A gas turbine engine includes first and second electrical machines coupled to the gas turbine engine, each of the first and second electrical machines electrically coupled to both a primary electrical bus and a secondary electrical bus. The gas turbine includes a first controller configured to control operation of the gas turbine engine, and a second controller coupled to the first controller, the second controller configured to respond to control inputs from the first controller and control an electrical output of the first and second electrical machines to the primary and secondary electrical busses. A converter controller is coupled to an energy storage system, the second controller, the primary electrical bus, and the secondary electrical bus.