Steam Turbine Power Flactuating

Hi

This my first communion .

i working in a refinery possess a stem turbines generators in utility area or power plant some they call it ,each turbine have 10 stages and generate 40MW. This area is under my responsibilities i normally doing as daily check for vibration ,bearings temperatures and other parameters for these turbines and other area equipments to verify no abnormal or problems happened during the operation effect to the machine reliability.

My question is one of the steam turbine operation decide to increase the load of the turbine from 21MW to 26MW but during load increase turbine power fluctuating so much i don know really the main reason which lead the turbine power to fluctuate at 26MW.

we usually found amount of condensate in the oil reservoir where as the purifier pump is always running.

we replace a new servo valve but still fluctuating is there.

Toady we increase the load again to 26MW and we notes no power fluctuate what is the reason you suspect cause power fluctuation.

Please advice me regarding this problem what to do?

Thank you all