Study On The Sensorless Control Of PMSM

Permanent magnet synchronous motor(PMSM) is widely used in the field of modern servo-motor drive due to its high accuracy, high reliability, simple economic structure and other characteristics. In the motor control system, the motor speed and other parameters are measured directly through sensor. However, the sensor increases not only the cost of the motor input, but also control system's complexity and inconvenience of installing special environment, and it reduces system reliability.First, the thesis introduces the development situation of permanent magnet synchronous motor, speed-Sensorless control of existing strategies were compared.Subsequently, it analyzes PMSM vector control method and the mathematical models of PMSM in different coordinate systems.Secondly, researching sliding mode variable structure control theory and the theory of model reference adaptive control. Sliding mode variable structure control method and Model Reference Adaptive method of estimating the rotor speed and position are simulated by using MATLAB/SIMULINK.Finally, A new motor speed and rotor position observer based on the IMM algorithm is proposed, which is used for identifying parameter that the speed of vector control system of permanent magnet synchronous motor with speed sensorless. In order to undermine the jitter of sliding mode observer, Improved dynamic properties of model reference adaptive observer. The observer is based on the core concept of interactive multiple model algorithm, under the condition of Id=0 vector control system of double closed-loop voltage magnet synchronous motor runs with the lack of direct speed measurements, by use the synovial membrane observer and modelling reference adaptive observer to evaluate instant rotational speed and rotor position of vector control system in parallel, calculate the two different values of SVPWM voltage import u? and u?, then assign the weight to interactively output voltage values.Though analyzing and simulating results show that the proposed speed sensorless vector control system of permanent magnet motor speed identification method have stronger robustness and satisfactory dynamic and static performance.