A control system is provided for a power generating system having a gas turbine, a flue gas exhaust stage and a blow-off valve assembly. The gas turbine includes a compression stage, a combustion stage and a driveshaft. The blow-off valve assembly is configured to selectively provide fluid communication between the combustion stage and the flue gas exhaust stage. The control system includes a controller configured to output a signal causing the blow-off valve assembly to provide the fluid communication in response to a sudden de-loading of the gas turbine.