Generator Field Excitation Audible Noise

[BrkfldEE]

I have a horizontal hydro unit, 3MVA, and when the excitation is applied to it, a screeching noise starts that is very loud and annoying. Does anybody know the reason for this? I have heard that it has something to do with the way the rotor was made?

 

[electricpete]

High electromagnetic noise can occur for a variety of reasons... can be inherent in the machine design based on winding configration including number of poles and rotor and stator slots. Can also be increased by eccentricity, overvoltage, and mechanical resonances.

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[edison123]

As pete says, electromagnetic noises are part of the machines. Did this problem pop up suddenly ? Is this a new unit or was recently repaired/refurbished/rewound ?

Muthu

http://www.edison.co.in

 

[BrkfldEE]

This unit has always done this since it was installed in 1985. That is why I was thinking it had to do with the way that the rotor was constructed.

 

[edison123]

How are the vibration levels ? Are they increasing from unexcited, to excited to loading ? Have you talked to the OEM ?

Muthu

http://www.edison.co.in

 

[powerjunx]

construction and installation, do matters with your prob. Try measure step increase of excitation current..note the noise comes out, if it does when excited at a certain level..it may cause probably core.


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