Stop the machine under speed while running the generator with 75% load.

I just ran into a special case when trying to load a generator:
- When the generator is running at 75% load, the speed fluctuates and the low speed error leads to machine stop. Cummins Model 6B-CP Generator.
- Before, after every 25% increase in load, all parameters were normal and responded correctly.
- May I ask if this is due to a faulty accelerator board or the fuel system.
The generator uses Woodward's DPG-2201-00X speed control board.


Thank you for your help.
 

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If a generator speed is fluctuating, that indicates either the load on the machine is fluctuating ( its not able to respond to load variations which can effect the speed).
Or it can be due to fluctuation in fuel input.
What are load connected to generator? how often is there a chance to vary the load?

I m assuming the generator is in isochronous mode and not in droop.
 
We need to know what operating mode is used...
Droop /isochronous..
Is that unit in commissioning...
Looks like the control system may be not tuned /configured correctly...

By replying to these questions.. We can then advise on how to get the issue fixed..
 
Thank you very much for your comments. ( munna, ControlsGuy25 )
The generator is runned standalone, not yet synchronized.
Currently I'm load test to check generator load response.
Today I isolated the control wire from the main electrical panel to the governor and ran the test again, the generator met the load.
But the customer ensures that while running in manual mode, the synchroniser has not yet sent a signal to the governor.
Tomorrow we will conduct a load test on the generator. I will continue to update the situation so we can discuss and partly help us get better and better. Thank you very much.
After the generator meets the full load. We will continue to synchronize the 2 generators. There will be many problems and we will continue to discuss the synchronization issue.
 
Thank you @Lee Tons for these inputs/highlights...

We still do not know about control scheme used... So it seems that there are more than one generator..
Droop or isochronous mode.. Which one is selected...
Is there kind of PMS installed
...
Looking forward to hear back from you soon
 
Thank you @[U]ControlsGuy25[/U],[U]PhilCorso[/U].
-Today we follow the process of suddenly increasing the load from no load to 50% of the load, then the motor can meet. From 50% to 100% ( 40kw to 80kw ) load, the engine speed gradually decreases from 1500rmp to 860 rpm and then shuts down. (If every 20kw increase, the generator can meet and run at 100% load for 2 hours. Engine works stably).
- The generator is using Woodward's governor ( Model: DPG-2201-002 ). and I was instructed to increase the Proportinal (P), Derivative (D), Gain Factor. To improve responsiveness to sudden load increases from 50% to 100 loads. I need some advice from you guys, and whether it will be better and will it affect the synchronization problem between the 2 generators.
- S:100KVA, P : 80Kw!
 
Thank you @Lee Tons for these hilights/inputs..
Still we do not know about Control scheme used ..and if PMS is installed/used ..

Did you follow carefully OEM instructions...I have read one manual talking about droop calibration procedure...and other parameters tuning ...

Can you post Governor parameters here...so we can have a better overview of what is goin on at your site..

Also a SLD or at least a draft of genset control mode would be welcome..

Cheers
James
 
Are you using PST or User interface ...
Are you sure about Torque limit parameter adjustement
How about frequency ...during that transient modes...
Any alarm annuciated..
 
Thank you @ControlsGuy25
I used PST to record RPM when I increase load and then load steady to check when there is abnormality.
I adjust the parameter by User interface because the generator reacts faster than adjusted with PST.
Attached photo below is a original of the generator. And it's not control the generator when the load increase from 0 to 50% load and decrease from 100% to no load.
I will increase the P ( Proportional ) and D ( Derivative ) and OVG to control the generator.
I will continue to check next Monday. If It will be OKE, I will begin the synchronizing 2 generator. The generator use AVR MX341 board.
Looking forward to your support ? Thanks
 

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Thank you @ControlsGuy25
I used PST to record RPM when I increase load and then load steady to check when there is abnormality.
I adjust the parameter by User interface because the generator reacts faster than adjusted with PST.
Attached photo below is a original of the generator. And it's not control the generator when the load increase from 0 to 50% load and decrease from 100% to no load.
I will increase the P ( Proportional ) and D ( Derivative ) and OVG to control the generator.
I will continue to check next Monday. If It will be OKE, I will begin the synchronizing 2 generator. The generator use AVR MX341 board.
Looking forward to your support ? Thanks
Try to make "Chart view " BY USING PST...see what happening during these transients mode...
 
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