Brushless direct current motor rotor positioning method and brushless direct current motor

Abstract

The invention relates to a brushless direct current motor rotor positioning method and a brushless direct current motor. The method comprises the following steps: S11, inputting a preset three-phase voltage pulse group into a motor in sequence, and collecting pulse current corresponding to each three-phase voltage pulse; S12, determining a first position interval of the rotor according to the pulse current corresponding to all the three-phase voltage pulses; S13, inputting a preset two-phase voltage pulse group to the motor in sequence, and collecting pulse current corresponding to each two-phase voltage pulse; S14, determining a second position interval of the rotor according to the pulse current corresponding to all the two-phase voltage pulses; and S15, determining a third position interval where the rotor is located according to the first position interval and the second position interval. Accurate positioning of the rotor is achieved under the condition of no position sensor, follow-up smooth starting is ensured, and the reliability of the brushless direct current motor controller is improved.

Description

technical field [0001] The invention relates to the field of brushless direct current motors, and more specifically relates to a method for positioning the rotor of a brushless direct current motor and the brushless direct current motor. Background technique [0002] For brushless DC motors, the controller needs to turn on the corresponding motor phases according to the position of the rotor to start the motor. In order to obtain the rotor position information, a position sensor is installed on the motor in the prior art, but the installation of the sensor not only leads to an increase in cost, but also has problems with machining accuracy. If the processing accuracy is not enough, the position deviation of the sensor will cause the commutation error of the motor, and even damage the controller. [0003] In the prior art, there have been brushless DC motor controllers that do not use position sensors. Under the condition of no position sensor, the motor positioning principl...

AI Technical Summary

Problems solved by technology

The back electromotive force of the motor is proportional to the speed of the motor. When the motor is stationary or the speed is very low, the back electromotive force amplitude is zero or very small. It is difficult to accurately judge the position of the rotor, which may lead to startup failure, especially when starting with load. Very prone to startup failures

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