# Homework Help

#### choco1

Joined Apr 30, 2006
2
Hi,
I got the following question that i gotta do for a college project.
I need a bitta help, understanding this is hard.

A three-phase Δ- connected generator has an impedance 0.009 + j0.09 Ω/Ø. When the load is removed from the generator, the magnitude of the terminal voltage is 13,800V. The generator feeds a Δ- connected load through a transmission line with an impedance of load is 7.056 + j3.417 Ω.
a) Construct a three-phase Δ-Δ system with above parameters. E Clearly indicates the generator voltage, transmission line and load impedance in the circuit.
B) Construct the single-phase equivalent circuit.
c) Calculate the magnitude of the line current
d) Calculate the magnitude of the line voltage at the terminal of the load
e) Calculate the magnitude of the line voltage at the terminal of the source
f) Calculate the magnitude of the phase current at the terminal of the load
g) Calculate the magnitude of the phase current at the terminal of the source
h) Calculate the total average power dissipated by the load

Have I got the basic idea for the following????

a) I have drawn the 2 delta systems etc,
The generator volatage I have is simply 4600V, as i just divided the 13800 by 3, as the magnitude voltage is really supplied by 3 phases.
The transmission line has no impedance as none is stated, although there is impedance in the delta lines, each being 0.009 + j0.09 Ω/Ø.
I have done the load impedance as (7.056 + j3.417 Ω)/ 3.

B) my single phase circuit has a 4600V source @ 0'. and 0.003 + j0.03 Ω as the load impedance.
Once again, no line impedance, but a load impedance of (7.056 + j3.417 Ω)/ 3 / 3.
I have divded by 3 again to make way for Y-Delta conversion.

c) i just have 5183.71A, but oviously if the first parts are incorrect, this will be too!

d) 4516.25 V, as above

e) 4516.25 V, as above above

Any comments are appreciated, as im still learning how to do this type of stuff I find it all quite difficult. My book has examples, but not ones that are similar to this in anyway!

Thanks

#### choco1

Joined Apr 30, 2006
2
I have noticed that people never seem to post on these forums!

#### Papabravo

Joined Feb 24, 2006
20,597
Originally posted by choco1@May 1 2006, 09:21 PM
I have noticed that people never seem to post on these forums!
[post=16727]Quoted post[/post]​
It's the end of the semester -- we're tired.