The Research And Implementation Of Sensorless Vector Control System Based On DSP

The speed control of AC motor is always a difficult problem, its speed controlperformance had been lagging behind DC motor,in the traditional control methods. Innineteen seventies, Induction motor vector control techniques was proposed, and thespeed control performance of induction was compared to DC motors’ in theory. Basedon this control mode of the inverter is also developed, used in papermaking and textile,which need wide speed range, high precision, tension control in process control field.In the asynchronous motor vector control system, high performance sensors willincrease the cost of transmission system, its installation also has some defects. So thespeed sensorless vector control got a lot of publicity, is becoming a research hotspot.Firstly, the paper introduces the topic research background and the researchstatus at home and abroad in the introduction, and this led to the speed sensorlessvector control.The next moment,the main research content and structure is proposed.Secondly, the paper introduces the basic principle of vector control, and amethod of estimation of AC rotor flux and speed which is very important for thesensorless system. And the related formulas are deduced. In this paper, two kinds ofclassical estimation model are combined to estimate the rotor flux and rotor angularvelocity, by calculating rotor flux of the current model in PI operation, using thecalculated results to compensate the flux of the voltage model. By adjusting the valueof the PI parameter, the voltage model plays a main role at high speed condition, andthe current model plays a main role at low speed condition, so then overcoming thedisadvantages of the two models, improving the estimation accuracy. The paper alsoanalyzes the concept of space vector pulse width modulation (SVPWM), and the rulesof deduction and the specific control algorithm is given.Thirdly, In this paper, hardware circuits and software flow chart of control system are designed, based on the above theory. The control system using chipTMS320F2812produced by TI as the main control chip. The program uses a modulardesign concept.Lastly, methods of simulate based on MATLAB for speed sensorless vectorcontrolled induction motor drives are discussed thoroughly. The SVPWM waveformand the whole system are simulated. The simulation results verify the feasibility of thesystem. On this basis, the experimental platform is built, the basic requirements of thecontrol system is achieved.