Research On The Vibration Of Russian TBB Generator Stator Ends

Generator is the very important and expensive main equipment in powersystem.Generator failure is not only a threat to the stability of power system,but also causedamage to the generator equipment probably and great losses to the power production. Alongwith the gradual increase of unit capacity, the electric power and mechanical power togenerator stator winding ends are also growing. The unit security and system stability is alsobecoming increasingly apparent，due to failure and impact caused by the vibration ofgenerator stator ends.The Cooling mode of Russian TBB generators is water-hydrogen-hydrogen.Theprevalent defects of end vibration and about100Hz oval vibration type of the naturalfrequency of the ends of the coil,which lead to problems such as insulation wear andtear,stator cooling water leak,hydrogen leak, loose of slot wedge, loose of iron core and thebreakage of winding bar,have an influence on the security and stablity of the generatoroperation.The processing of these problems each time is of high difficulty,large investmentand long time,so that reduction of generation plan and great economic loss are caused.The research on the vibration of Russian TBB generator stator ends has the importantpractical significance on the search for vibration source,the palliation of vibration and theprevent of loose,wear and leak. In this paper, the reasons of the vibration of the generator end,the structure characteristics of Russian TBB generator, domestic Russian generator typicalfailures and their processing methods, and the solution based on the whole process of thevibration to these problems are studied. The main research and harvests are as follows:1).The internal reasons of the vibration of generator stator ends are analysized fromdouble-frequency vibration,magnet leak of the ends and the air gap eccentricity by theapplication of generator electromagnetic theories. The external factors on the vibration ofgenerator stator ends such as the pipelines connected to the generator and the base ofgenerator stator are analysized based on the actual situation.2).The differeces between Russian generator and domestic one are compared from thestator bedplate,the stator core,the stator coil,the stator cooling water pipe and the hydrogencooler.The impact of these differences on vibration of the stator ends and the reasons how the vibration of Russian generator is more serious than the domestic one are found.3).The typical cases for Russian TBB generators used in domestic power plant aresummarized and the processing methods of them are compared.The paper propose the suitableplace and the advantages and disadvantages of local silver brazing and winding barreplacement.The successful cases of transformation of the ends and the stator cooling watersystem,and the successful processing experience in overheating of end ring, hydrogen leak ofoutlet sleeve,water leak of winding bar,overheating of the core and the deformation and crackof insulated water pipe are introduced.4).The solutions,which are based on the control of the whole vibration process and arefocus on prevention,are proposed in three aspects of the souce,route and receptor ofvibration,including reinforcement of the end lead wires and the generatorfoundation,improvement of vibration isolation of stator cooling water pipe,maintenance andinspection of sealing gasket of stator outlet sleeve, transformation of the return water pipe andthe flexible connection, reinforcement of slot wedge,repair of the core and binding of theends.The solutions are evaluated and recommended from reliability,economy,time,difficulty tofinal effect.