A dark lamp or bright lamp or synchroscope will check point at which the maximum brightness and darkness is found, it is going to check out the instantaneous peak voltage. frequency and voltage matching can be done, phase matching can be done that is R,Y,B but if a phase shift is present in the generator suppose R of generator A leads R of generator B by 30 degrees then all the phases of generator A lead by 30 degrees. how synchronisation is possible with a mismatch in phase angle?
Dear Sir,
I think this is through torque. I mean, suppose you have the grid, and connect a new, 300 MWatt alternator.
- First, you need to make sure to switch it on in phase, or a massive short circuit will develop tripping the circuit breakers.
- Second, as soon as its on the grid, it will keep phase, because it is constantly delivering a certain rated power. I mean with this, the alternator is connected to a steam turbine, and this in first approximation delivers a constant torque. Torque in alternator equals current, so the alternator will adjust such that it delivers the current/power delivered by the steam turbine to the grid. So, this means if the grid slows down, the alternator will slow down (because it cannot deliver more current/torque), and so it stays in sync with the grid.
Best Regards,
Henri.
Hello,
after a bit of contemplation:
1. you synchronize the voltage frequency and phase of the additional alternator with the grid frequency.2. voltage matching is not possible as the alternator's voltage is significantly higher than the grid's voltage until connected.
3. when connecting (my best guess would be: in the 0-crossing of the voltage), 2 things will happen:
* the voltage is going down as the alternator is connected to a load
* the current will build up
4. What you might not have considered: the angle between voltage and current depends on source and load resistance, plus all these capacitors and inductors. As source (and grid) resistance are changing when adding an alternator to the grid, the phase angle will most likely change too.
Compensating the phase angle is necessary, but really "tricky".
@Henri
Alternators tend to be frequency-controlled - at least until the power source (steam, water, whatever) is at its limits. So leave a bit of headroom for control :)
hi,
It is all instantaneous voltages.If there exists a phase difference inherently there will be voltage difference. The high voltage will act as source that tries to drive current in the other's winding I.e one will be in generator mode other will be motor
you are right Mr. Vasantha Kumar but I asked how this problem is solved.
Dear
with variation in speed of the alternator not only frequency but phase shift too will happen that's how dark or bright period is achieved.
with regrds
vasanth
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