End Winding Vibration Solutions

SENSOPLAN AG Gewerbestr. 6 79801 Hohentengen a.H., Germany Phone +49 7742 9298-0 Fax +49 7742 9298-10SENSOPLAN Inc. 1020 e Wall Street Mt. Pleasant, SC 29464, USA Phone +1 843 329 0275 Fax +1 843 329 0956

Please visit us at www.sensoplan.com, or send us a note to [email protected]

SB SENSOPLAN End Winding Solutions, SENSOPLAN 03/2007

SENSOPLANGenerator Services

Problems with the end winding?Friction dust, friction greasing?Excessive vibrations?Short-circuits in the transmission grid?

...then we recommend using this service!

Service Bulletin

End Winding Solutions

Stator end winding vibration problemssolved in a responsive and

qualified manner




Step 1: ANALYSISPrior to any analysis, a thorough visual inspection of the end winding under concern is performed. Traces of friction dust or greasing, as well as potentially loose bandages, provide valuable information regarding the condition of the end-winding and the further problem solution.The subsequent modal analysis determines the vibration behavior of the complete end winding by means of a bump test using highly sensitive and sophisticated measurement and calculation equipment.

Step 2: DIAGNOSISThe measured raw data is then used by SENSOPLAN in a second step, the diagnosis, to determine the specific characteristics of the end winding.To this end, powerful calculation programs are applied to determine and graphically depict frequencies, amplitudes and locations of the crucial n-node-vibrations. In conjunction with this, end winding stiffness (compliance) is calculated at critical locations.In parallel, the end winding is modeled in a 3D-Finite-Element (FE) model, with characteristics matching the results of the measurements obtained previously (validation).With all relevant data of the end winding available in data sets ready for further evaluations, the diagnosis step, i.e. the determination of the actual characteristics and condition of the end winding, is completed within the shortest possible amount of time.

SENSOPLAN End Winding Solutions

Your Requirements: Maximum service life Maximum availability and reliability No reduction in performance

of your generator.

Operative restrictions and downtime of generators must be regarded as the most unwanted and costly incidents in power generation units. A frequent cause of operative generator problems is the end winding, since it is very complex in design and electro-mechanically heavily loaded.With the SENSOPLAN End Winding Solutions service approach, SENSOPLAN is able to offer a comprehensive and systematic package providing qualified and economical solutions to any problem concerning the end windings in generators of all sizes including analysis, repair and re-commissioning.

Modal Analysis: Spectra of the measurements




3D-Finite-Element-Model of agenerator end winding

Repaired end winding with improvedsupports

End Winding ProblemsSolved in a responsive and qualified manner

Step 3: DESIGN SOLUTIONThe third step is comprised of the determination of the origin (root cause analysis) of the problems identified and the identification of proposals for their solution using the FE methodology with consideration given to all technical and economic boundary conditions. The primary target is to bring the generator back into operation as soon as possible without any restrictions to power output or service intervals.To determine the root cause, the data sets of the end winding generated in step 2 are used to calculate absolute and relative movements of bars, connectors, stiffeners, supports, etc. at different electrical operating conditions. These results, in combination with the results of the natural frequency and n-node-vibration calculations, allow the areas of concern to be precisely identified.With the precise problem identified, proposals for solution can be generated. Using a methodology invented by experienced SENSOPLAN experts, design modifications are built into the FE-model of the end winding at different locations, and their effects are determined and evaluated. This methodology delivers sound solutions to the problems quickly, including clear statements regarding the extent of the required measures to be taken. Thus, the usual trial-and-error approach, which can result in serious operating problems and extensive delays, is avoided.Based on the information obtained, SENSOPLAN decides, together with the client, on the technically and economically feasible solution to be implemented.

Step 4: REPAIR & RE-COMMISSIONINGIn the final step, SENSOPLAN executes the implementation of the selected end winding repair solution and supports the client with re-commissioning of the generator.The repair package determined in step 3 allows for a precisely defined installation, which is performed within the shortest possible amount of time. Finally, the project is completed by successful re-commissioning of the generator, supported by SENSOPLAN.

Your Benefits: Avoidance of costly downtime Fast problem solution Expert proposals for economical

modifications Qualified and speedy implementation




SENSOPLAN we have got the right solution:

Generator-Services:Stator:

Stator Vibration Services: Analysis and elimination of stator frame vibration problems SENSOCORE HI Checkup: Reliable on-site diagnosis of the generator stator lamination

stack using a high induction loop test under close-to-operating conditions SENSOCORE-Inject: Patented repair of lamination stack hot spots in deep layers Stator End Winding Vibration Services: Stator end winding vibration problems solved

in a responsive and qualified manner Resin Pressure Injection RPI: Repair of the coupling between stator winding bar and

slot wall by injection of resin Stator Rewind Services: Dedicated improvement of the stator winding design

Rotor: Rotor Vibration Services: Rotor vibration problems solved in a responsive and qualified

manner

Rotor Rewind Services: Dedicated improvement of the rotor winding design Top Tooth Cracking: Modification of the rotor shrink fit area Hydrogen Sealing Contour: Modification of the hydrogen sealing rings

Turbine-Services: Analysis and elimination of casing and shaft vibration problems Determination of residual life of steam turbines Steam Path Audit

Would you like more information?Please contact:

Europe USASENSOPLAN AG SENSOPLAN Inc.+49 7742 9298-0 +1 843 329 [email protected] [email protected]

Documents

End Winding Vibration Solutions