Research On The Verification Of Low-Speed Performance Of Direct Torque Control System Of The Asynchronous Motor

Induction motor Direct Torque Control(DTC) is a good motor driverstrategy with the development of Vector Control.As a new motor driver strategyof induction motor at the end of 1980's,it has rapidly developed for its newlycontrol thinking,excellent performance of static state and dynamic state,robustness and easy to be digitalized,etc.Especially,an application toproduct-oriented of direct torque control technology of the asynchronous motorbased on DSP was strong demand in the AC inverter market.It driectly analysisdigital model of asychronous under the stator coordinate and avid the influenceof motor parameters,but exist large ripple of torque and flux at a low speedunder the condition of flux obsever.In this paper,on the basis on research of traditional Direct Torque Controlsystem,the reason of low-speed properties is analyzed and an improved methodof low-speed character is proposed.Secondly,the improved DTC system of asych ronous motor is emulated inthe environment of the Matlab/Simulink7.1.At the same time,optimal methodsproposed and realized on the basis of simulink.The feasibility was verified theresult of principle.The simulink model of verified asychronous Direct Torque Control systemis built up on the basis of TMS320LF2407A DSP.According to the systemperformance,the DSP and its external circuit components device are selected,andthen the main circuit and control circuit are designed,the feasibility of changed system was verified.The new control stategy of asychronous DTCsystem caneffectively reduce the torque ripple and has a excellent performance of staticstate and dynamic state and owe a certain practical significance.