Vector Control Of Asynchronous Motor Based On Speed-sensorless Technology

The AC regulating system integrates the knowledge of motor theory, power electronic technology and computer control theory etc. The nature of the ac induction motor, nonlinear and strong coupling, limited the development of ac regulating system for a long time.The birth and development of the vector control, provided a theoretical basis of high performance speed control system. Vector control needs motor speed as feedback information in real time. Photoelectric encoders are used for speed identification usually, but some bad industrial situation limits the usage of encoders. As a result, the speed-sensorless vector control method became a research hotspot in recent years.This paper firstly introduces the main motor control and motor speed identification methods. Through the analysis of advantages and disadvantages, it makes up the plan of speed-sensorless vector control based on model reference adaptive method. Then introduce the vector control principle, coordinate transformation, mathematical model of ACIM and realization of SVPWM.Specific to MRAS speed identification methods, the paper firstly analyzes the shortcomings of MRAS model based on rotor flux and puts forward the compensation measurement. The other two new MRAS speed estimation methods are proposed as a supplement. Considering the actual noise existing in the current sampling signals, the paper proposes the tracking differentiator and morphology filter as two kinds of software filtering methods and compares the filtering effect through the simulation. Based on the above research, speed-sensorless vector control system of ACIM is set up in Simulink environment, and the simulation results are analyzed. At last, the whole system is realized on hardware platform based on DSP TMS320F28335 and obtain the good control effect eventually.