Transformer Bushing

[CKent]

Good day!

I'd like to know how does frequency affect the long term performance of a transformer bushing. Our system is 60hz but we have a polymer transformer bushing which is apparently rated 50hz. Is the effect significant?

CK

 

[alehman]

Wouldn't think so...

 

[CKent]

I understand that frequency has a negative effect on insulation materials. The higher the frequency the lower the dielectric strength of the insulation material. How does this theory affect a transformer bushing especially if it is made up of SiR outer sheds? Would the total dielectric strength of the bushing be significantly reduced at 60Hz?

Also, since the capacitance of a paricular bushing is constant, the bushing will have lower capacitive reactance (about 0.833) at 60Hz than at its designed 50hz application. How does it affect the operation of the bushing?