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Toshiyuki Maeda, Morimitsu Sekimoto, Hiroshi Hibino
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Publication number: 20200412292Abstract: In order to suppress vibration with a motor a load torque of which periodically fluctuates, an output torque of the motor is controlled to be periodically changed. In this case, in order to increase a vibration suppressing component by a direct power conversion apparatus, at least one of first control and second control is performed. In the first control, an output torque having a waveform including a fundamental frequency component of the load torque a fundamental frequency of which is a frequency in accordance with a fluctuation period of the load torque and at least one of a fourth harmonic and a sixth harmonic of a power source frequency of an AC power source is generated. In the second control, the output torque having a waveform including at least one of a second harmonic and a third harmonic of the fundamental frequency of the load torque and a second harmonic of the power source frequency of the AC power source is generated.Type: ApplicationFiled: September 15, 2020Publication date: December 31, 2020Applicant: DAIKIN INDUSTRIES, LTD.Inventors: Nobuo HAYASHI, Takurou OGAWA, Daisuke UEKI, Morimitsu SEKIMOTO
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Patent number: 10811997Abstract: A power converter includes a plurality of switching elements, a converter circuit that rectifies an AC voltage of an AC power source, a DC link that receives output of the converter circuit and generates a DC voltage, an inverter circuit that converts the DC voltage into an AC voltage of a predetermined frequency through a switching operation, and a control unit that controls the switching operation. A capacitance value of a capacitor is set so that a maximum value of the DC voltage becomes twice or more of a minimum value. The control unit controls the switching elements such that two or more extrema appear in a power source half cycle in a waveform synthesized from second, fourth, and sixth harmonics that have a power source frequency as a fundamental frequency and are extracted from a waveform of an absolute value of a motor current vector.Type: GrantFiled: September 27, 2018Date of Patent: October 20, 2020Assignee: Daikin Industries, Ltd.Inventors: Nobuo Hayashi, Takurou Ogawa, Morimitsu Sekimoto, Tomoisa Taniguchi
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Publication number: 20200220481Abstract: A power converter includes a plurality of switching elements, a converter circuit that rectifies an AC voltage of an AC power source, a DC link that receives output of the converter circuit and generates a DC voltage, an inverter circuit that converts the DC voltage into an AC voltage of a predetermined frequency through a switching operation, and a control unit that controls the switching operation. A capacitance value of a capacitor is set so that a maximum value of the DC voltage becomes twice or more of a minimum value. The control unit controls the switching elements such that two or more extrema appear in a power source half cycle in a waveform synthesized from second, fourth, and sixth harmonics that have a power source frequency as a fundamental frequency and are extracted from a waveform of an absolute value of a motor current vector.Type: ApplicationFiled: September 27, 2018Publication date: July 9, 2020Inventors: Nobuo HAYASHI, Takurou OGAWA, Morimitsu SEKIMOTO, Tomoisa TANIGUCHI
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Patent number: 10511233Abstract: The voltage detection circuit (33) is a voltage divider circuit including a plurality of resistances (34a to 34c and 35a to 35c) and detects voltages (Vac1, Vac2) correlating with a power source voltage (Vin) of the AC power source (91). The calculation unit (40) obtains the across voltage (VL) of the reactor (29) using detection results (Vac1, Vac2) of the voltage detection circuit (33), and estimates a power source current (Iin) based on the across voltage (VL). The calculation unit (40) corrects gains of the detection results (Vac1, Vac2) so that a value correlating with an average value per predetermined time period of the estimated power source current (Iin) matches a value correlating with an average value per the predetermined time period of a current (Iinv) downstream of the capacitor (26), and obtains the across voltage (VL) using the detection results (Vac1, Vac2).Type: GrantFiled: September 28, 2017Date of Patent: December 17, 2019Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Takurou Ogawa, Eiji Tooyama, Akiko Sera, Morimitsu Sekimoto
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Patent number: 10439542Abstract: An electric power conversion device includes: a converter circuit which includes a boost chopper; a capacitor which is connected between output terminals of the converter circuit; a boost chopper which boosts a terminal voltage of the capacitor; a multiphase inverter circuit; and a boost chopper controller. In a case where the operation of the boost chopper is continuously stopped, the capacitor has a capacitance allowing the terminal voltage of the capacitor to have a pulse frequency twice as high as that of the AC power source. The multiphase inverter circuit has an output power which is allowed to fluctuate in synchronization with a power source.Type: GrantFiled: September 30, 2015Date of Patent: October 8, 2019Assignee: Daikin Industries, Ltd.Inventors: Tomoisa Taniguchi, Morimitsu Sekimoto, Yasutaka Taguchi
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Publication number: 20190260304Abstract: The voltage detection circuit (33) is a voltage divider circuit including a plurality of resistances (34a to 34c and 35a to 35c) and detects voltages (Vac1, Vac2) correlating with a power source voltage (Vin) of the AC power source (91). The calculation unit (40) obtains the across voltage (VL) of the reactor (29) using detection results (Vac1, Vac2) of the voltage detection circuit (33), and estimates a power source current (Iin) based on the across voltage (VL). The calculation unit (40) corrects gains of the detection results (Vac1, Vac2) so that a value correlating with an average value per predetermined time period of the estimated power source current (Iin) matches a value correlating with an average value per the predetermined time period of a current (Iinv) downstream of the capacitor (26), and obtains the across voltage (VL) using the detection results (Vac1, Vac2).Type: ApplicationFiled: September 28, 2017Publication date: August 22, 2019Applicant: DAIKIN INDUSTRIES, LTD.Inventors: Takurou OGAWA, Eiji TOOYAMA, Akiko SERA, Morimitsu SEKIMOTO
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Patent number: 10148197Abstract: An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.Type: GrantFiled: January 21, 2009Date of Patent: December 4, 2018Assignee: Daikin Industries, Ltd.Inventors: Toshiyuki Maeda, Morimitsu Sekimoto, Hiroshi Hibino
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Publication number: 20180309390Abstract: An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.Type: ApplicationFiled: June 25, 2018Publication date: October 25, 2018Applicant: DAIKIN INDUSTRIES, LTD.Inventors: Toshiyuki MAEDA, Morimitsu SEKIMOTO, Hiroshi HIBINO
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Patent number: 9853559Abstract: Disclosed herein is a power conversion device including a storage and a power conversion controller. The storage stores multiple values, each correlated to a disturbance that causes distortion in a current to a power converter, in association with a phase angle of a voltage of an AC power supply. The power conversion controller controls ON/OFF operations by using the values stored in the storage to compensate for a manipulated variable of control performed by the power converter in association with the phase angle of the voltage of the AC power supply.Type: GrantFiled: March 27, 2015Date of Patent: December 26, 2017Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Tomoisa Taniguchi, Morimitsu Sekimoto, Takurou Ogawa, Eiji Tooyama, Nobuo Hayashi
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Publication number: 20170279398Abstract: An electric power conversion device includes: a converter circuit which includes a boost chopper; a capacitor which is connected between output terminals of the converter circuit; a boost chopper which boosts a terminal voltage of the capacitor; a multiphase inverter circuit; and a boost chopper controller. In a case where the operation of the boost chopper is continuously stopped, the capacitor has a capacitance allowing the terminal voltage of the capacitor to have a pulse frequency twice as high as that of the AC power source. The multiphase inverter circuit has an output power which is allowed to fluctuate in synchronization with a power source.Type: ApplicationFiled: September 30, 2015Publication date: September 28, 2017Applicant: DAIKIN INDUSTRIES, LTD.Inventors: Tomoisa TANIGUCHI, Morimitsu SEKIMOTO, Yasutaka TAGUCHI
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Publication number: 20170077829Abstract: Disclosed herein is a power conversion device including a storage and a power conversion controller. The storage stores multiple values, each correlated to a disturbance that causes distortion in a current to a power converter, in association with a phase angle of a voltage of an AC power supply. The power conversion controller controls ON/OFF operations by using the values stored in the storage to compensate for a manipulated variable of control performed by the power converter in association with the phase angle of the voltage of the AC power supply.Type: ApplicationFiled: March 27, 2015Publication date: March 16, 2017Applicant: DAIKIN INDUSTRIES, LTD.Inventors: Tomoisa TANIGUCHI, Morimitsu SEKIMOTO, Takurou OGAWA, Eiji TOOYAMA, Nobuo HAYASHI
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Patent number: 9257931Abstract: A power conversion apparatus is equipped with switching devices to perform power conversion of input AC power supplied from an AC power supply to output AC power having a predetermined voltage and a predetermined frequency, and to supply the power to a motor connected thereto. The apparatus includes a controller controlling switching of the switching devices, a capacitor smoothing a ripple generated by the switching of the switching devices, a current controller controlling a current flowing to the motor, and a voltage distortion corrector detecting a harmonic component caused by distortion in motor input power, and superimposing compensation values on an output of the current controller in accordance with a value of the harmonic component.Type: GrantFiled: January 18, 2012Date of Patent: February 9, 2016Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Eiji Tooyama, Morimitsu Sekimoto, Toshiyuki Maeda
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Patent number: 9214881Abstract: A DC link is provided, which includes a capacitor connected in parallel to an output of a converter circuit, and outputs a pulsating DC link voltage. An inverter circuit is provided, which converts an output of the DC link to AC by switching, and supplies the AC to a motor connected thereto. A controller is provided, which controls switching of the inverter circuit so that motor currents pulsate in synchronization with pulsation of a power-supply voltage. The controller controls the switching of the inverter circuit in accordance with a load of the motor or an operational state of the motor, and reduces pulsation amplitude of the motor currents.Type: GrantFiled: January 18, 2012Date of Patent: December 15, 2015Assignee: DAIKIN INDUSTRIES, LTD.Inventors: Morimitsu Sekimoto, Tomoisa Taniguchi, Hiroshi Hibino, Toshiyuki Maeda
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Patent number: 9178412Abstract: A bidirectional switch circuit includes two switching elements connected to conduct a current in both directions. The two switching elements are connected in series to each other. Of the two switching elements, the switching element to which a reverse voltage is applied, a voltage of a source of one of the switching elements being higher than a voltage of a drain of the one, is configured to conduct a current from the source to the drain even when an on-drive signal is not being input to a gate terminal of the one.Type: GrantFiled: January 18, 2010Date of Patent: November 3, 2015Assignee: Daikin Industries, Ltd.Inventors: Reiji Kawashima, Kazushi Hisayama, Hiroshi Hibino, Morimitsu Sekimoto, Toshiyuki Maeda, Sumikazu Matsuno
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Patent number: 9166493Abstract: A power converter circuit includes a diode group, a relay, a DC section and an inverter. The diode group includes a plurality of diodes arranged to rectify an output voltage of an alternating-current power supply. The relay is provided at a point located closer to the alternating-current power supply than the diode group. The DC section is where an output voltage of the diode group is applied. The inverter is arranged to output a three-phase alternating-electric current to a three-phase load. The DC section has a maximum pulse voltage twice as great as a minimum pulse voltage of the DC section. The DC section includes an energy-absorbing circuit having an electrolytic capacitor. The DC section further has a pathway arranged to apply the output voltage of the alternating-current power supply from the alternating-current power supply to the electrolytic capacitor via a rectifying circuit, not via the relay.Type: GrantFiled: May 27, 2010Date of Patent: October 20, 2015Assignee: Daikin Industries, Ltd.Inventors: Morimitsu Sekimoto, Toshiyuki Maeda
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Patent number: 9071159Abstract: A power converter includes a power converter section (4) (e.g., an inverter circuit) having a plurality of switching elements (Sp, Sn) in which a current can flow in a reverse direction, and a control section (10) which determines on-state time of each of the switching elements (Sp, Sn) according to an output voltage of the power converter section (4), thereby switching on/off states of the switching elements (Sp, Sn). The control section (10) instructs the power converter section (4) to perform synchronous rectification, and corrects the on-state time according to a drop of an on-state voltage of each of the switching elements (Sp, Sn).Type: GrantFiled: July 28, 2010Date of Patent: June 30, 2015Assignee: DAIKIN INDUSTRIES, LTD.Inventor: Morimitsu Sekimoto