Nsk Corporation

Tomohiro Miura

Takahiro Tsubaki

Masahiro Maeda

Yousuke Imamura

Nobuaki Kogure

Takashi Sunaga

Lilit Kovudhikulrungsri

Haruhiko Kamiguchi

An electric power steering apparatus includes a control substrate that controls a poly-phase motor having a multi-system motor winding, including a temperature sensor that detects a substrate temperature of said control substrate; and a coil temperature estimating section that obtains coil calorific values of respective phases of said poly-phase motor and a substrate calorific value of said control substrate by a motor current of said phase, and estimates a coil temperature of said phase by said coil calorific value, said substrate calorific value and said substrate temperature based on a heat transfer phenomenon between said respective phases that is caused by a difference in temperature between coils of said respective phases and a heat transfer phenomenon between said coil and said control substrate.

Electric power steering apparatus

An electric power steering apparatus that enables more precise estimation of a coil temperature by considering a heat transfer phenomenon between a control substrate and a poly-phase coil in addition to a heat transfer phenomenon between respective phases of the coil. The apparatus includes a control substrate that controls a poly-phase motor, a temperature sensor that detects a substrate temperature of the control substrate and a coil temperature estimating section that estimates coil temperatures of respective phases of the poly-phase motor by a motor current of the phase and the substrate temperature based on a heat transfer phenomenon between the respective phases that is caused by a difference in temperature between coils of the respective phases and a heat transfer phenomenon between the coil and the control substrate.

A motor control apparatus that calculates duty command values of respective phases for controlling currents of a motor by means of a control calculation, forms PWM-signals in correspondence to the duty command values, drives the motor by means of an inverter based on the PWM-signals, and which is provided a rotation sensor to detect a motor angle of the motor.

Motor control apparatus and electric power steering apparatus using the same

To detect and store occurrence of a reverse connection when the reverse connection has occurred, and to restricts a power assist at the next startup of a controller. In an ECU for controlling an electric motor that applies a steering assist torque on a steering mechanism, a microcomputer transmits a drive signal to a driver that drives an inverter, which controls current of the electric motor, in accordance with the drive signal. A reverse connection storage circuit is attached in parallel with the inverter, and detects and stores the occurrence of the reverse connection when the reverse connection of the ECU and a battery has occurred, and notifies the microcomputer of the occurrence of the reverse connection at the next startup of the ECU. The microcomputer transmits a signal indicating non-permission to the driver in accordance with the notification. The driver restricts the power assist upon receiving the signal.

To provide a power supply relay controller and an electric power steering apparatus capable of appropriately preventing contact failure of relays. When abnormal conduction between relay contacts occurs, a power supply relay circuit is opened and closed while a predetermined potential difference is applied between the relay contacts. At this time, an operation for turning on the relay contacts is performed while the charge of an electrolytic capacitor by a precharge circuit is limited. In this way, an ice layer between the relay contacts is removed by thermal energy of an arc that is generated between the contacts by a potential difference between the relay contacts.

Power supply relay controller and electric power steering apparatus

An object of the present invention is to provide a motor control device capable of suppressing voltage composite vector fluctuation to increase the output of a brushless motor, and a motor-driven power steering system using this device. The present control device calculates motor phase current command values based on a target current and a rotor rotational position detection value, calculates voltage command values based on the motor phase current command values and phase current detection values, and supplies phase currents to a three-phase brushless motor based on the voltage command values. The present control device outputs the phase current command values so that the absolute value of a composite vector of respective phase drive voltages is substantially a value &#x221a;3/2 times the power supply voltage.

Growing community of inventors

Maebashi, Japan

Tomohiro Miura