Single-phase sensorless brushless DC motor control system

Abstract

The invention relates to the technical field of motor control, and particularly relates to a single-phase sensorless brushless DC motor control system, which comprises an H-bridge control circuit respectively connected with two phases of wires of the motor. The output end of the H-bridge control circuit is connected with a current sensor; the current sensor is connected with a main controller; the main controller is provided with a first driving circuit and a second driving circuit for driving the H-bridge control circuit respectively; both the two phases of wires of the motor are connected with a counter electromotive force sampling circuit; the counter electromotive force sampling circuit is used for acquiring counter electromotive force comparison signals on the single-phase brushless motor and transmitting the counter electromotive force comparison signals to the main controller; and the main controller controls opening and closing state of the first driving circuit and the second driving circuit. The single-phase sensorless brushless DC motor control system can be well applied to a single-phase brushless motor, the rotor position of the single-phase brushless motor can be accurately detected and controlled, and a good basis is built for promotion and use of the single-phase brushless motor.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a single-phase sensorless brushless DC motor control system. Background technique [0002] Single-phase DC brushless motors are receiving more and more attention because of their ultra-high speed and lower cost than three-phase DC brushless motors. A single-phase brushless DC motor generally consists of a permanent magnet rotor, stator windings, and a position sensor, as shown in Figure 1. The rotor of the motor shown in Figure 1 is composed of two pairs of magnetic poles 1N, 1S, 2N, and 2S, and the corresponding windings are composed of four stator windings A, B, C, and D, where A and D, B and C are the same phase windings, That is, A and D generate the same magnetic field when electrified, and B and C generate another magnetic field. Position sensors are generally composed of Hall devices. [0003] Due to the existence of the position sensor, the operation of the motor...

AI Technical Summary

Problems solved by technology

However, the structure of the single-phase brushless DC motor cannot have idle phase lines like the three-phase brushless DC motor, so that the traditional method of detecting the rotor position by back EMF cannot be applied to single-phase brushless motors, and it cannot be used for single-phase brushless motors. The rotor position of the motor is accurately detected and controlled, which greatly limits the promotion and use of single-phase brushless motors

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