Full order state observer of stator flux for permanent magnet synchronous motor based on parameter adaptive identification

This paper presents a full order state observer of stator flux based on parameter adaptive identification for the direct torque control (DTC) system of surface permanent magnet synchronous motor (SPMSM) drive, in order to improve stator flux observation under motor parameter variation. The full order state observer of stator flux is established on the fixed a-β coordinate, and another adaptive stator current observer is designed on the synchronization d-q coordinate for adaptive identification of the motor parameters, which are used to update the matrixes of stator flux observer and eliminate the effect of motor parameter variation. The adaptive schemes of motor parameters and the observer gains are design based on Lyapunov theory. The simulation results prove that the proposed method can effectively identify the motor parameters, enhance the accuracy and robustness of stator flux observation and improve the performance of direct torque control system.