TNT equivalent for energy released in electrical fault
TNT equivalent for energy released in electrical fault
(OP)
Can anyone advise a simple relationship between the energy released in an electrical fault and the equivalent TNT explosive force?
For a specific example: if a 1,500 kVA transformer primary voltage 11 kV, has a fault which is cleared in 1 second, and the worst case fault current is 27. kAmps, what is the relationship between the energy produced (assuming reasonable accurate fault current is known, and voltage does not decrease)?
For a specific example: if a 1,500 kVA transformer primary voltage 11 kV, has a fault which is cleared in 1 second, and the worst case fault current is 27. kAmps, what is the relationship between the energy produced (assuming reasonable accurate fault current is known, and voltage does not decrease)?






RE: TNT equivalent for energy released in electrical fault
TNT equivalents have been used in other applications for "relative" comparison purposes. Nuclear bombs is the obvious; and as I recall, the Apollo space program used "TNT equivalent" to have a uniform scale for the explosive potential for all pressurized vessels (small or large) which were flying with the astronauts.
RE: TNT equivalent for energy released in electrical fault
The power factor is needed to obtain MWsec
Assume approximately cos(85°)=0.087=Power Factor
1 watts-second = 1 Joule
514.4 MVAses x 0.087 = 44.75 MWsec = 44.75 Mega Joules
This needs to be properly correlated to the TNT energy release.
RE: TNT equivalent for energy released in electrical fault
RE: TNT equivalent for energy released in electrical fault
See, various Electrical or Electronic Handbooks
RE: TNT equivalent for energy released in electrical fault
Yeh the theory is correct. Perform the mathematics and thats the equivalent.
As a note where the hell did you dig that number up Busbar? I don't dispute it but we have looked for it for some 20 years and never found it ( not the royal we but the crazy we being collegues -spelling?- and mad physicists).
Just to play devils advocate - consider that TNT is discharged in a compressed form and usually an electrical fault is generally "unrestrained" in terms of being an adiabatic reaction or not. This may alter the answer but who cares its one hell of a bang if your near it.
I post a star to busbar for the number
Regards Don
RE: TNT equivalent for energy released in electrical fault
and a star to jbartos for reminding me of a fundamental calc which had eluded me
Don
RE: TNT equivalent for energy released in electrical fault
Hope that answers your question.
RE: TNT equivalent for energy released in electrical fault
RE: TNT equivalent for energy released in electrical fault
RE: TNT equivalent for energy released in electrical fault
Megaconverter II, http://www.megaconverter.com/mega2/, gives (under Energy) 1 Ton of TNT = 4.18*10**9 Joules which is about 4609 Joules/gram. Very close to Busbar's answer.
RE: TNT equivalent for energy released in electrical fault