Research And Realization On Direct Torque Control System Of Asynchronous Motor Based On DSP

With the fast development of power electronic technology together with a variety of motor control technology, Direct Torque Control received widespread attention due to its structure simplicity,fast dynamic response,robustness and easy implementation,and therefore starting from the actual application, researching on the direct torque control system of the asynchronous motor based on (DSP) as the controller has great realistic significance.Firstly, analyzes the mathematical model of the induction motor, the basic principle of direct torque control is presented and introduces the hexagon flux control and circular flux control strategies of the traditional method on the basis of the analysis, under the PSIM environment,building the traditional direct torque control a method for the simulation modeling, the simulation results show that the direct torque control possesses very fast dynamic response. And the low speed performance lack of the traditional direct torque control is deeply analyzed.Secondly, on the basis of theoretical analysis and simulation, this paper accomplishes the direct torque control system hardware circuit design with DSP as controller chip, including main circuit and control circuit and software design of control algorithm, In the main circuit, there is a highly intelligent power module(IPM )as inverter, which includes seven IGBT, has high switch frequency and fault diagnosis function.Therefore control system is much smaller size and more flexible control. Software design of the system is completed under the CCS3.3 development environment,mainly completed the voltage, current and speed sampling and SVPWM direct torque control of relevant calculation.ultimately,completes based on DSP induction motor direct torque control system.At last,DTC system current, rotate speed,magnetic linkage experiments,system mechanical properties experiments,interference rejection experiments are accomplished. The laboratory results indicates that this system has very good steady- dynamic performance index.