Hello,

We have one of GT frame 5 mark VI controller the FSR work properly from start-up to acceleration-HP until the turbine speed reach 5100 rpm the FSR is speed/load. when unit is base load the FSR is temperature control. the problem is that FSR changing to acceleration for a while and this case repeated for many times.

Please advise us...

Thanks

 

Ayman,

What is the frequency doing when FSR is toggling between Acceleration and Temperature control?

Is Base Load selected using the BASE LOAD button or is the unit manually loaded until Temp control is active?

Or do you just put in a Pre-Selected Load setpoint until Temp control is active?

What fuel is being burned and is the fuel supply pressure stable?

Lastly, are there ANY Diagnostic Alarms active when this is occurring? Is the speed feedback from all the turbine shady speed sensors equal and stable?

Answers to ALL questions are important.

 

Dear CSA,

>What is the frequency doing when FSR is toggling between Acceleration
> and Temperature control?
yes Frequency changes in points (49.46 , 49.61, 49.54 , 49.58)all this happened with in 20 seconds

>Is Base Load selected using the BASE LOAD button or is the unit
> manually loaded until Temp control is active?
Yes using the Base Load Button

>Or do you just put in a Pre-Selected Load setpoint until Temp
> control is active?
Not happened in this case.

>What fuel is being burned and is the
Diesel fuel oil (LDO)

>fuel supply pressure stable?
yes, pressure is stable 3.5 Bar

>Lastly, are there ANY Diagnostic Alarms active when this is occurring?
No.

>Is the speed feedback from all the turbine shady speed sensors
> equal and stable?
We will check it later when the Unit is started again.

Thanks.

 

Ayman,

If the frequency is changing then the speed is also changing--and so is the acceleration. You can trend TNHA and FSRACC and FSRT and SFL1 and SFL2 and see what's happening.

Acceleration is there to protect against overspeed, and when an overspeed (true overspeed) begins it almost always starts with a high acceleration, hence acceleration control.

Hope this helps. You'll notice that when frequency--and speed (and acceleration) is stable FSR control won't toggle between acceleration and temperature control.