Load Sharing

[tyboy]

I have 3 Solar Taurus 60 turbines driving 4160 vac 4.75 KW generators and am having load sharing problems.I can share load with the B & C machines but cannot load share the A& C machines without getting into a reverse power condition.I have checked wiring from Allen-Bradley Load share modules and is wired accordingly.The only thing I am not sure of is the wiring (polarity) of the CT's as this was done by a contractor.Can anyone else out there suggest something I may be missing?

 

[busbar]

Maybe this is obvious, but have the VT circuits been checked, too?

 

[dpc]

I'm not familiar with the load sharing modules you refer to. What type of governor do these have? Normally, all three units would need to be on droop, with equal droop settings to share load.

Are these operating in parallel with a utility or as an island?

 

[tyboy]

Yes,we covered the Vt's in our pre-commissioning plan but like I said I am not sure about CT's

 

[tyboy]

(DPC)Unit has digital fuel control system and units are set to droop for parallel operation.FYI>These units are on a new offshore floating facility which is a spar design.I will need the 3rd unit to be able to start an additional 1500 and 2000 hp water injection pumps.

 

[DanDel]

Obviously, reversed polarity of CTs would cause a reverse power relay to pickup. Are you saying that you can't check the CTs?
Because that's the next logical step.

 

[zqew05]

TYBOY,

What brand of generator do you have? We had the same problem at my jobsite, please tell me more about your equipment. I don't think your LSM module is the problem. It may be something very simple. What platform are you on?

 

[kannanR]

tyboy,

You have mentioned that you face reverse power problem when you synchronise A & C, do you face the same problem when you synchronise A & B and A with other two generators running i.e B & C. What is the revese power setting in KW and trip time of the generators. Immediately after synchronisation what is the load current on the generator A before it trips on reverse power? Have you ensured that the LSM is sharing datas between them at the moment you initiate auot synchronisation?

 

[jbartos]

Suggestion: Allen-Bradley is supposed to provide information the system control for additional generators added to the existing two.
Visit

http://www.basler.com/downloads/VR_parallel.pdf

for more info on generator paralleling

 

[tyboy]

Thanks to everyone for sharing their information with me.My problem turned out to be a very simple one,at the time I was doing the trouble shooting I failed to check and set the droop settings on the voltage regulator after going through this process I was able to sync all three gen sets with no problem.For the person wanting to know what platform I am working on it is called Horn Mountain and is located 80 miles south of Venice Louisiana in Mississippi Canyon block 127.We are using Solar Taurus 60 turbines with Siemens generators.

 

[zqew05]

Tyboy,

I ran across the same simple problem during commissioning on a Solar T60 turbine. Before we found out how simple it was, we done tore up the equipment to figure out what's wrong, me and the Solar Field Representative. It was a humbling experience. Two other causes you might also encounter are people playing with the manual NGP and VOLTAGE Increase/Decrease buttons. If you can't load the generator up, compare how far off it is with the other generators. Once your generator is online and loadsharing with other gensets, your engine speed increase/decrease buttons are locked out. Your voltage Increase/Decrease will still work so it is possible for somebody to be playing with it and next thing you know, the generator tripped offline. I hope your platform load-shed logic is working properly, just in case. There is also a USCG and ABS required electronic inclinometer/collision sensors people are not aware of, if someone starts playing with it, it will cause an E-stop (no 4-minute cooling rundown timer prior to stopping).