Novel square wave driving filtering method of position sensorless motor

Abstract

The present invention relates to the technical field of motor control and particularly relates to a novel square wave driving filtering method of a position sensorless motor. The method comprises the steps that: a counter carries out counting while a motor runs; whether a commutation request is received or not is judged, the motor commutation action is carried out if so, and a current counting value is obtained; the motor continues to run and clear the counting value in the counter, and the counting is carried out again; a filtering depth value is obtained from the recently obtained counting value; whether the commutation request is received or not is judged again, and a current counting value is obtained if the commutation request is received again; whether the counting value is smaller than the filtering depth value or not is judged, the commutation request is ignored if so, and the motor is driven to run continuously. The software filtering of a comparator output is carried out, the abnormal signal interference of a low rotation speed is shielded, thus the compatibility of a low speed range is realized, thus the motor can smoothly run, and a wide speed adjustment range is obtained on the basis of not changing a hardware circuit.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a novel square wave drive filtering method for a positionless motor. Background technique [0002] In the existing square wave driving method of positionless motor, the counter electromotive force method is commonly used to detect the position signal of the rotor, and since the speed regulation range of the existing motor is generally between 0-21000rpm, if according to the setting The zero-crossing phase shift 30-degree electrical angle parameter setting is more accurate in the low-speed stage, but as the speed increases, the back electromotive force becomes larger and larger, and the 30-degree electrical angle will lag due to excessive filter capacitance, resulting in The real phase shift angle at the zero crossing point will be greater than 30 degrees, and the motor commutation lags behind; on the contrary, if the filter capacitor is too small, the real phase shift angle...

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Problems solved by technology

[0002] In the existing square wave driving method of positionless motor, the counter electromotive force method is commonly used to detect the position signal of the rotor, and since the speed regulation range of the existing motor is generally between 0-21000rpm, if according to the setting The zero-crossing phase shift 30-degree electrical angle parameter setting is more accurate in the low-speed stage, but as the speed increases, the back electromotive force becomes larger and larger, and the 30-degree electrical angle will lag due to excessive filter capacitance, resulting in The real phase shift angle at the zero crossing point will be greater than 30 degrees, and the motor commutation lags behind; on the contrary, if the filter capacitor is too small, the real phase shift angle at the zero crossing point can be 30 degrees electrical angle at the high speed stage, but at the low speed stage, The zero-crossing point will cause the filter capacitor to be too small, and the counter electromotive force will be relatively reduced at the moment of motor commutation, which will mistakenly trigger the comparator to output an abnormal signal, causing the motor to commutate ahead, or even fail to start; section, the zero-crossing phase shift angle is not equal to 30 degrees electrical angle, and the motor cannot even start, so the applicable speed adjustment range is too small

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