Good day, I have 2 cat generators (1.5MVA) in parallel, whenever there is a power utility failure, the two gen start (gen1 has priority over gen2) and they are loaded, after few minutes the gen2 drop load and show reverse power trip alarm When I try to clear the alarm on gen2 and put it on auto to start in parallel with gen1, afer it sync (loads) with gen1 few minute its dropped load and popup reverse power What are the causes or reverse power in generators? What are the causes or reverse power in generators?alarm.....One thing I discovered was that when gen2 sync and load with gen1, I noticed Gen1 power start increasing instead of dropping since gen2 has sync and loaded, after gen2 popup alarm the gen1 goes back to its normal power value



PLEASE WHAT COULD BE THE CAUSE OF THIS.......... Your answer will be appreciated

 

Good day, I have 2 cat generators (1.5MVA) in parallel, whenever there is a power utility failure, the two gen start (gen1 has priority over gen2) and they are loaded, after few minutes the gen2 drop load and show reverse power trip alarm When I try to clear the alarm on gen2 and put it on auto to start in parallel with gen1, afer it sync (loads) with gen1 few minute its dropped load and popup reverse power What are the causes or reverse power in generators? What are the causes or reverse power in generators?alarm.....One thing I discovered was that when gen2 sync and load with gen1, I noticed Gen1 power start increasing instead of dropping since gen2 has sync and loaded, after gen2 popup alarm the gen1 goes back to its normal power value



PLEASE WHAT COULD BE THE CAUSE OF THIS.......... Your answer will be appreciated

Good day,

Can you tell us if there is kind of load sharing model used in these units ?

A sort of PMS ( Power management system)?

After that we will be able to support you !

Also if you can share Protection relay /co,ntrol system trends datas ... that would be useful to troubleshoot this issue.

James

 

A quick reply from original poster would be welcome here ....

 

joseph4blues...
Paraphrasing CSA... Is this a new problem associated with a facility that's been in operation for a while? Or is it relatively new?
Regards, Phil Corso

 

joseph4blues...
My 2nd question... is synchronization being done automatically or manually ?
Regards, Phil Corso

 

joseph4blues...
My last question... does the problem only occur with the same 2 gensets ?
Regards, Phil Corso

 

joseph4blues...

All though you pleaded for help, I don't understand why you haven't participated !

In my experience there are two unique problems associated with paralleling combustion engine-driven generators.

a) The first is unheard of with, say, turbine-driven alternators. The fact is that a generator's voltage wave shape is not a pure sine-wave. Unfortunately, that characteristic of combustion-driven generators can't be changed.

b) The second has to do with the way speed is determined, A magnetic pickup located on the flywheel ring produces pulses proportional to generator speed. If the sensor is contaminated by oil or debris its accuracy is negatively affected!

If your answer to question 3 is yes, then the problems noted above could be the cause. But to be frank, I believe the real problem is a lack of understanding Sync-Zone-Protocol !

Regards, Phil Corso

 

"But to be frank, I believe the real problem is a lack of understanding Sync-Zone-Protocol !"

Phil Corso, that's the single most intelligent thing I've seen you write.

Now, why don't you proceed to give him, and us, an education--without asking any questions. (Sorry; I don't mean to hamstring you with that little qualification.)

You still need to know if there's a PSM (Power System Monitor)--something that is raising/lowering the load whilst monitoring frequency and/or voltage.

 

"Phil Corso, that's the single most intelligent thing I've seen you write."
Comes from the heart !

 

Aye; that it does!

From the very bottom of my heart.

 

joseph4blues and others...
I will give the answer(s) to what was asked earlier, but only if asked with a real name... on this forum or by contacting me at... [email protected] !
Regards, Phil Corso

 

Good day,

Can you tell us if there is kind of load sharing model used in these units ?

A sort of PMS ( Power management system)?

After that we will be able to support you !

Also if you can share Protection relay /co,ntrol system trends datas ... that would be useful to troubleshoot this issue.

James

Yes there is load sharing, the two generators (both 1500kav) are in pararrel and they have been working together in sync

Good day,

Can you tell us if there is kind of load sharing model used in these units ?

A sort of PMS ( Power management system)?

After that we will be able to support you !

Also if you can share Protection relay /co,ntrol system trends datas ... that would be useful to troubleshoot this issue.

James

Yes there is load sharing model use in the two generators (1500kva), they have been in pararrel working together before

Yes there is load sharing model use in the two generators (1500kva), they have been in pararrel working together before

joseph4blues...
Paraphrasing CSA... Is this a new problem associated with a facility that's been in operation for a while? Or is it relatively new?
Regards, Phil Corso

no problem with the facility, these two gen have been working together before, this issue just came up

no problem with the facility, these two gen have been working together before, this issue just came up

joseph4blues...
My 2nd question... is synchronization being done automatically or manually ?
Regards, Phil Corso

done automatically

joseph4blues...
My last question... does the problem only occur with the same 2 gensets ?
Regards, Phil Corso

yes

joseph4blues...

All though you pleaded for help, I don't understand why you haven't participated !

In my experience there are two unique problems associated with paralleling combustion engine-driven generators.

a) The first is unheard of with, say, turbine-driven alternators. The fact is that a generator's voltage wave shape is not a pure sine-wave. Unfortunately, that characteristic of combustion-driven generators can't be changed.

b) The second has to do with the way speed is determined, A magnetic pickup located on the flywheel ring produces pulses proportional to generator speed. If the sensor is contaminated by oil or debris its accuracy is negatively affected!

If your answer to question 3 is yes, then the problems noted above could be the cause. But to be frank, I believe the real problem is a lack of understanding Sync-Zone-Protocol !

Regards, Phil Corso

thanks for your reply, I will check the sensor

thanks for your reply, I will check the sensor

 

joseph4blues...
Since Synch-Scan-Protocol has to do with constraints used during synchronization, when was the auto-synchronizer last tested?
Regards, Phil Corso

 

So, it's been established that:

--There is a load sharing model in use (WTH is a load sharing "model"???)
--The Thread Starter (Control.com for original poster) did NOT respond to the question about a PMS
--The units are automatically synchronized (as opposed to manual synchronization)
--The issue is relatively new and the facility has been working without problems for some period of time
--The problem with changing loads begins a few minutes AFTER the second generator is synchronized with the first

The Thread Starter needs to answer the following questions:

1) What--or who--controls the division of load between the two generators when operating in island mode (independent of the utility/grid)? Is it human operator(s) or some kind of automated control system that monitors frequency and raises/lowers load on one or both generators as the load on the two generators changes? If it's an automated control system that's to be controlling frequency, please describe the system (manufacturer; model number).

2) When a single generator is operating independently of the grid what--or who--controls the frequency as the load on the generator changes ? Is the unit operating in Isochronous Speed Control mode (frequency control mode) or is an operator or some automated control scheme making changes to maintain frequency?

3) What is happening to the frequency of the load when this problem is occurring? Does it increase or decrease before the undesired load changes? What happens to the frequency when the undesired load changes occur?

If human operators are to be controlling frequency as load changes, the problem is human operators.

If some automated control system is to be controlling frequency as load changes, the problem is something with the automated control system has change OR someone has likely changed some setting on one of the generators.

But, this thread is like watching paint dry. Noting from the original poster for days, then incomplete tidbits of information. Then threats of answering questions and repeated questions. THIS is the result of poor automation practices--people operating/managing equipment that don't understand how systems work and are just looking for the one thing that will fix their "problem" (often times just a perceived problem). "I'll ask an expert--and the expert will CERTAINLY know exactly what to do and the "problem" will be solved! The World Wide Web forums are a wonderful thing!"

For me, the paint has dried. It's an ugly colour.

Blessed day to all.