The Simulating Research On Active Control To The Low Frequency Vibration Of A Large Rotor Shaft System With Multi-support

In this thesis, a study on low frequency flexural and torsional vibration of theexperimental model shafting of a 200/300MW turbo generator's rotor shaft system andits active control is introduced by dint of theoretically mathematical analysis, computersimulation and experimental approach. The study involved the nature analyzing ofvibration of the modeling shaft with multi-support, the theoretical analysis of the activecontrol of the vibration, design of control system and executive system, a design ofexperimental system of an active control, and making an experimental with shaftingmode in low rank vibration. The study is listed as follow.In the first place, we emphasize the presentation of the actuality and develop trendof research at home and aboard in aspect of a large scale shaft system low frequencyvibration and its control. And then on the basis of elastodynamics model of anexperimental shaft we made in ahead of the investigation, the characteristics of thevibration of the shaft is analyzed through using dynamic digital simulation and finiteelement method, so we make clear the natural frequency and relevant vibration type.Moreover, we investigate the response characteristic of the shaft in a few representativeexcitations.In the next place, to demonstrate optimal control theory application to shaftingvibration control aspect the control characteristics of some modern control theory arepresented. The application is basis of a lumped mass model and its vibrationperformances. A control system mode based state space is deduced, and a control law isbrought forward using linear quadratic and linear quadratic Gauss algorithm. Anoptimal control system is designed, and then a simulation of control based on thissystem is analyzed.Thirdly, for matching with an active control simulating experiment and projectapplication investigation, this object develops actuator for the active. The actuatoremployed a series of electromagnetic switch valves with high frequency responsemoving coils. In this paper, an electrohydraulic and cycle-oriented actuator iscreatively and obviously planned or calculated. Moreover, the dynamic responsecharacteristic and electromagnetic characteristic of this executive system are analyzed.Finally, based on these, the design of the active control experiment system forrotor shafting vibration both bending and torsion is presented. The system's otheraspects containing the arrangement and constituent parts, instruments and so on areintroduced too. In addition, the mode experiment of the model shafting, according asneeds, is made in the process of the investigation, and the experiment datumcorresponding was made an analysis and processing.In this dissertation, three crucial technology issues are figured out. Firstly, themodern control theory is taken application to control of the low frequency vibrationof shafting systems. Secondly, a new actuator is designed. Thirdly, the design ofactive control experiment system of low frequency flexural and torsional vibration ofa shafting is demonstrated.On account of the low frequency vibration of a large scale shaft system havingdistinctive features, such as big excitation energy, random system input and response,the active control technology perform perfect alleviating to this kind of rotor shaftingvibration. Technically and theoretically this approach is feasible, but to apply inengineering has a long way to go. However, we can assert that this technology willcome into being societal advantage and economical benefit if it is employed in theproject.