To Improve The Torque Performance Of Speed Sensorless Direct Torque Control System

Directly torque control system is a new control technology of AC motor control method. It has several advantage such as quick torque response, simple structure,excellent Static and dynamic performances, insensitivity to motor parameters. So it has became an important control method in the field of AC motor control.The text adopt a new technology, based on analyzing the directly torque control theory, which combine the discrete duty ratio voltage vector control technology with the achieved voltage selecting method. And based on the effect of zero voltage vector in different speed, the voltage space vector were arranged to depress the torque ripple and improve the torque performance in the same time. Then the improved directly torque control system was established. .On the basis of the math model of induction motor, the speed sensorless adaptive observer was constructed. This paper deduces the adaptive rotate speed identify rule on the observer stabilization condition to carry out speed sensorless directly torque control system by the stabilization theory such as Popov,Lyapunov.In Matlab/simulink enviroment,the simulate model of the improved directly torque control system and two adaptive rotate speed identify were constructed. Compared the simulate results of traditional directly torque control and improved directly torque control in multi-angle. Analysis the simulate figure and the result that the simulated data is according with theory data make it clear that the method is effective. A directly torque control hardware system,which main chip is TMS320F2812, and the programs of the main module and the control module was constructed.