Apparatus for controlling motor for electric vehicle and method for reducing torque ripple using the same

摘要

An apparatus controlling an electric vehicle motor and a method to reduce torque ripple using the same are provided.;A field current flowing in a rotor field coil is controlled by generating a negative phase ripple current with respect to torque ripple according to each position of the rotor, allowing torque ripple of the motor to be reduced without degrading output torque. Additionally, in an operation region of a high torque section, torque ripple is reduced by controlling a field current by increasing an AC component of a negative phase ripple current, and in an operation region of a low torque section, torque ripple is reduced by controlling a field current by decreasing an AC component of a negative phase ripple current. That is, torque ripple of a motor can be reduced by controlling only a field current.

主权项

1. An apparatus controlling an electric vehicle motor, the apparatus comprising:
a motor including a stator having an armature coil and a rotor having a field coil; a rotor position detection unit to detect a position of the rotor; and a field current control unit having
a field current detection unit to detect a field current flowing in the field coil; anda feedback control unit for feedback-controlling the detected field current, wherein an operation region is determined based on a torque reference received according to an accelerator angle of a driver and a rotation speed of the motor calculated according to a signal received from the rotor position detection unit, wherein the field current control unit generates a negative phase ripple current for each operation region by using a baseline field current detected at each position of the rotor, and feedback-controlling the field current with the generated negative phase ripple current to reduce torque ripple of the motor while maintaining a phase of an output current applied to the armature coil, wherein the operation region is separated to a first operation region and a second operation region according to a rotation speed of the motor, wherein a maximum torque of the first operation region is uniform according to the rotation speed of the motor and a maximum torque of the second operation region is variable according to the rotation speed of the motor, wherein the field current control unit increases an AC component of the negative phase ripple current when the torque reference is increased in the first operation region.