The Research On Direct Torque Control System Of Asynchronous Motor

Tesla use of the full copper rotor asynchronous motor in the electric vehicle since the application, AM because of its easy implementation, high efficient and stable driving, The technology of high performance speed control of AM and itself has attracted much attention.Direct torque control(DTC) of asynchronous motor as one of the representative. but there are problems in the system control effect is not good under the larger disturbance. And the speed sensorless has a large deviation between the estimated value of the rotational speed and the actual speed of the problem. Which limits the performance of the control system.Direct torque control System for asynchronous motor, the control system in the condition of large disturbance, the control effect is not good problem, put forward a new type of Automatic speed regulator(ASR), The new tape of ASR use subsection control. According to the deviation value of ASR input to subsection control use subsection control. When the error is big.Use improved proportional integral control. While the error is small, the fuzzy control is adopted. And the improved proportional integral control will be base on the rules, to connect or disconnect the integral control function of the improved proportional integral controller. By comparing the simulation results with Matlab/sumlink. Prove that the new scheme of Anti-disturbance Performance is better than the classical. When the DTC combined with speed sensorless technology to estimate the motor speed. There is a large deviation between the estimated value of the speed and the actual speed of the rotating speed. Put forward a new type of speed sensorless, According to the state of the system, the parameters of the proportional integral controller are adjusted online. Under different conditions, the speed of the motor is estimated by using different parameters.According to the design objectives, use Matlab to build the simulation model. Through the comparison of the simulation waveforms before and after improvement, verify the design scheme with effectiveness. The simulation results show that the improved direct torque control system of asynchronous motor is not only more strong than before, but also more accurate than before.