Patents by Inventor Yugo Tadano

Yugo Tadano 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: 20130135907
    Abstract: A current control unit takes a deviation between a current command value and a current flowing through an inverter of a power conversion device, and controls the inverter based on the deviation. A harmonic sensing part receives input of an output current of an AC filter, and outputs a predetermined order harmonic of the input current in a direct current value form. A disturbance observer estimates the disturbance of the harmonic based on the output current and a coefficient defined as an inverse function of a transfer function from harmonic suppression current command value to filter output current detection value. A harmonic suppression control unit takes the deviation between the estimated harmonic disturbance and a disturbance command value that suppresses the disturbance, and calculates a harmonic suppression current command value. The harmonic suppression current command value is superimposed on the current command value of the current control unit.
    Type: Application
    Filed: August 5, 2011
    Publication date: May 30, 2013
    Applicant: Meidensha Corporation
    Inventors: Kazunobu Oi, Yugo Tadano
  • Publication number: 20120306411
    Abstract: A periodic disturbance observer determines real part I?An and imaginary part I?Bn of an estimated current including a periodic disturbance, from value of identification identifying a system transfer function of an nth order torque ripple frequency component from a command torque to a detected torque value, with a one-dimensional complex vector having a real part P?An and an imaginary part P?Bn, a cosine coefficient TAn, a sine coefficient TBn, and the real part P?An and imaginary part P?Bn of the system transfer function; subtracts command compensating current IAn* and IBn* obtained through pulsation extracting filter GF, respectively, from the real part I?An and imaginary part I?Bn of the estimated current, and thereby determines estimated periodic disturbance current real part dI?An and imaginary part dI?Bn to cancel the periodic disturbance current.
    Type: Application
    Filed: February 22, 2011
    Publication date: December 6, 2012
    Applicant: MEIDENSHA CORPORATION
    Inventor: Yugo Tadano
  • Patent number: 8315077
    Abstract: [Object] The present invention provides a space vector modulation method for an AC-AC direct conversion device, which can convert input and output waveforms into sine waves and reduce the number of times of switching at an inter-sector shift. [Means to Solve] A vector state in which a line voltage of multi-phase AC output is expanded onto a two-phase static ?? coordinates is defined. Simple harmonic oscillation vector axes of a sector where an output voltage command value vector Vo* exists are defined as an X axis and a Y axis. Maximum/middle/minimum vectors in each axis, a zero vector that is an intermediate voltage of a phase voltage, and one rotation vector that is present in the sector, are set as base vectors. A switching selection pattern formed by a combination of four vectors among these vectors, which satisfies predetermined conditions, is determined by a selection means 15.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: November 20, 2012
    Assignee: Meidensha Corporation
    Inventor: Yugo Tadano
  • Patent number: 8299739
    Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to solve the task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: October 30, 2012
    Assignee: Meidensha Corporation
    Inventors: Toru Kakebayashi, Takashi Yamaguchi, Yugo Tadano
  • Patent number: 8232759
    Abstract: [Problem] In a pseudo-current source inverter which drives a motor at a high speed, a current phase adjustment is assured and facilitated to perform a field-weakening control or suppress a terminal voltage saturation at a time of the high-speed motor drive. [Means For Solving Problem] A phase advance correction is carried out for a magnetic flux phase information from which a 120 degree conduction pattern is obtained with a motor terminal voltage as a reference phase. The phase advance correction includes the correction of differentiating the terminal voltage detection signals of the motor, the adjustment of enlarging the phase advance correction quantity in a case where the motor load current is large, and delays the gate signals of the 120 degree conduction pattern in accordance with the speed estimation value through a delay counter and carries out the phase advance correction as the rising edge timing of the subsequent gate signal at the subsequent step phase.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: July 31, 2012
    Assignee: Meidensha Corporation
    Inventor: Yugo Tadano
  • Publication number: 20120109549
    Abstract: A motor drive device including a battery 10; switching elements 15 and 16 which are connected in series with a condenser C2 having a voltage Vdc resulting from an increase action of battery voltage and which are operated in a chopper control; a reactor L2 whose one end is connected with a common connection point of the switching elements 15 and 16; and an inverter 19 for driving a PM motor 20 which is connected between another end of the reactor L2 and a negative-pole terminal of the battery 10. In such a motor drive device, an electrical power W is determined based on the voltage Vdc of positive-side point P of the condenser C2, a current Idc flowing in the reactor L2, and a switching duty d1 of the switching element 15 which satisfies a condition of 0?d1?1, i.e., is determined by calculating Vdc·d1·Idc.
    Type: Application
    Filed: July 8, 2010
    Publication date: May 3, 2012
    Inventors: Takashi Yamaguchi, Yugo Tadano, Toru Kakebayashi
  • Publication number: 20110316463
    Abstract: Disclosed is a current source inverter device which controls the power factor in an arbitrarily configurable manner without a magnetic pole position detector. The device is provided with a current source inverter; a motor supplied with alternating current power from the current source inverter; and a control means which detects the terminal voltage of the motor, calculates the motor's internal induced voltage and the motor current that flows in the motor based on the detected terminal voltage, and controls the current source inverter. The control means calculates the phase difference (?c) between the terminal voltage and the motor current, the phase difference (?x) between the motor current and the internal induced voltage, and the phase difference (?v) between the terminal voltage and the internal induced voltage.
    Type: Application
    Filed: March 5, 2010
    Publication date: December 29, 2011
    Inventors: Takashi Yamaguchi, Yugo Tadano, Toru Kakebayashi
  • Publication number: 20100149848
    Abstract: [Problem] To provide a space vector modulation method for a matrix converter which uses only one carrier for three phases when a carrier comparison is made. [Means for solving problem] Provided is a matrix converter space vector modulation method in which bidirectional switches (SW1 through SW9) of a matrix converter (3) are PWM controlled in a space vector modulation from a multi-phase AC power source. Switching patterns for which virtual indirect space vectors are used are converted into switching patterns for which direct conversion space vectors constituted by five vectors are used. Any one of the converted switching patterns satisfying predetermined conditions is selected and duties of the five vectors of the selected switching pattern are calculated using duty relationship equations between the virtual indirect conversion space vectors and the direct conversion space vectors. Then, the matrix converter is PWM-controlled on a basis of the calculated duties.
    Type: Application
    Filed: March 12, 2008
    Publication date: June 17, 2010
    Inventors: Shota Urushibata, Yugo Tadano
  • Publication number: 20100148711
    Abstract: [Problem] In a pseudo-current source inverter which drives a motor at a high speed, a current phase adjustment is assured and facilitated to perform a field-weakening control or suppress a terminal voltage saturation at a time of the high-speed motor drive. [Means For Solving Problem] A phase advance correction is carried out for a magnetic flux phase information from which a 120 degree conduction pattern is obtained with a motor terminal voltage as a reference phase. The phase advance correction includes the correction of differentiating the terminal voltage detection signals of the motor, the adjustment of enlarging the phase advance correction quantity in a case where the motor load current is large, and delays the gate signals of the 120 degree conduction pattern in accordance with the speed estimation value through a delay counter and carries out the phase advance correction as the rising edge timing of the subsequent gate signal at the subsequent step phase.
    Type: Application
    Filed: June 12, 2008
    Publication date: June 17, 2010
    Inventor: Yugo Tadano
  • Publication number: 20100141188
    Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to Solve the Task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.
    Type: Application
    Filed: March 12, 2008
    Publication date: June 10, 2010
    Inventors: Toru Kakebayashi, Takashi Yamaguchi, Yugo Tadano
  • Publication number: 20100091534
    Abstract: [Object] The present invention provides a space vector modulation method for an AC-AC direct conversion device, which can convert input and output waveforms into sine waves and reduce the number of times of switching at an inter-sector shift. [Means to Solve] A vector state in which a line voltage of multi-phase AC output is expanded onto a two-phase static ?? coordinates is defined. Simple harmonic oscillation vector axes of a sector where an output voltage command value vector Vo* exists are defined as an X axis and a Y axis. Maximum/middle/minimum vectors in each axis, a zero vector that is an intermediate voltage of a phase voltage, and one rotation vector that is present in the sector, are set as base vectors. A switching selection pattern formed by a combination of four vectors among these vectors, which satisfies predetermined conditions, is determined by a selection means 15.
    Type: Application
    Filed: March 12, 2008
    Publication date: April 15, 2010
    Inventor: Yugo Tadano