关键词: 无刷直流电动机, 无位置传感器, 起动方法, 脉冲检测, 绕组电感, 电流变化率

Abstract:

To solve the problem that the sensorless control technology of BLDCM is difficult to detect back EMF when the motor is at zero speed and low speed, according to the principle of the winding inductance with the change of magnetic field, a new method of detecting the initial position of the rotor with the impulse voltage was proposed. The threshold for current detection was set before applying six short pulse voltages. The current rate of change was determined by synthesizing these two values by recording the time at which the current exceeded the threshold and the peak at which the current was reached each time the pulse voltage was applied, thereby determining the current position of the rotor. In the operation by detecting the two current pulses to determine the current rotor position, the traditional 6-pulse detection method was simplified. Finally, it was validated by the experimental platform based on STM32F031. This method can improve the accuracy of rotor positioning effectively.

Key words: brushless DC motor (BLDCM), position sensorless, starting method, pulse detection, winding inductance, current rate of change