Direct Torque Control System On DSP For Asynchronors Motor

The Direct Torque Control(DTC) is a second high performance AC motor control method after the Vector Control. The Direct Torque Control attracts more and more attention due to its robust characteristics\simple realization and excellent dynamic response.This paper discusses some problems of it.The paper first explains the running principle and the basic framework of the Direct Torque Control system for the asynchronous motor,and according to the arithmetic model of the asynchronous motor presents the arithmetic equation of flux and torque in stator coordinate by mathematical deduction.Furthermore,after the analysis of the state of converter switches,the dual closed loop control of flux and torque is discussed.On the basia of hexagon stator flux trace method with Band-Band control,some improvements are made in the paper on the key sector such as the observation of magnetic field and a new scheme of polygon(round) voltage vector control is presented in order to realize the fast regulation when three-value regulation is used to adjust torque.The core of the system mentioned in this paper is the digital signal processor(DSP) TMS320LF2407A and composes hardware design and completes software design with intelligent power module(IPM)\rectifying diode module and peripheral circuit.The results of digital simulation with MATLAB / SIMULINK and reatime experiment based on the designed hardware platform show that the performance is good,and meantime round stator flux scheme is superior to hexagon stator flux scheme.