I've come across a problem on unit commitment to a power system. i.e. which power plants to use to power a system, which is determined by their loading range, incremental cost of power generation, and the cost of the station running at all. However I'm being asked to also determine the governor gain of each operational unit (power station). Anybody able to help me out? What is governor gain and governor droop? I can't find anything about them online, I have a feeling they're perhaps terms my lecturer has coined himself.