Direct Torque Control Simulation Study Of The Elevator Door Motor Speed Control System

The application of AC drive is more and more popular in modern society and it has taken up most parts of the drive-field. With the development of power-electronics and computer technology, AC-drive has developed many schemes, but they all have their own shortcomings and are not capable of the practical application demands. Direct torque control (DTC), which emerged recent ten years ago, has its unique advantages that other drive schemes haven't.This paper made the feasibility study of the DTC system with Matlab\Simulink. Material recommend about the development and theory of DTC the composing of DTC-system is presented in this paper. Some important taches such as flux-linkages adjuster, frequency adjuster, the mathematics model of asynchronous motor in α-β coordinates and the choice of voltage-vectors are discussed detailedly. From this base, the simulation-models of all taches are set up and encapsulated, so users have their own element-model warehouse, depending on which the simulation-system of DTC in Maltab\Simulink is founded. This paper makes some betterment such as the three-segment adjuster of the torque to some taches in the former DTC-system. At last the simulation work for the DTC-system is completed according to the parameters of an actual AC-motor. The result indicates that the control effect is excellent, and when the speed is lower, the effect is not so perfect and this is the study hotspot of DTC in the future. The gate-motor system of the elevator is also discussed in rough as the research background. This paper also does some work about the self-adaptation function in the DTC-system and brings forward self-adaptation-system on software according to the requests of the gate-motor system. In the last part of the paper the foreground of DTC is discussed and simple recommend about the existing problems is presented.