Patent ID: 10868485

Abstract:
A constant torque control method for a permanent magnet synchronous motor. The method includes: 1) starting a motor; setting a torque T of the motor; calculating a given current iq_limit on a q-axis based on the torque T; setting a target current iq_A on the q-axis to be equal to the given current iq_limit; and allowing the motor to operate in a constant torque control mode by a current-based proportional integral (PI) controller on the q-axis; 2) presetting a reference speed Vref1 of the motor; measuring a real-time speed V of the motor; when the real-time speed V is less than the reference speed Vref1, increasing an extra current delta_iq to the given current iq_limit to intervene the real-time speed V of the motor; and 3) measuring the real-time speed V of the motor; and calculating a speed difference Err=V−Vref2.