Generator Synchronization

[yrb960]

Dear All ;
I have 4*1000KVA Generators that I have to connect in parallel and synchronize .
Can anyone support me with the safest way to do so and the instruments that I should have to accomplish this task

 

[ScottyUK]

Safest way... hire someone who knows what they are doing. Machines of that size aren't particularly forgiving if/when you get it wrong.

As a non-exhaustive list, you'll need a generator with the ability to accept external control signals for the AVR and governor, one or more synchronising relays depending if you want a complex switching scheme or have loads of money, a backup check-sync permissive relay for each machine, a switchboard equipped with voltage transformers to suit the sync relays at the right positions on the board, and breakers capable of remote operation.


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

 

[waross]

Three voltmeters good for twice the voltage of the generators a phase rotation meter and a synchroscope.
1. The generators must have the same phase rotation. Check phase rotation with the phase rotation meter.
2. The generators must be set for the same voltage.
3. The generator governors should have the same droop.
4. The AVRs should have the same droop.
5. A quadrature compensation circuit for var sharting is a good idea.
When you are ready to sync a generator for the first time, connect the three voltmeters across the open poles of the switch or breaker that you will close to connect the generator. You may have to use Potential Transformers. The voltage will vary up to 200% of generator voltage.
The voltmeters should track together. If the voltmeters don't track together you have a mistake in your power wiring.
You may consider using higher primary voltage PTs so that you may use light bulbs in place of the voltmeters.
The frequency will vary as the voltage varies. This was not a problem with the old D'Arsonval we used to use but may cause complications with some digital meters.
Once you have the voltages tracking together look at the voltages and the syncroscope. The voltages should be zero when the synchroscope is at 12:00 o-clock and the voltages should be maximum when the synchroscope is at 6:00 o-clock.
It is acceptable to use one synchroscope for the plant and a selector switch to connect it to the generator coming on line, IF you can find a location that is easily visible from the operating position of the breaker or switch that is used to put each generator on line.
This is not the place to scrimp.
If you need more than one synchroscope, install them. The cost of a synchroscope is peanuts compared to the probable cost the damage when someone makes a bad sync because the synchroscpe was difficult to read from his location.
Note; I said WHEN NOT IF.
But, if you have to ask, it may be a good idea to hire someone who has done this before to walk you through it for the first time.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rbulsara]

Where is the project and where do you live?

You should be able to find businesses who builds generator paralleling gear for living. Since you asked the question, it certainly is not a do-it-yourself project for you. Contacting the local generator vendors would be a good place to start asking.

Rafiq Bulsara

http://www.srengineersct.com

 

[genowen]

EGCP-2 controllers on all 4 sets, droop ct's for the AVR's, and you're away son.

 

[RichardKory]

Some additional questions about the system.
What is the system voltage?
Will it need to feed any line to neutral loads?
What is the grounding method?
Will the generators run in parallel with the utility?
Will you be selling power back to the utility?

 

[PQ101]

Woodward's digital synchronizer and load share control (DSLC) is one unit that you may want to consider for paralleling to infinit number of gensets. But this is not a cake walk and requires control & design wiring, field commissioning, etc.

If you are in Houston,TX area 'Stewart & Stevenson' or 'CAT Mustang' are the right folks to refer to. Aggreko is another outfit in UK or Ireland region with good team of folks to help with your project. Good Luck.

 

[rhatcher]

I agree with the previous posts. No matter how smart you may be, there is no reason to reinvent the wheel. I think that the most direct way would be to:

1 - contact the generator manufacturer and upgrade your generators to the proper configuration by including droop CT's, proper voltage regulators, proper engine governors, etc.

2 - contact a switchboard manufacturer to provide a switchboard(s) with the proper instrumentation and relays.