Forced dynamics control of electric drives employing pmsm with a flexible coupling

A control system based on the principle of forced dynamics control for an electric drive with a permanent magnet synchronous motor and a flexible coupling is presented and verified by simulations. The controller is of the cascade structure, comprising an inner speed control loop and an outer position control loop. The inner forced dynamics speed control loop respects the principles of vector control and requires an estimate of the load torque, which is estimated in an observer. The outer position control loop based on the same principle is designed to control the rotor angle or load mass angle in the presence of a vibration mode due to the flexible coupling and with an external load torque. The derived control law requires estimates of the load torque and its derivatives, which are estimated in the load torque observer. The simulations presented indicate that the control system operates according to theory and therefore further investigations including experimental implementation are recommended.