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GE Mark VI as DCS for the Whole Power Plant
Experience about GE Mark VIe as DCS for the whole power plant

Hello,

I wonder if anyone has hands on experience with GE Mark VIe DCS system. I received information that GE is now offering Mark VIe DCS system for the whole power plant (not only for turbine controller).

I have found a lot of information and references regarding the application of Mar VI control system for turbine controls (especially for gas turbines), but I cannot find much information about GE DCS for the whole power plant (boiler, generator, BOP). I wonder if that is something new and how this system can compare to other leading control systems such as Ovation, SPPA-T3000, ABB S+ and similar.

Best regards

1 out of 1 members thought this post was helpful...

Askic,

The GE Mark VIe control system has been supplied as a plant level control for GE combined cycle power plants (including HRSG and BOP) at least since 2008. Up front warning here: I may not be completely unbiased on this subject, since I am a retiree of GE (since late 2009). I personally designed plant level control systems using the Mark VIe on several projects. At the time I retired, GE was only supplying this control system for plants which were powered by GE gas turbines and usually with GE steam turbines. I do not know their current practices.

That said, you need to understand that the "whole" plant was not directly controlled by the Mark VIe, nor would it likely have been completely controlled by any competing DCS. The "whole" plant generally includes supporting systems that are controlled by local PLC's (water treatment, burner management for fired HRSG's, liquid fuel treatment, to name a few). These PLC controllers were usually connected to the Mark VIe via a MODBUS over Ethernet link so that the operators could monitor and issue start/stop type commands and display alarms from these systems. Using this approach enables these support systems to be tested with their own controllers as well as catering to on time delivery of the DCS, since vendor selection for these systems usually occurs too late in the procurement cycle to support direct control by the DCS.

So, in short, the Mark VIe control system should be able to do what you need in a plant level DCS and is a very good fit for combined cycle plants powered by GE turbines.

1 out of 1 members thought this post was helpful...

Askic,

You are using Mark VI and Mark VIe interchangeably; they are two separate, but somewhat similar, control systems. They share some I/O terminal boards but the Mark VI is physically much larger than the Mark VIe.

Both systems were developed to be able to have remote I/O--that is, to be able to have input/output terminal boards located remotely from the main processors. The Mark VI was used for the very first H-class advanced heavy duty gas turbines which had steam cooling for the shaft and needed to be able to control the HRSG (boiler) and auxiliary plant controls (BOP, etc.) in order to properly control and protect the gas (and steam) turbine(s). Several I/O-specific cards were developed to interface with balance of plant devices (for example, motor-operated valves), and many blocks were developed and written for controlling balance of plant functions (such as boiler drum level control, etc.).

The Mark VI and Mark VIe have both been used in many combined cycle power plants as DCS controls as well as turbine controls. The issue with this implementation--which is the same for any other controller manufacturer using the "same" control system for DCS/BOP and turbine control is: The turbine control portion of the control system is usually done by a group or groups (gas turbine group; steam turbine group) and the DCS/BOP portion of the control system is usually done by a group which is experienced with DCS/BOP design. And the groups don't usually communicate very well during the design, configuration and programming phase. This leads to LOTS of issues which must be resolved when all the different portions are finally put together during commissioning. Sometimes, the issues are easily resolved; sometimes not.

But the thing to remember about this is: It's NOT particular to GE Mark VI or Mark VIe. Any control system supplier or integrator using one control system is going to experience the same issues because there is so much specialization in today's world, and there's very little coordination at the configuration/programming phase. Also, different groups use different nomenclature for their control and protection schemes, which leads to confusing and conflicting programming (and can even cause problems during commissioning).

The Mark VI and Mark VIe are both fine control systems, and can be made to control many phases of a power plant in addition to the turbine(s). And, with the additional emphasis on DCS/BOP controls that have been placed by GE on the equipment and programming for the two control systems they are more than capable.

What everyone really wants is a single operator interface for all of their plant control systems. Yes; it would be nice to also have the same hardware, too. But, many control system manufacturers (including GE) use different hardware and components (all labeled as being of the same family of control) to implement the various portions of the control system. AND, many (including GE) also use different programming methods (ladder logic; FBDs (Function Block Diagrams); etc.) for the various portions of the "integrated" control system.

Will you be happy with a Mark VIe plant-wide control system? Yes. Will it be the integrated and seamless and holistic control system the salespeople are telling you it will be? No. Will it have advantages over some other systems? Yes. Will it have shortcomings over some other systems? Yes. Is it adequate? More than adequate. Is it superior to others? That's a totally subjective assessment.

It has been used, and is being used, as both a turbine control system and a DCS/BOP control system with great success. It has components (hardware and software) which are designed for both applications that work well together. It's a purpose-built control system--built primarily for controlling and protecting turbines and auxiliaries, but is also being successfully adapted for DCS/BOP control. It's not a PAC (Programmable Action Controller) or PLC (Programmable Logic Controller) which has a lot of converters and adapters and special card and software to allow it to function as a turbine control & protection system, and a DCS/BOP control system (such as high-speed speed sensing cards, and LVDT-mA converters, and bipolar servo-valve output controllers, and flame detector interfaces, and vibration sensing converters). It began life as a turbine control and protection system and can natively interface with all of the I/O typically used on turbines, and because turbines are used in power plants the capability of the Mark* control systems is naturally being expanded into the DCS/BOP realm by developing hardware and software to natively interface with components and equipment typically found in power plants.

But, remember--there are gas turbine groups who do things their way, and steam turbine groups who do things their way, and DCS/BOP groups who do things their way. And, usually it's left up to the commissioning people to sort out the details and get everything running and communicating. And, the various portions of the control system will have different nomenclature and programming methods which will add to some frustration. But, you will have similar hardware and a similar programming/troubleshooting and operator interface for the entire plant. All in a purpose-built control system. Is it going to be all alike and similar? No. But, it beats having several different control systems all with their own hardware and software. And, again--it's a purpose-built control system with decades of experience in the power plant business.

Hope this helps!

Hello CSA,

thank you very much for your reply. Yes I have used the terms Mark VI and Mark VIe interchangeably, but this is because I have no experience with GE DCS.

I have relative experience with the GE PLC controller RX3i used as a protection system for a steam turbine. And yes, indeed there would be excellent if one control system could be employed in the whole power plant, but I know that's not very likely.

On the other hand, I was in one coal power plant in which SPPA-T3000 is installed not only for control and monitoring boiler and turbine (R3000), but also on water treatment facility and coal handling.
A separate automation control cabinets and operator stations were placed in control rooms of these facilities and there are a optical link to the rest of DCS installed in the main control room of the unit. Some smaller plants have its own PLCs but approximately 90% I/Os were covered by one control system.

But if GE is delivering steam turbine and generator with its own control and monitoring, and there are two separate contracts for the new power plant (BTG and BOP), from the point of view of the customer it makes sense that control of boiler (I/Os, automation logic, HMI) can be covered with the GE system in order to achieve same HW and same HMI operator philosophy. GE can offer Mark VIe as DCS system for BTG in order to have one unique platform for the main equipment.

The real question is if GE Mark VIe DCS have its on boiler protection system and burner management system or it buys equipment form other manufacturers and integrate in its own system.

What is also hard for me is to find list of reference of Mark VIe in steam power plants (steam turbines) used also for boiler.
I also wonder what is the current market share of GE DCS comparing to Siemens, ABB, Emerson etc.

I know that GE is actually an American product, and I can imagine it's probably easier to use and to maintenance comparing to European products such as Siemens SPPA-T3000.

1 out of 1 members thought this post was helpful...

>The real question is if GE Mark VIe DCS have its on boiler protection
>system and burner management system or it buys equipment from other
>manufacturers and integrate in its own system.

In the case of an HRSG duct burner, the BMS (Burner Management System) is provided as part of the complete burner system package- the burner fuel skid, burner runners, and the BMS control system- by companies who specializes in burners and burner management (like Forney, DeJong, etc). The BMS plc then communicates with the DCS via modbus or similar communication link. Starting and stopping of the BMS as well as loading of the duct burner is handled by the MarkVIe, but Burner protection is handled by the BMS. HRSG boiler controls and protection are done by GE within the MarkVIe DCS. It is typical that the Duct Burner is provided as a sub-contract to the HRSG package.

Also, in the last few years GE has focused heavily on integrating their GT, ST, and HRSG systems. The engineers often sit close by and work as a team to support tighter integration.