Auxiliary power unit assembly and method of use

1. A locomotive assembly comprising:

a first locomotive comprising:

a primary power source; and

a first locomotive controller programmed to control the primary power source and transmit a first command signal to a first power unit electrically coupled to the first locomotive, the first power unit comprising:

a first auxiliary power source configured to burn a gaseous fuel; and

a first auxiliary controller programmed to:

receive the first command signal from the first locomotive controller; and

control the first auxiliary power source to produce a tractive power output; and

a first power interface configured to deliver the tractive power output to the first locomotive.

2. The locomotive assembly of claim 1 further comprising:

a tender car removably coupled to the first locomotive; and

an auxiliary fuel supply coupled to the first auxiliary power source; and

wherein the first power unit and the auxiliary fuel supply are located on the tender car.

3. The locomotive assembly of claim 1 further comprising:

a second power unit comprising:

a second auxiliary power source configured to burn a gaseous fuel; and

a second auxiliary controller programmed to:

receive a second command signal from the first locomotive controller; and

control the second auxiliary power source to produce a tractive power output; and

a second power interface configured to deliver the tractive power output of the second auxiliary power source to the first locomotive.

4. The locomotive assembly of claim 1 further comprising a second locomotive, the second locomotive comprising:

a second primary power source; and

a second locomotive controller programmed to control the second primary power source and transmit a second command signal to the first power unit; and

wherein the first power interface is configured to deliver at least a portion of the tractive power output of the first auxiliary power source to the second locomotive.

5. The locomotive assembly of claim 4 wherein the first auxiliary controller is further programmed to:

control the first power interface to deliver a first portion of the tractive power output of the first auxiliary power source to the first locomotive; and

control the first power interface to deliver a second portion of the tractive power output of the first auxiliary power source to the second locomotive.

6. The locomotive assembly of claim 4 further comprising:

a tender car removeably coupled to the first and second locomotives; and

an auxiliary fuel supply coupled to the first auxiliary power source; and

wherein the first power unit and the auxiliary fuel supply are located on the tender car.

7. The locomotive assembly of claim 1 further comprising a fault detection sensor coupled between the first locomotive and the first power unit, the fault detection sensor configured to:

detect at least one of a control fault and a power fault between the first locomotive and the first power unit; and

transmit a signal to at least one of the first auxiliary controller and the first locomotive controller responsive to the fault detection.

8. The locomotive assembly of claim 7 wherein the first auxiliary controller is further programmed to perform an autonomous action upon receipt of the signal indicating the fault detection, the autonomous action comprising at least one of: unloading the first power interface, deallocating power of the first power interface, shutting down the first power unit, notifying the first locomotive controller of the fault, storing the fault, and reducing an amount of tractive power provided to the first power interface.

9. The locomotive assembly of claim 7 wherein the first locomotive controller is further programmed to perform an autonomous action upon receipt of the signal indicating the fault detection, the autonomous action comprising at least one of: sending a status command to the first power unit, resending one at least one of a power command and a control command to the first power unit, determining a seriousness of the fault, displaying a fault alert.

10. A method of providing auxiliary power to a locomotive, the method comprising:

coupling at least one auxiliary power unit to the locomotive, the at least one auxiliary power unit comprising an auxiliary power source configured to burn a gaseous fuel and an auxiliary controller electrically coupled to the auxiliary power source;

allocating tractive power generation between the auxiliary power source and at least one power source on the locomotive; and

transmitting a power command signal from a controller on the locomotive to the auxiliary controller based on the allocation.

11. The method of claim 10 further comprising:

identifying a total power requirement of the locomotive;

identifying a plurality of available power sources, the plurality of available power sources selected from the auxiliary power source and at least one locomotive engine-generator set;

identifying an amount of power available from the plurality of available power sources;

allocating tractive power generation among the available power sources such that the total power requirement is divided among the plurality of available power sources; and

transmitting power commands to the plurality of available power sources via the controller on the locomotive to provide tractive power to the locomotive in accordance with the allocation.

12. The method of claim 11 further comprising:

detecting a fault in a control cable connecting the controller on the locomotive to a first auxiliary power unit of the at least one auxiliary power unit;

identifying the first auxiliary power unit as a non-available power unit based on the detected fault; and

modifying a power allocation in response to the detected fault, wherein modifying the power allocation comprises:

reallocating power generation among remaining available power sources of the plurality of available power sources such that the total power requirement is divided among the remaining available power units; and

providing modified power commands to the remaining available power sources to provide power in accordance with the reallocation.

13. The method of claim 11 further comprising:

detecting a fault in a power cable connecting the locomotive to an auxiliary controller of a first auxiliary power unit of the at least one auxiliary power unit;

identifying the first auxiliary power unit as a non-available power unit based on the detected fault; and

modifying a power allocation in response to the detected fault, wherein modifying the power allocation comprises:

reallocating power generation among remaining available power sources of the plurality of available power sources such that the total power requirement is divided among the available power units; and

providing modified power commands to the remaining available power sources to provide power in accordance with the reallocation.

14. The method of claim 10 further comprising:

transmitting a request from the controller on the locomotive to the at least one auxiliary power unit to obtain identifying information for the at least one auxiliary power unit;

receiving the identifying information from the at least one auxiliary power unit in the controller on the locomotive; and

controlling operation of the locomotive based on the received identifying information.

15. The method of claim 14 further comprising:

identifying a total power requirement of the locomotive;

identifying at least one available power source, the at least one available power source selected from the at least one auxiliary power unit and at least one locomotive engine-generator set,

determining power available from the at least one available power source based on the identification of the least one available power source;

determining an available power from the at least one locomotive engine-generator set;

allocating tractive power generation among the available power sources such that the total power requirement is divided among the available power sources; and

transmitting power commands to each allocated power source to provide power in accordance with the allocation.

16. The method of claim 15 further comprising allocating tractive power generation based at least in part upon an identified cost of generating power from the available power sources.

17. The method of claim 10 further comprising allocating tractive power generation to minimize a total cost of providing power to the locomotive.

18. A method of providing auxiliary power to a locomotive, the method comprising:

coupling at least one auxiliary power unit to the locomotive, the at least one auxiliary power unit comprising an auxiliary power source configured to burn a gaseous fuel and an auxiliary controller electrically coupled to the auxiliary power source;

transmitting a first power request from a primary controller located on the locomotive to the auxiliary controller;

controlling the auxiliary power source to provide a first tractive power output to the locomotive based on the first power request;

transmitting a second power request from the primary controller to a primary power source located on the locomotive; and

controlling the primary power source to provide a second tractive power output to the locomotive based on the second power request.

19. The method of claim 18 further comprising:

detecting a connection fault between the at least one auxiliary power unit and the locomotive; and

electrically disconnecting the at least one auxiliary power unit from the locomotive upon detection of the fault.