Design Of Sensor-less Vector Controller On Asynchronous Motor Based On DSP

The frequency conversion velocity modulation have become the most main velocity modulation way. In frequency conversion velocity modulation technology, there are some flaws, such as system cost's increase and work precision influenced by environmental condition easily, in the control system of asynchronous motor if installing velocity sensor. So people begin to study the sensor-less control method of asynchronous motor. The paper takes the drive system of asynchronous motor for the research object, takes vector control for the control mode, takes MRAS as the control arithmetic, takes DSP for control core, and designs the entire asynchronous motor sensor-less control system.According to frequency conversion velocity modulation actual situation, the merit of asynchronous motor sensor-less vector control system is analyzed, and its development and present situation is introduced. The high accuracy timeliness good system is a key point of the present studies.According to the vector control basic principle, the model of asynchronous motor is predigested the Voltage model and current model directed by the rotor flux, and the models is simulated and the flux observation result is feasible. The speed estimate method is obtained using MRAS and the models.Taking TMS320LF2407 for the control core, the entire circuit of the system is designed, which includes rectifier circuit, inversion circuit, drive circuit, examination circuit of current and voltage of motor, and breakdown diagnosis circuit, and the parameter of the electronic device is made the analysis.Through comparing the basic principle and the digital algorithm of each kind of SPWM, the unsymmetric rule sampling is chosen as the SPWM method of the paper. The design of PWM interrupt service software of the vector control system has been completed using MRAS, the precision of speed estimate is enhanced through using appropriate calibration, and the real-time character is enhanced through updating the angle of rotor flux, on which the design of the entire software is completed. According to system software flow chart, the simulation of the system software is completed using MATLAB, and the result is a well. From the simulation result, the current and speed of asynchronous motor has a better dynamic character and static character and can satisfy the request of the motor stable movement.The drive system of asynchronous motor is researched in the paper, applying MRAS to the vector control system of asynchronous motor, which has the reference value.