 #1
 609
 46
I'm studying Auto Transformer phasor diagram, and am having some doubts. I'd be grateful if someone could help me out with them.
Book has equation:
I understand that using Kirchoff's law we get minus sign for (I_{2}  I_{1}) term, but shouldn't it be positive as per concept?
Negative sign means the mmf of (I_{2}  I_{1}) aids the source, which can't be.
It is V_{1} that is eventually providing I_{2} So I_{2} has to oppose V_{1} and not aid it.
I understand that using KVL sign conventions we get the above equation with the signs above, but conceptually shouldn't (I_{2}I_{1}) oppose V_{1}
Doubt#2: And in the phasor diagram here:
They've added the terms V_{1} = E_{1} + I_{1}R_{1} + I_{1}X_{1} + (I_{2}I_{1})R_{1} +(I_{2}I_{1})X_{1}
Shouldn't the direction of I_{2}I_{1} be upwards when added with E_{1}?
SInce we're adding (I_{2}I_{1})(R_{1})
So if (I_{2}I_{1})R_{1} is facing south then the negative of it must face north.
Book has equation:
I understand that using Kirchoff's law we get minus sign for (I_{2}  I_{1}) term, but shouldn't it be positive as per concept?
Negative sign means the mmf of (I_{2}  I_{1}) aids the source, which can't be.
It is V_{1} that is eventually providing I_{2} So I_{2} has to oppose V_{1} and not aid it.
I understand that using KVL sign conventions we get the above equation with the signs above, but conceptually shouldn't (I_{2}I_{1}) oppose V_{1}
Doubt#2: And in the phasor diagram here:
They've added the terms V_{1} = E_{1} + I_{1}R_{1} + I_{1}X_{1} + (I_{2}I_{1})R_{1} +(I_{2}I_{1})X_{1}
Shouldn't the direction of I_{2}I_{1} be upwards when added with E_{1}?
SInce we're adding (I_{2}I_{1})(R_{1})
So if (I_{2}I_{1})R_{1} is facing south then the negative of it must face north.
Attachments

240.7 KB Views: 2,114

148.8 KB Views: 2,325