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

Abstract

The invention discloses a rotor positioning method, a rotor positioning device and a control system for a brushless direct current motor, wherein the positioning method comprises the following steps:when performing conduction control on the stator windings of the motor according to a preset conduction mode, applying a voltage detecting pulse of a first preset time to different phases of the stator windings of the motor in turn, and obtaining a plurality of current values by acquiring current values of the stator windings at each phase; acquiring a maximum current value among the plurality ofcurrent values, and marking the phase corresponding to the maximum current value as the first phase; acquiring the phase in which the current value is larger in the two phases adjacent to the first phase, and marking the same as the second phase; obtaining a sector in which the rotor of the motor is located according to according to the first phase and the second phase, and obtaining the positionof the rotor of the motor according to the sector in which the rotor is located. Therefore, the position of the rotor of the motor may be quickly and accurately obtained without the appearance of theproblem of abnormal noise as well as jitter and positioning errors. In addition, the method is simple, and the blind spotless positioning may be realized.

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 where the motor is required to start quickly; 2) In order to re...

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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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