Hello Everybody,

can anybody explain the meaning of units "PU/s" and "secrt" to me, which are used in "CONST_Q"-file of a MARK-V-LM2500-DLE application? The reason why I ask is the function "LAG-EULER" which is twice used in big-block "C_NOSTGEST" in SEQ_10 of control-sequence-program. This 1st-Lag function uses two additional inputs beside "IN" and "TAU", connected to two constants "KSTGRTLLJA" (-245.0 PU/s) and "KSTGRTULJA" (495.0 PU/s).

Another constant "KSTGTCJA" is used outside the Lag-Function to modify the time-constant "TAU" of 0.05. The range of input value is 0 to 10.0. What effect do these constants have on this lag-function? The execution time of "C_NOSTGEST" is 10ms.

Thanks a lot!
Marco

 

I give up, what is it?

 

>I give up, what is it?

I second that remark.

Presuming the Mark V was configured correctly, the descriptions of the Control Constants (such as they are) should be listed in LONGNAME.DAT. If they aren't in that file (and anything in that file may not be 100% correct), then you are going to have to deduce the function from context, by reading the Mark V sequencing.

You may be able to find them in the Control Specification document which should have been supplied with the equipment.

 

Dear Roy Matson,
Dear CSA,

thanks for writing and for trying to give me some good advice. I really appreciate it! I guess my question about these constants was a little bit too engine-specific to place it in this forum without any further or deeper explanation. Another problem is that sometimes I have some difficulties in finding the right words to express complex technical issues (for that english is not my first language...)

So I will try again, starting with some more basic points:

Have you ever worked with MARK-V-LM Control Panels controlling GE's LM2500+ Aeroderivative Gas-Turbine with a Triple-Annular Dry-Low-Emission-Combustor or do you know someone who has some experience with this type of engine and its control philosophy?It would be a real pleasure to share some experience and knowledge with somebody here!

Have you ever seen a first-order-lag-function (also called PT1 transfer-function) with more than two (input-signal and time-constant) input signals in a CSP for a Frame-5 or Frame-9 Heavy-Duty-Turbine?If yes, what are these inputs used for?And what signals, values or constants are connected to these additional inputs?

In the longname.dat-file you can find all the constants listed with its value, a brief description and its corresponding unit, that's right. I also agree that most things become clear if you read between the lines (or the context). But some units are still confusing me. What does the unit "PU/S" stand for? Is it also being used for a constant in a CSP for a Frame-3/5/9-engine?

I really hope these lines will help you to help me ( I almost needed 40 minutes to write them!). If not, I'm sorry for wasting your time...

Regards,
Marco