Energy management and storage system

• US 8,626,403 B2
• Filed: 10/06/2010
• Issued: 01/07/2014
• Est. Priority Date: 10/06/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Onsager, Michael Gordon, Helfrich, Joseph, Perugini, Dave L., Chmiel, Wayne George, Weber, Robert, Miller, Peter James
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): Nolan, Peter D
• Application Number:
  US12/899,375
• Publication Number:
  US 20120089279A1
• Time in Patent Office: 1,189 Days
• Field of Search: 701/22, 701/50, 180/65.1, 180/65.265, 180/65.27, 180/65.275, 180/65.28, 180/65.285, 180/65.31, 318/139, 318/140, 903/902, 903/903, 903/904, 903/906
• US Class Current: 701/50
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 50/13 using AC generators and AC motors
• 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 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

Heavy equipment is designed for operation in a substantially-repetitive work cycle that includes lifting, rotating, and lowering steps. The heavy equipment includes a generator, an electrical bus, an energy storage component, and working components. The generator provides a substantially constant electrical output to the electrical bus, which is communicated to the working components. As such, the working components of the heavy equipment are driven directly or indirectly by the electrical output of the generator. The controller selectively couples the energy storage component to the electrical bus, and the energy storage component is configured to store electricity provided by the generator, and to provide electricity to the working components by way of the electrical bus. The electrical output of the generator is less than the power used by the heavy equipment during a portion of the work cycle, and the controller couples the energy storage component to the electrical bus to supplement the electrical output of the generator during the portion of the work cycle in which the electrical output of the generator is less than the power used by the working components of the heavy equipment.

Claims

1. Heavy equipment configured for operation in a substantially-repetitive work cycle that includes lifting, rotating, and lowering steps, the heavy equipment comprising:

a generator for providing an electrical output;

working components of the heavy equipment that are driven directly or indirectly by the electrical output of the generator;

an electrical bus for communicating the electrical output of the generator to the working components;

an energy storage component configured to store electricity provided by the generator, and to provide electricity to the working components by way of the electrical bus; and

a controller for selectively coupling the energy storage component to the electrical bus;

wherein the electrical output of the generator is configured to be less than the power used by the heavy equipment during a portion of the work cycle;

wherein the controller couples the energy storage component to the electrical bus to supplement the electrical output of the generator during the portion of the work cycle in which the electrical output of the generator is less than the power used by the working components of the heavy equipment;

wherein, when a total power used by the heavy equipment throughout the work cycle is less than or equal to a total electrical output of the generator over the work cycle, the generator is operated to provide a first level of electrical output; and

wherein, when the total power used by the heavy equipment throughout the work cycle is greater than the total electrical output of the generator over the work cycle, (i) a portion of the power used by the heavy equipment during at least some repetitions of the substantially-repetitive work cycle is power that was regenerated during one or more previous repetitions of the work cycle and stored in the energy storage component, and (ii) the generator is operated to charge the energy storage component by providing a second level of electrical output that is greater than the first level during one or more initial repetitions of the work cycle.

2. The heavy equipment of claim 1, wherein the energy storage component is configured to augment the electrical output of the generator by at least 20-percent during the portion of the work cycle in which the electrical output of the generator is less than the power used by the working components of the heavy equipment.

3. The heavy equipment of claim 2, wherein the energy storage component comprises an ultra-capacitor.

4. The heavy equipment of claim 3, wherein the working components comprise an electric motor.

5. The heavy equipment of claim 4, wherein the working components further comprise a hydraulic pump coupled to the electric motor.

6. The heavy equipment of claim 5, wherein the working components further comprise a hydraulic actuator coupled to the hydraulic pump and configured to facilitate movement of the heavy equipment during one or more steps in the work cycle.

7. The heavy equipment of claim 6, wherein at least one of braking energy and gravitational energy is provided by the hydraulic actuator to the hydraulic pump, which drives the electric motor to regenerate electricity, which is received by the electrical bus and delivered to the energy storage component during one or more steps in the work cycle.

8. Heavy equipment configured for operation in a substantially-repetitive work cycle that includes lifting, rotating, and lowering steps, the heavy equipment comprising:

a generator for providing an electrical output;

working components of the heavy equipment, comprising;

an electric motor that is powered by the electrical output of the generator;

a hydraulic pump selectively driven by the electric motor;

a hydraulic actuator coupled to the hydraulic pump; and

an articulated arm configured to be moved by the hydraulic actuator;

an electrical bus for communicating the electrical output of the generator to the electric motor;

an ultra-capacitor configured to selectively store electricity provided by the generator and to selectively provide the electricity to the electric motor by way of the electrical bus;

a controller for coupling the ultra-capacitor to the electrical bus,

wherein the electrical output of the generator is configured to be less than the power used by the working components during a portion of the work cycle; and

wherein the controller couples the ultra-capacitor to the electrical bus to supplement the electrical output of the generator during the portion of the work cycle in which the electrical output of the generator is less than the power used by the working components;

wherein the ultra-capacitor is configured to augment the electrical output of the generator by at least 20-percent during the portion of the work cycle in which the electrical output of the generator is less than the power used by the working components;

wherein, when a total power used by the heavy equipment throughout the work cycle is less than or equal to a total electrical output of the generator over the work cycle, the generator is operated to provide a first level of electrical output; and

wherein, when the total power used by the heavy equipment throughout the work cycle is greater than the total electrical output of the generator over the work cycle, (i) a portion of the power used by the heavy equipment during at least some repetitions of the substantially-repetitive work cycle is power that was regenerated during one or more previous repetitions of the work cycle and stored in the ultra-capacitor, and (ii) the generator is operated to charge the ultra-capacitor by providing a second level of electrical output that is greater than the first level during one or more initial repetitions of the work cycle.

9. The heavy equipment of claim 8, wherein the generator comprises a diesel engine coupled to an alternator.

10. The heavy equipment of claim 9, wherein the diesel engine is configured to be run at a substantially constant speed during operation of the heavy equipment, regardless of the step of the work cycle.

11. The heavy equipment of claim 10, wherein the substantially constant speed corresponds to a speed of maximum efficiency of the diesel engine.

12. The heavy equipment of claim 10, wherein during one or more steps of the work cycle at least one of braking energy and gravitational energy associated with the articulated arm is communicated to the hydraulic pump by way of the hydraulic actuator, and wherein the hydraulic pump drives the electric motor to regenerate electricity, which is delivered to the ultra-capacitor by way of the electrical bus.

13. The heavy equipment of claim 12, wherein the articulated arm comprises a boom, an arm, and a bucket, wherein the boom is rotatably coupled to the arm, and at least one of the boom and the arm is rotatably coupled to the bucket, and wherein the hydraulic actuator extends between at least one of the boom and the arm, the boom and the bucket, and the arm and the bucket.

14. A method of operating heavy equipment configured for operation in a substantially-repetitive work cycle, comprising steps of:

providing;

an electrical bus;

a generator coupled to the electrical bus, wherein the generator includes an engine coupled to an alternator,

an energy storage component configured to selectively store from and release electricity to the electrical bus,

an electric motor powered by electricity from the electrical bus, and

an articulated arm configured to be driven directly or indirectly by the electric motor;

communicating an electrical output of the alternator to the electric motor;

storing the electrical output from the alternator on the energy storage component;

augmenting the electrical output of the alternator with electricity from the energy storage component;

raising at least a portion of the articulated arm; and

lowering the at least a portion of the articulated arm;

when a total power used by the heavy equipment throughout the work cycle is less than or equal to a total power output of the generator over the work cycle, operating the engine to provide a first level of power output; and

when the total power used by the heavy equipment throughout the work cycle is greater than the total electrical output of the generator over the work cycle;

augmenting the electrical output of the alternator during at least some repetitions of the substantially-repetitive work cycle using power stored in the energy storage component that was regenerated during one or more previous repetitions of the substantially-repetitive work cycle; and

operating the engine to provide a second level of power output higher than the first level of power output during one or more initial repetitions of the work cycle.

15. The method of operating heavy equipment of claim 14, further comprising:

regenerating energy provided by operation of the articulated arm.

16. The method of operating heavy equipment of claim 15, further comprising:

converting the regenerated energy into electricity.

17. The method of operating heavy equipment of claim 16, further comprising:

delivering the regenerated energy to the energy storage component by way of the electrical bus.

18. The method of operating heavy equipment of claim 17, further comprising:

repeating the raising and lowering steps at least 20 times in an hour.

19. The method of operating heavy equipment of claim 18, wherein the energy storage component augments the electrical output of the generator by at least 20-percent.

20. The method of operating heavy equipment of claim 19, wherein the energy storage component comprises an ultra-capacitor.