A self-tuning speed control method for permanent magnet synchronous motors based on the parameter identification

The paper proposes a coefficient self-tuning method for speed control of a permanent magnet synchronous motor (PMSM) based on identification of the rotational inertia and the friction factor in consideration of the variation of mechanical parameters of its servo system. The method identifies the rotational inertia and the friction factor with a model reference identification algorithm designed with the motion model simplified by using the load torque observed by the torque observer. And, in order to solve the problem that the actual coefficients of the proportional integral (PI) controller are not equal to the values of the theoretical calculation, it also gives a simple self-tuning method to adjust the controller coefficient according to the principles that the proportional coefficient is proportional to the rotational inertia, and the integral coefficient is proportional to the friction factor. This method can correct the controller coefficient according to the changes of mechanical parameters, and provide a good performance for speed control. The simulation results proved the effectiveness of the parameter identification method and the coefficient calibrating principle.