3 Phase unbalanced load AC electronics question.by rolls Tags: electronics, load, phase, unbalanced 

#1
Nov1609, 12:49 AM

P: 45

1. The problem statement, all variables and given/known data
This is a past exam questions which I am doing as revision, now I am confused about how to calculate the answers. 3. The attempt at a solution I have tried using millmans theorem which is Vsn = (Van/Za + Vbn/Zb + Vcn/Zc) / (1/Za + 1/Zb + 1/Zc) Assuming the following: Van = 240v @ 0 degrees Vbn = 240v @ 120 degrees Vcn = 240v @ 120 degrees As complex impedances: Van = 240 Vbn = 195 + 139i Vcn = 195  139i Za = 10 Zb = 15 Zc = 20i Vsn = 273 +32i Vsn = 275v @ 6.6degrees Now I feel like I am really guessing here and have no idea if what I have done is correct (I don't think it is) so any help would be greatly appreciated For the currents it is just Ia = Van/Za = 240/10 etc which is easy and then you can easily construct the phasor diagram as well from these. Either way I don't think my values for Van, Vbn, Vcn or my method for calculating Vsn is correct. 


Register to reply 
Related Discussions  
Uniformly Varying Load/Uniform Load to Concentrated Point Load  Engineering Systems & Design  4  
Unbalanced force question.  Introductory Physics Homework  1  
phase to phase wiring question  Electrical Engineering  13  
Force Unbalanced Beam  Introductory Physics Homework  1  
Load Line in Electronics..  Engineering, Comp Sci, & Technology Homework  6 