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Need help for Generator Synchronization

  1. Apr 8, 2012 #1
    I want to synchronize to generator. And I want to simulate using MATLAB. But I cannot understand how to do that. Because to do that I need equation's of voltage, phase and frequency. But I could not find. Please help me with that. And also I want to simulate those equation using MATLAB. is there any software which is better than MATLAB. If I have to use MATLAB, then please help me with the MATLAB code. Please.
     
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  3. Apr 8, 2012 #2

    jim hardy

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    i know nothing of Matlab.

    Here's how to synchronize a generator:
    Adjust its voltage to same as what you intend to synchronize to.
    Connect two lamps of same voltage as your generator in series and tie them between phase A of generator and phase A of whatever you want to synchronize it to.
    Do same with another phase, maybe B.

    Watch the lights. They will go from full brightness to completely extinguished as the generator and source roll in and out of phase.
    Adjust speed of generator until that bright/dim/dark cycle is very, very slow like once per minute.
    When all four lights are completely extinguished you are synchronized and in phase with voltage matched. That's a good time to close the breaker.

    Can you make Matlab simulate that?

    Do a search on "synchroscope" matlab probably has one in its library

    http://upload.wikimedia.org/wikipedia/en/c/ce/Synchroscope.jpg [Broken]
     
    Last edited by a moderator: May 5, 2017
  4. Apr 8, 2012 #3

    OldEngr63

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    Great description of actual synchronization operation, Jim!
     
  5. Apr 9, 2012 #4
    Thank you very much Jim. But I was actually looking for some MATLAB simulation to show the wave shapes of voltage, phase and frequency of running and incoming generator. But I cannot do that because I do not know which equation need to use.
     
  6. Apr 9, 2012 #5

    OldEngr63

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    Doesn't your Matlab simulation show the the output waveforms from both generators? The last one I did (several years ago) did. Those were the voltage waveforms, and from there, it should not bee too hard to implement what Jim has described in Matlab code. Look again at your simulation. What exactly is it giving you? What is your output information? From that output, you should be able to get back to this, I would think.
     
  7. Apr 9, 2012 #6

    jim hardy

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    Not knowing a thing about matlab, i'm at a bit of a loss what to say.

    but i do recollecct being afraid to tackle problems in an analog computing lab course for fear of failing. That was a psychological problem not an electrical one.
    Once i overcame that fear and got the first success under my belt i flew through the course and got "A". Loved it so much i used to go in Saturdays just to play with the analog computers (in my day they were faster at solving differential equations than were digital ones)

    So try a baby step with matlab
    Vgenerator = Vgenerator X sin(wgeneratort)

    Vline = Vline X sin(wlinet)

    and difference appears across synchronizing lamps.

    Next fix wline and set up a way to control wgenerator from whatever input device matlab uses.

    next make something that generates a signal of [wgenerator -wline ] and you have beginnings of an automatic synchronizer.

    success is a series of little victories.

    old jim
     
  8. Apr 10, 2012 #7

    NascentOxygen

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    I thought so, too! Very clearly stated, Jim. 5Rkyw.gif
     
  9. Apr 10, 2012 #8
    Thank you very much Jim, That was really helpful for me and again thanks for describing clearly.
     
  10. Apr 10, 2012 #9

    jim hardy

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    i thank all of for the kind words. They came just when i thought i'd failed.

    thank you.

    old jim
     
  11. Apr 10, 2012 #10
    You have access to Signal Generator block in your simulink. Its inputs are amplitude and frequency.

    OR

    You could generate time signal via a time block and feed a sine wave function with it. This way you will be able to control immediate frequency (which is time derivative of phase angle).

    OR

    You could work directly with the Sine Wave box. It's inputs are amplitude, frequency, and initial phase offset.

    With regards to estimating frequency and phase of a harmonic signal, you will need a structure called Phase Lock Loop. Those guys are done in both analog and digital domain and are widely used in power converters. The drawback is that the structures are not trivial to design as it's usually a third-order feedback system.
     
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