Dsp-based Asynchronous Motor Direct Torque Control

The direct torque control of Asynchronous Motors is one of the high performance control strategies, which was proposed after the vector control scheme. It directly controls the electromagnetic torque and stator flux, using the analyzing method of space vector and stator flux orientation. It has a good prospect in the industrial variable speed field because of its novel control method, simple structure, direct control means, and little dependence on the interior parameters of the motor.At present, it is an important direction in drive control field to design the asynchronous motor DTC system using the Digital Signal Processor (DSP) as the central controller. This paper introduces how to design a DTC lib system using TMS320LF2407 as the central controller and IPM as the main circuit. The system can be used to research the DTC and, on the other side, it can provide technology support for utility in the future.The content of this paper is on the below: by presenting the multi-variable mathematic model and the change of axis of the asynchronous motor and analyzing the principle of the direct torque control system. And then it raises the concept of voltage space vector and sees motors and drives as a whole and analyses the relationship between 8 voltage space vectors and stator flux and torque. It also explains how to choose correct voltage space vectors. After that the author builds the fundamental structure of DTC. Aimed at the limitation of stator resistance identification difficulty in low speed range of DTC, the paper gives a solvingscheme-a fuzzy DTC system having stator resistance fuzzy controller, fuzzy logicis used for estimating the stator resistance, which can improve the performance at low speeds and the response of the system. This paper also introduces the methods of design of fuzzy direct torque control system and the simulating model is built based on MATLAB/SIMULINK. The design and simulation of fuzzy direct torque control system is finished .some simulation result which is approximate to the theory analysis is presented to demonstrate this model is true. At last, the author chooses...