In an embodiment, a control system includes a processor. The processor is configured to receive signals from one or more sensors disposed in a gas turbine system, wherein the gas turbine system comprises a shaft mechanically coupled to an electric generator. The processor is further configured to predict a derived mechanical power for the shaft based on the signals. The processor is additionally configured to derive a power adjustment by executing at least one model. The processor is also configured to derive a corrected mechanical power by applying the power adjustment to the derived mechanical power; and to control the gas turbine system based on the corrected mechanical power.