Abstract:

When sensorless control system is applied in vector control and direct torque control system the responses are different for the different characters of the vector control system and direct torque control system. We analyze mathematic models of  PMSM(Permanent Magnet Synchronous Motor) and the results of rotor angle are generalized by the voltage and current which were meatured by sensors, the simulation results of vector control system and direct torque control system without position sensor are provided. The direct torque control system adopted MRAS (Model Reference Adaptive System) sensorless system are discussed and the results of the system are provided. The results indicate that rotor speed of vector control is steady. Ripple of rotor speed of direct torque control system is big and response of rotor speed is rapid. The ability of anti disturb of direct torque control system is better.

Key words: permanent magnet synchronous motor（PMSM）, vector control；direct torque control, sensorless control ,  model reference adaptive system(MRAS)