Development of a full parameterized FE-modeling tool for efficient vibration investigations on end windings of Turbo- and Hydro- generators

Schlegl, Bernd; Scheinecker, Christian; Marn, Andreas; Neumayer, Fritz; Himmelreich, M.; Heitmeir, Franz

doi:10.1109/icelmach.2012.6350309

Cited by 2 publications

(3 citation statements)

References 5 publications

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“…The boundary conditions used for the meshes are as follows. The stator bars inside stator core slots are supported by radial and tangential springs [4]. The spring constants are estimated on the basis of the measured natural frequencies of the lowest vibration mode, or bouncing mode, of the two generators.…”

Section: Natural Frequency Analyses Of Stator End Windingsmentioning

confidence: 99%

“…Moreover, in FE models, stator bars comprising several materials are simplified. The whole stator bar is generally homogenised and modelled as a single material with an equivalent elastic modulus [4,6,7,14,15]. Since these models cannot reproduce the spatial distribution of the rigidity in a cross-section of the stator bar, they may degrade calculation accuracy.…”

Section: Introductionmentioning

confidence: 99%

“…To withstand these electromagnetic forces, end winding support structures have to be carefully designed. The support components in the end winding region mainly consist of support rings [4] and support plates located around the stator bars, and the bars are bound to the components by resin‐impregnated glass roving (binding) [5]. In the design stage, the locations and dimensions of the components and the bindings are determined to avoid resonance between the electromagnetic forces and an end winding vibration mode and to ensure that the stress generated under fault conditions does not exceed the fatigue endurance limits of end winding components.…”

Section: Introductionmentioning

confidence: 99%

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Finite element modelling of turbine generator stator end windings for vibration analysis

Iga

Takahashi

Yamamoto

2016

IET Electric Power Applications

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In this study, the authors present methods for accurately modelling the bindings and the stator bars of turbine generator stator end windings for vibration analyses. The bindings are modelled with beam elements and multipoint constraint equations to take account of the bending, twisting, and shearing rigidities of the bindings. To reproduce the spatial distribution of rigidity in a cross-section of the stator bar, the bar is modelled as a composite material comprising a conductor bar with equivalent elastic moduli and ground insulation. The accuracies of the developed binding and stator bar models are verified by comparing measured natural frequencies of binding test pieces and stator bar specimens with calculated values. The developed models and conventional models are applied to the natural frequency analyses of stator end windings, and then the effects of the modelling methods on the calculation accuracy are investigated. While the maximum calculation errors of the conventional models are more than 12%, the calculation results of the developed models agree with the measured values within an error of 7%. Accordingly, for accurately calculating the end winding natural frequencies, end winding finite element models need to take the binding rigidities into account and reproduce the rigidity distribution of the stator bar.

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Section: Natural Frequency Analyses Of Stator End Windingsmentioning

confidence: 99%