Rotor positioning method, positioning device and control system of brushless DC motor

Abstract

The invention discloses a rotor positioning method and device and control system for a brushless direct current motor. The method comprises the steps that when conduction control is conducted on a stator winding of the motor according to a preset conduction manner, voltage detection impulses are sequentially exerted on different phase positions of the stator winding of the motor, and multiple times are obtained through obtaining the time needed for the current values of each phase position of the stator winding to reach preset current values; the shortest time in multiple times is obtained, and the corresponding phase position of the shortest time is marked as a first phase position; the phase position with the shorter time of the two adjacent phase positions of the first phase position isobtained and marked as a second phase position; a sector area where the rotor of the motor is located is obtained according to the first phase position and the second phase position, and the positionof the rotor of the motor is obtained according to the sector area where the rotor is located. By means of the method, the position of the rotor of the motor can be rapidly and accurately obtained, the problems of abnormal sounds, vibrations and positioning errors are avoided, the method is simple, and non-blind-area positioning can be achieved.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a rotor positioning method of a brushless direct current motor, a rotor positioning device of a brushless direct current motor and a control system of a brushless direct current motor. Background technique [0002] At present, in the field of brushless DC motor sensorless drive control technology, there are mainly two rotor positioning technologies when the motor is stationary and close to zero speed: forced pre-positioning method and pulse positioning method. [0003] Among them, the forced pre-positioning method does not consider the current position of the motor rotor, but energizes the fixed phase of the motor stator winding to make the motor rotor rotate to a predetermined position. However, this method has the following disadvantages: 1) The positioning time is long, which is not suitable for the occasion that requires the motor to start quickly; 2) In order to reduce...

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Problems solved by technology

For this reason, the first purpose of the present invention is to propose a rotor positioning method for a brushless DC motor, which can not only greatly reduce the time for starting and positioning the motor, but also ensure that the motor will not reverse when starting, and solve the problem of abnormal noise and vibration during positioning. Jitter can also solve the positioning error problem caused by the mismatch between the current waveform and the rotor position during pulse positioning, simplifies the pulse positioning rotor position identification method, and can realize full 360° no blind zone positioning

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