Electronic phase change detection circuit of position sensor-free brushless direct current motor

Abstract

The invention discloses an electronic phase change detection circuit of a position sensor-free brushless direct current motor, which is characterized in that a back electromotive force zero crossing point detection circuit detects a three-phase back electromotive force zero crossing point and sends the detect results isolated by a photoelectric isolating circuit into a microprocessor unit for further processing; a motor circuit, a detection circuit and the microprocessor unit are isolated from one another by the photoelectric isolating circuit, so that the interference generated by electric signals in the motor circuit and the detection circuit to an input signal of a microprocessor is prevented, the work stability and the system reliability of the microprocessor unit are enhanced, and a back electromotive force phase position is compensated through phase compensation information presorted in the microprocessor unit; and the back electromotive force zero crossing point and the phase change processing are determined, and further, the position of a rotor is determined without the adoption of the position sensor, so that the effect of the position sensor on the system reliability in the special environments of high temperature, high voltage, high interference, high vibration and the like is avoided, and further, and the system reliability is ensured.

Description

technical field [0001] The invention relates to the field of brushless direct current motors, in particular to a position sensorless brushless direct current motor electronic commutation detection circuit. Background technique [0002] The traditional brushed DC motor has the disadvantages of short life, high noise, poor reliability and complex structure because of the need to use brushes and commutators, so it cannot be applied to some special occasions. Brushless DC motors with position sensors require more lead wires and more precise sensor installation positions. In some special environments such as high temperature and high pressure, high interference, and high vibration, the use of position sensors will greatly reduce the reliability of the system. sex. The position sensorless drive technology of brushless DC motor is a method to solve the above problems. [0003] The speed of the brushless DC motor is controlled by the driving voltage, and at the same time, the elec...

AI Technical Summary

Problems solved by technology

[0002] The traditional brushed DC motor has the disadvantages of short life, high noise, poor reliability and complex structure because of the need to use brushes and commutators, so it cannot be applied to some special occasions

Brushless DC motors with position sensors require more lead wires and more precise sensor installation positions. In some special environments such as high temperature and high pressure, high interference, and high vibration, the use of position sensors will greatly reduce the reliability of the system. sex

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