Woodward 505 vs GE PLC based steam turbine governor

[TheCairn]

The is a follow-on question from another I possed about excitation control. We are also being offered the choice between a Woodward 505 and a GE RX3i PLC based governor for the speeed control system. Any thoughts on the merits of either one of these solutions? I think that the concept is that the GE PLC is going to be there anyway for the balance of the turbine protection so this keeps everything in one box so that there is better coordination and perhaps better ability to trouble shoot in the event of a trip.

One question that I know our people have is what sort of data aquisition is standard with each of these for trouble shooting trips. Any comments here on the capabilities of these proposed solutions? Are we going to need extra hardware to log this information at less than 15ms resolution?

 

[niallnz]

The 505 is a very nice reliable and robust turbine governor, but that is all it does, govern the speed/power output of the turbine. It doesn't have any built in data recording systems. To get all the information out of it that you probably want you will have to communicate to it using the Modbus RTU comms port(s) so you're not going to get 15mS resolution.

Can't comment on the RX3i PLC, but PLC's are being used as governors a lot now days as the processing power, software execution and hardware is up to the task. The main issue is does the programmer know all the tricks ans traps of PID speed control. Woodward have been doing it for years and the 505 is a product of that experience.
Cheers Niallnz