high neutral current

i work in a power station where auxilliries are supplied power through a 132kv/11 kv delta star transformer(star solidlly grounded0.This transformer is connected to a 11 kv bus.to same bus we have a 4 MW gen connected which is star.When ever the neutral of this gen is connected heavy current flows through neutral grounding transformer of the gen.Can
what can be the problem? can we run the gen without connecting neutral transformer

What country are you in?
What is your job title at this power station?
Don’t you have engineers and maintenance staff on site?
Sorry, can’t offer up advice on a problem this dangerous…

Possibly imbalanced windings or large harmonics in the generator. Talk to your engineers.


Are the generator and transformer neutrals connected together? Have you checked phase shift with a scope? Sketch a diagram of the connection points and the points where you measured the neutral current. Upload the sketch and your measurements.

You can run the generator without the neutral if all you need is three-phase. A 4MW generator is large enough to run a small manufacturing operation. Unless you are running a small number of large loads, or are feeding other Delta primary transformers, you will probably need the neutral.