DG Set Sizing

Deput a consultancy company and get the sizing done. This is a special study and is not free.

I think that you have wrongly indicated motor rating as 26MW instead of 26kW. 26MW motor on DG set and variable frequency drive is unbelievable. What is the voltage level of the motor? It is definetely hire a consultant to study your requirement.

The rating 26 MW is correct. The voltage is 11 kV.

And, yes, we will be appointing a consultant for this. I was looking for some pointers to increase my knowledge.

thanks

I don't have any experience in this size of gen set - but do in smaller applications. Several things come to mind:

1. Since some 35,000 hp are going to be required the engine will be a ship propulsion type. Try Google for Wartsila-Sulzer.

2. A gas turbine will be a likely candidate especially if fuel consumption is not an issue or if there are space constraints. Is this a prime power (continuous) duty cycle or is it in standby duty?

3. Variable frequency/SCR drives are hard on electrical generators. You might consider generating at a lower voltage (2400 or 4160) and letting the transformer absorb some of the feedback and provide isolation from the variable frequency drive, too.

4. The supplier of the variable frequency drive will know the characteristics of the drive and be able to help with the generator supplier sizing. The prime mover (engine or turbine) determines the mechanical hp available but the generator provide the electrical ability to start the motor. Starting inrushes can by 4-7 times running current (albeit at a low power factor) and this will determine electrical generator sizing.

Incredible!

I have seen many ridiculous posts here on CR4, but this is the apex. Why don't you go back to your local hardware store where you bought this motor and ask them for the manual? Or, is it stolen that you can't go to your supplier and get all the info you need? or maybe the people you work for, appointed you as a liaison, not knowing that you don't know the fist thing about it, and now you are fishing for info on this site, so you can present yourself as an expert/authority.

Any way you choose it, it is ridiculous. AND dangerous!.

Wangito.

Ridiculous. I dont think this forum is for free engineering solutuions.? Get a reputed consultant and do justice to ur job.

Allowing for a 20-25% voltage dip, which should be OK for your control gear but may be noticible in any lighting or computer equipment you are feeding from the same generator, and assuming about 30 second accleration time set in your invertor drive then a 32MVA generator set would be the minimum size necessary.

Other assumptions are peak pf at start of 0.65 and no heavy flywheel type application.