Improvement Research About The Direct Torque Control On Matrix Converter Actuating Asynchronous Motor

AC timing control technique Direct Torque Control(DTC) is a high-performance AC timing control technique which developed form the 20 century 80 s. It is a mathematical model which is used to analyze the motor in the stator reference frame.The space vector of the electromagnetic torque and the space vector of the stator flux linkage are directly set as the manipulated variables, which thus realizes the direct control on the electromagnetic torque, makes the control mode quicker and easier, and then improves the dynamic and static performance of the system. However, it brings harmonics pollution problems to the power network by AC-DC-AC voltage inverter.On the hand, the matrix converter has more advantages, such as inputting and outputting sinusoidal currents, bi-directional flow of the energy, working without DC energy storage capacitor, which therefore is allowed to AC speed control.This paper is themed by “Improvement Research about the Direct Torque Control on Matrix Converter Actuating Asynchronous Motor”. Firstly, principles and mathematical model of the direct torque control is presented, the respective control method for the flux track of hexagon and approximate circle of the direct torque control are analyzed, and a simulation study on the latter one is done.Secondly, specific to the features that matrix converter has many power devices and complex control method, starting from the base topology and operating principles,the matrix converter is modeled. Then, the space vector modulation strategy is proposed and the indirect space vector modulation is analyzed.Then, the matrix converter is applied to the direct torque control system, which plays to strengths of both the matrix converter and the direct torque control. The analysis of this system, the main problems, and the causes behind are presented. The basic principles which certify the feasibility of direct torque control on matrix converter is presented, this paper proposes the twelve-section control method of direct torque control of induction motor based on matrix converter., an improved method of twelve sectors is proposed, and a simulation model is built. This method improves the traditional look-up table method and avoids the error on voltage vector selection. The simulation result shows that this method which has good dynamic and steady performance can solve the problems of the traditional DTC-MC,such as the largetorque ripple, and weak anti-load-disturbance ability.In the end, based on the analysis on the simulation, a matrix converter prototype system centering on MS320F28335 of Texas Instruments(TI) is designed and built,main control boards of CPLD and DSP are made, and experimental design which lays a foundation for further experimental verification.is carried out.