Analysis of the dynamical performance of the two-mass drive system with the modified state controller

In this publication a modified state controller applied in the speed control loop of two-mass drive system is shown. A characteristic feature of this type of a drive system is an existence of oscillations of electromagnetic state variables, resulting from the finite stiffness of the connection between driven motor and the load machine. Effective damping of torsional vibrations in such a system is achieved by introducing additional feedback in the control structures of the two-mass drive. In the described control system the reduction of the feedbacks number is achieved by elimination of the one coming from the torsional torque. At the same time, it was assumed that the beneficial dynamic properties of the two-mass drive obtained in a case of the application of all possible additional feedbacks should be kept. Calculation of the controller gains was done using the pole placement method. Application of the pole placement method gives a possibility for setting the parameters of the control structure for given values of damping coefficient and resonance frequency of the close-loop system, so it is possible to influence the dynamic properties of the drive.