The first of our numerous work on the state estimation of rotating drives began with a project for the development of a state observer for power plant turbines. These turbo generators consist of a long shaft on which the generator is mounted for power generation and usually several turbines for driving the shaft.
In particular, the torsional vibrations of a turboset triggered by grid malfunctions or operating errors lead to fatigue of shaft components and can even trigger severe mechanical damage. The latter can, in some cases, induce additional permanent torsional vibrations in the rotational frequency and their harmonics.
Therefore, it is necessary to ensure continuous monitoring of a drive train for torsional vibrations.