A system includes a gas turbine system having a compressor, a combustor, and a turbine. The system further includes a power management system configured to supply an injection fluid into a host fluid of the gas turbine system to manage power production of the gas turbine system, wherein the injection fluid comprises a gas mixture comprising oxygen. The system further includes a model-based controller configured to control operation of the gas turbine system, wherein the model-based controller has one or more models including consideration of the injection fluid supplied by the power management system into the host fluid.