Research On Direct Torque Fuzzy Control Of Asynchronous Motor Of Mine Traction Locomotive

Mine traction locomotive is the main means of transportation inmine transporting, while the core power of traction locomotive is thepower part of AC traction motor, which is the key research question inthis paper. Induction motor with its simple structure has been morepopular among the majority of mine traction locomotive. But there aretwo kinds of control method used for regulating the high-performanceof induction motor. They are direct torque control method and vectorcontrol method. Compared with vector control, direct torque controlhas its own characteristics: simple calculation, smaller amount of thesignal processing, easy control.Direct torque control is to adopt a new control strategy whichwill put inverter and motor as a whole for controlling. During normaloperation of the motor, using a round presented in the trajectory of thestator flux running, with different situation of the space vector frominverter output to control the stator flux of motor, which can achievethe controlling effect. Simple as it is, the traditional direct torquecontrol has its own deficiencies,for example, torque ripple is severefluctuated. There are only six working voltage vectors and two zerovectors in the traditional direct torque control method, fewer quantitiesof voltage vectors can be selected when choosing it, which is onefactor of the torque fluctuation. Another main reason is because of thedirect torque control process control inverter switching output signalsis flux and torque hysteresis controller and hysteresis controller " is anon-zero " will lead to the selection of the output voltage vector theexternal environment is not well followed, resulting torque ripple.In the view of two reasons mentioned before, it proposes amethod of refining the voltage vector to solve the problem of fewerselection signals, using SVPWM method to synthesize the original sixto twelve work vector. Confronted with the shortcoming of hystereticcontrol, this paper would like to adopt fuzzy control, a kind ofintelligent control method, to solve the problem, combined flux error,torque error and the stator angle as input of the fuzzy controller, while the switching signal as output of the fuzzy controller, which in orderto make the control system be in good performance of anti-interferen-ce and following, different from the feature of the traditional PIregulator, a fuzzy PI regulator, adopted in this article, can be at anytime to follow the changes of the external environment.Through the improvement of research methods, in this paper, atheoretically simulation was firstly conducted in the software ofMatlab/Simulink and proved of the feasibility of this approach theory,compared with the waveform of traditional direct torque controlmethod, a better waveform of torque and speed is presented from newsimulation, which shows that this method is better than the traditionalone on regulating effect. Moreover this control method is put intoactual operation. Experimental platform, based on chip-TMS320F283-35as the core of controlling, regulates asynchronous motor, a betteranti-interference performance and strong robustness can be seen fromthe measured waveform in the experiment.