Patents by Inventor Ryuichi Shimada

Ryuichi Shimada 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).

  • Publication number: 20140152107
    Abstract: [Problem] An object of the present invention is to provide a photovoltaic power generation system that performs the MPPT control with respect to respective panels and minimizes the power loss due to the power conversion. [Means for Solving the Problem] The photovoltaic power generation system according to the present invention performs an MPPT control for each photovoltaic panel by charging the lacking voltage or current. The power charge section connected in series or parallel to each panel charges the lacking voltage or current being caused by the non-uniformity of light quantities of the photovoltaic panels or temperatures.
    Type: Application
    Filed: August 1, 2012
    Publication date: June 5, 2014
    Applicant: TOKYO INSTITUTE OF TECHNOLOGY
    Inventor: Ryuichi Shimada
  • Patent number: 8471477
    Abstract: A processing speed may be easily controlled over the wide range within the impedance variation range.
    Type: Grant
    Filed: March 24, 2011
    Date of Patent: June 25, 2013
    Assignee: Hitachi Kokusai Electric, Inc.
    Inventors: Masayuki Tomita, Katsunori Funaki, Shinji Yashima, Ryuichi Shimada
  • Patent number: 8395347
    Abstract: In an induction motor group control system, magnetic energy recovery switches (3) are connected in series to an induction motor (2) directly driven by a commercial power supply, and a plurality of induction motor control devices (10) enabling voltage control and reactive power control of the induction motor 2 are employed to control generation of reactive power so as to maximize a power factor of the entire plurality of AC loads including the induction motor or compensate variations in voltage of an AC power supply (1).
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: March 12, 2013
    Inventors: Kazuhiko Fukutani, Hideo Narisawa, Ryuichi Shimada, Takanori Isobe, Tadayuki Kitahara
  • Patent number: 8383978
    Abstract: This invention provides a steel pipe material weld zone heating method and apparatus for melting and welding the weld zone of a steel pipe material that during continuous induction heating and welding of moving steel pipe material as the material being heated controls temperature distribution and molten steel shape and weld frequency fluctuation with high accuracy and high efficiency, irrespective of the shape of the heated region of material being heated or the material properties of the material being heated, which comprises a first imaging device, a weld zone temperature distribution computation device, a heating control device, and a variable frequency alternating current power supply device.
    Type: Grant
    Filed: October 22, 2008
    Date of Patent: February 26, 2013
    Assignee: Nippon Steel Corporation
    Inventors: Kazuhiko Fukutani, Kenji Umetsu, Yoshiaki Nakamura, Kazuto Yamamoto, Takashi Miyakawa, Ryuichi Shimada, Tadayuki Kitahara, Takanori Isobe
  • Patent number: 8384333
    Abstract: The alternating voltage control apparatus which is inserted serially between an alternating-current power source and an inductive load and which controls adjustment of load voltage of the inductive load with a magnetic energy recovery switch reduces a voltage burden of a reverse conduction type semiconductor switch within the magnetic energy recovery switch and a capacitor and controls voltage to be supplied to the inductive load with a small advancing amount of a phase of current to be supplied to the inductive load.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: February 26, 2013
    Assignee: MERSTech, Inc.
    Inventor: Ryuichi Shimada
  • Publication number: 20120218798
    Abstract: A power conversion device (1) comprises an inductor (L) serried-connected to an alternating-current power source (20) and a load (30), a full-bridge MERS (100) parallel-connected to the load (30), a control circuit (110), a current direction switching part (200) serried-connected between the inductor (L) and load (30), and an ammeter (300). The control circuit (110) feeds back the current detected by the ammeter (300), repeatedly turns on/off either a pair of reverse conductive semiconductor switches (SW2, SW3) or a pair of reverse conductive semiconductor switches (SW1, SW4) constituting the full-bridge MERS (100), which corresponds to the positive/negative voltage output from the alternating-current source (20), and keeps the other pair being off.
    Type: Application
    Filed: October 8, 2010
    Publication date: August 30, 2012
    Applicant: MERSTech, Inc.
    Inventor: Ryuichi Shimada
  • Publication number: 20120037616
    Abstract: A power inverter (1) is provided with a full-bridge circuit (10), a shunt capacitor (CP), and a control circuit (20). The control circuit (20) controls the on/off state of each reverse-conductive semiconductor switch (SW1 to SW4) at a switching frequency of not more than the resonance frequency determined by the capacitance of the shunt capacitor (CP) and the inductance of an inductive load (LD) in such a matter than when a first reverse-conductive semiconductor switch (SW1) and a fourth reverse-conductive semiconductor switch (SW4) are in the on-state, a second reverse-conductive semiconductor switch (SW2) and a third reverse-conductive semiconductor switch (SW3) are brought into the off-state, and that when the first reverse-conductive semiconductor switch (SW1) and the fourth reverse-conductive semiconductor switch (SW4) are in the off-state, the second reverse-conductive semiconductor switch (SW2) and the third reverse-conductive semiconductor switch (SW3) are brought into the on-state.
    Type: Application
    Filed: October 27, 2009
    Publication date: February 16, 2012
    Applicant: MERSTech INC.
    Inventors: Tadayuki Kitahara, Shiro Fukuda, Ryuichi Shimada, Takanori Isobe
  • Publication number: 20120019188
    Abstract: In an induction motor group control system, magnetic energy recovery switches (3) are connected in series to an induction motor (2) directly driven by a commercial power supply, and a plurality of induction motor control devices (10) enabling voltage control and reactive power control of the induction motor 2 are employed to control generation of reactive power so as to maximize a power factor of the entire plurality of AC loads including the induction motor or compensate variations in voltage of an AC power supply (1).
    Type: Application
    Filed: March 10, 2010
    Publication date: January 26, 2012
    Inventors: Kazuhiko Fukutani, Hideo Narisawa, Ryuichi Shimada, Takanori Isobe, Tadayuki Kitahara
  • Patent number: 8097981
    Abstract: An AC/DC power converter which charges a secondary battery from an AC power supply and also converts power from the secondary battery to the AC voltage is provided. A capacitor C is connected to DC terminals of the four reverse-conductive type semiconductor switches in a single-phase bridge structure, and a secondary battery is connected via a DC inductance to the semiconductor switches. The semiconductor switches are connected via an AC inductance L with an AC power supply and opposing pairs of the semiconductor switches are alternately turned ON/OFF in synchronization with the phase of the supply voltage. When an AC power supply with a frequency which is lower than the resonance frequency of the LC is connected, the switching will be carried out in a zero-voltage-zero-current condition and AC/DC reversible power conversion is possible just through the control of the gate phase of the switches.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: January 17, 2012
    Assignee: Tokyo Institute of Technology
    Inventors: Ryuichi Shimada, Kazuhiro Usuki
  • Patent number: 8045309
    Abstract: In order to protect Magnetic Energy Recovery Switch (MERS) against an overvoltage and an overcurrent a voltage detection unit is provided for detecting the capacitor voltage of the MERS and control means is provided to control so as to turn ON the switch of the discharge circuit connected in parallel with the capacitor to make the capacitor discharge the electric charge thereof when the output of the voltage detection unit exceeds a predetermined value. Moreover, a current detection unit is interposed between the AC power supply and the load for detecting the current flowing to the load, and the current limiting is carried out by making the duty ratio of the ON/OFF of the pulse of the gate control signals of the MERS switches smaller than 0.5, when the output of the current detection unit exceeds a predetermined value.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: October 25, 2011
    Assignee: MERSTech, Inc.
    Inventor: Ryuichi Shimada
  • Publication number: 20110234100
    Abstract: A processing speed may be easily controlled over the wide range within the impedance variation range.
    Type: Application
    Filed: March 24, 2011
    Publication date: September 29, 2011
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Masayuki TOMITA, Katsunori FUNAKI, Shinji YASHIMA, Ryuichi SHIMADA
  • Publication number: 20110199061
    Abstract: Provided is an AC voltage control device for adjusting the voltage of a load to be connected with an AC power source, by a convenient method. In this AC voltage control device, a magnetic energy recovery switch including a capacitor and an AC switch circuit connected in parallel is connected between the AC power source and the load. The AC switch circuit is turned on several ms from such a timing of a zero capacitor voltage as occurs twice for one current cycle, so that a capacitor current is bypassed to reduce a reactance voltage thereby to adjust the voltage of the load.
    Type: Application
    Filed: October 28, 2008
    Publication date: August 18, 2011
    Inventor: Ryuichi Shimada
  • Patent number: 7974113
    Abstract: Reverse conducting type semiconductor switches are arranged in a bride from, an energy storage capacitor is connected with its DC terminal to obtain a magnetic energy regeneration switch, and then an induction coil is connected to its AC terminal. An AC pulse current of variable frequency is obtained by applying a gate signal to the semiconductor switch to thereby turn it ON/OFF; since a voltage is generated automatically by regenerating magnetic energy, a DC power supply is connected to the opposite ends of the capacitor through a smoothing coil, thus injecting power.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: July 5, 2011
    Assignee: Tokyo Institute of Technology
    Inventors: Ryuichi Shimada, Tadayuki Kitahara, Kazuhiko Fukutani
  • Publication number: 20110121774
    Abstract: The alternating voltage control apparatus which is inserted serially between an alternating-current power source and an inductive load and which controls adjustment of load voltage of the inductive load with a magnetic energy recovery switch reduces a voltage burden of a reverse conduction type semiconductor switch within the magnetic energy recovery switch and a capacitor and controls voltage to be supplied to the inductive load with a small advancing amount of a phase of current to be supplied to the inductive load.
    Type: Application
    Filed: May 15, 2009
    Publication date: May 26, 2011
    Applicant: MERSTech Inc.
    Inventor: Ryuichi Shimada
  • Publication number: 20110115417
    Abstract: The present invention provides a PM motor drive power supply apparatus which drives a three-phase permanent-magnet synchronous motor by utilizing a direct-current power source 1, wherein control means 7 controls to simultaneously perform ON/OFF operation of a diagonally positioned pair among reverse conductive semiconductor switches (S1 to S4) of pulse voltage generating means 2, controls to perform ON/OFF operation of switches of three lines of polarity switching means 5 in turns at the same timing as the reverse conductive semiconductor switches (S1 to S4) of the pulse voltage generating means 2, selects a switch of the polarity switching means 5 based on the rotational position signal, converts direct-current pulse output of the pulse voltage generating means 2 into polarities of the three-phase alternating-current, and supplies to a PM motor 4 as drive current.
    Type: Application
    Filed: June 27, 2008
    Publication date: May 19, 2011
    Applicant: MERSTech INC.
    Inventor: Ryuichi Shimada
  • Patent number: 7919887
    Abstract: In order to provide a pulse power supply device using regenerating magnetic energy stored in a discharge circuit to a capacitor so as to use it as next discharge energy and supplying a bipolar pulse current with high repetition, a bridge circuit is composed of four inverse-conductive semiconductor switches, a charged energy source capacitor is connected to a DC terminal of the bridge circuit, and an inductive load is connected to its AC terminal. A control signal is supplied to gates of the inverse-conductive semiconductor switches, and a control is made so that when a discharge current rises, is maintained, or is reduced, all the gates are turned off, and the magnetic energy of the electric current can be automatically regenerated to the energy source capacitor by a diode function of the switches. Further, a large current power supply is inserted into a discharge circuit so as to replenish energy loss due to discharge, thereby enabling high-repetition discharge.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: April 5, 2011
    Assignee: MERSTech, Inc.
    Inventors: Ryuichi Shimada, Taku Takaku
  • Patent number: 7898113
    Abstract: In order to provide a pulse power supply device using regenerating magnetic energy stored in a discharge circuit to a capacitor so as to use it as next discharge energy and supplying a bipolar pulse current with high repetition, a bridge circuit is composed of four inverse-conductive semiconductor switches, a charged energy source capacitor is connected to a DC terminal of the bridge circuit, and an inductive load is connected to its AC terminal. A control signal is supplied to gates of the inverse-conductive semiconductor switches, and a control is made so that when a discharge current rises, is maintained or is reduced, all the gates are turned off, and the magnetic energy of the electric current can be automatically regenerated to the energy source capacitor by a diode function of the switches. Further, a large-current power supply is inserted into a discharge circuit so as to replenish energy loss due to discharge, thereby enabling high-repetition discharge.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: March 1, 2011
    Assignee: MERTHTech, Inc.
    Inventors: Ryuichi Shimada, Taku Takaku
  • Publication number: 20110032652
    Abstract: In order to protect Magnetic Energy Recovery Switch (MERS) against an overvoltage and an overcurrent a voltage detection unit is provided for detecting the capacitor voltage of the MERS and control means is provided to control so as to turn ON the switch of the discharge circuit connected in parallel with the capacitor to make the capacitor discharge the electric charge thereof when the output of the voltage detection unit exceeds a predetermined value. Moreover, a current detection unit is interposed between the AC power supply and the load for detecting the current flowing to the load, and the current limiting is carried out by making the duty ratio of the ON/OFF of the pulse of the gate control signals of the MERS switches smaller than 0.5, when the output of the current detection unit exceeds a predetermined value.
    Type: Application
    Filed: February 20, 2008
    Publication date: February 10, 2011
    Applicant: MERSTECH INC.
    Inventor: Ryuichi Shimada
  • Patent number: 7843166
    Abstract: The present invention relates to an alternating-current power supply device which can improve a power factor of an alternating-current load, realizes low cost and miniaturization, and recovers magnetic energy. The alternating-current power supply device includes a bridge circuit composed of four reverse conducting semiconductor switches, a capacitor that is connected between direct-current terminals of the bridge circuit and absorbs the magnetic energy at the time of cutting off the current, an alternating-current voltage source that is connected to the induction load in series and is inserted between alternating-current terminals of the bridge circuit, and a control circuit that gives a control signal to gates of the respective reverse conducting semiconductor switches and controls on/off states of the respective reverse conducting semiconductor switches.
    Type: Grant
    Filed: June 23, 2009
    Date of Patent: November 30, 2010
    Assignee: MERSTech, Inc.
    Inventors: Ryuichi Shimada, Hideo Sumitani, Taku Takaku, Takanori Isobe
  • Publication number: 20100277138
    Abstract: In order to provide a pulse power supply device using regenerating magnetic energy stored in a discharge circuit to a capacitor so as to use it as next discharge energy and supplying a bipolar pulse current with high repetition, a bridge circuit is composed of four inverse-conductive semiconductor switches, a charged energy source capacitor is connected to a DC terminal of the bridge circuit, and an inductive load is connected to its AC terminal. A control signal is supplied to gates of the inverse-conductive semiconductor switches, and a control is made so that when a discharge current rises, is maintained or is reduced, all the gates are turned off, and the magnetic energy of the electric current can be automatically regenerated to the energy source capacitor by a diode function of the switches. Further, a large-current power supply is inserted into a discharge circuit so as to replenish energy loss due to discharge, thereby enabling high-repetition discharge.
    Type: Application
    Filed: July 19, 2010
    Publication date: November 4, 2010
    Applicant: MERSTech Inc.
    Inventors: Ryuichi Shimada, Taku Takaku