Damping Controller Design for a DFIM-based Shredder Drive using H-Infinity Optimization

Shredding processes are traditionally operated with fixed-speed drives, that are directly coupled with the supplying power grid. However, this solution has far-reaching disadvantages in terms of grid interaction and the mechanical stress in the drive train. The implementation of a variable-frequency drive with speed-elastic behavior that uses the kinetic energy of the drive train profitably may drastically improve both of these aspects. A dynamically controlled actuator also enables the mitigation of torsional vibrations and thus further reduces the mechanical loads in the drive train to a minimum. In this paper, an advanced controller design procedure using a cost function to solve the resulting multi-objective optimization problem is presented. The effectiveness of the controller is proven by means of simulation using relevant process data.