Patents by Inventor Toshiyuki Kikunaga
Toshiyuki Kikunaga 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: 8040702Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.Type: GrantFiled: May 31, 2007Date of Patent: October 18, 2011Assignee: Mitsubishi Electric CorporationInventors: Takahiro Urakabe, Matahiko Ikeda, Akihiko Iwata, Kiyoharu Anzai, Hirotoshi Maekawa, Toshiyuki Kikunaga, Masaru Kobayashi, Tatsuya Okuda
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Patent number: 8036008Abstract: Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.Type: GrantFiled: May 17, 2007Date of Patent: October 11, 2011Assignee: Mitsubishi Electric CorporationInventors: Matahiko Ikeda, Takahiro Urakabe, Kiyoharu Anzai, Akihiko Iwata, Hirotoshi Maekawa, Toshiyuki Kikunaga, Masaru Kobayashi, Tatsuya Okuda
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Publication number: 20100019753Abstract: Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.Type: ApplicationFiled: May 17, 2007Publication date: January 28, 2010Applicant: Mitsubishi Electric CorporationInventors: Matahiko Ikeda, Takahiro Urakabe, Kiyoharu Anzai, Akihiko Iwata, Hirotoshi Maekawa, Toshiyuki Kikunaga, Masaru Kobayashi, Tatsuya Okuda
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Patent number: 7619907Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the samType: GrantFiled: March 31, 2008Date of Patent: November 17, 2009Assignee: Mitsubishi Electric CorporationInventors: Takahiro Urakabe, Matahiko Ikeda, Masaru Kobayashi, Akihiko Iwata, Tatsuya Okuda, Hirotoshi Maekawa, Toshiyuki Kikunaga
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Publication number: 20090261793Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.Type: ApplicationFiled: May 31, 2007Publication date: October 22, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro Urakabe, Matahiko Ikeda, Akihiko Iwata, Kiyoharu Anzai, Hirotoshi Maekawa, Toshiyuki Kikunaga, Masaru Kobayashi, Tatsuya Okuda
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Publication number: 20080252145Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the samType: ApplicationFiled: March 31, 2008Publication date: October 16, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro URAKABE, Matahiko Ikeda, Masaru Kobayashi, Akihiko Iwata, Tatsuya Okuda, Hirotoshi Maekawa, Toshiyuki Kikunaga
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Patent number: 7348739Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.Type: GrantFiled: February 2, 2005Date of Patent: March 25, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Toshiyuki Kikunaga, Yuuji Kuramoto
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Publication number: 20070080659Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.Type: ApplicationFiled: February 2, 2005Publication date: April 12, 2007Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Toshiyuki Kikunaga, Yuuji Kuramoto
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Publication number: 20060055367Abstract: A load is connected to a first battery group. The first battery group and a second battery group are connected in series to each other. A bidirectional DC/DC converter for electric power migration between the first battery group and the second battery group is provided.Type: ApplicationFiled: November 8, 2005Publication date: March 16, 2006Inventors: Akihiko Iwata, Toshiyuki Kikunaga
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Patent number: 6989653Abstract: A load is connected to a first battery group. The first battery group and a second battery group are connected in series to each other. A bidirectional DC/DC converter for electric power migration between the first battery group and the second battery group is provided.Type: GrantFiled: May 9, 2003Date of Patent: January 24, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Toshiyuki Kikunaga
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Patent number: 6956305Abstract: Voltage compensation circuits connect DC voltages accumulated in capacitors having respectively different charging voltages which are 2K (where K=0, 1, 2, . . . ) times the minimum voltage into AC voltages. The voltage compensation circuits are connected in series to an electric power system in series. When the voltage dip occurs in an electric power system, a combination of voltage compensation circuits is selected from the voltage compensation circuits. The sum of the output voltage compensates the voltage dip. During normal operation, a high speed mechanical short circuit switch by-passes the voltage compensation circuits to reduce power loss.Type: GrantFiled: March 29, 2002Date of Patent: October 18, 2005Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Akihiro Suzuki, Hiroyuki Sasao, Kenichi Koyama, Toshiyuki Kikunaga, Mitsugu Takahasi
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Patent number: 6836006Abstract: In an IGBT module which contains an IGBT device and a diode device connected to each other and accommodated in a case and which radiates heat generated in operation through a radiation board, an object is to reduce the area of the module in the lateral direction to achieve size reduction. The collector electrode surface of an IGBT device is provided on a radiation board, and an element connecting conductor is bonded with conductive resin on the emitter electrode surface. The anode electrode surface of a diode device is bonded on it with the conductive resin. The IGBT device and the diode device are thus stacked and connected in the vertical direction.Type: GrantFiled: November 29, 1999Date of Patent: December 28, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hirotaka Muto, Takeshi Ohi, Takumi Kikuchi, Toshiyuki Kikunaga
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Publication number: 20040222771Abstract: A load is connected to a first battery group. The first battery group and a second battery group are connected in series to each other. A bidirectional DC/DC converter for electric power migration between the first battery group and the second battery group is provided.Type: ApplicationFiled: May 9, 2003Publication date: November 11, 2004Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Akihiko Iwata, Toshiyuki Kikunaga
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Patent number: 6812592Abstract: Voltage compensating circuits are connected serially to a power system, including capacitors each having different charging voltages (in relationship of approximately 2k (K=0, 1, 2, . . . ) times the smallest charging voltage value). The voltage compensating circuits convert DC voltages in the capacitors into AC voltages and output the AC voltages, respectively. The voltages of the capacitors are detected as detected values V1 to V3. The detected values V1 to V3 are used as bit signals for a reference value to check a voltage dip amount of the power system with the reference value and to convert the voltage dip amount into a binary signal. A combination is selected from the voltage compensating circuits in accordance with the binary signal so that the sum of output voltages of the selected voltage compensating circuits compensates the voltage dip of the power system.Type: GrantFiled: March 29, 2002Date of Patent: November 2, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Akihiro Suzuki, Hiroyuki Sasao, Kenichi Koyama, Toshiyuki Kikunaga, Mitsugu Takahashi
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Patent number: 6785108Abstract: In semiconductor equipment, a switching timing adjuster is provided between insulated gate bipolar transistors and a control signal generator. The switching timing adjuster includes an input decision circuit that decides whether a signal output from the overvoltage protector is a signal that has been output due to a deviation in the switching timing at a turn-off or turn-on time, a signal holding circuit that holds a signal that is output from the input decision circuit, and a pulse formation circuit that forms a corrected switching control signal based on a signal held in the signal holding circuit and a switching control signal from the control signal generator.Type: GrantFiled: May 16, 2002Date of Patent: August 31, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Nakatake, Akihiko Iwata, Toshiyuki Kikunaga
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Publication number: 20030095365Abstract: In the semiconductor equipment, a switching timing adjuster is provided between each IGBT and the control signal generator. The switching timing adjuster comprise an input decision circuit that decides that a signal output from the overvoltage protector is a signal that has been output due to a deviation in the switching timing at a turn-off or turn-on time, a signal holding circuit that holds a signal that is output from the input decision circuit, and a pulse formation circuit that forms a corrected switching control signal based on a signal held in the signal holding circuit and a switching control signal from the control signal generator.Type: ApplicationFiled: May 16, 2002Publication date: May 22, 2003Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Nakatake, Akihiko Iwata, Toshiyuki Kikunaga
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Publication number: 20020171294Abstract: A plurality of voltage compensation circuits P1-P3, N1-N3 converts DC voltages accumulated in a capacitor 11 having respectively different charging voltages (which is 2K times of the minimum voltage (K=0, 1, 2, . . . )) into AC voltages. The plurality of voltage compensation circuits are connected to the electric power system in series. When the voltage dip occurs in an electric power system, a desired combination is selected from the plurality of voltage compensation circuits P1-P3, N1-N3. The total sum of the output voltage compensates the voltage dipped. At the normal time, the high speed mechanical short circuit switch by-passes the voltage compensation circuits to reduce apparatus loss.Type: ApplicationFiled: March 29, 2002Publication date: November 21, 2002Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Akihiro Suzuki, Hiroyuki Sasao, Kenichi Koyama, Toshiyuki Kikunaga, Mitsugu Takahashi
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Publication number: 20020140294Abstract: Voltage compensating circuits are connected serially to a power system, including capacitors each having different charging voltages (in relationship of approximately 2k-fold (K=0, 1, 2, . . . ) of the smallest charging voltage value). The voltage compensating circuits convert DC voltages in the capacitors into AC voltages and output the AC voltages respectively. The voltages of the capacitors are detected as detected values V1 to V3. The detected values V1 to V3 are used as bit signals for a reference value to check a voltage dip amount of the power system with the reference value and to A/D convert the voltage dip amount into a binary signal. A desired combination is selected from the voltage compensating circuits in accordance with the binary signal so that the total sum of output voltages of the selected voltage compensating circuits compensates the voltage dip of the power system.Type: ApplicationFiled: March 29, 2002Publication date: October 3, 2002Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Akihiro Suzuki, Hiroyuki Sasao, Kenichi Koyama, Toshiyuki Kikunaga, Mitsugu Takahashi
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Publication number: 20020043708Abstract: In an IGBT module which contains an IGBT device and a diode device connected to each other and accommodated in a case and which radiates heat generated in operation through a radiation board, an object is to reduce the area of the module in the lateral direction to achieve size reduction. The collector electrode (32) surface of an IGBT device (28) is provided on a radiation board (26), and an element connecting conductor (35) is bonded with conductive resin (36) on the emitter electrode (30) surface. The anode electrode (33) surface of a diode device (29) is bonded on it with the conductive resin (36). The IGBT device (28) and the diode device (29) are thus stacked and connected in the vertical direction.Type: ApplicationFiled: November 29, 1999Publication date: April 18, 2002Inventors: HIROTAKA MUTO, TAKESHI OHI, TAKUMI KIKUCHI, TOSHIYUKI KIKUNAGA
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Patent number: RE40528Abstract: Voltage compensating circuits are connected serially to a power system, including capacitors each having different charging voltages (in relationship of approximately 2k (K=0, 1, 2, . . . ) times the smallest charging voltage value). The voltage compensating circuits convert DC voltages in the capacitors into AC voltages and output the AC voltages, respectively. The voltages of the capacitors are detected as detected values V1 to V3. The detected values V1 to V3 are used as bit signals for a reference value to check a voltage dip amount of the power system with the reference value and to convert the voltage dip amount into a binary signal. A combination is selected from the voltage compensating circuits in accordance with the binary signal so that the sum of output voltages of the selected voltage compensating circuits compensates the voltage dip of the power system.Type: GrantFiled: November 1, 2006Date of Patent: October 7, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akihiko Iwata, Akihiro Suzuki, Hiroyuki Sasao, Kenichi Koyama, Toshiyuki Kikunaga, Mitsugu Takahashi