Patents by Inventor Hajime TOYODA
Hajime TOYODA 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: 11817768Abstract: Provided is a power conversion device that can suppress interference between control of input current from an AC power supply and voltage control for a DC capacitor to perform both the controls with high accuracy, and can reduce the capacitance and size of the DC capacitor. A power conversion circuit includes a rectification bridge circuit, a leg circuit having upper and lower legs connected in series, a DC capacitor, a smoothing capacitor, and a reactor. A control circuit performs PWM control of the leg circuit by generating a duty cycle so as to control a voltage of the DC capacitor while controlling an input current from an AC power supply, in a control cycle. When the duty cycle is generated, a sum of duty cycles is made constant in one cycle for each leg.Type: GrantFiled: December 13, 2018Date of Patent: November 14, 2023Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Hajime Toyoda, Takaaki Takahara
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Publication number: 20230336092Abstract: This power conversion device includes: a reactor, switching elements, a first capacitor, and a second capacitor provided between an AC power supply and a DC load; and a controller for controlling operations of the switching elements. The controller controls voltage of the first capacitor and voltage of the second capacitor to predetermined command values, while, in accordance with load information regarding the DC load, performing changeover between a first control method of controlling the switching elements at a constant switching frequency over an AC cycle of the AC power supply, and a second control method of controlling them at a frequency lower than the switching frequency in the first control method.Type: ApplicationFiled: December 23, 2020Publication date: October 19, 2023Applicant: Mitsubishi Electric CorporationInventor: Hajime TOYODA
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Publication number: 20230336090Abstract: A power conversion apparatus includes a rectification unit that rectifies a first alternating-current power supplied from a commercial power supply; a capacitor connected to output terminals of the rectification unit; an inverter that is connected across the capacitor, converts power output from the rectification unit and the capacitor into a second alternating-current power and, outputs the second alternating-current power to a load including a motor; and a control unit that performs operation control on the inverter to cause the second alternating-current power that includes a pulsation based on a pulsation of power that flows into the capacitor from the rectification unit to be output from the inverter to the load, to restrain a current that flows into the capacitor.Type: ApplicationFiled: October 26, 2020Publication date: October 19, 2023Inventors: Takaaki TAKAHARA, Koichi ARISAWA, Keisuke UEMURA, Haruka MATSUO, Koyo MATSUZAKI, Kenji TAKAHASHI, Akira SATAKE, Hajime TOYODA
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Publication number: 20230038757Abstract: A power converting apparatus that converts alternating-current power from an alternating-current power supply into direct-current power and outputs the direct-current power to a direct-current load includes at least two switching circuits connected in parallel with the direct-current load; a coupling reactor that includes at least three connection terminals with two of the at least three connection terminals connected to an alternating-current terminal of one switching circuit different from two switching circuits among the at least two switching circuits; and a control unit that performs, at least once in a half period of the alternating-current power supply, a simple switching control that short-circuits the coupling reactor to the alternating-current power supply through the two switching circuits.Type: ApplicationFiled: January 21, 2020Publication date: February 9, 2023Inventors: Koichi ARISAWA, Takaaki TAKAHARA, Hajime TOYODA, Satoshi MURAKAMI, Keisuke UEMURA, Takahiko KOBAYASHI
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Patent number: 11323025Abstract: A DC capacitor and a leg are connected in parallel to a high-voltage-side power line and a low-voltage-side power line. The leg includes a plurality of semiconductor switching elements connected in series between the power lines with an output end, connected to a load, between the plurality of semiconductor switching elements. An attenuator for attenuating a resonance is connected to a main circuit loop formed of the DC capacitor, the high-voltage-side power line, the low-voltage-side power line, a semiconductor switching element in ON state, and a drain-source parasitic capacitance of a semiconductor switching element in OFF state.Type: GrantFiled: May 16, 2019Date of Patent: May 3, 2022Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Takaaki Takahara, Hiroto Mizutani, Hajime Toyoda, Hiroyasu Iwabuki, Yasunori Otsuka
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Publication number: 20210344277Abstract: Provided is a power conversion device that can suppress interference between control of input current from an AC power supply and voltage control for a DC capacitor to perform both the controls with high accuracy, and can reduce the capacitance and size of the DC capacitor. A power conversion circuit includes a rectification bridge circuit, a leg circuit having upper and lower legs connected in series, a DC capacitor, a smoothing capacitor, and a reactor. A control circuit performs PWM control of the leg circuit by generating a duty cycle so as to control a voltage of the DC capacitor while controlling an input current from an AC power supply, in a control cycle. When the duty cycle is generated, a sum of duty cycles is made constant in one cycle for each leg.Type: ApplicationFiled: December 13, 2018Publication date: November 4, 2021Applicant: Mitsubishi Electric CorporationInventors: Hajime TOYODA, Takaaki TAKAHARA
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Publication number: 20210119530Abstract: A DC capacitor and a leg are connected in parallel to a high-voltage-side power line and a low-voltage-side power line. The leg includes a plurality of semiconductor switching elements connected in series between the power lines with an output end, connected to a load, between the plurality of semiconductor switching elements. An attenuator for attenuating a resonance is connected to a main circuit loop formed of the DC capacitor, the high-voltage-side power line, the low-voltage-side power line, a semiconductor switching element in ON state, and a drain-source parasitic capacitance of a semiconductor switching element in OFF state.Type: ApplicationFiled: May 16, 2019Publication date: April 22, 2021Applicant: Mitsubishi Electric CorporationInventors: Takaaki TAKAHARA, Hiroto MIZUTANI, Hajime TOYODA, Hiroyasu IWABUKI, Yasunori OTSUKA
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Patent number: 10749440Abstract: A power conversion device includes an input detector for detecting input parameters of the DC input to the inverter; an output detector for detecting output parameters of the DC output from the power converter device; a duty calculator for calculating a duty for the switching elements of the inverter; a frequency search range calculator for determining an upper limit and a lower limit of a frequency search range for determining the drive frequency after the operating condition is changed, using at least one parameter of the input parameters, the output parameters, and a duty parameter; and a frequency search processor for determining the drive frequency by searching the frequency search range.Type: GrantFiled: August 24, 2017Date of Patent: August 18, 2020Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Hajime Toyoda, Takaaki Takahara, Ryota Kondo, Hiroyasu Iwabuki
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Publication number: 20200132143Abstract: Provided is a friction member (such as a disc brake pad) having light weight by reducing weight of a back plate and having improved durability after repeated braking. Specific examples of the friction member include a friction member having a friction material disposed on one surface of the back plate comprising a material having a lower specific gravity than that of steel, wherein heat conductivity in a thickness direction of the friction material is 0.40 W/m·K or less.Type: ApplicationFiled: June 14, 2018Publication date: April 30, 2020Inventors: Mitsuo UNNO, Yoshihisa TAKAHASHI, Hajime TOYODA
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Patent number: 10608542Abstract: A full-bridge inverter is configured with a parallel connection of a first leg and a second leg, and controlled in a dual-leg resonant mode in which a positive-side switching element of the first leg and a negative-side switching element of the second leg are turned on/off at the same time and a negative-side switching element of the first leg and a positive-side switching element of the second leg are turned on/off at the same time, and controlled in a single-leg resonant mode in which the positive-side switching element of the first leg and the negative-side switching element of the second leg, and the negative-side switching element of the first leg and the positive-side switching element of the second leg are turned on/off shiftedly in time by a phase shift amount.Type: GrantFiled: May 10, 2017Date of Patent: March 31, 2020Assignee: Mitsubishi Electric CorporationInventors: Takaaki Takahara, Hiroto Mizutani, Hajime Toyoda, Hiroyasu Iwabuki
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Publication number: 20190393792Abstract: A power conversion device includes an input detector for detecting input parameters of the DC input to the inverter; an output detector for detecting output parameters of the DC output from the power converter device; a duty calculator for calculating a duty for the switching elements of the inverter; a frequency search range calculator for determining an upper limit and a lower limit of a frequency search range for determining the drive frequency after the operating condition is changed, using at least one parameter of the input parameters, the output parameters, and a duty parameter; and a frequency search processor for determining the drive frequency by searching the frequency search range.Type: ApplicationFiled: August 24, 2017Publication date: December 26, 2019Applicant: Mitsubishi Electric CorporationInventors: Hajime TOYODA, Takaaki TAKAHARA, Ryota KONDO, Hiroyasu IWABUKI
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Publication number: 20190214916Abstract: A full-bridge inverter is configured with a parallel connection of a first leg and a second leg, and controlled in a dual-leg resonant mode in which a positive-side switching element of the first leg and a negative-side switching element of the second leg are turned on/off at the same time and a negative-side switching element of the first leg and a positive-side switching element of the second leg are turned on/off at the same time, and controlled in a single-leg resonant mode in which the positive-side switching element of the first leg and the negative-side switching element of the second leg, and the negative-side switching element of the first leg and the positive-side switching element of the second leg are turned on/off shiftedly in time by a phase shift amount.Type: ApplicationFiled: May 10, 2017Publication date: July 11, 2019Applicant: Mitsubishi Electric CorporationInventors: Takaaki TAKAHARA, Hiroto MIZUTANI, Hajime TOYODA, Hiroyasu IWABUKI
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Patent number: 10263534Abstract: A power conversion device includes a reactor, a single-phase inverter, and a single-phase converter which are connected in series to each other between an AC power supply and a smoothing capacitor, and performs power conversion between AC voltage of the AC power supply and DC voltage of the smoothing capacitor. The power conversion device includes a control unit which controls switch elements of the single-phase inverter and switch elements of the single-phase converter so that charging operation and discharging operation of the DC capacitor are performed in one switching cycle of the single-phase inverter and the charging amount and the discharging amount thereof are equal to each other.Type: GrantFiled: August 29, 2016Date of Patent: April 16, 2019Assignee: Mitsubishi Electric CorporationInventors: Takaaki Takahara, Ryota Kondo, Satoshi Murakami, Hajime Toyoda
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Publication number: 20190006952Abstract: A power conversion device includes a reactor, a single-phase inverter, and a single-phase converter which are connected in series to each other between an AC power supply and a smoothing capacitor, and performs power conversion between AC voltage of the AC power supply and DC voltage of the smoothing capacitor. The power conversion device includes a control unit which controls switch elements of the single-phase inverter and switch elements of the single-phase converter so that charging operation and discharging operation of the DC capacitor are performed in one switching cycle of the single-phase inverter and the charging amount and the discharging amount thereof are equal to each other.Type: ApplicationFiled: August 29, 2016Publication date: January 3, 2019Applicant: Mitsubishi Electric CorporationInventors: Takaaki TAKAHARA, Ryota KONDO, Satoshi MURAKAMI, Hajime TOYODA