Asynchronous Motor Speed Sensorless Vetor Control System Design And Realization

Asynchronous motor due to simple structure, performance advantages in speed hasbeen widely applied in the field of speed regulation. In the speed closed-loop control,the installation of mechanical speed sensor for obtaining rotation information, not onlyincreases the cost of the system, but also limits the range of applications and reduces thereliability of the system. Therefore, speed identification studies, to achieve speedsensorless vector control system has important theoretical value and practicalsignificance.This paper is set in “National Science and Technology Major Project” of the lab,the speed identification technology and speed sensorless vector control system carriedout research work. Summarizes the development status of ac speed regulating systemand speed sensorless vector control; Vector control theory is studied, and the coordinatetransformation formula was deduced, and gives the mathematical model ofasynchronous motors in different coordinate system, analyses the voltage space vectorpulse width modulation (SVPWM) technique principle and algorithm implementation;Through the establishment of rotor flux observer model, the paper analyses the integralinitial value and dc drift of the pure integral part of voltage model on the accuracy offlux observation, proposed the improved method of using the variable cut-off frequencylow-pass filter with saturation feedback link instead of pure integral part; Elaborated themodel reference adaptive system (MRAS) on the principle of parameter identificationand theoretical basis in detail, on the basis of the design model based on rotor fluxlinkage MRAS speed identification algorithm, and proves that the system stability;Modeled separately for each module and achieve the complete control system model inthe Matlab/Simulink platform, through the simulation verify the effectiveness of theimproved speed identification algorithm; Using TI’s dedicated motor control chipTMS320F28335as a hardware platform, and adopts motion control platform ofhigh-precision numerical control laboratory independent research platform assoftware-based, according to component design ideas to achieve the complete speedsensorless vector control system, the experimental results show that the the system hasgood dynamic performance.Finally, the paper summarizes the work, the article in improving the rotor fluxvoltage model rotor flux made contributions to improve the accuracy of the rotor fluxobserver, to improve the speed identification precision so as to realize the asynchronousmotor speed sensorless vector control system of the follow-up research work providesdirection.