Forced dynamics position control algorithm for drives with flexible coupling including damping

Control system designed for a.c. drives with a significant torsion vibration mode and applied to PMSM, which takes into account damping factor is described. Derived control algorithms for speed and position control are based on forced dynamics principles and achieve prescribed speed and position responses. Inner speed control loop complies with principles of vector control. Outer position control algorithm respects damping factor of flexible coupling and achieves control of the load position with prescribed closed loop dynamics. Position control system with the measurements of motor current and load position only is completed with the set of observers, which generate all the state variables necessary for control including torques acting on the motor and load side. The simulations confirm that the proposed model based position control system can operate with moderate accuracy.