Study On MRAS-Based Speed Sensorless Vector Control System

The speed sensorless vector control of induction motor technology enhances the reliability of AC driving system, and reduces the realization cost. The key problem is that how we can get the speed of motor accurately. The MRAS based on speed estimation was widely considered as the brightest outlook among high performance speed estimation schemes, because of its medium calculation ability requirement and very high precision. MRAS-based speed sensorless vector control system is studied in the thesis.Speed sensorless vector control of induction motor system and MRAS math model are analysed in the thesis. Three speed estimation model based on the flux MRAS, the emf MRAS and the instantaneous reactive power (IRP) MRAS are analysed especially in the thesis, and compare them each other, the results show that the method based on IRP model MRAS has excellent speed identification performance in theory.The simulation model of system is set up according to the basic theories of the speed sensorless vector control system and MRAS algorithm, at the same time simulate using MATLAB/SIMULINK, and compare the simulation results using the three MRAS speed estimation models mentioned above, the simulation results show that speed identification performance using IRP model MRAS is best, it accord with theory analysis.Some experiments have been done in the test-bed based on the dual DSP.V/F and rotor field-orientation indirect vector control experiment have accomplished. Also the initial experiment of speed sensorless vector control based on IPR MRAS has been done, the results prove that the speed identification algorithm is feasible.