Current Transformer Sizing and Saturation - Solution Demonstration 

Thanks for the video. Just a quick question about ETAP. Can I specify the type of CT that I am using? I mean, I would like to see the behavior of TPZ, TPY, and TPX CTs. Can I specify that on ETAP? The different features of each type of CT? Thanks

This is incredible. Can you please allow the ability to import a comtrade file so we could put in actual real life fault current data and see the saturation? Also the ability to see the residual connection and it’s false residual current when all three CTs are summed up would be a huge addition

We had to study saturation, the physical nature of it. Recall that magnetization requires aligned electron spins (aka 'aligned magnetic domains'). Electron spin is the magnetic moment of the electron. 1) current applied to primary winding, electron spins in the winding begin to align, leading to magnetic field building up around the winding 2) electron spins in the core material begin to be magnetically torqued into alignment by the electron spins that are aligning in the primary 3) the core material's electron spins do not align instantaneously - during the time they are being torqued into position, they exert magnetic torque against an 'instant' alignment of electron spins of the primary winding This is just how the self-inductance works; the five (5) L/R time constants required to fully build up the magnetic field around a coil - or a transformer primary - is caused by the time required for the alignment of the coil's electron spins and the core's electron spins. Five L/R time constants. SATURATION 4) once the full magnetic field is established in the core - ie. once all electron spins in the core are aligned - they can no longer impede (can no longer magnetically torque) against further changes in the magnetizing current in the coil or primary winding. 5) With the removal of the burden (due to saturation) of needing to magnetically torque the core's electron spins into alignment (because in saturation they are all aligned, ie. a full B field), the magnetizing current in the primary or coil can now grow (change) with less impedance. Adding a gap to the core slows the alignment of electron spins in the core, which then slows the alignment of electron spins in the primary winding or inductor. Or to say it another way, the Vacuum - free space - in the gap lacks the magnetic dipoles that could remain aligned. The magnetic dipoles in the core remain aligned due to the external energy added to the core by the magnetizing current. Once the crystal lattice, the adjacent particles in the core, have re-situated after electron spin alignment in the core, to de-cohere (un-align) the electron spins in the core, energy must come from either heat (the Curie temperature) or from a change (reversal, say) of the magnetizing current. .

Please reales video about capacitor & battery