Auxiliary power unit assembly and method of use

1. An auxiliary power unit assembly for a locomotive comprising:

an auxiliary power unit removably coupleable to a rail car chassis, the auxiliary power unit comprising:

a housing; and

an auxiliary engine-generator set positioned within the housing, the auxiliary engine-generator set configured to provide an auxiliary power to the locomotive; and

an auxiliary controller electrically coupled to the auxiliary engine-generator set, the auxiliary controller programmed to:

receive a command; and

control at least one aspect of the auxiliary power unit in response to the command.

2. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to provide a response signal on a control interface of the auxiliary power unit.

3. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to determine a power setting corresponding to an amount of power provided by the auxiliary power unit to a locomotive power bus.

4. The auxiliary power unit assembly of claim 3 wherein the auxiliary controller is further programmed to set the amount of power to the locomotive power bus without changing the configuration of the auxiliary engine-generator set.

5. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to control the auxiliary power unit to configure the auxiliary engine-generator set to produce a selected amount of power.

6. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to communicate with one or more fuel sources fluidly coupled to the auxiliary power unit.

7. The auxiliary power unit assembly of claim 1 further comprising a fault sensor electrically coupled to the auxiliary controller; and

wherein the fault sensor is configured to monitor at least one of a control input, a power input, an operation of the auxiliary engine-generator set, a fuel subsystem, one or more fuel tanks, and one or more operational aspects of the auxiliary power unit.

8. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to:

identify an amount of signal degradation in the command based on a length of travel of the command between the primary locomotive controller and the auxiliary controller;

adjust the command to account for the identified signal degradation; and

selectively control the auxiliary engine-generator set based on the adjusted command.

9. The auxiliary power unit assembly of claim 1 further comprising:

a plurality of independently controllable power cables coupleable to a power bus;

a power sensor operably connected to the power cables and the auxiliary controller;

a meter operably connected to the power cables and the auxiliary controller, the meter configured to measure an amount of power transferred over the power cables;

a power regulator operably connected to the power cables and the auxiliary controller effective to regulate the amount of power output to the power bus; and

a switch operably connected to the power cables and the auxiliary controller effective to logically disconnect the power unit from the output power bus.

10. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller comprises one of an autonomous digital controller and an autonomous analog controller; and

wherein the auxiliary controller operates independently.

11. The auxiliary power unit assembly of claim 1 further comprising at least one fuel assembly fluidly coupled to the auxiliary power unit, the at least one fuel assembly comprising:

at least one removable gaseous fuel supply;

a valve system fluidly coupling the removable gaseous fuel supply to the auxiliary engine-generator set; and

wherein the auxiliary controller is further programmed to:

identify characteristics of the removable gaseous fuel supply; and

regulate operation of the auxiliary engine-generator set based on the identified characteristics of the removable gaseous fuel supply.

12. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to:

store identifying information for the auxiliary power unit assembly, the identifying information comprising at least one of performance information of the auxiliary power unit, an equipment configuration of the auxiliary power unit, operational history of the auxiliary power unit, and a current status of the auxiliary power unit; and

periodically transmit the identification information on a control interface of the auxiliary power unit at predefined time intervals.

13. The auxiliary power unit assembly of claim 1 wherein the auxiliary controller is further programmed to:

receive a fault indication from a fault sensor; and

respond to the fault indication by taking at least one of the following actions: disconnect the auxiliary power unit from a power bus, send a message on a control interface, change settings of the auxiliary engine-generator, change a fuel valve setting, and record the fault indication in a memory.

14. An auxiliary power unit assembly for a locomotive comprising:

an auxiliary power unit removably coupleable to a rail car chassis, the auxiliary power unit comprising:

a housing; and

an auxiliary engine-generator set positioned within the housing, the auxiliary engine-generator set configured to provide an auxiliary power to the locomotive; and

an auxiliary controller electrically coupled to the engine-generator set, the auxiliary controller programmed to:

receive an engine control setting;

transform the engine control setting to a power command; and

selectively control the auxiliary engine-generator set to produce a desired amount of power responsive to the received power command.

15. The auxiliary power unit of claim 14 wherein the auxiliary controller is further programmed to:

receive the power command from a primary locomotive controller; and

control power production by the auxiliary engine-generator set to cooperate with power produced by the locomotive.

16. A locomotive assembly comprising:

a locomotive comprising:

a power bus;

a primary engine-generator set electrically coupled to the power bus; and

a locomotive controller programmed to control the primary engine-generator set; and

a first power unit comprising:

a first auxiliary engine-generator set electrically coupled to the locomotive power bus; and

a first auxiliary controller programmed to:

receive a command signal from the locomotive controller indicating a desired amount of power; and

control the first auxiliary engine-generator set to produce the desired amount of power.

17. The locomotive assembly of claim 16 wherein at least one of the locomotive controller and the first auxiliary controller are further programmed to determine a connection status of the first power unit to the power bus.

18. The locomotive assembly of claim 16 wherein the locomotive controller is further programmed to:

identify operating parameters of the first power unit; and

determine a desired amount of power from the first power unit based on the identified operating parameters of the first power unit; and

transmit the command signal to the first auxiliary controller indicating the desired amount of power.

19. A method of providing auxiliary power by an auxiliary power unit, the method comprising:

coupling the auxiliary power unit to a power bus of the locomotive, the auxiliary power unit comprising an auxiliary engine-generator set and an auxiliary controller electrically coupled to the auxiliary engine-generator set;

coupling the auxiliary controller to a primary locomotive controller;

receiving a power command from the primary locomotive controller in the auxiliary controller; and

controlling the auxiliary engine-generator set to generate an auxiliary power for delivery to a power bus of the locomotive responsive to the power command.