UPS Battery Types 2

[Yme48]

Hello all,

I need help identifying the different types of large scale UPS (750kVA, 480V) batteries. Sealed lead acid, gell cell, wet cell, etc...

Can anyone explain the differences between them, advantages/disadvantages of each type. Perhaps a good baseline reference?

Thanks

Yme

 

[itsmoked]

Of course you raise good points ScottyUK.

A wafer fab in our town had huge problems with power blinking causing control systems to reboot which would lunch a million dollars worth of wafers in ovens. They tried UPS (Battery) then a trailer with a rotary UPS, rotating mass with engine rotating(i'm told), appeared in the parking lot with cables running to the building. After about six months they removed the trailer and put in 5(?) units! Seems they worked very well.

Your breaker point is a very important one.. And probably hard to avoid.. I think I've heard a few sob stories that were exactly that, "we spent a forture to prevent power outages, then a breaker tripped..."

I once had a product I was developing explode an across-the-line cap. Instead of tripping the local 40A breaker it tripped a 5000A breaker supplying one half of a refrigerated container yard, 125 containers!

You mention the diesel/clutch/storage system as not being available in small sizes Yme48 was saying 750kVA is that not "large" enough?

 

[ScottyUK]

Hi itsmoked,

There are two very different types of rotary UPS. I think we're probably advocating the same one with a large rotating mass in the rotor of a special design of electrical machine. They have good fault-clearing capability. I think these are excellent.

The other type use a flywheel rotating in a vacuum which develops DC power feeding into a power electronic converter to produce AC output. These suffer some of the same drawbacks as a conventional battery-based static UPS, the only difference being one uses a chemical battery and the other uses a rotary 'battery'.

750kVA is right in the ballpark of the first type described above. It would be a great choice if funding allowed it.





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