grounding of 12 pulse transformer

[eliahud79]

i start to design project with 1600hp,069kV motor driven by 12 pulse VSD,the supplying transformer to VSD shall be 12 pulse transformer 22/o.69/o.69kV DYn11 Dd0, do i need to ground the Y seconary, and how the VSD monitor ground leakage in the trafo secondary.

 

[electricuwe]

Take a close look into the drives manual. Not grounding the incoming supply will expose some parts ot the drive (driver circuits, current sensing)to higher voltage stress, at least when there is an unintended ground connection elsewhere.

 

[Skogsgurra]

I guess you will have a problem grounding the Delta secondary. Unless you corner ground it - which I wouldn't recommend.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[davidbeach]

Go by what the drive manufacturer requires. A ground reference in the wrong place on a multi level converter can let lots of magic smoke escape. A missing ground reference when one is needed can have similar effects.

 

[electricuwe]

Grounding the starpoint on the Y winding will also provide a sound reference for the rest of the converter. The alternative would be no grounding at all (and -of course-isolation monitoring)