I'm trying to gather as much information/knowledge on what controls usually reside within the GE Mk5 Speedtronics controller, for example the DCS system in place looks after such items as;

Gas Turbine - Fuel gas treatment
Gas Turbine - On/Off Load Cleaning
Gas Turbine - Oil Treatment
Gas Turbine - Generator Excitation
etc..

I understand that not all Mk5 are the same but im only looking for an overview of the "Normal" controls this system would look after.

Any documentation or links on this would be greatly received.

Regards
TF

 

TF,

The turbine control system, if it has enough I/O capacity, can control fuel treatment systems and other "balance of plant" systems required for turbine operation at some sites. ("Balance of plant" generally refers to the remainder of plant auxiliaries and controls other than the basic turbine and auxiliary systems. In other words, if you divide all the plant-wide control systems and auxiliaries into two groups--those just required to operate a basic turbine and its auxiliaries, the remaining plant control systems--or the "balance" of the plant control systems--are those not required for the basic operation and control of the turbine and its auxiliaries.)

A typical gas turbine control system just handles the control and protection of the basic turbine and auxiliaries. If fuel treatment is required, that's not typical and generally falls into the "balance of plant" control system group. Compressor washing isn't required (recommended, but not required), and can be performed by most turbine control systems--but at additional cost. So some plant designers decide to provide it in the DCS to try to reduce the turbine cost. (I don't believe the generator exciter is actually a part of the DCS--rather, it's just sending voltage RAISE and LOWER commands to the generator exciter, maybe even "through" the Mark V).

If you can find the P&IDs for a GE-design heavy duty gas turbine you will see the majority of the systems the gas turbine control system interfaces with. If you want to understand what processes the Speedtronic controls, I suggest you locate the Control Specification document provided with every Speedtronic turbine control system as that details most of the control and protection processes/functions.

Programming and configuring a gas turbine control system to deal with "balance of plant" control functions requires a LOT of communication and coordination during the plant design and construction, and that is not usually a very good process (communication and coordination between various vendors and the gas turbine packager). A lot of things aren't always known when the gas turbine control system is being programmed and configured and if left to be done at site during commissioning--it usually doesn't get accomplished very well, or on time. And, then the gas turbine packager usually gets very unfairly blamed for the problems associated with incorporating the "balance of plant" functions into the gas turbine control system.

So, the gas turbine control--while capable of more--isn't usually programmed and configured to do much more than basic turbine control and protection, including basic necessary auxiliaries for turbine operation and protection.

Hope this helps!

You should know that this is a ubiquitous situation at just about every power plant in the world--multiple control systems for various control systems and loops and equipment, sometimes each with their own HMI or operator interface/control panel. And, most of the time, they don't "communicate" very well with each other--if at all. Or only by discrete inputs and outputs, including minimal 4-20 mA inputs and outputs.

A LOT of DCS manufacturers and control system integrators are offering lots of "solutions" to this situation. Some are better than others. Asking the turbine manufacturer or packager to control other systems outside their "core competencies" and typical business is just asking for trouble. It can be--and has been--done, with varying degrees of success all the way from wildly successful to a complete disaster. But, it generally leads to lots of problems during commissioning.

People have tried to use PLCs (Programmable Logic Controllers), or PACs (Programmable Automation Controllers) as both turbine- and DCS control systems, again with widely varying success rates. It really depends on the experience and knowledge of the control system integrator whether or not the project of "merging" control systems into as few as possible is successful.

Some of the best "integrations" I have seen have involved just using a single HMI package to communicate with multiple control systems--but, again, the experience of the HMI supplier is key to the success of the project. This helps the operators, but not necessarily the technicians who still must deal with multiple control systems.

 

Give me an Email address, I can send you some documents.