Speed Regulation System Of AC Asynchronous Motor Direct Torque Control

Direct torque control speed regulation system of ac asynchronous motor is mainly studied on in this article. Firstly, development history and research actuality of modern AC speed regulation technique is introduces, basic theory of direct torque control recounted, and math model, electromagnetic torque model and flux linkage model of an motor in static two-phase coordinate of stator recommended. Impacts on electromagnetic torque and stator flux linkage made by voltage space vector is analyzed, stagnant loop controller of electromagnetic torque and stator flux linkage is designed, and on-off state table of traditional direct torque control is set up. Moreover, limitations of traditional direct torque control is analyzed, a new control strategy is adopted that is anticipated resultant vector direct torque control eliminating the intrinsic pulsation of torque and flux linkage, and the realization of random voltage space vector based on SVM(Space Vector Modulation) is introduced.Simulation models of traditional direct torque control system and direct torque control system based on anticipated resultant vector are set up making use of MATLAB/Simulink, simulation experiments of the two models are carried out, and by contrast of simulation results, it verifies that the two control srategies are both right and feasible, and applying the later one can reduces the pulsation of torque and flux linkage, and improve control performance of direct torque. According as direct torque control theory, DSP chip TMS320LF2407 special for motor control is taken as the core, a suit of traditional direct torque control variable frequency speed regulation system is designed and exploited based on SVM. In hardware, main circuit and control circuit taking TMS320LF2407 DSP as controller is designed. In software, programs are made with TMS320LF2407 assemble language to realize SVM voltage space vector modulation and traditional direct torque control and therefore to attain the purpose of variable frequency speed regulation.In the experiment waves of current, flux linkage, torque and speed of the experimental motor are collected and carried on comparison with the simulation results, which indicates that the direct torque control speed regulation system designed in this paper has some specialties such as structure simple, performance well and operating stable, which establishes nicer theory and technique foundation for high-performance variable frequency speed regulation of ac asynchronous motor.