Abstract:

Accurate identification of load torque and moment of inertia is one of the keys to realize high-performance servo control of permanent magnet synchronous motor. Currently, the identification of load torque and moment of inertia is mostly limited to itself, which is not related to the interaction and restriction between load torque and moment of inertia. In view of this problem, firstly, an interconnected extended sliding mode observer is designed, which fully considers the interaction between load torque and moment of inertia, and the identified moment of inertia is applied to the proportional coefficient and integral coefficient of motor speed loop, so that the two extended sliding mode observers have more accurate and stable speed input. The comparison between the proposed strategy and other algorithms show that the new identification strategy makes the identification of load torque and moment of inertia have faster response ability and better identification accuracy. In addition, in order to verify the anti-interference ability and identification stability of the identification system, the identification is carried out based on the variable speed and load mutation environment. The simulation results show that the new strategy in this study still has a relatively stable identification effect even in the complex environment.

Key words: permanent magnet synchronous motor, extended sliding mode observer, load torque, moment of inertia, parameter identification, speed loop, PI controller, self tuning