Research On Speed Sensorless Vector Control System Of3-phase AC Induction Motor

With the improvement and development of AC motor frequency control technology, ACdrive has been widely used in industrial control and vector control technology plays asignificant role in the AC drive system. Therefore, the research and development of a highperformance sensorless vector control system is of great significance and has extensivemarket demand.Firstly, this paper analyzes the advantages and disadvantages of voltage flux observationmodel based on the theory of rotor flux field-oriented control of induction motor. In order toovercome the shortcomings of the voltage model, this paper puts forward perpendicular fluxobserver with compensation feedback and voltage current hybrid flux model. Low pass filteris used in the perpendicular flux observer with compensation feedback to replace the pureintegrator of the voltage model, and amplitude and phase error caused by the low pass filterhas been compensated. Voltage current hybrid flux observation model makes the voltagemodel and current model respectively play a leading role in the high speed and low speed bysetting the appropriate PI parameter to takes full advantage of the two models. Secondly, thispaper analyzes the basic principle of direct calculation method which is simple and sensitiveto motor parameters. This paper also analyzes MRAS models based on rotor flux linkage,counter electromotive force and reactive power. MRAS model based on electromotive forcehas stronger robustness than other speed estimation models and is more stable. The regulatorparameters of MRAS model based on back EMF has been optimized by using the small signalmodel. Thirdly, this paper proposes a fully automated off-line identification method of motorparameters which is simple and accurate and doesn’t need the transformer and the powermeter. Finally, this paper simulates the above modules and compares the simulation results.The hardware and software of vector control system have been designed based onTMS320F28335DSP. Experiments have been carried out on a15kW asynchronous motor toverify the performance of the vector control system.