Research Of Speed Sensorless Vector Control In The Induction Motor System

Over the past few years, in case of the rapid evolution of digital mathematical units andgreate improvement of power electronic devices, AC vector control formula has beenobviously promoted, vector control is a typical representative speed control fromula thathas excellent capability, but vector control position must know the definite rotation angle,which requires precise measurement of real-time rotor speed, outstanding performanceFVC system ipmrove budget, vulnerabile to the working condition, decrease the reliabilityof the control system.Hence, it is extremely essential to discuss the application of SVCsystem.In this article, based on the ideology of MRAS theory, we use the Adaptive observer toidentify the speed.as well, the voltage model has a pure integral part which will causeproblems, we use the switching signal to imitate the voltage signal of stator, and theaplitude-limiting feedback link has instead of the pure integral part, and verification theeffect on a3KW experiments equipment at last. Meanwhile, discuss the possible limits ofRr.variation of the rotor resistance in practice, check the sensitivity of the method of rotorresistance variation, and give th theoretical derivation.This dissertation is separated into five parts: At first it is a brief presentation on thebackground of undergraduate studies and research status on speed sensorless vector controlsystem, and explain the work of this dissertation; The second part, introduced the basicprinciples of asynchronous motor,and gives the simulation results; Third part gives anadaptive observer and come up with the amplitude-limiting feedback integrator to improvethe property of pure integrator, examine the sensitivity of the system when rotor resistancechanged;The fourth part verificate the final result on the3kW experiment system;Atlast,give the extend work to continue.