Peak Demand Reduction in Mining Haul Trucks Utilizing an On-Board Energy Storage System

• US 20110094808A1
• Filed: 10/23/2009
• Published: 04/28/2011
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Siemens Large Drives LLC
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: Mazumdar, Joy, Köllner, Walter
• Granted Patent: US 8,499,909 B2
• Time in Patent Office: Days
• US Class Current: 180/65.22
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2200/36 Vehicles designed to transport cargo, e.g. trucks
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 50/12 using AC generators and DC motors
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: B60L 9/22 polyphase motors
• CPC Class Codes: E21F 17/06 Distributing electric power; Cable networks; Conduits for cables circuit arrangements for supplying or distributing electric power in general H02J
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A mining haul truck driven by electrical wheel motors is powered by a trolley power system during an uphill climb. Retard energy captured during braking action on either the uphill climb or downhill descent is stored by an on-board electrical energy storage system. Electrical power is supplied from the on-board electrical energy storage system to reduce the peak power demand on the trolley power system during the uphill climb. One implementation of the on-board electrical energy storage system uses an ultracapacitor system.

Claims

1. A method for supplying electrical power to an electrical motor on a vehicle, wherein the electrical motor operates in at least one propel interval and in at least one retard interval, the method comprising the steps of:

charging an on-board electrical energy storage system with electrical power from the electrical motor during the at least one retard interval; and

supplying electrical power to the electrical motor during the at least one propel interval with electrical power from the on-board electrical energy storage system and a trolley power system.

2. The method of claim 1, wherein the step of supplying electrical power to the electrical motor comprises the step of:

supplying electrical power to the electrical motor during the at least one propel interval with electrical power simultaneously from both the on-board electrical energy storage system and the trolley power system.

3. The method of claim 1, further comprising the steps of:

monitoring the power supplied from the trolley power system to the electrical motor;

determining whether the power supplied from the trolley power system is greater than a power limit; and

supplying power from the on-board electrical energy storage unit only when the power supplied from the trolley power system is greater than the power limit.

4. The method of claim 1, wherein:

the on-board electrical energy storage system comprises at least one ultracapacitor.

5. The method of claim 4, further comprising the steps of:

monitoring the voltage across the at least one ultracapacitor;

determining whether the voltage is greater than a voltage limit; and

supplying electrical power from the on-board electrical energy storage system only when the voltage is greater than the voltage limit.

6. The method of claim 1, wherein:

the on-board electrical energy storage system comprises at least one battery.

7. The method of claim 1, further comprising the step of:

charging the on-board electrical energy storage system with electrical power supplied from an auxiliary power supply.

8. The method of claim 7, wherein:

the auxiliary power supply comprises a generator driven by an engine.

9. The method of claim 7, wherein:

the auxiliary power supply comprises the trolley power system.

10. A electrical power system for supplying electrical power to an electrical motor on a vehicle, wherein the electrical motor is configured to draw electrical power during at least one propel interval and to generate electrical power during at least one retard interval, the electrical power system comprising:

an on-board electrical energy storage system configured to receive the electrical power generated by the electrical motor during the at least one retard interval; and

an inverter configured to;

receive electrical power from the on-board electrical energy storage system;

receive electrical power from a trolley power system; and

supply electrical power to the electrical motor.

11. The electrical power system of claim 10, further comprising a controller configured to:

supply electrical power to the electrical motor from only the trolley power system when the electrical power drawn by the electrical motor during the at least one propel interval is less than or equal to a power limit; and

supply first electrical power to the electrical motor from the trolley power system and second electrical power to the electrical motor from the on-board electrical energy storage system when the electrical power drawn by the electrical motor is greater than the power limit.

12. The electrical power system of claim 10, wherein:

the on-board electrical energy storage system comprises at least one ultracapacitor.

13. The electrical power system of claim 12, further comprising a controller configured to:

monitor the voltage across the at least one ultracapacitor;

determine whether the voltage is greater than a voltage limit; and

supply electrical power from the on-board electrical energy storage system only when the voltage is greater than the voltage limit.

14. The electrical power system of claim 10, wherein:

the on-board electrical energy storage system comprises at least one battery.

15. The electrical power system of claim 10, further comprising:

an engine; and

an electrical generator coupled to the engine, wherein the electrical generator is configured to supply electrical power to the on-board electrical energy storage system.

16. A method for increasing the service life of a trolley power system, the trolley power system comprising a trolley cable, a contact strip, and a feeder cable conducting electrical current from the trolley cable to an electrical motor on a vehicle, wherein the electrical motor operates in at least one propel interval and in at least one retard interval, the method comprising the steps of:

charging an on-board electrical energy storage system with electrical power from the electrical motor during the at least one retard interval;

monitoring a current flowing through the trolley cable;

determining whether the current is greater than a current limit;

supplying electrical power to the electrical motor only from the trolley cable when the current is less than or equal to the current limit; and

supplying first electrical power to the electrical motor from the trolley cable and second electrical power to the electrical motor from the electrical energy storage system when the current is greater than the current limit.

17. The method of claim 16, wherein:

the on-board electrical energy storage system comprises at least one ultracapacitor.

18. The method of claim 16, wherein:

the on-board electrical energy storage system comprises at least one battery.

19. An apparatus for supplying electrical power to an electrical motor on a vehicle, wherein the electrical motor operates in at least one propel interval and in at least one retard interval, the apparatus comprising:

means for charging an on-board electrical energy storage system with electrical power from the electrical motor during the at least one retard interval; and

means for supplying electrical power to the electrical motor during the at least one propel interval with electrical power from the on-board electrical energy storage system and a trolley power system.

20. The apparatus of claim 19, wherein the means for supplying electrical power to the electrical motor comprises:

means for supplying electrical power to the electrical motor during the at least one propel interval with electrical power simultaneously from both the on-board electrical energy storage system and the trolley power system.

21. The apparatus of claim 19, further comprising:

means for monitoring the power supplied from the trolley power system to the electrical motor;

means for determining whether the power supplied from the trolley power system is greater than a power limit; and

means for supplying power from the on-board electrical energy storage system only when the power supplied from the trolley power system is greater than the power limit.

22. The apparatus of claim 19, wherein:

the on-board electrical energy storage system comprises at least one ultracapacitor.

23. The apparatus of claim 22, further comprising:

means for monitoring the voltage across the at least one ultracapacitor;

means for determining whether the voltage is greater than a voltage limit; and

means for supplying electrical power from the on-board electrical energy storage system only when the voltage is greater than the voltage limit.

24. The apparatus of claim 19, wherein:

the on-board electrical energy storage system comprises at least one battery.

25. The apparatus of claim 19, further comprising:

means for charging the on-board electrical energy storage system with electrical power supplied from an auxiliary power supply.

26. The apparatus of claim 25, wherein:

the auxiliary power supply comprises a generator driven by an engine.

27. The apparatus of claim 25, wherein:

the auxiliary power supply comprises the trolley power system.

28. An apparatus for increasing the service life of a trolley power system, the trolley power system comprising a trolley cable, a contact strip, and a feeder cable conducting electrical current from the trolley cable to an electrical motor on a vehicle, wherein the electrical motor operates in at least one propel interval and in at least one retard interval, the apparatus comprising:

means for charging an on-board electrical energy storage system with electrical power from the electrical motor during the at least one retard interval;

means for monitoring a current flowing through the trolley cable;

means for determining whether the current is greater than a current limit;

means for supplying electrical power to the electrical motor only from the trolley cable when the current is less than or equal to the current limit; and

means for supplying first electrical power to the electrical motor from the trolley cable and second electrical power to the electrical motor from the electrical energy storage system when the current is greater than the current limit.

29. The apparatus of claim 28, wherein:

the electrical energy storage system comprises at least one ultracapacitor.

30. The apparatus of claim 28, wherein:

the electrical energy storage system comprises at least one battery.