Motor driving system for electric vehicle

摘要

To provide a motor driving system for an electrically powered automotive vehicle, in which the drive motor is rotationally controlled to increase the reliability, the use is made of an angle sensor for detecting the relative rotational angle between a stator and a rotor of a drive motor for driving the electric vehicle and a controller for controlling the rotation of the drive motor on the basis of the relative rotational angle detected by the angle sensor. The angle sensor is provided in a plural number. The controller includes an angle sensor switching unit operable to select and activate one of the plurality of the angle sensors and then to switch over to an activation of another one of the angle sensors in the event that the one of the angle sensors is determined abnormal.

主权项

1. A motor drive system for a wheel of an electrically powered automotive vehicle, which system comprises:
a plurality of angle sensors, each of the angle sensors being configured to detect a relative rotational angle between a stator and a rotor of a drive motor for driving the automotive vehicle; and a controller for controlling the rotation of the drive motor on the basis of the relative rotational angle detected by one of the angle sensors, the controller including a driver circuit subunit which is provided with an inverter and a voltage varying circuit, the inverter applying an inverter voltage output to a coil of the stator of the drive motor, the voltage varying circuit variably controlling a voltage of a battery to be supplied to the inverter; wherein the controller comprises an angle sensor switching unit operable to select and activate one of the plurality of the angle sensors and then to switch over to an activation of another one of the angle sensors in the event that the one of the angle sensors is determined abnormal, and wherein the angle sensor switching unit is operable to switch over to a sensorless drive mode, in the event that all of the angle sensors are determined abnormal, and the controller estimates the relative rotational angle between the stator and the rotor of the drive motor from an inverter voltage output applied to the stator of the drive motor and an electric current flowing across a coil of the stator and then controls the rotation of the drive motor on the basis of the relative rotational angle so estimated.