Patents by Inventor Tsunehiro Endo

Tsunehiro Endo 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).

  • Patent number: 8035330
    Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: October 11, 2011
    Assignees: Hitachi, Ltd., Hitachi Information & Control Solutions, Ltd.
    Inventors: Daisuke Maeda, Tsunehiro Endo, Hidefumi Shirahama, Kenji Sakurai, Hiroyuki Hasegawa, Mitsuhiro Mishima
  • Publication number: 20110182096
    Abstract: Provided is a control technique of a PWM conversion type power converter capable of compensating for a voltage error due to voltage drop mainly at a switching element and managing a switching time of a PWM signal at the same time, and capable of suppressing increase/decrease of software operation load and addition of a hardware circuit to the minimum. A semiconductor integrated circuit having a PWM signal generating unit which generates a PWM signal is provided with a PWM timer unit including a counter counting a pulse width of a pulse signal inputted from the outside with delay from a PWM signal, a register loading a counter value of the counter in synchronization with the PWM signal, and an A/D converting unit converting an analog signal serving as a source signal of the pulse signal inputted from the outside to a digital signal.
    Type: Application
    Filed: April 5, 2011
    Publication date: July 28, 2011
    Inventors: Takahiro Suzuki, Yasuo Notohara, Tsunehiro Endo, Yuji Mori
  • Patent number: 7944720
    Abstract: Provided is a control technique of a PWM conversion type power converter capable of compensating for a voltage error due to voltage drop mainly at a switching element and managing a switching time of a PWM signal at the same time, and capable of suppressing increase/decrease of software operation load and addition of a hardware circuit to the minimum. A semiconductor integrated circuit having a PWM signal generating unit which generates a PWM signal is provided with a PWM timer unit including a counter counting a pulse width of a pulse signal inputted from the outside with delay from a PWM signal, a register loading a counter value of the counter in synchronization with the PWM signal, and an A/D converting unit converting an analog signal serving as a source signal of the pulse signal inputted from the outside to a digital signal.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: May 17, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Takahiro Suzuki, Yasuo Notohara, Tsunehiro Endo, Yuji Mori
  • Publication number: 20110018485
    Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.
    Type: Application
    Filed: October 5, 2010
    Publication date: January 27, 2011
    Inventors: Daisuke MAEDA, Tsunehiro ENDO, Hidefumi SHIRAHAMA, Kenji SAKURAI, Hiroyuki HASEGAWA, Mitsuhiro MISHIMA
  • Patent number: 7839113
    Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: November 23, 2010
    Assignees: Hitachi, Ltd., Hitachi Information & Control Solutions, Ltd.
    Inventors: Daisuke Maeda, Tsunehiro Endo, Hidefumi Shirahama, Kenji Sakurai, Hiroyuki Hasegawa, Mitsuhiro Mishima
  • Patent number: 7839663
    Abstract: A converter includes a converter circuit 1 having a plurality of bridge-connected semiconductor switching devices for converting AC power into DC power, a smoothing condenser connected in parallel to the DC side of the converter circuit and a current detector provided in a condenser circuit to control a condenser current flowing through the smoothing condenser to be a set value. The condenser current is controlled to be the set value (e.g. zero) to thereby reduce the capacity of the smoothing condenser and make the converter small.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: November 23, 2010
    Assignee: Hitachi Appliances, Inc.
    Inventors: Takahiro Suzuki, Yoshitaka Iwaji, Tsunehiro Endo, Yasuo Notohara, Yoshiaki Kurita, Tatsuo Ando, Chikara Tanaka
  • Patent number: 7821223
    Abstract: In a system in which current is detected in an inexpensive manner or in a system in which a position detector is omitted, the present invention provides a high-efficiency vector controller for a permanent magnet motor that can minimize current at the same torque even when there is setting error (R?R*) in resistance. Even when a current value commanded for the d-axis is set to zero, a virtual inductance value calculated from a detected q-axis current value is used for output voltage value calculation and phase error estimation calculation; so even if there is setting error (R?R*) in resistance, current can be minimized at the same torque and thereby the present invention can provide a high-efficiency vector controller for a permanent magnet motor.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: October 26, 2010
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd
    Inventors: Kazuaki Tobari, Tsunehiro Endo, Kiyoshi Sakamoto, Daisuke Maeda, Shigehisa Aoyagi
  • Patent number: 7619385
    Abstract: 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: Grant
    Filed: July 28, 2006
    Date of Patent: November 17, 2009
    Assignees: 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
  • Patent number: 7602138
    Abstract: 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: Grant
    Filed: September 27, 2006
    Date of Patent: October 13, 2009
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Daigo Kaneko, Takahiro Suzuki, Tsunehiro Endo, Kazuaki Tobari, Hajime Uematsu
  • Publication number: 20090135630
    Abstract: A converter includes a converter circuit 1 having a plurality of bridge-connected semiconductor switching devices for converting AC power into DC power, a smoothing condenser connected in parallel to the DC side of the converter circuit and a current detector provided in a condenser circuit to control a condenser current flowing through the smoothing condenser to be a set value. The condenser current is controlled to be the set value (e.g. zero) to thereby reduce the capacity of the smoothing condenser and make the converter small.
    Type: Application
    Filed: December 16, 2008
    Publication date: May 28, 2009
    Inventors: Takahiro Suzuki, Yoshitaka Iwaji, Tsunehiro Endo, Yasuo Notohara, Yoshiaki Kurita, Tatsuo Ando, Chikara Tanaka
  • Patent number: 7528568
    Abstract: A vector controller for a permanent magnet synchronous motor according to the present invention has a motor constant identifying unit for identifying motor constants of the permanent magnet synchronous motor, which is connected to an electric power converter in the vector controller, by using a second d-axis current command value, a second q-axis current command value, a detected output current of the electric power converter, and motor constant settings. The vector controller uses the motor constants identified by the motor constant identifying unit in vector control calculation so as to control the driving of the permanent magnet synchronous motor. Thereby, the vector controller achieves torque control with high accuracy and superior responsiveness.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: May 5, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Tobari, Tsunehiro Endo, Yoshiki Ito
  • Patent number: 7521887
    Abstract: A vector controller for a permanent magnet synchronous motor uses current command values and detected currents of the d-axis and q-axis, a calculated frequency, and motor constant settings to control the output voltage of a power converter; the motor constants are identified by use of active or reactive power obtained from the output voltage and detected current of the power converter, the calculated frequency, and the detected current immediately before or during an actual operation.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: April 21, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Tobari, Tsunehiro Endo
  • Publication number: 20090066384
    Abstract: Provided is a control technique of a PWM conversion type power converter capable of compensating for a voltage error due to voltage drop mainly at a switching element and managing a switching time of a PWM signal at the same time, and capable of suppressing increase/decrease of software operation load and addition of a hardware circuit to the minimum. A semiconductor integrated circuit having a PWM signal generating unit which generates a PWM signal is provided with a PWM timer unit including a counter counting a pulse width of a pulse signal inputted from the outside with delay from a PWM signal, a register loading a counter value of the counter in synchronization with the PWM signal, and an A/D converting unit converting an analog signal serving as a source signal of the pulse signal inputted from the outside to a digital signal.
    Type: Application
    Filed: August 14, 2008
    Publication date: March 12, 2009
    Inventors: TAKAHIRO SUZUKI, Yasuo Notohara, Tsunehiro Endo, Yuji Mori
  • Patent number: 7471525
    Abstract: A converter includes a converter circuit 1 having a plurality of bridge-connected semiconductor switching devices for converting AC power into DC power, a smoothing condenser connected in parallel to the DC side of the converter circuit and a current detector provided in a condenser circuit to control a condenser current flowing through the smoothing condenser to be a set value. The condenser current is controlled to be the set value (e.g. zero) to thereby reduce the capacity of the smoothing condenser and make the converter small.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: December 30, 2008
    Assignee: Hitachi Appliances, Inc.
    Inventors: Takahiro Suzuki, Yoshitaka Iwaji, Tsunehiro Endo, Yasuo Notohara, Yoshiaki Kurita, Tatsuo Ando, Chikara Tanaka
  • Patent number: 7443120
    Abstract: A field weakening vector controller is disclosed which calculates a d-axis current command value for a power converter to drive a permanent magnet synchronous motor. The field weakening vector controller includes a stabilization calculator, a d-axis current command calculator, a q-axis current command calculator, and a phase calculator. The d-axis current command calculator corrects the d-axis current command value, while the stabilization calculator calculates a product of the phase error and the d-axis command value. The q-axis current command calculator corrects the q-axis current command value using this product.
    Type: Grant
    Filed: October 19, 2006
    Date of Patent: October 28, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Tobari, Daisuke Maeda, Tsunehiro Endo
  • Publication number: 20080203962
    Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.
    Type: Application
    Filed: January 25, 2008
    Publication date: August 28, 2008
    Inventors: Daisuke Maeda, Tsunehiro Endo, Hidefumi Shirahama, Kenji Sakurai, Hiroyuki Hasegawa, Mitsuhiro Mishima
  • Patent number: 7388341
    Abstract: A vector control system for a permanent magnet synchronous motor, using a current control equivalent output value, a frequency instruction value, a current detection value, an inference phase error value, and a motor constant, identifies a motor resistance equivalent or a resistance setting error equivalent. Next, the vector control unit, using the identified value, corrects a set value R* equivalent of a voltage instruction calculation unit and a n inference phase error calculation unit. Thereby, a vector control system for a permanent magnet synchronous motor can realize a robust control characteristic for changing of a resistance constant of a motor in a low rotation speed area under position sensor-less control. Further, a vector control system for a permanent magnet synchronous motor can be applied in common in a system performing inexpensive current detection.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: June 17, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Tobari, Kiyoshi Sakamoto, Tsunehiro Endo, Yoshitaka Iwaji, Yukio Kawabata, Shigehisa Aoyagi
  • Patent number: 7342378
    Abstract: A driving apparatus of a synchronous motor fixes all the switching devices of an inverter at OFF in accordance with a value of an all-OFF control pulse signal outputted by a pulse generator. A motor current keeps flowing through free wheel diodes for a predetermined period even after all the switching devices shift to the OFF state. Therefore, pulse generator changes an induced voltage detection signal to an H (high) level after the passage of the time in which a motor current drops down to zero. A terminal voltage of the motor is taken in to acquire an induced voltage and a rotor position is estimated.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: March 11, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoshi Sakamoto, Tsunehiro Endo, Hidefumi Shirahama, Yoshiaki Ajima
  • Patent number: 7332882
    Abstract: A voltage detector is connected to a connection terminal connected to one phase of an AC output of an inverter through a diode. A removable charge power supply is connected to said connection terminal and another connection terminal. A charge-power-supply connection judging circuit judges whether the charge power supply is or isn't connected, based on a charge power supply voltage detected by a voltage detector. A mode change control circuit outputs switch signal by the result of said judgment. By receiving this switch signal, the inverter controller switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode. Thereby, a motor drive device detects a connecting status of an external charge power supply and steadily switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: February 19, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Shigehisa Aoyagi, Tsunehiro Endo, Hidefumi Shirahama, Yoshiki Ito
  • Patent number: 7276876
    Abstract: 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: Grant
    Filed: August 18, 2005
    Date of Patent: October 2, 2007
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Daigo Kaneko, Yoshitaka Iwaji, Kiyoshi Sakamoto, Tsunehiro Endo, Tomofumi Okubo