Three-phase sensorless brushless direct-current motor control system

Abstract

The invention discloses a three-phase sensorless brushless direct-current motor control system, which comprises a driving controller and a zero-crossing detection circuit. The input end of the zero-crossing detection circuit is input with three-phase signals output by a motor, and the three-phase signals are converted into a feedback signal containing zero-crossing information; the driving controller outputs a motor control signal according to the feedback signal of the zero-crossing detection circuit. The system also comprises a phase compensation circuit, which outputs a PWM waveform, and the zero-crossing point of the output feedback signal coincides with the commutation point of the three-phase signals output by the motor. According to the invention, the phase compensation circuit is used for directly carrying out source compensation on the zero-crossing signal, so that a signal obtained after AD acquisition and comparison is a real commutation signal; and the controller is used for outputting PWM, so that the compensation time can be adjusted more conveniently.

Description

technical field [0001] The invention belongs to the field of brushless direct current motor control and relates to a three-phase sensorless brushless direct current motor control system. Background technique [0002] The brushless DC motor (BLDC) uses an electronic commutator to replace the traditional mechanical commutator. It not only has the characteristics of good speed regulation and dynamic performance of the DC motor, but also has the advantages of a simple structure, no commutation sparks, and reliable operation of the AC motor. and easy maintenance. [0003] Sensorless BLDC can not only avoid many limitations of position sensors, such as cost, sensor leads, and damage to reliability, but also expand the application range of brushless DC motors. For example, some occasions with strict dimensions cannot be adapted due to position sensors. Machine requirements. [0004] For the above reasons, it is of great significance and application prospect to study the sensorles...

AI Technical Summary

Problems solved by technology

[0006] Large companies such as TI and ST have FOC (Field-Oriented Control, field-oriented control) technical solutions, but the problem is that if the motor is started with no load or with a light load, the effect is ideal, but if it is started with a heavy load, there are problems. Jitter and out-of-sync problems

However, in addition to the increase in volume, the cost of time-delay relays also increases.

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