Patents by Inventor Yuhi NAKADA
Yuhi NAKADA 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: 11870375Abstract: A motor apparatus is provided. The motor apparatus includes a motor having a rotor and a stator, an inverter used to covert an input voltage into a three-phase alternating current (AC) voltage and provide the three-phase AC voltage to the motor, an inverter controller used to control the inverter, and a rotation angle sensor. The rotation angle sensor is fixed to the motor and is used to detect a rotation angle of the motor. The inverter controller includes a calculator. The calculator calculates an offset angle of an installation position of the rotation angle sensor according to a difference between a measured value and a theoretical value of a voltage phase of the motor.Type: GrantFiled: April 6, 2022Date of Patent: January 9, 2024Assignee: NIDEC ELESYS CORPORATIONInventors: Takashi Koikegami, Satoshi Shimazu, Yuhi Nakada
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Patent number: 11791758Abstract: An inverter device is provided. The inverter device converts power from a power source and drives a motor. The inverter device includes an inverter circuit having a switch, a driver circuit that switches the switch on and off, and a controller that controls the driver circuit. The controller has a speed calculator used to calculate a minimum speed of the motor based on a power source voltage. After the controller performs fail-safe control, when a speed of the motor is less than the minimum speed, the fail-safe control is ended.Type: GrantFiled: April 6, 2022Date of Patent: October 17, 2023Assignee: NIDEC ELESYS CORPORATIONInventors: Satoshi Shimazu, Yuhi Nakada
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Publication number: 20220385206Abstract: The disclosure relates to an inverter device, including: an inverter circuit including a plurality of switching elements and a capacitor; an active discharge circuit including a first discharge resistor and a discharge switch connected in series, and connected between a positive electrode and a negative electrode of the capacitor; and a control circuit including a controller respectively connected to the switching elements and the discharge switch. The controller controls the switching elements and the discharge switch. The controller turns on the discharge switch to discharge the capacitor when the controller receives a discharge command from outside the inverter device and an electric motor is rotating.Type: ApplicationFiled: May 25, 2022Publication date: December 1, 2022Applicant: NIDEC ELESYS CORPORATIONInventors: Kazuhiro SAKAI, Satoshi Shimazu, Yuhi Nakada
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Patent number: 11472472Abstract: A power conversion device includes a first inverter and a control circuit that controls an on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings, where n is an integer of three or more. The control circuit generates a control signal to turn off all of n low-side switches and n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches and measures the n-phase voltages that change depending on patterns of on failures of the switches, and executes a first failure diagnosis to diagnose the on failures of the n low-side switches and the n high-side switches based on the measured n-phase voltages by referring to a table associating the patterns of the on failures of the switches with n-phase voltage levels.Type: GrantFiled: June 22, 2018Date of Patent: October 18, 2022Assignee: NIDEC CORPORATIONInventors: Takashi Koikegami, Yuhi Nakada, Kaori Nabeshi
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Publication number: 20220329185Abstract: A motor apparatus is provided. The motor apparatus includes a motor having a rotor and a stator, an inverter used to covert an input voltage into a three-phase alternating current (AC) voltage and provide the three-phase AC voltage to the motor, an inverter controller used to control the inverter, and a rotation angle sensor. The rotation angle sensor is fixed to the motor and is used to detect a rotation angle of the motor. The inverter controller includes a calculator. The calculator calculates an offset angle of an installation position of the rotation angle sensor according to a difference between a measured value and a theoretical value of a voltage phase of the motor.Type: ApplicationFiled: April 6, 2022Publication date: October 13, 2022Applicant: NIDEC ELESYS CORPORATIONInventors: Takashi Koikegami, Satoshi Shimazu, Yuhi Nakada
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Publication number: 20220329192Abstract: An inverter device is provided. The inverter device converts power from a power source and drives a motor. The inverter device includes an inverter circuit having a switch, a driver circuit that switches the switch on and off, and a controller that controls the driver circuit. The controller has a speed calculator used to calculate a minimum speed of the motor based on a power source voltage. After the controller performs fail-safe control, when a speed of the motor is less than the minimum speed, the fail-safe control is ended.Type: ApplicationFiled: April 6, 2022Publication date: October 13, 2022Applicant: NIDEC ELESYS CORPORATIONInventors: Satoshi Shimazu, Yuhi Nakada
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Patent number: 11205986Abstract: An inverter device includes a motor, a power supply that supplies the motor with electric current, an inverter that, during regenerative operation of the motor, performs switching between a first state in which regenerative current generated in the motor is returned to the motor again and a second state in which the regenerative current is supplied to the power supply, a first detector that detects a first condition electrically acting on the inverter, a second detector that detects a second condition electrically acting on the power supply, and a determiner that performs a first determination to perform switching between the first state and the second state, based on a detection result by the first detector or the second detector.Type: GrantFiled: February 20, 2020Date of Patent: December 21, 2021Assignees: NIDEC CORPORATION, NIDEC ELESYS CORPORATIONInventors: Yuhi Nakada, Ryo Tachibana, Koji Mukaiyama
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Patent number: 11063545Abstract: A power conversion device includes a first inverter and a control circuit that controls on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings where n is an integer of three or more. The control circuit generates a control signal to turn on one low-side switch of a first specific phase among n low-side switch in the first inverter, turn off the remaining n?1 low-side switches, and turn off all n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches in a state where a neutral point of a motor is provided, measures n-phase voltages that change depending on patterns of disconnection failures of the n-phase windings, and diagnoses a disconnection failure based on the measured n-phase voltages by referring to a table associating the patterns of the disconnection failures with n-phase voltage levels.Type: GrantFiled: July 10, 2018Date of Patent: July 13, 2021Assignee: NIDEC CORPORATIONInventors: Takashi Koikegami, Yuhi Nakada, Takahiro Kikuichi, Jun Katsumata, Hironori Takano
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Publication number: 20200313596Abstract: An inverter device includes a motor, a power supply that supplies the motor with electric current, an inverter that, during regenerative operation of the motor, performs switching between a first state in which regenerative current generated in the motor is returned to the motor again and a second state in which the regenerative current is supplied to the power supply, a first detector that detects a first condition electrically acting on the inverter, a second detector that detects a second condition electrically acting on the power supply, and a determiner that performs a first determination to perform switching between the first state and the second state, based on a detection result by the first detector or the second detector.Type: ApplicationFiled: February 20, 2020Publication date: October 1, 2020Inventors: Yuhi NAKADA, Ryo TACHIBANA, Koji MUKAIYAMA
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Publication number: 20200274461Abstract: An electric power conversion device includes a first inverter connected to one end of each phase winding of a motor, a second inverter connected to another end of each phase winding, and a control circuit to control operation of the first and second inverters. The control circuit configures a neutral point in the first inverter and applies a voltage to a path in which a high-side of the second inverter, the first-phase winding, the neutral point, the second-phase winding, and a low-side of the second inverter are connected, and diagnoses whether the first and second inverters are faulty.Type: ApplicationFiled: June 11, 2018Publication date: August 27, 2020Inventors: Takashi KOIKEGAMI, Yuhi NAKADA, Takahiro KIKUICHI
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Publication number: 20200247464Abstract: A power conversion device includes a first inverter and a control circuit that controls an on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings, where n is an integer of three or more. The control circuit generates a control signal to turn off all of n low-side switches and n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches and measures the n-phase voltages that change depending on patterns of on failures of the switches, and executes a first failure diagnosis to diagnose the on failures of the n low-side switches and the n high-side switches based on the measured n-phase voltages by referring to a table associating the patterns of the on failures of the switches with n-phase voltage levels.Type: ApplicationFiled: June 22, 2018Publication date: August 6, 2020Inventors: Takashi KOIKEGAMI, Yuhi NAKADA, Kaori NABESHI
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Publication number: 20200186075Abstract: A power conversion device includes a first inverter and a control circuit that controls on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings where n is an integer of three or more. The control circuit generates a control signal to turn on one low-side switch of a first specific phase among n low-side switch in the first inverter, turn off the remaining n?1 low-side switches, and turn off all n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches in a state where a neutral point of a motor is provided, measures n-phase voltages that change depending on patterns of disconnection failures of the n-phase windings, and diagnoses a disconnection failure based on the measured n-phase voltages by referring to a table associating the patterns of the disconnection failures with n-phase voltage levels.Type: ApplicationFiled: July 10, 2018Publication date: June 11, 2020Inventors: Takashi KOIKEGAMI, Yuhi NAKADA, Takahiro KIKUICHI, Jun KATSUMATA, Hironori TAKANO
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Publication number: 20200136471Abstract: A cooling system includes a coolant circulation flow path, a motor thermometer, an inverter thermometer, and a controller connected to the motor thermometer and the inverter thermometer. An oil cooler that cools oil supplied to the motor, the inverter that supplies electric power to the motor, a radiator that cools the coolant, and a coolant pump that pumps the coolant are arranged in series in a channel of the coolant circulation flow path. The controller executes a first step of calculating a drive output of the coolant pump based on the temperature of the motor, a second step of calculating a drive output of the coolant pump based on the temperature of the inverter, and a third step of selecting one of a calculation result of the first and second step having a larger drive output to drive the coolant pump.Type: ApplicationFiled: October 18, 2019Publication date: April 30, 2020Inventors: Keisuke FUKUNAGA, Yuhi NAKADA, Satoshi SHIMAZU
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Publication number: 20190334465Abstract: A motor drive includes limiting circuitry that controls a motor based on an instruction torque, and calculates a limitation rate that limits the instruction torque. The instruction torque is limited based on the limitation rate calculated by the limiting circuitry. The motor drive also includes a controller that outputs electric power to drive the motor based on the limited instruction torque.Type: ApplicationFiled: April 24, 2019Publication date: October 31, 2019Inventors: Yuhi NAKADA, Takashi KOIKEGAMI, Isao SAMBOMMATSU, Koji MUKAIYAMA