ENERGY SYSTEM FOR HEAVY EQUIPMENT

• US 20120086220A1
• Filed: 09/27/2011
• Published: 04/12/2012
• Est. Priority Date: 10/06/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Bucyrus International Incorporated (Caterpillar Incorporated)
• Inventors: Nasiri, Adel, Miller, Peter, Abdel-Baqi, Omar, Helfrich, Joe
• Granted Patent: US 8,606,451 B2
• Time in Patent Office: Days
• US Class Current: 290/40.B
• CPC Class Codes: E02F 9/0808 Improving mounting or assembling, e.g. frame elements, disposition of all the components on the superstructures for disposition of specific components, E02F9/0858
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2091 Control of energy storage means for electrical energy, e.g. battery or capacitors energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

An energy system for heavy equipment having an actuator for operating a tool includes a bus, an engine, a generator, an energy storage device, and a controller. The bus is for providing electricity to the actuator as a function of operation of the tool. The engine is for providing a power output and the generator is coupled to the engine and configured to provide electricity to the bus. The energy storage device is configured to receive electricity from the bus for storage of energy, and is further configured to provide electricity to the bus to supplement the electricity provided by the generator. The controller is configured to change the power output of the engine as a function of electrical demand on the bus. In response to a change in the electrical demand, the controller is configured to change the power output of the engine at a rate that is less than a maximum capability of the engine.

Claims

1. An energy system for heavy equipment having an actuator for operating a tool, the energy system comprising:

a bus for providing electricity to the actuator as a function of operation of the tool;

an engine for providing a power output;

a generator coupled to the engine and configured to provide electricity to the bus;

an energy storage device configured to receive electricity from the bus for storage of energy, and further configured to provide electricity to the bus to supplement the electricity provided by the generator; and

a controller configured to change the power output of the engine as a function of electrical demand on the bus,

wherein, in response to a change in the electrical demand, the controller is configured to change the power output of the engine at a rate that is less than a maximum capability of the engine.

2. The energy system of claim 1, wherein the energy storage device is configured such that a net short-term dynamic response of the energy system to the change in demand on the bus is substantially unaffected by the rate of change in power output of the engine.

3. The energy system of claim 2, wherein when the demand on the bus increases, the controller is configured to restrain a throttle of the engine such that the power output of the engine increases at the rate that is less than the maximum capability of the engine.

4. The energy system of claim 3, wherein the controller is configured to optimize the rate of change in power output of the engine with respect to fuel economy, minimal wear, reduced emissions, or a combination thereof.

5. The energy system of claim 4, wherein the controller is configured to optimize the rate of change in power output of the engine with respect to fuel economy.

6. The energy system of claim 4, wherein the controller is configured to optimize the rate of change in power output of the engine with respect to both fuel economy and minimal wear to the engine.

7. The energy system of claim 3, wherein the energy storage device is configured to provide increased electrical power in response to an increase in the demand on the bus at a rate that is faster than the engine is capable of providing to the bus via the generator.

8. The energy system of claim 7, wherein the energy storage device comprises an ultra-capacitor and the engine and generator are parts of a diesel generator set.

9. The energy system of claim 1, wherein the energy system is designed for use with the heavy equipment operating in a substantially repetitive work cycle, and wherein the engine is designed to operate with an optimal power output that corresponds to or is less than an average demand on the bus during the substantially repetitive work cycle.

10. The energy system of claim 9, wherein the engine is not designed to efficiently meet a peak demand of the substantially repetitive work cycle.

11. An energy system for heavy equipment having an actuator for operating a tool, the energy system comprising:

a bus for providing electricity to the actuator as a function of operation of the tool;

an engine for providing a power output;

a generator coupled to the engine and configured to provide electricity to the bus;

an ultra-capacitor configured to receive electricity from the bus for storage of energy, and further configured to provide electricity to the bus to supplement the electricity provided by the generator; and

a controller configured to change the power output of the engine as a function of electrical demand on the bus,

wherein, in response to a change in the electrical demand, the controller is configured to optimize the rate of change in power output of the engine with respect to fuel economy.

12. The energy system of claim 11, wherein the ultra-capacitor is configured such that a net short-term dynamic response of the energy system to the change in demand on the bus is substantially unaffected by the rate of change in power output of the engine.

13. The energy system of claim 11, wherein the energy system is designed for use with the heavy equipment operating in a substantially repetitive work cycle, and wherein the engine is designed to operate with an optimal power output that corresponds to or is less than an average demand on the bus during the substantially repetitive work cycle.

14. The energy system of claim 13, wherein the engine is not designed to efficiently meet a peak demand of the substantially repetitive work cycle.

15. A method of controlling an energy system for heavy equipment, comprising:

providing electrical power to a bus from a generator driven by an engine for powering an actuator operating a tool of the heavy equipment;

providing electrical power to the bus from an energy storage device in response to an increased electrical demand on the bus; and

increasing the power output of the engine driving the generator at a rate less than a maximum capability of the engine, and correspondingly decreasing the power provided to the bus from the energy storage device.

16. The method of claim 15, wherein the energy storage device provides electrical power to the bus such that a net short-term dynamic response of the energy system to the increase in demand on the bus is substantially unaffected by the rate of increase in power output of the engine.

17. The method of claim 16, further comprising charging the energy storage device with electrical power provided by the bus.

18. The method of claim 17, wherein the rate of change in power output of the engine is optimized with respect to fuel economy, minimal wear, reduced emissions, or a combination thereof.

19. The method of claim 18, wherein the rate of change in power output of the engine is optimized with respect to fuel economy.

20. The method of claim 19, wherein the energy storage device comprises an ultra-capacitor and the engine and the generator are parts of a diesel generator set.