Stator Winding 1

[jan63]

I am working in a power station.The generators installed here are of 175MW capacity and installed in 1982.Recently we faced a problem.There is a whitish powdered deposit on the stator bars just at the entrance to the slot.I am attaching pictures.Can any one suggest the reason and what remedy should we adopt.Will a spray of varnish or glyptol be sufficient

 

[Skogsgurra]

Any rebuilding or construction work nearby? Looks like concrete dust to me.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[jan63]

no such work nearby.And the deposits are not on all bars.It can be seen on some and not all.Also trend is that there are deposits on four then eight are clear.

 

[edison123]

It's a case of slot end partial discharges. The stator bars corona protection have crossed the useful life. Since the winding is more than 3 decades old, the winding insulation would also be in the end of its useful life. Time to rewind your machines.

Muthu

http://www.edison.co.in

 

[jan63]

in short term if we apply proper insulation at the effected area will it work

 

[edison123]

Applying insulation varnish or epoxy would not solve the corona discharge problem.

Muthu

http://www.edison.co.in