Direct torque control system and method for improving motor torque performance

Abstract

The invention discloses a direct torque control system and method for improving motor torque performance. The direct torque control system comprises a torque regulator, a flux linkage regulator, a rotating speed regulator, a sector judgment module, a voltage vector option table generation module, a driving signal generation system, a duty ratio calculation module, a flux linkage observer for obtaining flux linkage information of a motor stator, a torque observer for obtaining electromagnetic torque information of the motor, and a rotating speed observer for obtaining the rotating speed of a motor output shaft. According to the direct torque control system and method, the motor can be effectively controlled.

Description

technical field [0001] The invention belongs to the technical field of direct torque control of electric motors, and relates to a direct torque control system and method for improving the torque performance of electric motors. Background technique [0002] Direct torque control (DTC) technology has been continuously optimized and improved in the development process, but it has not been perfected, and there are still many researches on this theory. It abandons the idea of ​​decoupling in vector control, and uses a hysteresis comparator and a switch logic table to directly generate a stator voltage vector acting on the motor according to the position of the stator flux linkage, the error of the stator flux linkage and the torque, and drive the motor to run . It has the advantage of little dependence on the parameters of the motor model, and has become a new hot spot in AC drives, but its disadvantages are asymmetrical flux linkage control, large current and torque ripples, et...

AI Technical Summary

Problems solved by technology

It has the advantage of little dependence on the parameters of the motor model, and has become a new hot spot in AC drives, but its disadvantages are asymmetrical flux linkage control, large current and torque ripples, etc.

In order to overcome the shortcomings of traditional DTC, many methods have been proposed, such as LascuC proposed space vector modulation (SVW) technology, J.-K.Kang and S.-K.Sul proposed the method of torque ripple minimization, L.ROMERAL and A .ARIAS proposed fuzzy logic self-adaptive method, Wu Xiaodong and Nan Yurong proposed a method to make the average torque approach the reference value in one cycle, but the algorithms of these methods are more complex and depend on multiple motor parameters

The current direct torque control method, when considering the influence of the stator resistance voltage drop, the interval selection is inaccurate, and the control performance becomes poor when the stator flux linkage is near the section line, but the precondition of torque increase and the flux linkage are not considered. The critical condition of the change, and the torque ripple is reduced but not ideal, so the motor cannot be controlled accurately and effectively

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