Research Of Mixed Sliding Mode Variable Structure Controller In Vector Contorl Of Asynchronous System

In AC motor control system, asynchronous motors have advantage of highreliability, low manufacturing cost, easy maintenance cost and have been used in manyfields widely. But asynchronous motor are a strong coupling and time-varying systemthat cannot separate control the excitation current from the torque current Which makesthe mathematical model of induction motor be a deviation in speed control and thecontrol performance cannot meet the controller accuracy．Asynchronous motors based on vector control in AC control system can solve agiven rotor flux coupling problems, improve control performance. However, vectorcontrol system for geting a good speed control performance depends on the precisemathematical model motor of induction motor. During operation, uncertainties changes,temperature rise and other issues can make the asynchronous motors parametersinevitably be interference, which will slow the speed control performance. Sliding modevariable structure control didn’t depend on an accurate mathematical model and hasgood robustness.To further enhance vector contorl of asynchronous drive system get agood control perfomance and anti-jamming capability.Firstly, this papeper established the induction motor vector control model inMATLAB/Simulink simulation software. Followed by the third chapter study the slidingmode variable structure control we can get that sliding mode structure can get a goodcontrol perfomance but it can make the systems chattering. In order to reduce controlsystem buffeting, In the fourth chapter, this paper established an improved sliding modevariable structure controller based on the vector controll system in asynchronous motors.The new sliding mode variable structure controller uses an improved index reaching lawand can automatically adjust the speed according to the sliding distance.Finally, chapter5will establish PI controller, the conventional variable sliding mode structure controllerand improved variable structure controller model in MATLAB/Simulink software andthe system control simulation results show the improved sliding mode variable structurecontroller can effectivel improve system dynamic speed capability make the AC motorcontrol system get robustness.