Brushless double-fed motor direct torque control method capable of reducing torque pulsation

Abstract

Provided is a brushless double-fed motor direct torque control method capable of reducing torque pulsation. According to the technical scheme, a rotating speed PI adjuster, a torque PI controller, a magnetic linkage PI controller, a torque observer, a magnetic linkage observer, a 3 / 2 coordinate converter, an MT / [alpha][beta] coordinate converter, a spatial voltage vector PWM generator, an incremental encoder and a voltage and current sensor are installed in a brushless double-fed motor control system. In the operation process of a brushless double-fed motor, an inverter is controlled by a spatial vector modulation method. The PI controllers are used to replace double-hysteresis controllers used in a traditional direct torque control method, and a spatial vector modulation technology replaces voltage switching table and obtains a voltage vector random in size and direction by means of synthesis. From the simulation result, the method can effectively compensate the present torque and magnetic linkage errors and reduce the torque pulsation of the motor.

Description

technical field [0001] The invention relates to a direct torque control method of a brushless doubly-fed motor based on space vector modulation, which belongs to the technical field of control. Background technique [0002] In recent years, more and more occasions have begun to use brushless doubly-fed motors for frequency conversion speed control. Brushless double-fed motor is a new type of motor developed in recent years. This motor has two sets of three-phase symmetrical stator windings and one rotor winding. One set of stator windings is a power winding and the other is a control winding. The basic principle of the brushless doubly-fed motor is that the specially designed rotor enables the two sets of stator windings to produce different pole pairs of rotating magnetic fields to interact indirectly, and the interaction can be controlled to achieve energy transfer. It has the common advantages of asynchronous motors and synchronous motors, and has the characteristics of ...

AI Technical Summary

Problems solved by technology

However, because the traditional DTC uses a double hysteresis loop controller to control the torque and flux linkage separately, only one effective voltage vector acts in each sampling period, and it is impossible to fully compensate the torque and flux linkage errors, thus Increased torque pulsation amplitude

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