Novel direct torque control method of brushless DC motor

Abstract

The invention belongs to the technical field of brushless DC motor control design, and particularly relates to a novel direct torque control method of a brushless DC motor. The method comprises the following steps of acquiring three phase currents i, i and i<C>, three phase inductance L, L and L<C>, three phase counter potential waveforms f(Theta<r>), f(Theta<r>) and f<C>(Theta<r>) and a rotor position angle Theta<r> as acquisition information; calculating to obtain a stator flux position angle Theta<s>, stator flux amplitude Psi<s>, a stator flux amplitude expected value Psi<*><s>, an electromagnetic torque feedback value T<e> and an electromagnetic torque preset value T<*><s> as judgment information of the brushless DC motor according to the acquisition information andpreset control information of the brushless DC motor; generating a corresponding control instruction according to the judgment information; and outputting a corresponding voltage vector according to the control instruction, wherein the voltage vector is used for driving the brushless DC motor. Compared with an existing control method, the method has the advantages that the comprehensive control performance of the brushless DC motor can be comprehensively improved.

Description

technical field [0001] The application belongs to the technical field of brushless direct current motor control design, and in particular relates to a novel direct torque control method of a brushless direct current motor. Background technique [0002] The brushless DC motor with a trapezoidal back EMF waveform has the advantages of high power density, high efficiency, and fast dynamic response, and its application range is wide. At present, the control method of brushless DC motor with trapezoidal back EMF waveform is mainly based on the two-phase conduction three-phase star-shaped six-state pulse width modulation control method, which belongs to the scalar control method, which is simple and easy to implement, but it cannot The magnetic field and torque of the brushed DC motor are accurately and highly dynamic closed-loop control, and there are the following problems: [0003] 1) The phase torque ripple is large and the torque control accuracy is low; [0004] 2) The dyn...

AI Technical Summary

Problems solved by technology

[0003] 1) The phase torque ripple is large and the torque control accuracy is low;

[0004] 2) The dynamic response performance is limited by the proportional integral control algorithm;

[0005] 3) The maximum torque-to-current ratio control and the minimum copper loss control cannot be achieved, and the motor torque output capability, operating efficiency and power density need to be improved;

[0006] 4) Accurate field weakening control cannot be achieved, and the speed regulation range needs to be widened

[0007] At present, technical personnel in the field have proposed a variety of improvement methods for the above problems, but they can only improve or optimize one or several of the above problems in a targeted manner, and cannot realize the comprehensive improvement of the brushless DC motor. Overall improvement in control performance

Images