What are the steps to shift the turbine control from
1) Speed Control To Load Control
2) Load Control to Pressure Control
3) Pressure Control to Load Control

 

MOST digital programmable electrohydraulic steam-turbine governing systems just have "buttons" to choose the mode of operation for load control and (inlet) pressure control. The programming of the governors use software to make the transition from one mod to another (and back) smooth and "bumpless" (meaning there is no sudden swing or jump ("bump") in operation/control).

If you're asking how it's done on YOUR particular governor (turbine control system)--we can't answer that without a LOT of information.

Steam turbines typically use speed control (Isochronous Speed Control, to be exact) to get from zero speed (or turning gear operation) to full speed in preparation for synchronization. And, when the machine's generator breaker closes to produce power the governor automatically transfers from speed control to load control, OR from Isochronous Speed Control to Droop Speed Control (which is a method for controlling the steam flow-rate into the turbine in order to increase or decrease electrical load between 0 MW and full load; it also does some amazing other things, but that's really the basic function of Droop Speed Control--to be able to change load smoothly). Yes, load control does something similar, but it's reference is load (MW) whereas in Droop Speed Control the reference is turbine speed (not actual turbine speed because when a synchronous generator is synchronized to a grid with other synchronous generators (and their prime movers) they ALL spin (or should spin) at a constant speed defined by the frequency of the grid they are synchronized to. (Synchronism, in electrical power generation, is a VERY powerful work and concept!)

Speaking of speed, according to the photo you attached to your original post, the machine is spinning at 3065 RPM--which is 102.17% of rated speed for a two-pole, 50 Hz generator--which means the frequency of the generator, and of the grid it is synchronized to is 2.17% higher than "normal." I hope that elevated speed (frequency) is not typical for the grid the machine is synchronized with.

In order for us to provide better answers you would have to provide a LOT more information. And, just about EVERY digital, programmable control system, while they operate similarly, is programmed slightly differently. Unless we had someone with experience with the particular governor (control system) used on the machine you are working on/operating it's not likely we could say much more about how it actually works and what happens at your site. USUALLY, but not always, there are other displays for monitoring and selecting different operations and operating modes. You may find that clicking on the colored area next to PRESS CTRL INIT or LOAD CTRL or SPEED CTRL will cause a window to open on the display with more information and "buttons" to select the mode and to set the reference for the mode. But, you haven't given us enough information to be of much use at this point.

I would suggest if you are new at the plant that you find someone who has the original training manuals used when the plant was new and ask to borrow them to study. Or, find the plant operations manuals which may describe how modes are chosen and enabled and what to expect during the mode transfer (mode transition). The steam turbine manual may also have some specific information for the machine at your site/plant.

Best of luck! Hopefully you found something useful in this response.