Rotor end winding cracks

Generator endwindings experience mechanical vibration during operation. The poletopole crossover completes the winding circuit, connecting the. Ge generator rotor design, operational issues, and refurbishment options. The rotor can be classified into two types namely the phase wound and the squirrel cage. What is the meaning of open end winding induction motor. Found 0 sentences matching phrase rotor endwinding retaining ring. End winding vibration can lead to cracking of the coilbar insulation just outside of the stator slot and, in severe cases, may cause the copper conductors to fatigue crack leading to high arcing currents. In a motor, the rotating part is known as the rotor.

End winding vibration and degradation sidewinders llc. Engineering firms and endusers perhaps need to provide. Open end winding means the neutral point of the machine is. Include generators and exciters in your outage inspections. The resulting forces lead to vibration within the stator core, but more seriously at the stator end windings and their support structures. Bump test was performed in order to confirm the repairs had improved the condition of the machine. Ger 4212 ge generator rotor design, operational issues, and. Ge generator rotor design, operational issues, and refurbishment options ventilating duct wedge wedge chafing strip copper winding slot insulation. Large electrical generators condition assessment rotor. The end rings complete these circuits, thus a 2pole winding end ring will be subject to more current than with a higher number of poles in the winding. Translation memories are created by human, but computer aligned, which might cause mistakes.

These currents appear as side bands around the supply line frequency 60 hz peak, and. Note that the width of the crack gets progressively narrower away from the phase break. If a rotor winding cracks, the performance of the motor will degrade and the stator end windings could also get damaged. The greater the number of poles, the greater the number of rotor circuits. End winding and damper winding condition the rotor end windings are subjected to high centrifugal forces and thermal cycling. Endwinding vibration monitoring using fiber optic accelerometers provides. Tapered end winding and retaining ring exerts axial force on rotor body end with. The hairline crack in fig 12 was caused by a sudden short circuit. Methods of detecting cracked rotor bars in electric motors.

This requirement only applies to steam turbines with end bells manufactured from type 885 mnnicr or 184 mncr steel, which are prone to stress corrosion due to the combination of humid conditions and type of steel. The diagnostic method of the rotor cracks and local demagnetization which. Recommended maintenance practice for electric motors and. Current flowing in the rotor and stator give rise to magnetic fields. The rotor includes the rotor winding as well as rotor core. Normally the machine is supplied from one side of the stator winding only and the other side is isolated connected in star or delta. Shown in fig 11 is a fracture that has occurred at the end of the core, with forces concentrated at the phase break. Generator endwinding vibration analysis a capstone. With rotors, cycling service can cause lowcycle fatigue cracking of forged rotors, including cracks in tooth tops, snap ring grooves and fluted areas, windings, slot wedges, wedge grooves, and.

Wrhd heavy duty rotor winding line for a complete solution to enable the fast and effective winding of rotor pole coils. Many units show crack initiation in some components within as few as. Index terms motor, generator, winding failure, rotor winding. The rotor induces currents back in the stator windings. End winding stiffening was performed using specific resins and epoxies. Endwinding vibration can lead to cracking of the coilbar insulation just outside of the stator slot. The vibration of generator end windings has been a topic of concern since the beginning of power generation. A permanent solution to generator vibration problems. Operating experience with a generator stator endwinding vibration. The rotor field current is carried to the rotor endwinding through the. Although rotor tooth top cracking occurring at the ends of the rotor. Onehalf of the rotor failures occurred in the cage winding.