Robust control of turbine generators including consideration of torsional stability

By considering the unmodelled torsional dynamics as the plant perturbation of the rigid rotor, a robust H_∞ filtering approach for the speed of the turbine generator shafts is developed based on the general observer. Though the plant perturbation exists between the flexible shafts and the rigid rotor used for controller design, it is proved that the control system with the general observer of the rigid speed preserves the separation principle between the pole of the control system and that of the observer. So the controller and the general observer of the rigid speed can be designed independently to ensure control performance and torsional stability respectively. This is a practical design approach for the robust control of turbine generators.