Synchroscope animation 2

[ScottyUK]

I found this link while looking for some information on the net. I think the animation is excellent, and the ability to change the parameters makes it all the clearer when demonstrating the principles. Well done to the author!

http://www.eece.maine.edu/Power/Java/synchro/synchro.html

ps. Don't maximise your browser, otherwise you hide the sub-window with the animated vector display. Guess who made this mistake!




------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[busbar]

It’s kinda’ humorous to walk into a newer 525kV-yard control house and see that very implementation as a “last ditch” means of synchronization.

Add GPS and you get

http://tesla.selinc.com/synchrophasors/live-synchrophasors.html

 

[Skogsgurra]

Scotty,

I don't get it. I tried that applet with 60.0 Hz on both sides of the breaker and synchronoscope still rotates.

And, when I run the generator backwards (grid still positive sequence), the lamps stil vary between dark and light. I had expected them to be all bright in that case. In my mind, I then have connected the lamps to a 120 Hz constant RMS voltage. Is it my Java, the author or me that is wrong here?

I will tell you about the Jaerpstroemmen/NEA incident sometime. It was very similar to this.

 

[ScottyUK]

Hi skogsgurra,

I can't reproduce your problem here. Is it possible that you did not hit 'return' after entering one of the 60.0 values into the program? When I do this, the two phase groups lock together and the differential voltage plot freezes.

Regarding the lamps, the author has connected his virtual lamps a - A, b - B, c - C using his terminology. Thus when all are in phase with correct rotation, all lamps are dark. When the rotation sequence is reversed, it is possible to have only one of the voltages a - A, b - B, c - C equal to zero, but at this moment the others will be displaced by 120 degrees with line-line voltage between them. This explains the one dark lamp and two bright lamps. The brightest lamp condition occurs when two phases, say a and A, are 180 degrees apart in phase giving a voltage of 2x line-ground voltage. You can watch this occur on the vector diagrams if you set the frequencies to 61Hz and 60Hz respectively so everything happens nice and slowly. Re-sizing the vector window makes it much easier to see what is going on.

I've also seen synchroscopes where the lamps are connected a-A, b-C, c-B, which gives an of synchronous conditions by one dark lamp and two lamps of equal brightness. These are, in my opinion, slightly better than the type illustrated by the website because in a well-lit switchroom it is difficult to determine how dark a 'dark' bulb really is, but is quite easy to match the intensity of two brighter bulbs.





------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[Skogsgurra]

Yes Scotty, I had forgotten to hit the Enter button.

The other problem I had is that I had expected the lamps to behave like IRL i.e. light continously and very bright when connected to a 120 Hz source (generator negative and grid positive). The lamps in the simulation do not, and that is because everything has been scaled down time-wise. I am not so sure if that is a good teaching technique because some students will remember the slowly varying glow and think that that is what it shall look like. Other students, that dig a little deeper, will understand.