The Large Turbine Generator Stator Winding End Of The Modal And The Natural Vibration Frequency Measurement And Prevention

With the continuous increasing of manufacturing level and stability of the transmission-line system of electric power, the capability of single generator is increasing. The secure running of large-scale generator is becoming more and more important to the whole transmission-line system of electric power. The alternate emf. under normal operating or instantaneous emf. when inner shorting happens acts on the generator stator endings. With the increasing generator capability, the electro motive force and the mechanical force increases acting on the stator endings. The frequency of electromagnetic force that acts on the endings is twice greater than normal (50Hz), its radial component is rather bigger than tangential and axial, and its shape is quasi ellipse. Because of these, if the inherent frequency of the generator stator endings is close to 100Hz, especially a kind of ellipse emf. vibration of 100Hz frequency exists on stator endings under generator normal operation, strong resonance will happen with the endings structure. If the generator stator windings tank fixed and end support, lashing fixed and technology that do not meet the requirements, even less exciting force will be larger induced vibration. The vibration after long period will definitely causes the insulation fraying, structure loosening, bars fatigue and breaking, etc., eventually the insulation system breaks down and shorts fault happens. So it is very necessary to monitor the vibration of large-scale generator stator endings and take preventive measures about it.With the capacity of generator increasing, the load of generator gets numerical high, that making electromagnetic force that stator bars are suffered is also growing. Because its design o is not only to try to secure fixed to withstand powerful electromagnetic force, while also paying attention to their vibrational frequencies from the electromagnetic force to prevent a terrible resonance frequency, generator stator windings structure is complicated. The bar out of the slot bending curve into space, more complicated geometrical shape is to be caused. It is very difficult to establish the model of the stator end. One of these experiments is that large turbine generator stator end of the two-tier network predigests streamline continuous conical woven conical shell-beam structure or laminated reinforced cone shell model, after experimental modal analysis to identify various parameters,...