Patent ID: 6912451

Claim:
A method for controlling a motor/generator and an engine coupled to a machine, comprising the steps of: selecting a first operating mode, a second operating mode or a third operating mode based on one or more parameters; driving the machine with the engine whenever the first operating mode is selected; driving the machine with the motor/generator whenever the second operating mode is selected; driving the machine and the motor/generator with the engine such that the motor/generator generates electricity for delivery to an electrical network connection whenever the third operating mode is selected; and wherein the first operating mode is selected whenever a first estimated operational cost for the engine is less than an estimated operational cost for the motor/generator, the second operating mode is selected whenever an estimated operational cost for the motor/generator is less than or equal to the first estimated operational cost for the engine, and the third operating mode is selected whenever a selling price for the electricity is greater than a second estimated operational cost for the engine.