Emerson Ovation vs GE Mark VIe

C

Thread Starter

CRSwanson

The facility is a Cogen Power Plant with 2 Alstom Gas Turbines, 2 HRSGs and 1 Alstom Steam Turbine. The new DCS would be used to control all turbines, HRSGS, switchgear, MCCs, Water Treatment Plant and all balance of plant equipment. Our DCS has been obsolete for years and needs to be replaced. I'm considering Emerson Ovation or GE Mark VIe. I am looking for positive and negative comments about these 2 systems from engineers, operators and technicians. Any comments you can share will be very valuable to me. I thank you in advance for your experiences and guidance in helping me make this decision.

Please also comment on the HMIs that go with either of these systems.
 
There is a GE NEXUS DCS that is much cheaper than Mark VIe system and very robust. If you could leave your office e-mail, i could send the technical datasheet and other information.
 
B

Bob Peterson

I don't know enough about the merits of either system to comment on whether one is better than the other for a specific application.

What I will say is that the quality of the integrator is probably far more important than what control system is selected.
 
You would never use a SIL rated safety system like the Mark VIe as a typical DCS. It is too expensive and complicated for general control.
We used a Fisher PROVOX DCS, since upgraded to Honeywell Experion, for regulatory control, monitoring and discrete control and Triconex Tricon TMR SIS systems for boiler BMS and turbine control.

I also believe that the Mark VIe does not have all the SCADA and OPC drivers that new more open DCS systems have.

I could be completely wrong but you will only know by evaluating the systems based on price, capability, expandability, redundancy and interoperability, and the cost for all the options.
 
We have Mark V Control systems on our turbines and have considered upgrading to all of the newer versions that GE offers. We have also considered other systems such as the Emerson Ovation system. The problem with GE's upgrade is that it is not an open control system. Many people we have spoken with who have the VIe do not like this feature. I was at a conference where GE said basically there are only a few people in GE who have access into all of the controls on the VIe. So if you get or have an issue with the black box logic it will take some time to get resolved.

We decided to shelf the control system upgrade for a couple of years.
 
CRSwanson, I have held off commenting since I like CSA have some strong opinions that I don't want to taint my comments. That being said here goes.

I have worked quite a lot on the Emerson Ovations systems, the older WDPF, GE MKVI, MKV and MKVE, GE Fanuc PLC's, Allen Bradley controllers, and some smaller ABB products. I had the privilege of being part of a build and commissioning of a combined cycle plant using an Ovation system for the DCS and GE MKVI for gas turbine control. Steam turbine control was ABB.

The Ovation platform is a spawn from Emerson's purchase of the older Westinghouse WDPF controls platform. The Ovation hardware is very good. It is not meant for use outside of areas that are not climate controlled. In these areas I typically see some brand of PLC's in use. The Ovation programming atmosphere is very simple windows based point, click, no brainer that my 12 year old could figure out. In my experience it is one of the cleanest and nicest looking for SAMA type logic. Emerson has lots of communication drivers that will talk to various other devices fairly easy. They also have SCADA software and modules that can talk DNP3, Modbus, Allen Bradley DF1 etc. Ovation graphics on the other hand are the worst I have ever worked with. The graphics language is I think a hand me down from the old WDPF system. Emerson does not provide a full library of objects like other vendors but instead only provides a custom set of macros and other objects for your project. Building or customizing anything is a nightmare, unless you enjoy programming in source code. Emerson is good at selling services. They have an "Evergreen" program that suggests upgrading workstations every 4-5 years, depending on hardware and how many revisions of Ovation have passed since your initial install. They sell other add-on packages for hardware support, anti-virus and windows patches, and Sureservice support. Their service has degraded exponentially since I started working with them in 2003. They have lost many good older engineers. Their Sureservice support group has been moved out of the country. If you call them with anything other than a simple request expect to be on hold for a long time, or be told they will call you back later when they have an answer. With all this would I still buy an Ovation system for a DCS-YES. Would I suggest it for a turbine control system-NO.

GE MKVIE is a migration from the older MKVI platform. In my understanding the MKVI was originally designed as a purpose built turbine control system. Controllers were arranged with multiple cores for redundancy and protection for overspeed and overtemp. Controllers designed to execute logic at 10-40 millisecond rates for fast control and protection. Hardware was purposely built with devices specifically designed to control hydraulically actuated fuel and steam valves, hardware and software for synchronization, and integration of vibration protection. The MKVI had limitations since its communication to remote hardware was based on older Ethernet communications using coax. The programming atmosphere is SAMA based like the Ovation, but not as nice looking. It is still point, click etc. and has a reasonable amount of macros and other objects for simple programming. GE uses Cimplicity for the graphic GUI system. The graphic objects are easier to use in my opinion compared to Emerson, but CSA might argue with me on this one. GE has some communication drivers, but not as many as Emerson. Cimplicity also has many communication drivers if you are only needing to communicate with devices and display information graphically but not really need to use this information in logic. GE does not do a great job at selling services in my opinion. I do not know if GE is offering any type of contract support like Emerson. They too seem to have a shortage of good engineers and field service staff like Emerson. Getting support is a challenge. They offer packages for anti-virus and windows support. Would I suggest the MKVIE for a DCS-Hmm I'd like to see one. Would I suggest for turbine control-absolutely.

My other thoughts based on some comments from other contributers and personal experience.

Control system cost-I constantly hear arguments for cost. Using a PLC for turbine control has been done and can be done well, but it can also be done very poorly. If you are basing purchasing a control system solely on cost, then I wish you luck.

Using a system like the MKVIE for DCS will cost you more. That is true in my experience. The "MARK" system, previously known as the "Speedtronic" platform was built to control a turbine. Hardware is expensive and will cost more than a PLC or a system designed to be a DCS.

Open control system. I hear this argument a lot, and LAUGH! Emerson and others will promise to replicate your existing control by sending your logic overseas to be reverse engineered. They will give you exactly what you have now that is totally open. If you have simple logic that has worked since the beginning of time, that is what you will have with your new system. But if you have any problems with logic, or have a desire to upgrade logic or parts of the turbine I would suggest that Alstom will probably be less than helpful if you have a Emerson or GE system controlling your Alstom turbine. If you are fortunate enough Emerson or the integrator will have some engineer they hired away from Alstom that might understand your logic and the proper operation of your turbine, or maybe not. The GE black box logic is another point a hear a lot. I am not trying to defend GE, but they built and designed the turbine, they designed the logic and spent time and money to write specific controls. Some of these include model based control, special frequency response algorithms etc. People seem to complain that this logic is not open and deemed proprietary. I don't understand this argument. If you are going to upgrade a control system and want to use the same logic you have in use today that is open, then make this part of the spec. to the supplier that your existing logic remain open and unlocked. If you are upgrading a turbine control system and want additional logic that brings new features like new combustion algorithms or frequency response then expect that some of this logic might be locked up. In my experience Emerson is great at copying other vendors logic. Ask them to write you new code for frequency response or model based control or whatever you want, and see what they say. I just personally don't think its fair to expect a company to invest money writing special logic that is open, so another vendor can copy it and offer it as their own.

In my perfect world a plant would be controlled by one central system. It would eliminate all the headache of getting different devices and systems to communicate. Minimize spare parts and personnel training. Hardware would be reliable and suited for extreme temperatures and vibration etc. The supplier would have knowledgeable staff that understands the system, and operation of your specific turbines. But I have not yet found this plant. I still don't think that one system exists that fits as a DCS, specific turbine control system, and controls field devices in high temperature and high vibration areas, or areas with specific requirements for atmosphere or otherwise.

I think I better step off the soapbox for now. I hope this helps.
 
MikeVI

Thank you for your comments. It is always good to hear more than one opinion.

I get the impression that the upgrade from Mark VI to VIe was to make the Mark control system more adaptable to total plant control, not just GT control. Is that true?

Do you know how long the Mark control system has been used for total plant control? Example: GT + HRSG + BPO, or Steam Turbine + Boiler + BOP?

Also, as the Mark control system went through improvements, Mark I, II, III, IV, V and VI how difficult was it to install the upgrades? Were there significant hardware changes that required I/O terminations to change? If it was difficult, do you know if GE has changed their upgrade philosophy?

Thank you and others for any response to these questions.
 
Thirty-three thumbs up for MIKEVI!!! He said it MUCH better than the response I have been working on for two days.

Open system means many things to many people. And we do live. in a predominantly capitalist world and people, companies and corporations are allowed to profit and protect their innovations.

GE does themselves a disservice by not documenting their blocks better. If people would take the time to learn to "read"/understand the graphics in the blocks and combine that with any available Block Help information they generally find the application code (logic; sequencing) very easy to understand (it's pretty basic, actually). But by not clearly documenting blocks and turbine- and auxiliary operation they add to the myth of the system being closed (and I'm not referring to EPIC Mark* systems or MBC (Model-Based Control) Mark* systems). It would even help their field service personnel to learn, commission and troubleshoot units. But that costs money with no measurable monetary return in the present quarter (three-month period).

The single thing that causes most technicians and plant managers to get upset about so-called "closed systems" is that when a "problem" arises they have ill-formed opinions (I started to write preconceptions--but that presumes some previous consideration of the situation and that usually doesn't occur) about what <b>THEY THINK</b> the control system should be doing or not doing that is not based on any understanding of the turbine and its systems. And when they are aware of what the application code that has been running, sometimes for decades, was doing they insist, "Where is that written?" as if some written documents in a manual should supersede the long-running application code. Or, "It shouldn't do that! Should it?" Or, my favorite,"It never did THAT before you put that Mark VIe in there!"

That's all perception--and nothing more. It has nothing to do with open-ness or closed-ness, just perception And lack of knowledge and experience and training and personal ambition and drive and motivation. Even though the units have graphics they aren't video games--which oftentimes are not intuitive especially when one is first starting gaming. But, if one is motivated and ambitious and willing to put some effort into the game it--and many others--all of a sudden become more intuitive. Like everything. But it has nothing to do with being open or closed. And, again, that means many different things to many different people. Often not the same thing to two people discussing it.

Purpose-built, in this discussion, means built for the purpose of controlling, monitoring and protecting turbines using the types of I/O used for controlling, monitoring and protecting turbines. No special converters or interfaces that add to the wiring and complexity. And built-in methods for implementing the designers control and protection philosophies and redundancy schemes--all to improve reliability and availability. Does that cost some money? Yes. Can the same--or, rather, similar things be done with PLCs/PACs? Maybe--but usually not without proprietary cards (I refer to Solar gas turbine TurboTronic control systems which use A-B/Rockwell PLC platforms with proprietary cards developed by or for Solar to interface turbine control and protection devices to their turbines).

Everyone's ideal plant control system is a single system for all equipment in the plant. That can be done with Mark VIe and Mark VIe $IL components. It's designed specifically for power plants and auxiliaries. The problem will be that each gas turbine and steam turbine will have its own control system, and the balance of plant will have its own "(DCS") control system. And the gas turbines will be programmed by one group with their own nomenclature and methods, and the steam turbine by another group with its own nomenclature and methosds, and the DCS by another group with its own nomenclature and methods. And the integration will probably be less than ideal.

Now, all the turbines and the balance of plant could be done by a single Mark VIe and Mark VIe $IL components if desired or necessary, but that's so rarely done by GE that every one is a one-off, and the different turbines and balance of plant bits would still be programmed by different groups with different nomenclature and methods.

But, you're going to find the same from any control system supplier that claims to be able to supply a single control system for the entire plant--it's NOT peculiar to GE. The world is just too specialized today, and every group thinks their way is the right way, no one really wants to risk changing to conform to a single philosophy and nomenclature and methodology.

Now, that's not to say it hasn't been tried or "done"--but in my experience the three places I've know of where they've used a single control system for multiple turbines and generators and balance of plant, it has taken years to get working smoothly and correctly. And the control system supplier/integrator has usually either had to walk away from an incomplete project or was asked not to return, with the bulk of the remaining integration being done by the plant technicians. After a princely sum was paid for the control system and engineering to the control system integrator/supplier and years after the project was supposed to be complete. I know of one large multi-steam turbine coal-fired power plant that has been working for eight years to get all the plant equipment to run in automatic after finding serious deficiencies in the control schemes. And it's still not fully automatic.

The choice of any control system for any application of this magnitude should be based primarily on the knowledge and experience of the control system integrator's application engineers, their proven track record verified by talking to references (plants where they supplied the same or similar equipment) and their after-warranty service and support. The commissioning record for previous similar plants should also be considered heavily. Cost is important, and "ease of use" is important--but just about any programmable control today can be made to do just about anything--<i>if the integrator/supplier understands the application and has knowledgeable, experienced people to complete the project.</i> Full stop. Period. End of statement.

It's all about the knowledge and experience of the people configuring, programming and commissioning whatever control system is being used. If it works--it will seem "open" and intuitive and simple, even if it has idiosyncrasies and some warts regardless of the control system being used. But if it doesn't work and it's found to be a hodge-podge of different programming philosophies and methodologies then it's going to seem closed and foreign and difficult.

Technicians at the power plants that have "tried" a single control system for all the equipment will all say they like it better than multiple different control systems, but it is/was hell getting to whatever point in the project they are at. No question--a single platform is ideal, but it can be implemented in many not so integrated ways--no matter what control system is used.

The choice should be primarily based on the knowledge, experience and proven track record of the control system integrator and secondarily on the control system hardware/platform. Get and check references from any supplier/integrator you will be seriously considering. It's not easy, but it's better to learn about past execution records before a project starts than after. And it seems more people find out after than before when a couple of emails and some phone calls would have been very informative.

And that's that.

MIKEVI provided some excellent and informative information about certain systems/platforms, as well as some great thoughts on "open systems." Thanks again, MIKEVI!

I'm climbing down from my soapbox now and signing off this thread.
 
One of the main benefits of the upgrade from Mark VI to Mark VIe was to allow for dual redundancy configuration of controls for the HRSG and BOP, reserving the TMR controllers for the gas and steam turbines. (TMR could be used for the HRSG and BOP, but dual redundant controls were less expensive and nearly as reliable. The competing control systems from Emerson, ABB, Invensys Foxboro, etc. are all dual redundant.) Another benefit of the Mark VIe is the ability to use remote I/O.

The Mark VI was used for GT + HRSG + BOP beginning with the first H series GE gas turbines and was also used on some projects with 9001FA and 7001FA gas turbines. This was around 1998 to 2005. The Mark VIe came out around 2006 and replaced the Mark VI.

During the Mark V era of turbine controls, the HRSG and BOP control was mainly done with Foxboro IA and ABB/Bailey Infi 90 controls. The Mark V turbine controls were TMR architecture microprocessor based controls.

During the latter part of the Mark IV era GE provided (1985 to 1988) the DATATRONIC control system for HRSG and BOP control. The Mark IV turbine controls were triple redundant microprocessor based controllers (not TMR architecture). The BOP DATATRONIC controls were hot backup dual redundant architectures (but with a single I/O processor - nice single failure point!!).

There was no MARK III SPEEDTRONIC gas turbine control - that was to be a minicomputer based system that was obsolete before it ever got into production. There was a Mark III steam turbine control which was made by the Steam Turbine Department of GE (not Drive Systems in Salem, Virginia).

Mark II SPEEDTRONIC gas turbine controls used some relay logic, some TTL logic, and low level integrated circuit analog controls. Later versions of Mark II included limited microprocessor based exhaust temperature control and combustion monitors. Mark II began around 1971 and lasted until around 1982.
Mark I SPEEDTRONIC gas turbine controls used relay logic sequencing and discrete (transistor) solid state analog controls.

I don't know if there were any upgrades from Mark I to Mark II. I don't think it would have made much sense to do that. GE did provide Mark IV Simplex upgrades for the Mark I and Mark II controls.
As far as I/O terminations changing, it would depend on the original configuration of the Mark I or II. The control panel had to be replaced. If the control panel was in a PECC supplied by GE, with plug connectors to the gas turbine, the Mark IV replacement would have been built with mating connectors to minimize the field I/O wiring changes. The interconnections to the Generator controls might have required new terminations.
 
CRSwanson, I think Otised did a fantastic job of answering most of your questions but here a couple more comments.

"I get the impression that the upgrade from Mark VI to VIe was to make the Mark control system more adaptable to total plant control, not just GT control. Is that true?"

Yes I think this was the reason, but I was never a GE employee so I can't tell you this was their thought process. But the MKVI was based on a European VME chassis standard, that did not really work well as a "Distributed" system. The MKVIE being Ethernet based is more adaptable to being "Distributed". The movement of all newer controllers and hardware from different OEM's seems to be shifting to Ethernet based communication. Previous communication media like Devicenet, Profinet, etc. seem to be shifting to Ethernet.

"Do you know how long the Mark control system has been used
for total plant control? Example: GT + HRSG + BPO, or Steam
Turbine + Boiler + BOP?"

I think Otised covered this perfectly. One other comment here is about using the Mark system for anything other than turbine control. Turbine control is what GE did, and what the Mark system was designed for since GE built lots of gas and steam turbines. Controlling BOP and boiler systems was not their primary focus back then.

"Also, as the Mark control system went through improvements, Mark I, II, III, IV, V and VI how difficult was it to install the upgrades? Were there significant hardware changes that required I/O terminations to change? If it was difficult, do you know if GE has changed their upgrade philosophy?"

This could open up a whole different discussion so I will try to keep it short. I really can't speak to anything older than the MKIV. Since introduction of the "E" platform GE has been working to offer different upgrade options for older systems. I think that this kind of started mainly with the MKV system. It has a large installed base with lots 7FA turbines that were installed prior to the bubble burst of 2000. GE has been offering lots of upgrades for the 7FA platform that maxed out the available I/O and computing power of the MKV. For this reason I think(just my understanding) they offered a MKVE or MKV Life extension that kept original terminal boards in place and installed new processor boards. The original MKV cabinets were very compact and difficult to work on so many do not like this kind of upgrade option. But it provides an upgrade to hardware and software in a quick turn-around and it cheaper than a full rip and replace. GE has this same option available for the MKIV and MKVI now. It comes back to time and money. I think most people given the choice would opt for a full rip and replace for an older MKIV or MKV with perfect drawings, termination lists and cleanly landed wires in cabinets. But bosses and managers look at the bottom line and time offline and opt for the quick and cheap, and I am not saying that's wrong, its just what I see quite often. So does GE have options to upgrade-yes. The "E" platform I think should be around for a while. GE is still learning some things on the robustness of the hardware at this point based on temperature and vibration limits. It seems like they are working more with GE Fanuc to design things so maybe they can learn some from mistakes of each.
 
I have found GE in the last several years to be just as the other Manufactures are. Schneider, Rockwell Automation, Siemens etc... If you don't have a service contract with them, you won't get much information at all. If you do have a service contract you will get limited information via Telephone. If they are on-site it will depend on the Rep and the documentation will never be how the job was actually done. The old days of the Documentation to anything is usually an example of a system about 2 years older than yours. With that being said, your best avenue is to use Forums like this one to get information from users that are still working on this equipment who don't mind sharing it. Some are still in the little owned personal Black book. Usually after your over about 50 years old you find that you grow out of that. I have a good friend that he and I worked on a MKIV GE system together. He is now working on MKVI's and tells me the documentation from GE is almost Nil that goes with their Algorithms. The only thing I will say to that is, Constants. You better know what they do if your going to change them. I have an interface with Schneider (Foxboro) on a GE System. It's done via MODBUS interface.

It's like everything else the participants have been saying on here, it would be great if we had One system, a DCS to run it all. I've never seen a plant that it has ever happened at. I have 4 different Systems at my Plant. Rockwell Automation, Foxboro, Siemens T3000, CITECT/Modbus, and numerous stand alone systems, Yokagawa, MODICON, Automation Direct, Turbonet, Siemens S7, Siemens VFD's, Yaskagawa etc... Welcome to the Controls industries Ladies and Gentleman where No system will be to hard for you to figure out and work on but we as in the Plant Management just says: aren't they all the same..???. I'm not complaining, I'm just putting this on here to show it's about the same everywhere.

It's Friday and about 70 DEGF in Central Florida. have a Good weekend and Be Thankful we all have a Job...!!! Thank you everyone for your comments, sharing your experience and knowledge.
 
C

controls engineer

If you have the privilege of going with one system for everything, Ovation would easily be my choice.

Emerson is very customer focused and has done an excellent job filling the gaps that giants like GE have left wide open. The hardware is robust and compatible with legacy hardware. The software is very user friendly and focused on the ability to make changes with the process running without causing trips since software changes are loaded one controller at a time. New GE systems also do this but whether the controller will require a reboot is anyone's guess.

Have worked at a facility with Ovation DCS and Mark VIe turbine controllers and we had no issues loading logic changes online in the Ovation but wouldn't risk a change in the GE.

Ovation gets my vote.
 
Dear all,

thank you very much for the info you all provided here, it's been very useful. I am trying to figure out what are the key differences between the gas turbine control system provided by GE vs. what Emerson would offer as a retrofit with Ovation. In a nutshell why would anyone currently working with the gas turbine OEM's control system switch to the Ovation?

What we have heard is that Ovation could increase the effiency compared to the native system, but I was wondering if anyone had direct experience with this.

Thanks a lot!
 
CAPRAEZ,

EVERY potential control system supplier is going to say the same thing. They all believe their automation system is better than what's currently installed--or at least they want potential buyers to believe that. Unless they have extensive experience with combustion systems and fuel nozzles and combustion liners and turbine nozzles and turbine buckets and IGVs and exhaust duct back-pressure, they are essentially going to supply what you have now--because that's about all they can do.

Ask them to provide guarantees for efficiency increases. Ask them how they are going to quantify the efficiency increase. Are they going to run a performance test BEFORE the control system replacement (upgrade; retrofit; upgradation)? Are they going to run a performance test AFTER the control system replacement? Are they going to use the same instrumentation for both performance tests? Will you be observing the tests and collecting your own data?

Many sites have switched to Ovation--for many different reasons. A big one is that the plant DCS (Distributed Control System) is Emerson Ovation, so there will be SOME similarities in hardware and programming and HMIs. ONE HMI for the entire (or most of the entire) plant is ALWAYS enticing. And, throw in that bit about increasing efficiency, and well, how can anyone resist?

What you want to know is: What is the knowledge and experience of the people who will be configuring and programming the Ovation as a turbine control system?

What is the knowledge and experience of the people who will be performing the demolition/removal of the old turbine control system, and how will the prepare the wiring for the new Ovation control system?

What is the knowledge, experience--and past track record--of the people who will be performing the installation, commissioning and check-out of the Emerson Ovation?

Because, just about ANY PLC (Programmable Logic Controller) or PAC (Programmable Action Controller) can be made to control a turbine--eventually, and with enough converters and modifications (usually in the field, during commissioning and check-out). One just has to know what is supposed to happen, and when.

Ask them how they will ensure a smooth transition from Droop Speed Control to Exhaust Temperature Control (Base Load) and back from Exhaust Temperature Control (Base Load) to Droop Speed Control?

Emerson have experience doing this; it's just that not everyone in the organization has the amount of experience and knowledge when it comes to turbine- and auxiliary control and protection. And, not every start-up person has the required experience to efficiently and properly wire, commission and check out (test the various sequences and functions--like purging, cooldown, acceleration, synchronization, loading/unloading under different scenarios (manual; automatic), and water-washing (on-line and/or off-line), fired shutdown, etc. These are the things you want and need to maintain a reliable system--and to work as close to the way they work now (unless you are making some BIG changes to the turbine (new combustion system; new shroud blocks; new combustion liners; new turbine nozzles and/or -buckets; etc.).

Even GE has problems properly executing a control system change-out (demolition/installation, commissioning and check-out.) They just lack experienced people--but what they DO have are engineering resources that can be called upon to assist with issues. Their recent track record regarding schedule isn't all that great, either. And, unfortunately, that's what people remember about a new turbine control system. Was the change done on time, on budget, without over-runs, without damage, how were problems encountered during the commissioning and check-out handled (quickly and smoothly; or was there a lot of finger-pointing and delay). GE is also going to make changes to the way your turbine operates--and they ARE NOT going to be able to tell you what those changes are BEFORE the commissioning/check-out. And, often, their field service personnel don't know about the changes. But, the salesperson DID SAY, "You will be getting the latest and greatest turbine control system with all the latest and greatest enhancements which make your unit run like a well-oiled machine and be more efficient and you are going to love it!" Ask them what all the enhancements they are going to make to YOUR unit are? Before, or even after, the control system change-out.... (Emerson salespeople probably have a very similar spiel.)

And lost production (electrical; steam; etc.) because of a schedule over-run during commissioning and check-out, and the lost revenue associated with that is also not very palatable. So, knowing how the potential control system supplier--ANY supplier--handles execution of the project in the field (demolition/removal; installation; commissioning; check-out) is KEY to doing one's due diligence to try to ensure the fewest possible issues based on past experience and track records during past control system changes.

How do you find this out? You ask the potential supplier (including GE!) for references, contacts at recent jobs. And, you do the difficult thing--you contact the individuals and you ask them, "What was your impression of the overall job? Was the field work completed on time, or ??? What is the after-installation service like? Where there a lot of deficiencies (often called "punch list" items)? How were the deficiencies handled? What is the reliability of the control system now? How satisfied are you with the service and response when you called for help with warranty issues?"

And, if you get and efficiency guarantee--let us know! Due diligence. Not cost. Not promises. Past performance is the best indicator of future performance. It's not easy; but it can save a LOT of headaches and consternation and frustration.

Hope this helps!
 
CSA, great notes and suggestions!

I have talked with several customers that have similar debates on their controls. At the end of the day, their main reason for switching from Mark VIe to Emerson was due to the lack of support by GE. Emerson does offer better response than GE. However their engineering teams are still learning about the GT realm. I think GE still has better internal knowledge about the GT machines...if only they had better customer service.

I am biased to the Mark VIe. But techincally, I think it is a more robust system than most out there.

Anyway you go, I would recommend migrating all to one system. I always struggle when end users try to split the controls into 2 systems. This adds so much frustertation and extra work with 3rd party interfacing. They may save some money on the front end, but they always end up spending more for maintanence, training, spare parts, support, etc. Also, from an engineering standpoint, this adds more break points.

I am happy to talk more on the subject, if there is interest.
 
ME42,

GE's Customer support issues are actually two-fold. First, the field service personnel are not trained in turbine operation, so it's difficult for them to determine if the control system (any version of Mark*) is working correctly or not. This extends to the field devices--they are not taught, and many do not realize, that the turbine control system MUST work with the field devices; they just think their job is to sit in front of the HMI and it's someone else's job to go out and check if field devices are working properly.

Second, there IS NOT a unified way of applying the Mark VIe to turbines and plant control applications. In fact, there are at least three different groups working on applying Mark VIe to various equipment: gas turbines (heavy duty and others); steam turbines; and plant controls. Why does this make a difference? Because each group uses different signal naming conventions AND programming blocks and methods--which makes understanding the system at a plant, especially when it's used for turbines AND plant controls VERY difficult for one person to learn and become familiar with. And, when GE send field service personnel to site to troubleshoot or commission these systems it's very difficult for them to learn and become familiar with, also.

The Mark VIe is a FINE and robust system--it's the application and the knowledge and experience of the people installing, commissioning and servicing it that is its downfall.

And, the same can be said for ANY control system being used for both turbine- and plant control in the same plant. Many integrators--and even manufacturers--have the majority of their experience with balance of plant/plant controls NOT turbine applications. And, they are slow to ramp up their turbine experience, which means that with new people and unstandardized control algorithms mistakes are made and feedback from the field is lacking.

Sure, ideally--it would be great to have one control system in the plant for all applications! BUT, most companies (manufacturers and control system integrators) are not set up to provide a uniform application of these very powerful control systems across multiple product lines and equipment. If even one of these manufacturers or integrators would start small and develop a cohesive and uniform application (signal naming; consistent programming methodology; etc.) across multiple products (turbines; plant controls) they would find people rushing to their doorstep for their product.

The promise of using programmable control systems for a wide range of applications, in a power- or combined-cycle plant is dreamy stuff--it certainly seems it should be possible, and indeed: it is. But, with the business model of different groups having responsibility for different applications (gas turbines; steam turbines; plant controls; etc.) the reality is never going to match the promise.

SOMEONE has to change their business model/paradigm to make this dream come true. Just using the same control system--even with purpose-built modules and algorithms--but using different philosophies and trying to integrate them in the field, is not working out. Whomever realizes this is going to garner market share quickly. It's the Holy Grail of plant controls. But the current implementation of just about ANY system leaves a LOT to be desired.

Most field technicians almost relish the challenge of making things work--it's making them work together seamlessly and cohesively that isn't being achieved. The turbine people make their stuff work; and the plant control people make their stuff work. But no one really has the authority or responsibility for making work together seamlessly and cohesively and able to be understood by the plant personnel without having to learn widely varying signal naming schemes and programming methods. And, to be honest, there are few technicians out there working in plants today that have the drive or motivation to dive in and do what's necessary to learn--nor do they have the time. They typically run from one "fire" to another. BUT, if things were done consistently in a single control system that probably wouldn't be happening nearly as often. And everyone's life would be simpler and easier and more productive.

The problem with that thinking is that then plant owners and managers would be looking to reduce head counts even further, and spread people even thinner. And, while that may be possible, they're not willing to pay for that.

Anyway, good discussion. I wish people would read this and similar discussions when considering changing turbine control systems. Salespeople promise a LOT, and the promise of automation these days is very enticing--but the reality is that it's really just in its infancy. Improved performance? Give me details--not promises! Less expensive? Tell me precisely how over the life of the product, not just the initial cost!
 
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