Control device and method based on phase angle of phase current of direct-current brushless motor

Abstract

The invention discloses a control device and method based on a phase angle of a phase current of a direct-current brushless motor. The control device comprises a speed setting module, a central processing unit, a current amplifying circuit, an intelligent power module, Hall sensors and a power source module which provides power for the speed setting module, the central processing unit, the current amplifying circuit, the intelligent power module and the Hall sensors. The control method comprises the steps that the real-time rotation speed of the direct-current brushless motor is collected and counter emf is obtained at the same time; the real-time phase current of the direct-current brushless motor is collected, and speed PI adjustment is conducted on a speed difference between the real-time rotation speed and a set rotation speed, so that a speed adjustment signal is obtained; PWM compensation calculation is conducted on the real-time counter emf and the phase deviation of the phase current of the direct-current brushless motor, so that a PWM compensation amount is obtained; a PWM duty ratio signal is obtained through calculation conducted by the central processing unit according to the speed adjustment signal and the PWM compensation amount; the PWM duty ratio signal is output to the intelligent power module, so that control over the phase of the phase current of the direct-current brushless motor is achieved. By the adoption of the control device and method based on the phase angle of the phase current of the direct-current brushless motor, the motor efficiency is improved, and the amount of emitted-heat is reduced.

Description

technical field [0001] The present invention relates to a control device and method of a brushless DC motor, in particular to a control device and method based on the phase angle of the phase current of the DC brushless motor. Background technique [0002] The permanent magnet DC brushless motor has many advantages such as high efficiency and good controllability. Although in terms of the manufacturing cost of the motor, the permanent magnet brushless DC motor is higher than the capacitor-started single-phase asynchronous motor, and the permanent magnet DC brushless motor must have a supporting controller to work normally, so that the permanent magnet DC brushless motor The motor has high controllability and can be applied to various working environments. [0003] The working efficiency of the permanent magnet DC brushless motor (<500W in the small power range) is about 90%. Due to the objective reason of low power, it will be futile to reduce the mechanical loss, magne...

AI Technical Summary

Problems solved by technology

Because the customization of brushless DC motors is made by winding enameled wires, there is a certain amount of inductance. It is precisely because of the existence of inductance that the phases of the current and voltage passing through the stator coil will have a certain phase difference, resulting in input The power factor on the side decreases, so that the reactive power increases

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