Transformer Noise 1

[SidiropoulosM]

Any ideas on reducing noise from a 230/115 kv transformer without reducing operating voltage? The noise occurs when the transformer operates at 107% nominal voltage.

 

[busbar]

Likely the NLTC has been set for highest ratio? [I have no immediate reference, but ISTR acoustical noise roughly increases with the square of voltage. 1.07 puV <> 1.145 pu noise]

 

[SidiropoulosM]

Busbar, thanks for your comment. You're right on, we can solve the problem by changing the NLTC position, but not on this transformer, on an upstream 500/230 kv transformer. This is probably what we'll end up doing. This will effectively reduce the operating voltage at the 230 kv bus, which will have some drawbacks during peak load conditions. I was asking for ideas on solving the problem without changing the voltage, which may not be possible.

 

[busbar]

Looked through the online IEEE T-PWRD index, and only found material on transformer acoustic measurement techniques, not mitigation—short of noise cancellation by active means. The V² r&#8729;o&#8729;t is from an associate that has considerable power-transformer experience.

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