Motor control device for electric automobile

摘要

A magnetic force estimating unit (38) for estimating the magnetic force of a permanent magnet of a rotor of a motor (6), a determining unit (39), and a demagnetization responsive timing changing unit (40) are provided in an inverter device (22) or an electric control unit (21). The magnetic force estimating unit (38) performs a determination of the magnetic force with a predetermined rule from detection signals of at least two of the motor rotation number, motor voltage and motor current. The determining unit (39) determines whether or not a demagnetization occurs. In response to the result of determination by the determining unit (39), the demagnetization responsive timing changing unit (40) changes the timing, at which the maximum electric current relative to the phase of the rotor is fed, so that with respect the motor drive by the inverter device the reluctance torque of the motor may be increased.

主权项

1. A motor control device for an electric automobile of a type equipped with a motor drive control unit configured to perform a control appropriate to a magnetic pole position of a motor rotor relative to an embedded permanent magnet synchronous motor, which is a motor used to drive a vehicle wheel, the motor control device comprising:
a plurality of sensors configured to detect at least two of the motor rotation number, motor voltage and motor current of the motor respectively; a magnetic force estimating unit configured to estimate the magnetic force of a permanent magnet, used in the motor rotor of the motor, from detection signals indicative of at least two of the motor rotation number, the motor voltage and the motor current of the motor in accordance with a predetermined rule; a determining unit configured to determine whether or not the magnetic force estimated by the magnetic force estimating unit is within a predetermined permissible range which is determined as a range in which no demagnetization occur; and a demagnetization responsive timing change unit configured to make the motor drive control unit change the timing, at which the maximum electric current relative to a phase of the motor rotor is fed, in order to enable the reluctance torque of the motor to be increased in the event that the determining unit determines the magnetic force to be out of the predetermined permissible range.