I've got quite a problem here trying to solve this 3 phase system (2nd U12 should be U31) and hope you can help me:
I'm trying to calculate the single phase voltages and currents for the drawn case with the connected neutral and once for the disconnected neutral.
However, the first problem for me already arises with the fact, that the sum of the phase to phase voltages is not zero, as indicated by the phasor diagram below:
After hours of research on the internet or in literature I couldn't find a single problem, calculation or simulation where this case was treated and if I think about it, it just doesn't make sense that the sum of phase to phase voltages isn't zero.
Therefore, the underlying question: Is this system even possible?
Thanks for reading and hoping for your answers!
Best Answer
The commented and suspected conflict exists. You have probably a wrong assumption on how the dual presestations of U12 should be interpreted. Check it!
To avoid the conflict one of the interline voltages must not be given or it should be right, too. Assuming that there is no given value for U31 the conflict disappears. But the dual presentation for U12? That also is a conflict. Check if one U12 really should be the given U1. Namely one of the line voltages can be given, if two interline voltages are given. The first U12 = 400V is the most probable candidate to be changed to U1=400V because it has the angle =0 or it's a RMS scalar value.