Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

IEEE CT Saturation Calculator Question

Status
Not open for further replies.

sky2020

Electrical
Joined
May 21, 2019
Messages
39
Location
CA
I have a question about this calculator. Should not the secondary current be computed at the maximum dc offset? Why the calculator does not show this?

at t = 0, the peak value of DC offset current is obtained but the time at which fault strikes and phase angle of the AC voltage should be taken into account hence the computed fault current by this calculator is not the maximum.

I am not happy with this calculator. It can also show the CT is not saturating while it is not the case. Am I right?

temp_zokzsl.gif
 
The amount of DC offset is determined by the X/R ratio and when the fault happens on the waveform. The most offset it will be is when at T=0, the current is zero. Go review the equations in the linked PDF. The waveforms above are nearly fully offset and you can see it by the waveform being mostly positive.

 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top