132kV Current transformers - Live tank or Dead tank

[RRaghunath]

Friends,
I have come across live tank design current transformers in 400kV system.
In general, when should we prefer dead tank design transformers over live tank one and why?

I have come across people saying dead tank design is obsolete and I also find from ABB website that they only make dead tank design CTs. I am not sure.

Thanks in anticipation.

 

[jbartos]

Comment: The dead tank concept is used up to certain voltage level, e.g. medium voltage level. High voltage level and extra high voltage lever use live tanks.

 

[jbartos]

Suggestion: Visit

http://www.meppi.com/gcbdept.html

http://www.abb.com/global/seitp/seitp332.nsf/0/C1256CCB004E670DC1256B5100363A28?OpenDocument

etc. for more info

 

[xabproject]

Hi RRN,
Welcome back! Quo Vadis?
The 380/400/420/500kV dead tank design of CB will have adequate turret space to mount the dead tank CT and hence they go together very well. However, there were cases where live tank CT had to be provided additionally, say because a strange spec clause called for a physically separate metering CT and the protection schemes demanded 5 number CT on each turret - remember the Bkr and Half schemes! (most manufacturers agree to 3 on one side, 4 on the other). Installation arrangements demanded an elaborate layout. Desert S/S provide that kind of large outdoor land allocations and "solutions" are possible!
So I see that if the dead tank design cannot meet all the requirements, you use a live tank CT to complement/supplement.
I am not very sure of the Hybrid design, and I will return with more info (perhaps based on the CIGRE working group) shortly.
To sum it up, I have not come across a strict technical criterion/ a set of criteria favouring 'live' against 'dead' or vice versa. It has been "Client favours", existing network's O&M choice since most equipment is of one type or the other, most important-COST, etc
None of this information is of archaic nature!
I will be glad to receive any information contrary to this!
I wonder how we will adopt the low energy new technology optical CT PT with all this;-) Are these to be considered Live Tank designs or Dead Tank design? ;-()

 

[jbartos]

Suggestion: Visit

http://www.epa.gov/highgwp1/sf6/pdf/middletonppt.pdf

for: Technical Considerations, Slide number 22