# Help in drawing a 3-Phase diagram on induction motor and a nuclear power generator

Discussion in 'Homework Help' started by Mountain_cat, Jul 11, 2016.

1. ### Mountain_cat Thread Starter New Member

Jul 11, 2016
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0
I'm given a Y-connected induction machine, it's magnetizing reactance value (10.04 ohm) and it's leakage reactances (0.226 ohm) (from stator and rotor).

This is connected to a Y-connected nuclear power generator through a cable whose reactance is 0.1 ohm and resistance is 0.01 Ohms per phase.

The neutral connection between the motor’s and generator’s neutral is also at a reactance is 0.1 Ohms and resistance is 0.01 Ohms

So my first step is to draw a three phase diagram that illustrates this system. I don't know if I'm expecting something more out of this, but don't I just connect the four wires (3 phase plus neutral) from the generator to the four wires of the motor? I guess I can represent the cable resistance as a resistor, but what else would I have to have in this diagram? Or am I completely missing the point here? Please help clarify.

2. ### #12 Expert

Nov 30, 2010
16,671
7,314
What's your goal? To get the motor to run? To present this homework problem to your teacher? To calculate how many nuclear power plants it requires?
In other words, you don't need all those specification about leakage and cable reactance to connect a motor to a power line. What are you up to?

3. ### Mountain_cat Thread Starter New Member

Jul 11, 2016
5
0
The ultimate goal is the analyze the fault currents out of the generator when phase A and Phase B is short circuit, and then suggest some cable protection schemes that are common and can be used here.

I would have to do some transient responses for the fault in Simulink, but before I can do all of that, I need to set up the diagram so I can understand what exactly i'm dealing with.

4. ### Kermit2 AAC Fanatic!

Feb 5, 2010
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It is a good problem for homework, but I fail to see the need for specifying a nuclear generator. Would it be different if the power source was provided by 10 million hamsters in a huge wheel?

Geez

5. ### Mountain_cat Thread Starter New Member

Jul 11, 2016
5
0
The problem states "nuclear power generator that is assumed to be ideal and of infinite current capacity"

Maybe the capability of the generator affects the fault current, I don't know, just throwing out ideas here

6. ### Kermit2 AAC Fanatic!

Feb 5, 2010
3,847
963
Ideal with infinite current capacity means it can maintain the output voltage it is designed for into a zero ohm short circuit.
That is infinite current capacity.
Real generators will experience a voltage drop when shorted by a very low resistance.

7. ### #12 Expert

Nov 30, 2010
16,671
7,314
In my world, "reactance" means inductive reactance.
In yours, it might mean resistance. Double check this with the person who handed you the problem.
The National Electrical Code recommends fuses or circuit breakers.

8. ### BR-549 Well-Known Member

Sep 22, 2013
2,177
418
Was a voltage or current given? And what exactly was the question or assignment?

9. ### KeepItSimpleStupid Well-Known Member

Mar 4, 2014
1,265
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How about some ocean front property in the state of Arizona?

Both are unattainable!