Sensorless Vector Control Of In-Duction Machines Based On Slide Mode

The response of induction motor with vector control act badly during the operationprocess, due to the disturbance of load and variation of inner parameters. It is need to use amore advanced control strategy when a better performance system of vector control isdesigned. A velocity sensor is usually implemented to accomplish the feedback of velocityin the system of vector control. However many issues as installing difficult or low speedproblem are discovered. Therefore, researches of vector control based on sensorless arebecoming hotspots.The first part of this article focus on using a slid-mode controller to replace thetraditional PI controller as a adjuster in velocity loop and flux loop. First of all, severalissues with the designing and application of the slide-mode control are researched,including goal and methods of slide mode controller designing, dynamic quality andchattering when using slide mode controller. Then due to different requirements of outputresponse, the slide mode speed controller and the slide mode flux controller are designed.At the second parts of the article, several popularity methods of velocity estimatingare analyzed. First of all, a novel method of velocity estimating with MRAS is designed,and in this model the problems in the traditional MRAS method are resolved. Then ananalysis method of system stability on the adaptive observer is submitted and a noveldesign method of error matrix is used. Lastly the adaptive methods in the two estimatingmodels on the basis of Lyapunov theorem and Popov hyperstability theorem are designed.