Control.com - Nerds in Control

Hello everybody,

I was reading one article about control loops and there I read one of the most interesting and complex control is controlling steam power plant's power (boiler with drum). Article doesn't go into details, but mention "Boiler leading - Turbine following" and "Turbine leading - Boiler following" mode. I'd like to know more details about this.

I'm not sure if I understood well, but I think that Turbine leading - boiler following mode means that boiler maintain constant pressure in front of the turbine, while power is controlled by manipulating turbine's control valves. Doing oposite represents turbine following mode.

Can you explain in more details difference between boiler following and turbine following modes?

Thank you.