How Do You Calculate Line Current for Different Connections in a 3 Phase Line?

[scorpio_wan1945]

3 x 15Ohm resistor (R) and 3 x 3.83 mH reactors (L) are connected in different ways across a 500V, 3 phase line. without drawing a phasor diagram, calculate the line current for each of the following connections:

a. R and L in series, connected in wye

b. R and L in parallel, connected in delta

i have difficulty in starting to solve...anyone could shed some light here?

thanks

 

[berkeman]

Well, in -a-, you just have a 15 Ohm resistor in series with a 3.83mH inductor from each phase to Neutral, right? It seems that the current in each leg would be identical and independent...

For -b-, you can look first at Wye-Delta transformations,

http://en.wikipedia.org/wiki/Y-delta_transform

or you could solve it using the phase angle differences...