Study Of Full Digital Induction Motor Speed-Sensorless Vector Control VVVF System

In the VWF system of induction motor, it is indispensable to need a speed-sensor in order to realize speed close-loop control. Some matters that are brought by speed- sensor fixed and the system running condition usually become the system's a breakdown root and low the system's dependable, which is in contravention of people's original intention to use induction motor.In the last few years, the speed-sensorless VWF system ofinduation motor has become a new study hotspot and development trend .The paper primarily studied the design method and software of speed-sensorless VWF system of induction motor based on the digital signal processor (DSP) TMS320F240.The paper lucubrated the control theory of induction motor'svector transform and the method of calculating speed by induction motor's torque current weight,based on which, the paper designed a close-loop speed-sensorless vector control VWF system and realized the system in MATLAB/SIMULINK. The simulink result proved the feasibility of speed calculation model.In addition ,it also proved that the control system has a better dynamic > static performance. The simulink provided the base for the implementation of the control system afterwards.The key of the implementation of the full digital speed-sensorless VWF system lies in how to obtain the speed calculation modeK voltage vector decoupling modeK speed adjuster model and how to obtain the PWM switch signal. The paper primarily analyzed the four-part detailed and provided the designingTand programing thought.On the research and development platform based oM digital signal processor TMS320F240, the paper made experiment of the, control system with 2.2kw induction motor. The result proved that the system has better capabilities of draging load , vary ing frequency and calculating speed.In the last few years, a lot of high performance speed identification methods have been appeared in order to obtain the same speed performance of the speed-sensorless control system as that of speed-sensor control system (or direct torque control). The paper went deep into speed identification to improve the precision of calculating speed. The paper mainly adopted to the method of model reference adaptive,and simulinked it in the MATLAB/SIMULINK, however, simulink result has not been perfected because time limited.