Patents by Inventor Kazutoshi Ogawa
Kazutoshi Ogawa 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: 11701971Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.Type: GrantFiled: April 10, 2020Date of Patent: July 18, 2023Assignee: Hitachi, Ltd.Inventors: Takeshi Shinomiya, Naoki Kunihiro, Kazutoshi Ogawa, Katsumi Ishikawa, Kuniaki Otsuka, Hiroyuki Shirata, Tomomi Kanazawa, Takeo Takagi, Shuichi Terakado, Kiyoshi Nakata
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Publication number: 20220234450Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.Type: ApplicationFiled: April 10, 2020Publication date: July 28, 2022Inventors: Takeshi SHINOMIYA, Naoki KUNIHIRO, Kazutoshi OGAWA, Katsumi ISHIKAWA, Kuniaki OTSUKA, Hiroyuki SHIRATA, Tomomi KANAZAWA, Takeo TAKAGI, Shuichi TERAKADO, Kiyoshi NAKATA
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Patent number: 9171831Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.Type: GrantFiled: September 10, 2014Date of Patent: October 27, 2015Assignee: HITACHI, LTD.Inventors: Katsumi Ishikawa, Kazutoshi Ogawa
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Patent number: 8952642Abstract: Temperature rise in semiconductor switching element that is part of a power conversion device is estimated to assess the degradation and remaining lifetime of the switching element. This is accomplished with a heat generation amount calculation unit in a calculation processor, where current command values Id* and Iq* and voltage command values vu*, vv* and vw* are used to calculate a chip loss. Current values iu*, iv* and iw* of all output phases are estimated from the current command values. The ON/OFF loss of the chip is represented by a function of an estimated value for a current flowing in each output phase, and the loss can be derived by integration with a PWM carrier frequency f. With respect to a conduction loss, a conduction time is integrated with the estimated current value and a saturation voltage, which is a function of the estimated current value.Type: GrantFiled: June 23, 2011Date of Patent: February 10, 2015Assignee: Hitachi, Ltd.Inventors: Hideki Ayano, Katsumi Ishikawa, Kazutoshi Ogawa, Tsutomu Kominami, Mami Kunihiro
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Publication number: 20150003133Abstract: Ringing is securely reduced in a case where a Schottky barrier diode of a wide-gap semiconductor is applied to a power conversion circuit. A gate voltage increasing circuit 11a is included. In a period since a gate voltage of a semiconductor switching element in one of upper and lower arms starts being increased from a value in an off-state until the gate voltage reaches a value in an on-state, the gate voltage increasing circuit 11a is configured to make a gate voltage of the semiconductor switching element in the other one of the upper and lower arms change from a value in an off-state into a value larger than the value in the off-state and is configured to control the value larger than the value in the off-state for a predetermined period of time.Type: ApplicationFiled: January 22, 2013Publication date: January 1, 2015Applicant: Hitach, Ltd.Inventors: Kazutoshi Ogawa, Katsumi Ishikawa
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Publication number: 20140374794Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.Type: ApplicationFiled: September 10, 2014Publication date: December 25, 2014Inventors: Katsumi Ishikawa, Kazutoshi Ogawa
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Publication number: 20140334214Abstract: In a switching circuit in which a power semiconductor switching element and a unipolar type diode are connected in parallel, the noise due to ringing is reduced. When the main circuit current flowing is equal to or less than a predetermined value, an Si-IGBT is switched and driven by a gate resistance. In this case, when the main circuit current detected is equal to or more than a threshold value, a main circuit current detection circuit changes a gate resistance switching pMOS from ON state to OFF state. Accordingly, the Si-IGBT operates with a summation of a gate resistance and a gate resistor. More specifically, a gate resistance value of a gate drive circuit of the Si-IGBT increases. Therefore, dv/dt of the collector-emitter voltage of the Si-IGBT, i.e., the recovery dv/dt of the unipolar type diode, is small, and therefore, the noise due to ringing can be reduced.Type: ApplicationFiled: October 12, 2012Publication date: November 13, 2014Inventors: Kaoru Katoh, Katsumi Ishikawa, Kazutoshi Ogawa
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Patent number: 8860170Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.Type: GrantFiled: March 18, 2013Date of Patent: October 14, 2014Assignee: Hitachi, Ltd.Inventors: Katsumi Ishikawa, Kazutoshi Ogawa
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Patent number: 8829838Abstract: The present invention provides a power converter which, while ensuring safety, implements control for the flow of a constant current in a specified switching element, more accurately determines the lifetime of a switching element, and reduces the number of temperature detectors. The power converter is provided with a mechanism which causes a brake device to operate or which confirms that a brake mechanism is operating. The power converter supplies current to the d-axis and the q-axis of a rotational coordinate system, within the range of the braking torque of the brake mechanism, and passes the desired current to the desired element. Furthermore, temperature detectors are attached only in chips in sections where a crack readily develops in the upper solder layer or peeling is readily generated in the wire bonding, and in chips where a crack readily develops in the lower solder layer.Type: GrantFiled: March 10, 2010Date of Patent: September 9, 2014Assignee: Hitachi, Ltd.Inventors: Hideki Ayano, Katsumi Ishikawa, Kazutoshi Ogawa, Tsutomu Kominami, Mami Kunihiro
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Patent number: 8619448Abstract: In order to reduce the average power of the ringing noise, the present invention provides a power converter comprising: an arm circuit including a high-voltage side switching device to which a first diode is connected in parallel and a low-voltage side switching device to which a second diode is connected in parallel; and a main power supply connected to a series circuit of the high-voltage side switching device and the low-voltage side switching device, wherein a connecting point between the high-voltage side switching device and the low-voltage side switching device is connected to a load, and a resonant frequency calculated from inductances of wirings of a closed circuit including the first diode, the second diode, and the main power supply and a capacitance across the first diode is different form that calculated from the inductances of the wirings and a capacitance across the second diode.Type: GrantFiled: July 6, 2011Date of Patent: December 31, 2013Assignee: Hitachi, Ltd.Inventors: Kazutoshi Ogawa, Katsumi Ishikawa
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Patent number: 8471622Abstract: The invention provides a switching circuit of a power semiconductor device having connected in parallel SiC diodes with a small recovery current, capable of significantly reducing turn-on loss and recovery loss without increasing the noise in the MHz band, and contributing to reducing the loss and noise of inverters. The present invention provides a switching circuit and an inverter circuit of a power semiconductor device comprising a module combining Si-IGBT and SiC diodes, wherein an on-gate resistance is set smaller than an off-gate resistance.Type: GrantFiled: April 15, 2010Date of Patent: June 25, 2013Assignee: Hitachi, Ltd.Inventors: Katsumi Ishikawa, Kazutoshi Ogawa, Masahiro Nagasu
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Publication number: 20130119912Abstract: A temperature rise of a semiconductor switching element, which is part of a power conversion device such as an inverter, is estimated by an extremely simple method to assess the degradation and remaining lifetime of the semiconductor switching element. In a heat generation amount calculation unit 12 in a calculation processor 3, current command values Id* and Iq* and voltage command values vu*, vv* and vw* are used to calculate a chip loss. First, current values iu*, iv* and iw* of all output phases are estimated from the current command values. The ON/OFF loss of the chip is represented by a function of an estimated value for a current flowing in each output phase, and the loss can be derived by integration with a PWM carrier frequency f. In addition, with respect to a conduction loss, it is necessary to integrate a conduction time with the estimated current value and a saturation voltage, which is a function of the estimated current value.Type: ApplicationFiled: June 23, 2011Publication date: May 16, 2013Applicant: HITACHI LTD.Inventors: Hideki Ayano, Katsumi Ishikawa, Kazutoshi Ogawa, Tsutomu Kominami, Mami Kunihiro
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Patent number: 8441075Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.Type: GrantFiled: February 18, 2010Date of Patent: May 14, 2013Assignee: Hitachi, Ltd.Inventors: Katsumi Ishikawa, Kazutoshi Ogawa
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Patent number: 8395422Abstract: The threshold value for a normally-off junction FET is a low value. Accordingly, in a semiconductor driver circuit using the normally-off junction FET, there have existed such problems as high-accuracy voltage control, high-speed charging into an input capacitor, and misoperations. A semiconductor driver circuit which is the most suitable for the normally-off junction FET is proposed by applying the high-accuracy gate-voltage generation scheme based on a Zener diode, a reduction in the turn-on loss based on a speed-up capacitor, the connection of an inter-gate-source capacitor, and a misoperation-preventing circuit based on the source-terminal optimum implementation scheme.Type: GrantFiled: September 29, 2010Date of Patent: March 12, 2013Assignee: Hitachi, Ltd.Inventors: Kazutoshi Ogawa, Katsumi Ishikawa
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Publication number: 20130015799Abstract: The present invention provides a power converter which, while ensuring safety, implements control for the flow of a constant current in a specified switching element, more accurately determines the lifetime of a switching element, and reduces the number of temperature detectors. The power converter is provided with a mechanism which causes a brake device to operate or which confirms that a brake mechanism is operating. The power converter supplies current to the d-axis and the q-axis of a rotational coordinate system, within the range of the braking torque of the brake mechanism, and passes the desired current to the desired element. Furthermore, temperature detectors are attached only in chips in sections where a crack readily develops in the upper solder layer or peeling is readily generated in the wire bonding, and in chips where a crack readily develops in the lower solder layer.Type: ApplicationFiled: March 10, 2010Publication date: January 17, 2013Applicant: Hitachi LtdInventors: Hideki Ayano, Katsumi Ishikawa, Kazutoshi Ogawa, Tsutomu Kominami, Mami Kunihiro
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Patent number: 8110944Abstract: The invention provides a switching circuit and a power converter having a built-in power source for a conduction control terminal even if they have a single-arm structure. In the switching circuit having a switching device and a conduction control terminal power source capacitor, a negative terminal of the capacitor is connected to a reference voltage terminal of a main power source and to the gate terminal selectively through a half-bridge circuit and a positive terminal of the capacitor is selectively connected to a positive terminal of the main power source and to a source terminal of the switching device through a half-bridge circuit. The capacitor is charged when the positive terminal is connected to the main power source and discharges when the negative terminal is connected to the gate terminal and the positive terminal is connected to the source terminal and applies voltage to the gate terminal of the switching device.Type: GrantFiled: February 17, 2010Date of Patent: February 7, 2012Assignee: Hitachi, Ltd.Inventors: Kazutoshi Ogawa, Katsumi Ishikawa
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Publication number: 20120007533Abstract: In order to reduce the average power of the ringing noise, the present invention provides a power converter comprising: an arm circuit including a high-voltage side switching device to which a first diode is connected in parallel and a low-voltage side switching device to which a second diode is connected in parallel; and a main power supply connected to a series circuit of the high-voltage side switching device and the low-voltage side switching device, wherein a connecting point between the high-voltage side switching device and the low-voltage side switching device is connected to a load, and a resonant frequency calculated from inductances of wirings of a closed circuit including the first diode, the second diode, and the main power supply and a capacitance across the first diode is different form that calculated from the inductances of the wirings and a capacitance across the second diode.Type: ApplicationFiled: July 6, 2011Publication date: January 12, 2012Inventors: Kazutoshi OGAWA, Katsumi Ishikawa
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Publication number: 20110080192Abstract: The threshold value for a normally-off junction FET is a low value. Accordingly, in a semiconductor driver circuit using the normally-off junction FET, there have existed such problems as high-accuracy voltage control, high-speed charging into an input capacitor, and misoperations. A semiconductor driver circuit which is the most suitable for the normally-off junction FET is proposed by applying the high-accuracy gate-voltage generation scheme based on a Zener diode, a reduction in the turn-on loss based on a speed-up capacitor, the connection of an inter-gate-source capacitor, and a misoperation-preventing circuit based on the source-terminal optimum implementation scheme.Type: ApplicationFiled: September 29, 2010Publication date: April 7, 2011Inventors: Kazutoshi Ogawa, Katsumi Ishikawa
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Publication number: 20100265746Abstract: The invention provides a switching circuit of a power semiconductor device having connected in parallel SiC diodes with a small recovery current, capable of significantly reducing turn-on loss and recovery loss without increasing the noise in the MHz band, and contributing to reducing the loss and noise of inverters. The present invention provides a switching circuit and an inverter circuit of a power semiconductor device comprising a module combining Si-IGBT and SiC diodes, wherein an on-gate resistance is set smaller than an off-gate resistance.Type: ApplicationFiled: April 15, 2010Publication date: October 21, 2010Inventors: Katsumi ISHIKAWA, Kazutoshi OGAWA, Masahiro NAGASU
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Publication number: 20100244092Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.Type: ApplicationFiled: February 18, 2010Publication date: September 30, 2010Inventors: Katsumi ISHIKAWA, Kazutoshi Ogawa