Patents by Inventor Kenichiro Nagashita
Kenichiro Nagashita 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: 10020748Abstract: An electric power conversion circuit comprises U-phase and V-phase switching circuits, a transformer, and an ?-phase switching circuit. A primary winding of a transformer is connected between the U-phase switching circuit and the V-phase switching circuit, and both ends of a secondary winding are connected to the ?-phase switching circuit. The ?-phase switching circuit comprises positive and negative terminals, a half bridge including and two switching devices, and a voltage divider circuit. The half bridge is provided between the positive terminal and the negative terminal, and a common connection point between the two switching devices is connected to one end of the secondary winding. A voltage divider output point of the voltage divider circuit is connected to the other end of the secondary winding.Type: GrantFiled: August 19, 2016Date of Patent: July 10, 2018Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi Takagi, Shuntaro Inoue, Takahide Sugiyama, Kenichiro Nagashita, Yoshitaka Niimi, Masaki Okamura
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Patent number: 9882491Abstract: There is provided a power supply system including a first power supply and a second power supply. The power supply system includes a power conversion circuit capable of bidirectionally sending and receiving power by bidirectional voltage conversion between the first power supply and the second power supply, converting the first voltage from the first power supply to output a third voltage and a fourth voltage, and converting the second voltage from the second power supply to output the third voltage and the fourth voltage.Type: GrantFiled: March 24, 2015Date of Patent: January 30, 2018Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masanori Ishigaki, Kenichi Takagi, Kenichiro Nagashita, Takahiro Hirano, Jun Muto
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Patent number: 9744856Abstract: A power conversion apparatus is configured to supply a power to an auxiliary device provided in a vehicle, and the power conversion apparatus includes: a primary side circuit including a primary side port; a secondary side circuit including a plurality of secondary side ports and magnetically coupled with the primary side circuit via a transformer; a control unit configured to control a transmitted power that is transmitted between the primary side circuit and the secondary side circuit by changing a phase difference between a switching of the primary side circuit and a switching of the secondary side circuit; an inverter connected to a first secondary side port and supplying the power to the auxiliary device via the primary side port; and a charger connected to a second secondary side port and supplying the power to the auxiliary device via the primary side port.Type: GrantFiled: April 2, 2015Date of Patent: August 29, 2017Assignee: Toyota Jidosha Kabushiki KaishaInventor: Kenichiro Nagashita
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Patent number: 9742296Abstract: The present invention provides a power conversion circuit system in which a circulating current can be reduced by accurately detecting the circulating current, to thereby improve efficiency in power conversion. The power conversion circuit system includes a power conversion circuit composed of a primary conversion circuit having left and right arms and a secondary conversion circuit having left and right arms, and a control circuit for controlling switching of switching transistors in the primary and secondary conversion circuits. The control circuit detects the circulating current at at least one of timings lagged by ?/2+?/2 from at least either a peak timing or a valley timing in a carrier counter where ? represents a difference in phase between the primary and secondary conversion circuits, and performs feedback control for reducing the detected circulating current to zero.Type: GrantFiled: March 8, 2016Date of Patent: August 22, 2017Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Shuntaro Inoue, Kenichi Takagi, Takahide Sugiyama, Kenichiro Nagashita, Masaki Okamura, Yoshitaka Niimi
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Patent number: 9660543Abstract: An electric power conversion circuit system for reducing core loss in a transformer particularly during light loading and improving conversion efficiency during light loading comprising an electric power conversion circuit composed of a primary side conversion circuit having a left arm and a right arm and a secondary side conversion circuit having a left arm and a right arm, and a control circuit for controlling switching of switching transistors of the first side conversion circuit and the secondary side conversion circuit. When the output voltage is at a relatively light load, the control circuit controls to change the duty of the transmitting side among the primary side conversion circuit and the secondary side conversion circuit and controls to change the half-bridge phase differences of the left arm and the right arm of the primary side conversion circuit and the secondary side conversion circuit, respectively.Type: GrantFiled: March 8, 2016Date of Patent: May 23, 2017Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi Takagi, Shuntaro Inoue, Takahide Sugiyama, Kenichiro Nagashita, Yoshitaka Niimi, Masaki Okamura
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Publication number: 20170063245Abstract: An electric power conversion circuit comprises U-phase and V-phase switching circuits, a transformer, and an ?-phase switching circuit. A primary winding of a transformer is connected between the U-phase switching circuit and the V-phase switching circuit, and both ends of a secondary winding are connected to the ?-phase switching circuit. The ?-phase switching circuit comprises positive and negative terminals, a half bridge including and two switching devices, and a voltage divider circuit. The half bridge is provided between the positive terminal and the negative terminal, and a common connection point between the two switching devices is connected to one end of the secondary winding. A voltage divider output point of the voltage divider circuit is connected to the other end of the secondary winding.Type: ApplicationFiled: August 19, 2016Publication date: March 2, 2017Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi TAKAGI, Shuntaro INOUE, Takahide SUGIYAMA, Kenichiro NAGASHITA, Yoshitaka NIIMI, Masaki OKAMURA
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Patent number: 9570995Abstract: A magnetically coupled reactor includes a coupled core member, a first coil, and a second coil. The coupled core member includes a first core and a second core made of a magnetic material and disposed to face each other, a coil channel, and a sheet-like magnetic body by which a coupling portion between cores is put between the first core and the second core at an outer portion of the first and second cores. Each coil is wound around a leg through the coil channel in a lap winding manner such that the coils are overlapped on top of each other in the coil channel when seen in an axial direction. The sheet-like magnetic body extends from the coupling portion between coils into the coil channel and includes a portion arranged between coils located between the coils in the axial direction.Type: GrantFiled: September 9, 2015Date of Patent: February 14, 2017Assignee: Toyota Jidosha Kabushiki KaishaInventors: Shuntaro Inoue, Kenichi Takagi, Takahide Sugiyama, Masaru Sugai, Kenichiro Nagashita, Fumiki Tanahashi
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Publication number: 20160285377Abstract: An electric power conversion circuit system for reducing core loss in a transformer particularly during light loading and improving conversion efficiency during light loading comprising an electric power conversion circuit composed of a primary side conversion circuit having a left arm and a right arm and a secondary side conversion circuit having a left arm and a right arm, and a control circuit for controlling switching of switching transistors of the first side conversion circuit and the secondary side conversion circuit. When the output voltage is at a relatively light load, the control circuit controls to change the duty of the transmitting side among the primary side conversion circuit and the secondary side conversion circuit and controls to change the half-bridge phase differences of the left arm and the right arm of the primary side conversion circuit and the secondary side conversion circuit, respectively.Type: ApplicationFiled: March 8, 2016Publication date: September 29, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi TAKAGI, Shuntaro INOUE, Takahide SUGIYAMA, Kenichiro NAGASHITA, Yoshitaka NIIMI, Masaki OKAMURA
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Publication number: 20160276940Abstract: The present invention provides a power conversion circuit system in which a circulating current can be reduced by accurately detecting the circulating current, to thereby improve efficiency in power conversion. The power conversion circuit system includes a power conversion circuit composed of a primary conversion circuit having left and right arms and a secondary conversion circuit having left and right arms, and a control circuit for controlling switching of switching transistors in the primary and secondary conversion circuits. The control circuit detects the circulating current at at least one of timings lagged by ?/2+?/2 from at least either a peak timing or a valley timing in a carrier counter where ? represents a difference in phase between the primary and secondary conversion circuits, and performs feedback control for reducing the detected circulating current to zero.Type: ApplicationFiled: March 8, 2016Publication date: September 22, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Shuntaro INOUE, Kenichi TAKAGI, Takahide SUGIYAMA, Kenichiro NAGASHITA, Masaki OKAMURA, Yoshitaka NIIMI
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Patent number: 9450499Abstract: There is provided an electric power conversion circuit system having a primary side electric power conversion circuit, a secondary side electric power conversion circuit, and a control circuit. The control circuit sets at least one of a half-bridge phase difference between a lower-left-arm transistor and a lower-right-arm transistor of the primary side electric power conversion circuit and a half-bridge phase difference of the secondary side electric power conversion circuit based on OFF periods of the primary side and secondary side electric power conversion circuits, dead-times of the primary side and secondary side electric power conversion circuits, and an amount of change of a power supply voltage so that a current in a non-transmission period of electric power is zero between the primary side and secondary side electric power conversion circuits.Type: GrantFiled: February 24, 2015Date of Patent: September 20, 2016Assignees: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi Takagi, Masanori Ishigaki, Takahide Sugiyama, Takaji Umeno, Kenichiro Nagashita, Takahiro Hirano, Jun Muto
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Publication number: 20160172984Abstract: An electric power conversion circuit and a control circuit are provided. The electric power conversion circuit includes a primary conversion circuit and a secondary conversion circuit. The primary conversion circuit has switching transistors and a primary coil of a transformer. The secondary conversion circuit has switching transistors and a secondary coil of the transformer. Reactors and a connection port are connected between a connection point of the switching transistors and a connection point of the other the switching transistors in the primary conversion circuit.Type: ApplicationFiled: December 8, 2015Publication date: June 16, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi TAKAGI, Shuntaro INOUE, Takahide SUGIYAMA, Kenichiro NAGASHITA, Yoshitaka NIIMI, Masaki OKAMURA
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Patent number: 9358889Abstract: The power conversion apparatus converts power among a plurality of ports, and includes: a first voltage conversion unit that converts a voltage of a first port and outputs power having the converted voltage to a second port; and a second voltage conversion unit that performs a first operation of converting a voltage of one port of the second port and a third port and outputting power having the converted voltage to the other port, or a second operation of converting a voltage of the other port and outputting power having the converted voltage to the one port, and when performing the first operation the second voltage conversion unit switches from the first operation to the second operation when a vehicle condition where power of the one port is insufficient is detected.Type: GrantFiled: November 5, 2014Date of Patent: June 7, 2016Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Kenichiro Nagashita
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Publication number: 20160105120Abstract: A power conversion apparatus includes a primary side circuit and a secondary side circuit magnetically coupled to the primary side circuit through a transformer. Transmitted power transmitted between a primary side port provided in the primary side circuit and a secondary side port provided in the secondary side circuit changes in accordance with a phase difference between switching of the primary side circuit and switching of the secondary side circuit, and a frequency of the switching of each of the primary side circuit and the secondary side circuit. The power conversion apparatus includes a control unit that adjusts the frequency in accordance with a port voltage of at least one of the primary side port and the secondary side port.Type: ApplicationFiled: May 20, 2014Publication date: April 14, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiro HIRANO, Kenichiro NAGASHITA
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Publication number: 20160079873Abstract: A magnetically coupled reactor includes a coupled core member, a first coil, and a second coil. The coupled core member includes a first core and a second core made of a magnetic material and disposed to face each other, a coil channel, and a sheet-like magnetic body by which a coupling portion between cores is put between the first core and the second core at an outer portion of the first and second cores. Each coil is wound around a leg through the coil channel in a lap winding manner such that the coils are overlapped on top of each other in the coil channel when seen in an axial direction. The sheet-like magnetic body extends from the coupling portion between coils into the coil channel and includes a portion arranged between coils located between the coils in the axial direction.Type: ApplicationFiled: September 9, 2015Publication date: March 17, 2016Inventors: Shuntaro Inoue, Kenichi Takagi, Takahide Sugiyama, Masaru Sugai, Kenichiro Nagashita, Fumiki Tanahashi
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Patent number: 9270187Abstract: An electric power conversion system includes: a primary electric power conversion circuit including a primary coil connected to a connection point between a plurality of transistors; a secondary electric power conversion circuit configured similarly to the primary electric power conversion circuit and including a secondary coil corresponding to the primary coil; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits. The control circuit executes feedforward control for setting one of an on/off ratio of a terminal voltage signal of the primary coil and an on/off ratio of a terminal voltage signal of the secondary coil, in response to at least one of fluctuations in voltage ratio between both waveforms and fluctuations in phase symmetry between both waveforms, when the terminal voltage waveform of the primary coil and the terminal voltage waveform of the secondary coil are different from each other.Type: GrantFiled: March 18, 2014Date of Patent: February 23, 2016Assignee: Toyota Jidosha Kabushiki KaishaInventors: Kenichi Takagi, Masanori Ishigaki, Takaji Umeno, Takahiro Hirano, Jun Muto, Yasuharu Terada, Kenichiro Nagashita
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Patent number: 9209701Abstract: An electric power conversion system includes: a primary electric power conversion circuit including primary right and left arms; a secondary electric power conversion circuit including secondary right and left arms; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits by magnetically coupling a primary coil to a secondary coil. The control circuit sets an interphase difference in switching between right and left arm lower transistors in the primary electric power conversion circuit and an interphase difference in switching between right and left arm lower transistors in the secondary electric power conversion circuit on the basis of off times of the primary and secondary electric power conversion circuits such that a phase difference between terminal voltage waveforms of the primary and secondary coils is 0 and duty ratios of the terminal voltage waveforms are equal to each other.Type: GrantFiled: February 21, 2014Date of Patent: December 8, 2015Assignee: Toyota Jidosha Kabushiki KaishaInventors: Kenichi Takagi, Masanori Ishigaki, Takaji Umeno, Kenichiro Nagashita, Takahiro Hirano, Jun Muto, Yasuharu Terada
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Publication number: 20150291035Abstract: A power conversion apparatus is configured to supply a power to an auxiliary device provided in a vehicle, and the power conversion apparatus includes: a primary side circuit including a primary side port; a secondary side circuit including a plurality of secondary side ports and magnetically coupled with the primary side circuit via a transformer; a control unit configured to control a transmitted power that is transmitted between the primary side circuit and the secondary side circuit by changing a phase difference between a switching of the primary side circuit and a switching of the secondary side circuit; an inverter connected to a first secondary side port and supplying the power to the auxiliary device via the primary side port; and a charger connected to a second secondary side port and supplying the power to the auxiliary device via the primary side port.Type: ApplicationFiled: April 2, 2015Publication date: October 15, 2015Inventor: Kenichiro Nagashita
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Publication number: 20150280579Abstract: There is provided a power supply system including a first power supply and a second power supply. The power supply system includes a power conversion circuit capable of bidirectionally sending and receiving power by bidirectional voltage conversion between the first power supply and the second power supply, converting the first voltage from the first power supply to output a third voltage and a fourth voltage, and converting the second voltage from the second power supply to output the third voltage and the fourth voltage.Type: ApplicationFiled: March 24, 2015Publication date: October 1, 2015Inventors: Masanori ISHIGAKI, Kenichi TAKAGI, Kenichiro NAGASHITA, Takahiro HIRANO, Jun MUTO
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Publication number: 20150244279Abstract: There is provided an electric power conversion circuit system having a primary side electric power conversion circuit, a secondary side electric power conversion circuit, and a control circuit. The control circuit sets at least one of a half-bridge phase difference between a lower-left-arm transistor and a lower-right-arm transistor of the primary side electric power conversion circuit and a half-bridge phase difference of the secondary side electric power conversion circuit based on OFF periods of the primary side and secondary side electric power conversion circuits, dead-times of the primary side and secondary side electric power conversion circuits, and an amount of change of a power supply voltage so that a current in a non-transmission period of electric power is zero between the primary side and secondary side electric power conversion circuits.Type: ApplicationFiled: February 24, 2015Publication date: August 27, 2015Inventors: Kenichi TAKAGI, Masanori ISHIGAKI, Takahide SUGIYAMA, Takaji UMENO, Kenichiro NAGASHITA, Takahiro HIRANO, Jun MUTO
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Publication number: 20150194256Abstract: A magnetic coupling inductor includes a pair of windings that are magnetically coupled. A same phase current and a reverse phase current both flow through the pair of windings, and each winding has a plurality of turns in one layer in the axial direction of the windings. The windings through which the currents of opposite phases flow of the one layer of the pair of windings are oppositely arranged to each other in the axial direction of the windings.Type: ApplicationFiled: December 10, 2014Publication date: July 9, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichi TAKAGI, Masanori ISHIGAKI, Takahide SUGIYAMA, Takaji UMENO, Kenichiro NAGASHITA, Takahiro HIRANO, Jun MUTO