Method for controlling operation of permanent-magnet synchronous motor through sensorless vector control

Patent metadata

Field	Value
Publication number	US-12375018-B2
Application number	US-202318382039-A
Country	US
Kind code	B2
Filing date	Oct 19, 2023
Priority date	Jul 20, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

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.

First claim

What is claimed is:

1. A method for controlling operation of a permanent-magnet synchronous motor through sensorless vector control, the method comprising:
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 from the real-time speed Vi;
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;
wherein when the MCU blocks the PWM pulse, the permanent-magnet synchronous motor continues rotating due to inertia, and the control signal sent by the external device is constantly monitored; if, at this stage, the MCU receives another new startup signal, all lower bridge switch transistors are activated, causing the permanent-magnet synchronous motor to enter a dynamic braking mode for a duration t 1 ; the MCU gives commands to input currents to the phase windings sequentially to lock a rotor position for a duration t 2 ; and the permanent-magnet synchronous motor reenters into a sensorless startup state according to the new startup signal; and
wherein the permanent-magnet synchronous motor is a three-phase permanent-magnet synchronous motor with a three-phase winding comprising three sets of coils U, V, W; when the MCU blocks the PWM pulse and the MCU receives the new startup signal, three lower bridge switch transistors Q 4 , Q 5 , and Q 6 are activated, causing the permanent-magnet synchronous motor to enter the dynamic braking mode for the duration t 1 ; and the MCU gives commands to input currents to the three sets of coils U, V, and W sequentially to lock the rotor position for the duration t 2 .

2. The method of claim 1 , wherein when the motor receives the shutdown signal from the external device, the MCU controls the motor to decelerate; when the shutdown signal exceeds or equals a set time duration t 3 , the MCU blocks the PWM pulses.

3. The method of claim 1 , wherein the reference speed Vref is in the range of 200 to 400 rpm.

4. The method of claim 1 , wherein the permanent-magnet synchronous motor rotates at the parameter approaching to the target speed V corresponding to the new startup signal from the real-time speed Vi with a step size V0 increasingly or decreasingly.

5. The method of claim 4 , wherein the step size V0 is determined based on the rotational inertia and a difference between the real-time speed Vi and the target speed V corresponding to an acquired tap position signal.

Assignees

• Zhongshan Broad Ocean Motor Co

Inventors

• Lan Jinghao
• Bian Wenqing

Classifications

• H02P25/022

  Synchronous motors (H02P25/064 takes precedence) · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• H02P3/18

  for stopping or slowing an AC motor · CPC title

• H02P21/34

  Arrangements for starting · CPC title

• H02P21/36

  Arrangements for braking or slowing; Four quadrant control · CPC title