wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
Say we have a transformer with a 480V delta secondary, and we apply a 48 ohm resistance across lines A and B as the only load. So the line currents | Ia |= | Ib | = 10A, and Ic=0A.
Let's call the coil currents Iab, Ibc, and Ica, where (1) Ia = Iab - Ica, Ib = Ibc - Iab, and Ic = Ica - Ibc, as phasors. How do we determine the actual coil currents from the loading? The 3 equations (1) are not invertible.
I'm thinking for an ideal transformer we can't determine the coil currents, so we'll have to consider the impedance of the coils to figure out how the current divides between Iab vs Ibc plus Ica. If so, what is the typical phase angle and order of magnitude for these impedances?
Cheers, Wayne
P.S. This question is a prelude to trying to answer https://forums.mikeholt.com/threads/current-flow-with-l-l-autotransformer-fault-to-n.2576343/
Let's call the coil currents Iab, Ibc, and Ica, where (1) Ia = Iab - Ica, Ib = Ibc - Iab, and Ic = Ica - Ibc, as phasors. How do we determine the actual coil currents from the loading? The 3 equations (1) are not invertible.
I'm thinking for an ideal transformer we can't determine the coil currents, so we'll have to consider the impedance of the coils to figure out how the current divides between Iab vs Ibc plus Ica. If so, what is the typical phase angle and order of magnitude for these impedances?
Cheers, Wayne
P.S. This question is a prelude to trying to answer https://forums.mikeholt.com/threads/current-flow-with-l-l-autotransformer-fault-to-n.2576343/