LCI with ge fanuc plc..& EX2000 software Troubleshootings/modifications

Hello All,

I would like to know If somebody here have a procedure for EX2000&LCI with GE fanuc plc software modifications...


Thanks for your reply
Controlsguy25.
 
ControlsGuy25,

I have experience with the GE fanuc plc and its software, mostly with the GE VersaMax PLC. I also have experience with the configuration of the EX2000 utilizing the software from GE for configuring exciters. I have worked with the EX2000 utilizing I/O to send conditions to a GE PLC for user information on multi-bridge exciters.

Unfortunately, I have no idea what your question is asking for.
 
ControlsGuy25,

I started to remember what you might be looking for. I have attached to EX2000 one line from a multi-bridge I worked on years ago.

Basically, a ge series 90 was used to interact as a FDI (foreign device interface) for a DCS system for info and control of the EX2000.

Heard of the LCI being used, but we used the UC2000 as the middleman.

Never the less, It was sold as a package and never utilized. The Mark V and EX2000 did all the work via Status-S and nobody knew the difference.

Good luck!!!
 

Attachments

ControlsGuy25,

I started to remember what you might be looking for. I have attached to EX2000 one line from a multi-bridge I worked on years ago.

Basically, a ge series 90 was used to interact as a FDI (foreign device interface) for a DCS system for info and control of the EX2000.

Heard of the LCI being used, but we used the UC2000 as the middleman.

Never the less, It was sold as a package and never utilized. The Mark V and EX2000 did all the work via Status-S and nobody knew the difference.

Good luck!!!
Curious One,

First Thank you so much for these gathering datas and clarifications...

I will explain here more precisely the case I am facing with....

Client is asking following request :


.

  • The power plant is an old one (built late in the 90th) stopped in 2012 and now back to operation, It is a combined cycle / Single shaft / 9FA, with LCI.
  • The unit is on markV for Steam and gas turbines. EX2000 on CE Control System Toolbox, the LCI on a Fanuc PLC.
  • A new option has been introduced to keep the unit on 140 rpm during the shutdown and to start the next day from that Speed.
  • During the normal start up we are going from 4rpm on the turning gear motor to purge speed (25% Setpoint on the LCI) then ignition speed (15% Speed) …. Until disconnecting the LCI at 85% speed ….FSNL then synchronising …..
  • During shutdown we have two options, either we go back to 4 RPM on Turning gear (Normal Situation), Or we wait until 4% Speed then we reconnect the LCI to set up the 4.6% Speed (Slow Roll Option) (Working properly 52SS / 89SS /41AC Closed and 89ND Open) 4.6 % speed reference on the LCI.
  • In the second option when we try to start up, we have noticed that we could send the firing speed setpoint to the LCI (15%) but we could see the 41AC dropping and then the LCI setpoint is dropping to 0 : Preventing the start up and going back to 4rpm.


They are facing issue to get the second option " configuration fixed " on LCI /MARKV/EX2000

I told to client to check with GE first for getting their approbation.

I mean to check IF That option is envisageable , as per OEM recommandations ( Thermal stress, Mechanical Parts wear /fatigue & thermodynamic issues...)

I asked client why he need that option ...his response is that they need to keep the HRSG pressurized during night shift/shutdown/ its like kind of cooldown of the unit..and be able to restart from 140rpm ...

The thing is that ( if GE agreed for the controls/logic modifications) it will necessary to change/modify the shutdown curve of this single shaft unit (LCI /EX2000/MARKV signals exchanges /logic modifications).

Indeed that will ask also to check the feasibility of the Generator ( operation as Motor WITH LCI) to get the 140rpm set point on shutdown....
As the Generator is offline ( 52G opened) & field breaker (40AC will be opened) during shutdown phase...

How to get that Generator operating as Motor to keep the unit at 140rpm ...( during Normal shutdown )?

For me That is not good for the safety and integrity of the equipments ....as it will need to reconfigure the other 89ND/89SS/52SS/40AC breakers and signals exchanging form the whole controls systems ( setpoints /signals feedback) FOR SAFE& SMOOTH OPERATION DURING THAT PHASE...

Reconfiguring those breakers when shaft is "rolling down" and applying voltage on generator stator & excitation( current ) on field/rotor can be bad/dangerous for the safety of the unit...

What you think about that case? I mean is that possible to reconfigure the Generator as Motor during shutdown ( and send a 140rpm setpoint to LCI )... what about TORQUE operation (ON/OFF) also ?

Thank you for sharing your expertise / feedback /know how on such operating event/option ...

So many questions come through my mind ...but I am confident to get them cleared with support of experts from this great forum!

Whatever it is possible or not Client need approbation from GE first to do anything....

Best regards,

James
 
https://tcexg.com/7fa-9fa-gas-turbine-startup-failures/
It appears that if you try to lean too hard on that older LCI, failures will occur. The video is long(1 hr) but skipping through introduction and such will shorten it greatly.
Thanks Curious One for your support !

I have that website already checked and it is a good database indeed !

I got the company CEO & others employees contacts in my professionnal network but I don tthink

The thing is that client at site want to modify capability curve of the LCI and so on by modify this it can be bad for the equipments !
Can you confirm that ...

I told that to the client ....His answer is that they want to have the unit at 4.6 % FSNL DURING SHTUDOWN for keeping HRSG PRESSURIZED ( I dont have much details ) help LCI ( i mean apply some torque on the shaft ) by throtlling steam on the LP side of the steam turbine at a " slow roll speed" (140 nearly 4.6%FSNL) then go to Purging speed (25%FSNL )
Then go back to 15%speed... and be able to send firing command signal to the GT...
The unit sustain speed till around more than 15%FSNL but the field Excitation breaker get opened and they got no reason why ...

I am pointing that it is the LCI or EX2000 limitations getting reached (Torque vs Voltagevs frequency vs current) as it is V/HZ control command...
I need arguments to say if we can or not do some modifications to get that Unit reach whatever speed at whatever time needed (I mean LCI controlling geenrator as a motor ) for getting customer expectations..

Can somebody here share an analysis or experience feedback on such event.....

I always used to support people here & now I see that just You & Anees can support me...

Thats not an SOS but just ascertainment...

Iam confident taht this case will be solved soonly ( I need to preapre the job first at home ) as I have to travel to site next week ...

Thank you for your support , I appreciate it!

James.
 
Most of the Combined Cycle plants I worked at that wanted to 'bottle up' the HRSGs to keep them warm and be able to start them faster the next day tried to anything they could to prevent airflow through the HRSG and stack to keep the pressure up and the HRSG as warm as possible. So, this idea of 4.6% TNH during Cooldown is kind of strange, to say the least. Many Customers have actually installed industrial roll-up doors (same are used in warehouses) downstream of the turbine inlet air filters that they would close to prevent air flow through the HRSG and stack--which, when warm, actually create a pretty good air flow through the HRSG and stack which can cool the HRSG and drop steam pressure and temperature pretty quickly. A hot stack acts like a hot chimney--it creates a draft, which when there's no more fire can evacuate a room or house of warm air pretty quickly (hence the old-timers used to use the damper when they went to bed at night after the fire had died down to keep warm air in the house, and make it easier to start the fire the next morning--kind of like a modern-day roll-up door can do for a GT and HRSG).

It would surely be interesting to really understand how they think rolling the unit at 4.6% TNH (138 RPM on a 3000 RPM machine) is going to keep the HRSG warmer. It sort of makes sense about how keeping a small amount of steam flowing through the steam turbine will help keep it warm, but not air through the HRSG.

There must be something which can be traced to the cause of the 41AC breaker tripping....
 
Most of the Combined Cycle plants I worked at that wanted to 'bottle up' the HRSGs to keep them warm and be able to start them faster the next day tried to anything they could to prevent airflow through the HRSG and stack to keep the pressure up and the HRSG as warm as possible. So, this idea of 4.6% TNH during Cooldown is kind of strange, to say the least. Many Customers have actually installed industrial roll-up doors (same are used in warehouses) downstream of the turbine inlet air filters that they would close to prevent air flow through the HRSG and stack--which, when warm, actually create a pretty good air flow through the HRSG and stack which can cool the HRSG and drop steam pressure and temperature pretty quickly. A hot stack acts like a hot chimney--it creates a draft, which when there's no more fire can evacuate a room or house of warm air pretty quickly (hence the old-timers used to use the damper when they went to bed at night after the fire had died down to keep warm air in the house, and make it easier to start the fire the next morning--kind of like a modern-day roll-up door can do for a GT and HRSG).

It would surely be interesting to really understand how they think rolling the unit at 4.6% TNH (138 RPM on a 3000 RPM machine) is going to keep the HRSG warmer. It sort of makes sense about how keeping a small amount of steam flowing through the steam turbine will help keep it warm, but not air through the HRSG.

There must be something which can be traced to the cause of the 41AC breaker tripping....
CSA,

Thank you for adding these precisions /clarifications ..I appreciate it!


I have seen on an old article that :

Site experienced an explosion back in 2018, that can be related to customer request for getting this singleshaft rotatiting at predetermined speed (4.6%FSNL )..and keep HRSG "bottle up " ...

The thing is that ok for restart from that point to "wobullating purge" (25%FSNL "with help" of torque added on shaft by throttling LP control valve with auxiliary steam from OTHER frame 6b combined cycle ), THEN Unit go back to 15% (firing command sent ) THATS WHEN "things go bad" <<<41AC get opened/tripped >>>

I cannot state on why because till now, because the ControlST toolbox that i have installed on my laptop is not compatible with MSwindows 10. I have been told that, The version 6 can handle with Windows10, anyway i still need to procure a dongle...

My opinion is that LCI Torque internal Thresholds / limits getting reached maybe exceeded so LCI give signal to EX2000 for getting that 41AC open...
I need to go at site and check LCI/EX2000 programs/SOE/trip log report /trends to get my opinion confirmed ....

Client want/request something but the things are not so simple as he think as ususal !

Changing a singleshaft combined cycle startup/shutdown curves, can be bad at least , and very bad for safety and integrity of equipments ...
I do not know if that LP steam CV throttlling to "add some torque on the shaft" in order to( help and avoid overheating of LCI/MOTOR) is a normal procedure , or if it come from client mind/hat....

I will share more details /feedbacks on this great FORUM, as soon I will be on site...

The thing is with that new covid "mutation /version" it makes the travel to site little bit more complicated .... .

TO BE CONTINUED....

James
 
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