A method of operating a generator arrangement includes selecting an operating mode as a function of at least one of: a speed of an engine, a temperature of at least a portion of the engine, a property of an exhaust fluid of the engine, and whether an engine braking command signal is received by the controller; controlling the flow of fluid from a first engine outlet to a first turbine by setting, based on the selected operating mode, an operating condition of a first flow control mechanism, the first turbine being part of a turbocharger having a compressor in fluid flow communication with an engine inlet; and controlling the flow of fluid from a second engine outlet to a second turbine by setting, based on the selected operating mode, an operating condition of a second flow control mechanism, the second turbine being parallel to the first turbine and being part of an electrical generator.