Comparison of sliding mode and forced dynamics control of electric drive with a flexible coupling employing PMSM

The paper presents comparison of two control techniques (a) sliding mode and (b) forced dynamics for control of electric drives employing permanent magnet synchronous motors with flexible coupling. The designed controllers are of the cascade structure, comprising an inner speed control loop and an outer position control loop. The inner speed control loop for both controllers is based on forced dynamics and respects the principles of vector control. The outer position control loops are designed to control load mass angle in the presence of a vibration mode with an external load torque. Derived control laws requires estimates of the load torque and the second one also its derivatives, which are estimated in the especially designed load torque observer. The simulations presented indicate that the control systems operate according to theory and therefore further investigations including experimental implementation are recommended.