Research On The Vibration Of Large Tuirbo-enerator Stator End-Windings

Recently, accidents caused by the vibration of stator end windings have occurred time and time, which is bound to threaten the security and stability of power grids and generators. Therefore, research on the vibration problems of stator end windings is significant for improving the reliability of operation of generators. This paper will be summarized as the following sections:1. A brief description of the cause and characteristics of vibration is given and the testing method of stator end windings'vibration along with the development status at home and abroad is introduced.2. The common structures of stator end windings of generators manufactured at home and abroad are introduced. The sources of vibration are analyzed in detail.3. The principle of hammer exciting is analyzed and problems which should be paid attention to when modal test is done are introduced. Factors affecting the natural frequency are analyzed and how to use the modal parameters to speculate the actual running status of generator is analyzed. Finally, on the basis of the modal data which is obtained by Hebei Electric Power Research Institute, a system of analyzing modal information of turbo-generators is made. It can record the modal data, analyze the trend of natural frequency and show modal shape of stator end windings.4. The radial force which the stator end-winding endures along the generator's circle distributes like an ellipse, but the trend of circumferential force which is at the same level as the radial force is not known clearly. So, with the reasonable simplification of stator end windings, we propose a simple method to calculate the circumferential force and analyze its overall trend in detail.