A newer version of the Speedtronic. Its a gas turbine, the amount of effort to ensure that a PLC will do what an upgraded version of the Speedtronic will be quite significant, and likely outweigh any benefit in reduction of equipment cost. At the very least I'd be talking to the OEM for replacement options before considering any 3rd party generic PLC for the application.
now OEM control system is mark 6E which is very expensive, therefore I heard many PLCs has same reliability features and less expansive . if somebody has any recommendation.
There are solutions to many engineering problems which cost a lot of money, but are cheaper than getting it wrong!
You can go to GE who designed the Frame 5 and its associated Speedtronic control, or you can go to others who have designed their own replacement. As Jref says you need to assess how they will help you at all stages, in comparison to GE.
Unless you already have a great relationship with an Allen Bradley supplier, and use their systems for other applications with good results,,, stay away. I don't know if you're familiar with the expression "the devil and the deep blue sea", but A-B and GE have always played those roles in my experiences.
I'd say to accomplish what you're showing us to be your goal, you need to keep this up and be patient. Ask around and work the web forums, user groups, etc pretty hard to find others doing it and getting good results. It'll take some time.
I think it depends on what the application is especially if is is a unique one of a kind application. For ease of use I like Rockwell Control and Compact Logix. For tricky algorithms I like Siemens but it is a bitch to use. If I were making something I could sell many times I may try a Mitsubishi, Ormron or PLC Direct because of the recurring savings of the software. However, if I am doing just one application I would chose the software that would let me get the job done the fastest. That usually would be with Rockwell RS5000.
If the speed of the gas turbine needs to be controlled a PLC may not be fast enough or the PID good enough. A motion controller may do much better if there isn't a lot of I/O.
PNachtwey, you reminded me of something. I found out that some cranes on north sea oil platforms were controlled by Solar Gas Turbine Controllers. This was because they were more suitable than plcs for real time control for crane positioning.
Consider Emerson's Ovation platform. It is the successor to Westinghouse's WDPF II which was designed for power plant applications including gas and steam turbines and all of the balance-of-plant. Ovation built on that and is well-supported out of Warsaw and Pittsburgh. It's significantly less expensive than GE's Speedtronic Mk. VI for equivalent functionality, and backed up by a lot of turbine control experience on machines of similar and larger size. The Frame 5 is a fairly simple engine in hardware terms but you may find that the biggest difficulty isn't in the hardware but in the control logic: I don't imagine GE will be in a rush to disclose proprietary information on the maximum firing curve, stall characteristics, and other data which is unique to their engine.
The PLC itself is not important. There are many brands of PLC that will work just fine. PLC hardware is simple, and many brands have near copycat models of other brands. They are probably all made in the same Asian factory anyway.
There are three things to consider:
1. Software cost (some software is free)
2. Programming time (some softwares are more user friendly than others)
3. Maintainability/service (who is available, other than you, to provide support)
You should pick a platform that is serviceable over the long term. I agree with HCBFlash about the perils of Allen Bradley. However I use them frequently because in my region (Western US) there are plenty of people available who can program AB. They are not cheap, and I don't think the are necessarily better than other platforms. I would ask the plant's technicians what they would be most comfortable with.
While the PLC platform itself arguably isn't hugely important, the availability of someone with detailed understanding of the gas turbine itself to program the PLC is very important. The majority of turbine control and monitoring signals are analogue, so the chosen platform needs to be able to handle large these and ideally needs to do so in a simple manner for the sake of the maintenance teams.
Support for complex graphic interfaces for the turbine operator is also very important, and it's something which some PLC brands do far better than other. Provision of other functions such as alarm handling, data recording and trending, ability to handle bad or forced signals, etc are all important to the end user. Some of these functions are more commonly found in a DCS rather than a PLC, although the line between the two has certainly blurred over the last ten - fifteen years as PLC processing capability has advanced.
