Multiple prime power source locomotive control

• US 7,906,862 B2
• Filed: 04/25/2006
• Issued: 03/15/2011
• Est. Priority Date: 04/25/2005
• Status: Expired due to Fees

• Current Assignee: Railpower, LLC
• Original Assignee: Railpower, LLC
• Inventors: Donnelly, Frank, Wolff, Bruce, Watson, John, Tarnow, Andrew
• Primary Examiner(s): Waks; Joseph
• Application Number:
  US11/912,389
• Publication Number:
  US 20080296970A1
• Time in Patent Office: 1,785 Days
• Field of Search: 290/4.R, 290/40.C, 318/108
• US Class Current: 290/6
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2260/165 of converters
• CPC Class Codes: B60L 2260/167 of motors or generators
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/30 using propulsion power stored mechanically, e.g. in fly-wheels
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/22 Dynamic electric resistor braking, combined with dynamic electric regenerative braking
• CPC Class Codes: B60L 9/00 Electric propulsion with power supply external to the vehicle electric propulsion for monorail vehicles, suspension vehicles or rack railways B60L13/00; in combination with batteries or fuel cells within the vehicle B60L50/53
• CPC Class Codes: B60L 9/16 using ac induction motors
• CPC Class Codes: B61C 7/04 Locomotives or motor railcars with two or more different kinds or types of engines, e.g. steam and IC engines
• CPC Class Codes: F02D 25/04 by cutting-out engines
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 7/10 : characterised by using auxiliary engines or apparatus of combustion type by using explosive cartridges F02N13/00
• CPC Class Codes: H02M 3/1552 : Boost converters exploiting the leakage inductance of a transformer or of an alternator as boost inductor
• CPC Class Codes: H02P 2201/09 : Boost converter, i.e. DC-DC step up converter increasing the voltage between the supply and the inverter driving the motor general aspects of plural converters in cascade H02M
• CPC Class Codes: H02P 25/16 : characterised by the circuit arrangement or by the kind of wiring
• CPC Class Codes: H02P 9/305 : controlling voltage H02P9/302 takes precedence
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 30/00 : Transportation of goods or passengers via railways, e.g. energy recovery or reducing air resistance

Abstract

A control strategy for operating a plurality of prime power sources during propulsion, idling and braking and is applicable to large systems such as trucks, ships, cranes and locomotives utilizing diesel engines, gas turbine engines, other types of internal combustion engines, fuel cells or combinations of these that require substantial power and low emissions utilizing multiple power plant combinations. It is directed at a general control strategy for multi-engine systems where the power systems need not be of the same type or power rating and may even use different fuels. It is based on a common DC bus electrical architecture so that prime power sources need not be synchronized.

Claims

1. A propulsion system, comprising:

(a) a plurality of prime power systems, each prime power system comprising;

a prime power source device; and

an energy conversion device operable to convert energy output by the prime power device into direct current electrical energy;

(b) a direct current bus connecting the plurality of prime power systems, the direct current bus being operable to carry the direct current electrical energy to and/or from the prime power systems;

(c) a voltage sensor for measuring a voltage level across the direct current bus;

(d) a plurality of current sensors, each current sensor measuring a direct current electrical energy outputted by a selected prime power system; and

(e) a control system operable, based on the measured voltage level across the direct current bus and the respective measured direct current electrical energy into and/or out of each prime power system, to control at least one of;

(i) a mechanical parameter of the selected prime power system;

(ii) an electrical parameter of the selected prime power system; and

(iii) an electrical parameter of the direct current bus.

2. The propulsion system of claim 1 wherein the prime power system is an engine and the energy conversion device is a mechanical-to-electrical energy conversion device operable to convert mechanical energy output by the engine into direct current electrical energy.

3. The propulsion system of claim 2 wherein the control system controls (i) and wherein the mechanical parameter is at least one of a mechanical power setting of the selected engine, a mechanical rotary speed setting of the selected engine and a fuel supply to the selected engine.

4. The propulsion system of claim 2, wherein the control system controls an engine power and/or rotary speed operating point to the selected engine.

5. The propulsion system of claim 2, wherein the plurality of mechanical-to-electrical energy conversion devices are connected in parallel to the bus, wherein the control system controls (ii), wherein the output electrical parameter is at least one of an output electrical voltage, an output electrical current and output electrical power of the selected engine system, wherein the mechanical-to-electrical energy conversion devices comprise an electrical converter operable to inhibit reverse flow of direct current electrical energy from the bus to a selected engine system and further comprising:

a control device for providing at least one of a rotary speed, a winding configuration and a magnetic flux modification to a selected mechanical-to-electrical energy conversion device to vary an output voltage of the selected mechanical-to-electrical energy conversion device.

6. The propulsion system of claim 2, wherein the control system controls (ii) and wherein the electrical parameter is at least one of an output electrical voltage, an output electrical current and output electrical power and further comprising:

a voltage boost circuit for the selected engine electrically connected with each armature of an alternator corresponding to the selected engine to boost the voltage generated by each armature, wherein the armature of the alternator acts as an inductor in the voltage boost circuit.

7. The propulsion system of claim 1 wherein the prime power system is a fuel cell and the energy conversion device is an electrical converter device.

8. The propulsion system of claim 7 wherein the control system controls (i) and wherein the mechanical parameter is at least one of a mechanical flow rate of a fuel component of the selected fuel cell and mechanical fuel pressure level of a fuel component of the selected fuel cell.

9. The propulsion system of claim 7, wherein the control system controls a fuel cell electrical power and/or electrical current operating point of the selected fuel cell.

10. The propulsion system of claim 7, wherein the plurality of electrical converter devices are connected in parallel to the bus, wherein the control system controls (ii), wherein the electrical parameter is at least one of an output electrical voltage, an output electrical current and output electrical power of the selected fuel cell system, and further comprising:

an electrical circuit operable to inhibit reverse flow of direct current electrical energy from the bus to a selected fuel cell system; and

a controller for providing at least one of a voltage regulation, a voltage increase and a voltage reduction function to a selected electrical converter device to maintain a selected output voltage of the selected electrical converter device.

11. The propulsion system of claim 1, wherein the control system controls (iii) and wherein the electrical parameter of the direct current bus is at least one of a voltage level across the bus and a total electrical power carried by the bus and further comprising:

a power control device positioned between the bus and at least one load device.

12. The propulsion system of claim 1, wherein the control system varies the at least one of (i), (ii), and (iii) for a set of two or more of the prime power systems, wherein the control system selects at least one desired operating point for the set of prime power systems and/or for a prime power system in the set, determines a corresponding power output for a selected prime power system in the set based on the desired operating point, and controls the at least one of (i), (ii), and (iii) for the selected prime power system based on the corresponding power output, wherein each prime power system in the set has a corresponding desired operating point, wherein the desired operating point is associated with at least one of a desired fuel consumption rate, an emissions level rate of at least one target emission component, a desired prime power system power output, and a desired prime power system lifetime, and wherein the desired operating point is associated with an emissions level rate of at least one target emission component and the at least one target emission component is at least one of a compound of nitrogen and oxygen and a compound of carbon and oxygen.

13. A propulsion system, comprising:

(a) an engine system comprising;

an engine; and

an n-phase alternator operable to convert mechanical energy output by the engine into alternating current electrical energy, each phase corresponding to an armature winding;

(b) at least one traction motor in electrical communication with the alternator;

(c) a voltage boost circuit electrically connected with each of the n-armature windings of the alternator to boost the output voltage associated with each armature winding, wherein each armature winding provides an inductance for the voltage boost circuit.

14. The propulsion system of claim 13, further comprising:

a rectifying diode network in electrical communication with the alternator to convert the outputted alternating current electrical energy into direct current electrical energy; and

wherein the voltage boost circuit comprises;

an IGBT switch, a capacitor and n-diodes in electrical communication with the alternator and rectifying diode network; and

a control system operable, based on a measured mechanical or electrical parameter of the alternator, to control the switching rate of the IGBT such that the IGBT, the capacitor, and the n-diodes form a variable voltage boost circuit with each of the n-armature coils of the alternator during the corresponding power phase of the nth armature coil, whereby the output voltage of the engine system can be varied independently of engine speed.

15. The system of claim 13, wherein the voltage boost circuit does not boost the voltage when a revolutions-per-minute of the engine is greater than a first threshold and boosts the voltage when the revolutions-per-minute of the engine is less than the first threshold.

16. A propulsion method, comprising:

(a) in a first mode in which a switch is conducting, directing an output electrical current of an n-phase alternator along a first path through a first set of diodes, through the switch, and back to an armature coil of the alternator, thereby storing electrical energy in the armature coil; and

(b) in a second mode in which the switch is nonconducting, directing the output electrical current along a second path through a second set of diodes to a load, wherein the second path bypasses the switch.

17. The method of claim 16, wherein the armature comprises n-armature coils, each armature coil being in the first mode at a different time, wherein a control system, based on a measured mechanical or electrical parameter of the alternator, controls the on-off duty cycle of the switch between the first and second modes such that the switch, the capacitor, and the first set of diodes form a variable voltage boost circuit with each of the n-annature coils of the alternator during the corresponding first mode of the nth armature coil, whereby the output voltage of the engine system can be varied independently of engine speed.

18. In a multi-prime power source vehicle, a propulsion method, comprising:

(a) determining an operating voltage range for a direct current electrical bus;

(b) determining a power requirement to be provided to the direct current electrical bus by a plurality of prime power systems;

(c) selecting at least a subset of the prime power systems to provide the determined power requirement to the direct current electrical bus;

(d) determining a first magnitude of an operational parameter for each of the selected prime power systems to provide, to the direct current electrical bus, the selected prime power system'"'"'s portion of the determined power requirement;

(e) setting each of the selected prime power systems to the corresponding first magnitude of the determined operational parameter to provide the selected prime power system'"'"'s portion of the determined power requirement to the direct current electrical bus;

(f) measuring an electrical parameter of each of the selected prime power systems;

(g) comparing the measured electrical parameter of each of the selected prime power systems to the corresponding portion of the determined power requirement; and

(h) if needed, adjusting at least one of (i) the first magnitude of the operational parameter of the selected prime power system and (ii) the electrical parameter of the selected prime power system to produce the corresponding required electrical power output for the selected prime power system.

19. The method of claim 18, wherein each prime power system comprises at least one of an engine and a fuel cell and further comprising:

adjusting power to a load attached to the direct current electrical bus.

20. The method of claim 19, wherein a power requirement to be provided to the direct current electrical bus by a plurality of prime power systems is modified by adjusting power to a load attached to the direct current electrical bus.

21. The method of claim 18, wherein the power requirement is based on a physical location of the prime power systems as sensed by an on board position tracking system, wherein an electrical power outputted by the selected prime power system is proportional to a current outputted by the selected prime power system, wherein step (f) is performed by measuring electrical power outputted by each of the at least a subset of prime power systems and wherein, in step (g), the measured current is compared to a corresponding required current for the selected prime power system.

22. The method of claim 18, wherein step (h) is performed by at least one of the following:

(i) adjusting an output voltage of each of the selected prime power system; and

(ii) adjusting a power outputted by the prime power source.

23. A propulsion method in a multi-prime power source vehicle, comprising:

(a) determining an operating voltage range for a direct current electrical bus;

(b) determining a power requirement to be provided to the direct current electrical bus by a plurality of prime power systems;

(c) selecting a prime power source operating mode from among a plurality of differing prime power source operating modes;

(d) based on the determined power requirement and selected prime power source operating mode, selecting at least a subset of the prime power systems to provide the determined power requirement to the direct current electrical bus; and

(e) based on the determined power requirement and selected prime power source operating mode, setting at least one of (i) an operational mechanical parameter for each of the selected prime power systems and (ii) an operational electrical parameter for each of the selected prime power systems, to provide the selected prime power system'"'"'s portion of the determined power requirement to the direct current electrical bus.

24. The method of claim 23, wherein each prime power system comprises at least one of an engine and a fuel cell and wherein the setting step (e) comprises the substep of setting an operational mechanical parameter and wherein the operational mechanical parameter is at least one of an output mechanical power of the selected prime power system, an output mechanical rotary speed of the selected prime power system, an operating pressure level of the selected prime power system, and an input prime power source operating point to the selected prime power system.

25. The method of claim 23, wherein the setting step comprises controlling an input fuel supply to the selected prime power system.

26. The method of claim 23, wherein each member of the subset of prime power systems is connected in parallel to the bus, wherein the setting step (e) comprises the substep of setting an operational electrical output parameter, wherein the output parameter is at least one of an output electrical voltage, an output electrical current and an output electrical power of the selected prime power system, wherein an electrical converter comprises an electrical circuit operable to inhibit reverse flow of direct electrical energy from the bus to a selected prime power system and further comprising:

providing a control electrical signal to a selected electrical converter device to maintain an output voltage of the selected electrical converter device within a selected range.

27. The method of claim 23, wherein the prime power source comprises an engine operatively engaged with an alternator and in the setting step (e), the electrical parameter is set and wherein the electrical parameter is at least one of an output electrical voltage, an output electrical current and output electrical power and further comprising:

boosting an output voltage of a selected engine system using a voltage boost circuit, the voltage boost circuit being electrically connected with each armature of the alternator corresponding to the selected engine to boost the voltage generated by each armature, wherein the armature of the alternator acts as an inductor in the voltage boost circuit.

28. The method of claim 23, wherein, in the setting step (e), the electrical parameter is set and wherein the electrical parameter of the direct current bus is at least one of a voltage level across the bus and a total electrical power of the bus and further comprising:

controlling a power level supplied to a load device using a power control device positioned between the bus and the load device.

29. The method of claim 23, further comprising:

selecting a desired operating point for the plurality of prime power systems;

determining, for each of the prime power systems, the corresponding power requirement based on the corresponding desired operating point; and

controlling at least one of a mechanical parameter and an electrical parameter for each of the each of prime power systems based on the corresponding power output.

30. The method of claim 29, wherein the desired operating point is associated with at least one of a desired fuel consumption rate, an emissions level rate of at least one target emission component substance, a desired prime power system power output, and a desired prime power source lifetime, wherein the desired operating point is associated with an emissions level rate of at least one target emission component substance and the at least one target emission component substance is at least one of a compound of nitrogen and oxygen and a compound of carbon and oxygen.

31. The method of claim 29, wherein the desired operating point is associated with a desired fuel consumption.

32. The method of claim 23, wherein the operating modes are at least two of the following:

an emissions mode in which prime power system emission of a selected substance is less than a specified level, a prime power lifetime mode in which prime power system power output is maintained below a specified level to provide for increased prime power system operating life, a maximum fuel efficiency mode in which prime power system power output is maintained below a specified level to provide for at least a selected level of fuel consumption, a noise emissions mode in which prime power system noise emissions are maintained less than a specified level, and a maximum power mode in which prime power system power output is substantially maximized, wherein first and second prime power systems are simultaneously in differing operating modes.

33. The method of claim 23, wherein the selection of the operating mode is based on a physical location of the prime power system as determined by an on board location tracking system.

34. The method of claim 23, wherein subset of prime power systems is selected based upon at least one of an operating history of each prime power system, a random number generator output value, a pseudo-random number generator output value, and a round robin scheduler value.

35. A propulsion system, comprising:

(a) a plurality of engine systems, each engine system comprising;

an engine;

an induction alternator operable to convert mechanical energy output by the engine into alternating current electrical energy;

an electrical converter operable to convert the outputted alternating current electrical energy into direct current electrical energy and to permit electrical energy to flow reversably in each of two directions; and

(b) a direct current bus connecting the plurality of engine systems, the direct current bus being operable to carry the direct current electrical energy to and/or from the engine systems, wherein, at a selected time, at least a first engine system is turned off and at least a second engine system is turned on, wherein the electrical converter of the second engine is switched to provide electrical energy to the DC bus at a selected voltage level, and the electrical converter of the first engine is switched to receive electrical energy from the DC bus at a selected voltage level, whereby the first engine is activated using electrical energy supplied, via the DC bus, by the second engine.

36. A propulsion system, comprising:

(a) a plurality of engine systems, each engine system comprising;

an engine;

one or more energy storage systems;

an induction alternator operable to convert mechanical energy output by the engine into alternating current electrical energy;

an electrical converter circuit operable to convert the outputted alternating current electrical energy into direct current electrical energy and to permit electrical energy to flow reversably in each of two directions; and

(b) a direct current bus connecting the plurality of engine systems, the one or more energy storage systems, the direct current bus being operable to carry the direct current electrical energy to and/or from the engine systems and the one or more energy storage systems, wherein, at a selected time, at least a first engine system is turned off and at least a second engine system or an energy storage system is turned on, wherein the electrical converter of the second engine or energy storage system is switched to provide electrical energy to the DC bus at a selected voltage level, and the electrical converter of the first engine is switched to receive electrical energy from the DC bus at a selected voltage level, whereby the first engine is activated using electrical energy supplied, via the DC bus, by the second engine or an energy storage system.