Patents by Inventor Daigo Kaneko
Daigo Kaneko 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: 8760095Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.Type: GrantFiled: December 12, 2011Date of Patent: June 24, 2014Assignee: Hitachi, Ltd.Inventors: Yoshitaka Iwaji, Daigo Kaneko, Kento Mochizuki, Takeshi Shinomiya, Daisuke Kori, Seikichi Masuda
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Patent number: 8674647Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.Type: GrantFiled: February 18, 2011Date of Patent: March 18, 2014Assignee: Hitachi, Ltd.Inventors: Yoshitaka Iwaji, Daigo Kaneko, Kouki Yamamoto
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Patent number: 8541971Abstract: When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time ?t since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.Type: GrantFiled: August 20, 2010Date of Patent: September 24, 2013Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Toshifumi Sakai, Yoshitaka Iwaji, Kiyoshi Sakamoto, Yoshiyuki Taguchi, Daigo Kaneko
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Publication number: 20120146567Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.Type: ApplicationFiled: December 12, 2011Publication date: June 14, 2012Applicant: Hitachi, Ltd.Inventors: Yoshitaka IWAJI, Daigo Kaneko, Kento Mochizuki, Takeshi Shinomiya, Daisuke Kori, Seikichi Masuda
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Publication number: 20110204831Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.Type: ApplicationFiled: February 18, 2011Publication date: August 25, 2011Inventors: Yoshitaka Iwaji, Daigo Kaneko, Kouki Yamamoto
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Publication number: 20110050140Abstract: When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time ?t since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.Type: ApplicationFiled: August 20, 2010Publication date: March 3, 2011Inventors: Toshifumi Sakai, Yoshitaka Iwaji, Kiyoshi Sakamoto, Yoshiyuki Taguchi, Daigo Kaneko
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Patent number: 7719226Abstract: Current command values are used instead of detected current values to estimate axis error by calculation. An axis error command value is generated according to a speed command value, and a difference between the generated axis error command value and the estimated axis error value is used to control an estimated frequency value.Type: GrantFiled: December 27, 2007Date of Patent: May 18, 2010Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Kazuaki Tobari, Yoshitaka Iwaji, Daigo Kaneko, Hajime Uematsu, Masakazu Hase
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Patent number: 7619385Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.Type: GrantFiled: July 28, 2006Date of Patent: November 17, 2009Assignees: Hitachi, Ltd., Hitachi Industrial Equipment Systems, Co., Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Takahiro Suzuki, Tsunehiro Endo, Kazuaki Tobari, Daigo Kaneko, Daisuke Maeda, Akira Yamazaki
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Patent number: 7602138Abstract: An apparatus for controlling the drive of an electric motor, having a current detector for detecting the current through an externally connected electric motor; a controller for generating a control signal to control the electric motor on the basis of the current detected by the current detector and the speed command for specifying the rotational speed of the electric motor; wherein the apparatus includes a load estimator for estimating the mechanical load condition associated with the electric motor on the basis of the current detected by the current detector and the speed command, and the controller controls the electric motor current on the basis of the detected current, the speed command and the estimated load condition.Type: GrantFiled: September 27, 2006Date of Patent: October 13, 2009Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Daigo Kaneko, Takahiro Suzuki, Tsunehiro Endo, Kazuaki Tobari, Hajime Uematsu
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Publication number: 20080157709Abstract: Current command values are used instead of detected current values to estimate axis error by calculation. An axis error command value is generated according to a speed command value, and a difference between the generated axis error command value and the estimated axis error value is used to control an estimated frequency value.Type: ApplicationFiled: December 27, 2007Publication date: July 3, 2008Inventors: Kazuaki Tobari, Yoshitaka Iwaji, Daigo Kaneko, Hajime Uematsu, Masakazu Hase
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Patent number: 7276876Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.Type: GrantFiled: August 18, 2005Date of Patent: October 2, 2007Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Daigo Kaneko, Yoshitaka Iwaji, Kiyoshi Sakamoto, Tsunehiro Endo, Tomofumi Okubo
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Publication number: 20070159130Abstract: An apparatus for controlling the drive of an electric motor, having a current detector for detecting the current through an externally connected electric motor; a controller for generating a control signal to control the electric motor on the basis of the current detected by the current detector and the speed command for specifying the rotational speed of the electric motor; wherein the apparatus includes a load estimator for estimating the mechanical load condition associated with the electric motor on the basis of the current detected by the current detector and the speed command, and the controller controls the electric motor current on the basis of the detected current, the speed command and the estimated load condition.Type: ApplicationFiled: September 27, 2006Publication date: July 12, 2007Inventors: Daigo Kaneko, Takahiro Suzuki, Tsunehiro Endo, Kazuaki Tobari, Hajime Uematsu
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Patent number: 7199547Abstract: In order to control the position of a mobile body without using a position detector, a magnetic pole position of a rotor of a synchronous motor is estimated based on electrical quantities in relation to electric power supplied to the synchronous motor and then the mobile body position is estimated based on the estimated magnetic pole position.Type: GrantFiled: October 19, 2001Date of Patent: April 3, 2007Assignee: Hitachi, Ltd.Inventors: Daigo Kaneko, Hiromi Inaba, Tsunehiro Endo, Ikuo Yamato, Naoto Ohnuma
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Publication number: 20070024232Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.Type: ApplicationFiled: July 28, 2006Publication date: February 1, 2007Inventors: Takahiro Suzuki, Tsunehiro Endo, Kazuaki Tobari, Daigo Kaneko, Daisuke Maeda, Akira Yamazaki
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Publication number: 20060113948Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.Type: ApplicationFiled: August 18, 2005Publication date: June 1, 2006Inventors: Daigo Kaneko, Yoshitaka Iwaji, Kiyoshi Sakamoto, Tsunehiro Endo, Tomofumi Okubo
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Patent number: 7030589Abstract: An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.Type: GrantFiled: February 27, 2004Date of Patent: April 18, 2006Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Daigo Kaneko, Yoshitaka Iwaji, Kiyoshi Sakamoto, Tsunehiro Endo, Tomofumi Okubo
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Publication number: 20040263114Abstract: An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.Type: ApplicationFiled: February 27, 2004Publication date: December 30, 2004Inventors: Daigo Kaneko, Yoshitaka Iwaji, Kiyoshi Sakamoto, Tsunehiro Endo, Tomofumi Okubo
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Publication number: 20020175651Abstract: In order to control the position of a mobile body without using a position detector, a magnetic pole position of a rotor of a synchronous motor is estimated based on electrical quantities in relation to electric power supplied to the synchronous motor and then the mobile body position is estimated based on the estimated magnetic pole position.Type: ApplicationFiled: October 19, 2001Publication date: November 28, 2002Applicant: Hitachi, Ltd.Inventors: Daigo Kaneko, Hiromi Inaba, Tsunehiro Endo, Ikuo Yamato, Naoto Ohnuma