Abstract: A method for controlling operation of a permanent-magnet synchronous motor includes: during operation of the permanent-magnet synchronous motor, receiving, by the permanent-magnet synchronous motor, a shutdown signal from an external device; uninterruptedly outputting, by a microcontroller unit (MCU), a deceleration pulse to an inverter, instead of directly blocking a PWM pulse to the inverter, and constantly monitoring a control signal sent by the external device; during a deceleration process, when the MCU receives a new startup signal and a real-time speed Vi of the permanent-magnet synchronous motor is greater than or equal to a reference speed Vref, controlling the permanent-magnet synchronous motor to rotate at a parameter approaching to a target torque T or a target speed V corresponding to the new startup signal; and blocking, by the MCU, the PWM pulse when the real-time speed Vi of the permanent-magnet synchronous motor is lower than the reference speed Vref.

Abstract: A method for controlling the start-up phase of a sensorless permanent magnet synchronous motor, the method including: 1) according to the formula T=K×Iq where T is a torque, K is a coefficient, and Iq is a current on a q-axis of a coordinate system of a motor mathematical model, based on a maximum output torque Tmax of a motor, calculating a maximum current Iq_max on the q-axis, setting the maximum current Iq_max as an upper limit of current on the q-axis, and controlling the motor to run in an open-loop control mode; and 2) when an actual running speed V of the motor reaches a first target speed V_ref1, reducing the maximum current Iq_max to a target current Iq0 on the q-axis corresponding to a target torque T0 set by users, and controlling the motor to run in a closed-loop control mode under the first target speed V_ref1.

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.

Abstract: A method for controlling the start-up phase of a sensorless permanent magnet synchronous motor, the method including: 1) according to the formula T=K×Iq where T is a torque, K is a coefficient, and Iq is a current on a q-axis of a coordinate system of a motor mathematical model, based on a maximum output torque Tmax of a motor, calculating a maximum current Iq_max on the q-axis, setting the maximum current Iq_max as an upper limit of current on the q-axis, and controlling the motor to run in an open-loop control mode; and 2) when an actual running speed V of the motor reaches a first target speed V_ref1, reducing the maximum current Iq_max to a target current Iq0 on the q-axis corresponding to a target torque T0 set by users, and controlling the motor to run in a closed-loop control mode under the first target speed V_ref1.

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.