A combined engine system is disclosed which may help to meet electrical power demand of a common load that can vary in an unpredictable manner. The system comprises at least one primary engine and one or more secondary engines. An after-treatment system is connected to the engines to receive exhaust flow from each of the engines. A controller is configured to operate the system in a first operating mode when only the primary engine is running and a second operating mode when the secondary engines are run together with the primary engine. Exhaust flows from each of the engines are passed through the after-treatment system which allows the after-treatment system to be heated by the exhaust flow of the primary engine before receiving exhaust flows from the secondary engines.

A propulsion system that includes a plurality of power units, a plurality of propulsors, where respective power units of the plurality of power units are controllably coupled to the plurality of propulsors, and a controller configured to receive a desired throttle value corresponding to a desired propulsive force, determine a number of power units of the plurality of power units to be coupled to the plurality of propulsors to achieve the desired propulsive force based on a respective power value associated with each respective power unit of the plurality of power units, and cause the number of power units of the plurality of power units to be coupled to the plurality of propulsors.

A propulsion system that includes a plurality of power units, a plurality of propulsors, where respective power units of the plurality of power units are controllably coupled to the plurality of propulsors, and a controller configured to receive a desired throttle value corresponding to a desired propulsive force, determine a number of power units of the plurality of power units to be coupled to the plurality of propulsors to achieve the desired propulsive force based on a respective power value associated with each respective power unit of the plurality of power units, and cause the number of power units of the plurality of power units to be coupled to the plurality of propulsors.

In a control system for an internal combustion engine, the internal combustion engine includes a first exhaust catalyst that is a three-way catalyst disposed in an exhaust path of the internal combustion engine, a second exhaust catalyst that is a three-way catalyst disposed in the exhaust path on a downstream side of the first exhaust catalyst, and a motor configured to drive the internal combustion engine. The control system includes an electronic control unit configured to, when operation of the internal combustion engine is stopped, stop fuel injection in the internal combustion engine and then, execute motoring in which the internal combustion engine is rotationally driven using drive power of the motor, and execute the motoring in a range in which an oxygen occlusion amount of the first exhaust catalyst becomes an oxygen occlusion amount smaller than an upper limit oxygen occlusion amount of the first exhaust catalyst.

In a control system for an internal combustion engine, the internal combustion engine includes a first exhaust catalyst that is a three-way catalyst disposed in an exhaust path of the internal combustion engine, a second exhaust catalyst that is a three-way catalyst disposed in the exhaust path on a downstream side of the first exhaust catalyst, and a motor configured to drive the internal combustion engine. The control system includes an electronic control unit configured to, when operation of the internal combustion engine is stopped, stop fuel injection in the internal combustion engine and then, execute motoring in which the internal combustion engine is rotationally driven using drive power of the motor, and execute the motoring in a range in which an oxygen occlusion amount of the first exhaust catalyst becomes an oxygen occlusion amount smaller than an upper limit oxygen occlusion amount of the first exhaust catalyst.

A method for operating a system having a plurality of internal combustion engines coupled together such that then outputs are drawn off by a common load, a downstream individual exhaust gas aftertreatment device, in which the exhaust gas of a particular engine undergoes an individual exhaust gas aftertreatment, positioned downstream of each engine, or a common exhaust gas aftertreatment device, in which the exhaust gas undergoes a common exhaust gas aftertreatment, positioned downstream of to the engine. To regenerate an exhaust gas aftertreatment device, the drive output of one engine is reduced, the temperature of the exhaust gas is increased, and the drive output of a second engine is increased such that the drive output reduction is at least partially compensated for.

A method for operating a system having a plurality of internal combustion engines coupled together such that then outputs are drawn off by a common load, a downstream individual exhaust gas aftertreatment device, in which the exhaust gas of a particular engine undergoes an individual exhaust gas aftertreatment, positioned downstream of each engine, or a common exhaust gas aftertreatment device, in which the exhaust gas undergoes a common exhaust gas aftertreatment, positioned downstream of to the engine. To regenerate an exhaust gas aftertreatment device, the drive output of one engine is reduced, the temperature of the exhaust gas is increased, and the drive output of a second engine is increased such that the drive output reduction is at least partially compensated for.

A propulsion system that includes a plurality of power units, a plurality of propulsors, where respective power units of the plurality of power units are controllably coupled to the plurality of propulsors, and a controller configured to receive a desired throttle value corresponding to a desired propulsive force, determine a number of power units of the plurality of power units to be coupled to the plurality of propulsors to achieve the desired propulsive force based on a respective power value associated with each respective power unit of the plurality of power units, and cause the number of power units of the plurality of power units to be coupled to the plurality of propulsors.

Locomotives comprising a chassis configured for receiving various modules such as, for example, fuel storage modules and/or power modules. By employing a selected combination of fuel storage modules and power modules, a locomotive may be constructed to employ any of one or more types of fuel, such as liquid fuels and gaseous fuels. Batteries may be employed to maximize energy use. Multiple locomotives may function together as a consist having differing types of engines and using different types of fuel. A control system may be employed to optimize use of the engines by prioritizing factors such as cost, fuel efficiency, noise reduction, emissions reduction, etc.

Locomotives comprising a chassis configured for receiving various modules such as, for example, fuel storage modules and/or power modules. By employing a selected combination of fuel storage modules and power modules, a locomotive may be constructed to employ any of one or more types of fuel, such as liquid fuels and gaseous fuels. Batteries may be employed to maximize energy use. Multiple locomotives may function together as a consist having differing types of engines and using different types of fuel. A control system may be employed to optimize use of the engines by prioritizing factors such as cost, fuel efficiency, noise reduction, emissions reduction, etc.