3 phase assignment help!

Discussion in 'Homework Help' started by brady123, May 7, 2008.

May 5, 2008
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could anyone give me the answer to ...
what is the synchronous speed of a 50hz 10 pole generator?
any help very appreciated!

2. mrmount Active Member

Dec 5, 2007
59
7
It is 1800 rpm.

May 5, 2008
7
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thanks alot mate
what is the equation to work this out?

4. recca02 Senior Member

Apr 2, 2007
1,211
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I think it should be 600 RPM.

Synchronous speed(in RPM) = 120*frequency/(number of poles)

5. mrmount Active Member

Dec 5, 2007
59
7
The equation is 120*f/p, where f is the frequency and p is the number of poles per phase. So Recca02's answer is correct if you assume 10 poles per phase and my answer is correct if you consider a total of 10 (so 10/3) poles. Having said that, in general they give number of poles per phase and you might want to check on that.

6. JoeJester AAC Fanatic!

Apr 26, 2005
4,065
1,774
Where did the OP state he had a three phase generator?

I don't think I've seen that question ever posed with the total poles as the sum of each pole in each phase, although I'm sure it could happen. It would depend if the instructor's intent is ensuring you read the question.

Last edited: May 8, 2008
7. omri karni Member

May 8, 2008
12
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hello

"The equation is 120*f/p"

The equation shuldn't be 60*f/p ?

8. recca02 Senior Member

Apr 2, 2007
1,211
1
I think it is 120f/p instead of 60f/p as poles work in pairs to create North and South. Thus in equation they are 60*f/(p/2)= 120*f/p.
I found this to prove that if poles per phase is 10 and frequency is 50 speed is 600.

Last edited: May 8, 2008
9. omri karni Member

May 8, 2008
12
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you were right friend in the equation that I suggested we must put the poles

in pairs(p/2)

Nov 21, 2006
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11. omri karni Member

May 8, 2008
12
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It's very nice article
maybe in the future we will be able to change the numbers of poles in the machine and consequently to change the valocity but I think that now it's just a nice theory.