- #1
crom1
- 57
- 1
Homework Statement
Find the current measured by Ammeter .
Homework Equations
$$ U_f=\frac{U_l}{\sqrt{3}} $$, Millman's theorem ...
The Attempt at a Solution
[/B]I know I can't just find U_f, divide it with impedance, and add all three currents (I am not 100% sure why I can't do that, can someone explain when can I do just that, and when exactly is forbidden?)
My first idea was to find U_f, find U_{0'0} (with Millman's theorem), subtract those two, and then find current for every phase, add them up and that's it.
However, after trying something else, I found that finding U_{0'0} , and then evaulating
$$ U_{0'0}\cdot (\frac{1}{Z_1}+\frac{1}{Z_2}+\frac{1}{Z_3}) \approx 60 $$
gives correct solution.
Can someone explain why , because it doesn't make any sense to me.
Point 0' is where where 3 lines L1,L2,L3 meet