Synchronous generator droop, and motor speed regulation

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akyip

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Hey guys,

I just want to ask a clarification about synchronous generator droop and motor speed regulation.

Now, as I've always understood it, speed regulation is:

S.R. = (nNL - nFL) / nFL

For synchronous generator droop, according to the textbooks and Spin-Up PE Practice Exam:

Droop = (nNL - nFL) / nNL

However, I see in a reference handbook that:

Droop = (nNL - nFL) / nFL

Which is the correct formula for synchronous generator droop?

Thanks!

 
Hey all,

I just noticed that I accidentally posted this topic 3 times by accident. On my screen, when I was trying to post this, an error message kept on popping up. Sorry for the triple post!

 
Hey all,

I just noticed that I accidentally posted this topic 3 times by accident. On my screen, when I was trying to post this, an error message kept on popping up. Sorry for the triple post!
you can report the other posts to the mods and have them delete them

 
Alright, I will.

But is anyone able to answer my question about the correct formula for generator droop?

I always thought it was no-load speed (or frequency) on the denominator based on the Spin Up Exams and one of my textbooks about power system stability...

But I have another reference handbook that uses full-load speed on the denominator...

It should be no-load speed on the denominator for generator droop specifically, right?

 
Hey guys,

I just want to ask a clarification about synchronous generator droop and motor speed regulation.

Now, as I've always understood it, speed regulation is:

S.R. = (nNL - nFL) / nFL

For synchronous generator droop, according to the textbooks and Spin-Up PE Practice Exam:

Droop = (nNL - nFL) / nNL

However, I see in a reference handbook that:

Droop = (nNL - nFL) / nFL

Which is the correct formula for synchronous generator droop?

Thanks!
I am seeing speed regulation formula following the same formula as voltage regulation with the synchronous speed at full load in the denominator. I confirmed with Graffeo's book and an online reference sheet I had printed out a while back. Just to confirm droop is another term for speed regulation? I don't typically deal with that level of motors/generators at work.

 
image.png

*probably wrong*

 
Last edited by a moderator:
Thank you, Chattaneer. It definitely looks like there's a difference between motor speed regulation and generator droop.
Hold up. Checked my generator book and found

image.png

 
Last edited by a moderator:
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