paralelism or synchronism?
paralelism or synchronism?
(OP)
after the blackout of a Large Grid, the restoration of the system begins by SE-230kV substation;
As a start, SE-230 is found to have two independent busbas 230kV energized;
The A-busbar is connected to A-load a priority that is being supplied by the A-power plant via a 110km -230kV line.
B-busBar is connected to high-priority B-load which is being supplied with the B-power plant through a 10km-230kV line.
system B defines the frequency of Large Grid. It is necessary to connect the A-busbar with B-busbar to continue the restoration of Large Grid.
You must install a synchronization system in the SE-230kV;
question:
1 - that is parallel or synchronism of system A to B?
2 - What would the procedure for the synchronization (or parallelism) knowing that the A-powerplant is 100km away.
As a start, SE-230 is found to have two independent busbas 230kV energized;
The A-busbar is connected to A-load a priority that is being supplied by the A-power plant via a 110km -230kV line.
B-busBar is connected to high-priority B-load which is being supplied with the B-power plant through a 10km-230kV line.
system B defines the frequency of Large Grid. It is necessary to connect the A-busbar with B-busbar to continue the restoration of Large Grid.
You must install a synchronization system in the SE-230kV;
question:
1 - that is parallel or synchronism of system A to B?
2 - What would the procedure for the synchronization (or parallelism) knowing that the A-powerplant is 100km away.






RE: paralelism or synchronism?
As for the procedure, generally there will be a synchro check relay in the Bus-coupler panel that will enable bus-coupler breaker's closing when the synchronising conditions are met. I'm not sure whether it matters or not if you have a differently loaded bus at the time of synchronising.
RE: paralelism or synchronism?
I am not so sure. This is not unload generator. There are two independent island system operating in 60Hz. Phase angle of frequency are differents.
This is a big difference:
- synchronism
For manual synchronization I have to install synchronoscope and synchrocheck relay at synchronization panel. There will be remote comunication between operators of SE-230kV and A-power plant A.
-paralelism
For manual paralelism I have to install synchrocheck relay at synchronization panel. Operator at SE230kV close circuitbreaker meanwhile operator of A-power plant A will change regulation of power slowly up to synchrocheck relay operate at close circuit of CB.
RE: paralelism or synchronism?
If the frequencies are exactly equal but more than about 5 deg. displaced they will never come into synchronization.
This is a window of +5 deg. to -5 deg. or 10 Deg. compared to 360 Deg, that is one chance in 36 that equal frequencies will be able to synchronize.
Bill
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"Why not the best?"
Jimmy Carter
RE: paralelism or synchronism?
We can not permit frequencies exactly equal but more than about 5 deg. displaced they will never come into synchronization.If you change frequency A-power plant from 60.1 to 59.9 Hz you can get mismatch.
I guess some transmission substation use up to 30 degree to close ring system.