Powertrain operation and regulation

• US 10,023,195 B2
• Filed: 08/11/2016
• Issued: 07/17/2018
• Est. Priority Date: 08/11/2016
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Miller, Peter J., Abdel-Baqi, Omar
• Primary Examiner(s): Tran, Dalena
• Application Number:
  US15/234,695
• Publication Number:
  US 20180043894A1
• Time in Patent Office: 705 Days
• Field of Search: 701 22, 180 65285, 180 6521, 180 65265, 903902, 903903, 903916, 290 40 A, 290 40 R
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/305 Power absorbed by auxiliaries
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/1884 Avoiding stall or overspeed of the engine
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2300/1884 Avoiding stall or over-speed of the engine
• CPC Class Codes: E02F 3/30 with a dipper-arm pivoted on a cantilever beam , i.e. boom
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2217 : with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2246 : Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

One or more powertrains can include a motor-generator disposed therein that is electrically coupled to an energy storage device through an inverter gate. A regulation strategy can monitor operation of the powertrain to regulate the inverter gate to selectively discharge energy from the energy storage device to the motor-generator to assist the powertrain or to charge energy from the motor-generator to the energy storage device for future use. In an aspect, the regulation strategy may maintain a consistent speed of an internal combustion engine associated with the powertrain. In another aspect, the regulation strategy may regulate simultaneous operation of first and second powertrains disposed a parallel relation.

Claims

1. A method of regulating operation of a powertrain having an internal combustion engine, a motor-generator, and a powertrain load coupled in series, the method comprising:

operating the internal combustion engine at a first engine speed;

charging an energy storage device coupled to the motor-generator through an inverter gate disposed between the energy storage device and the motor-generator;

registering a change in the powertrain load;

determining if the change represents a torque change condition or a speed change condition;

operating the inverter gate to maintain the first engine speed under the torque change condition; and

operating the inverter gate to accelerate the internal combustion engine to a second engine speed under the speed change condition.

2. The method of claim 1, wherein the step of operating the inverter gate to maintain the first engine speed comprises:

determining if the torque change condition represents a torque increase condition or a torque decrease condition.

3. The method of claim 2, further comprising discharging energy from the energy storage device through the inverter gate to the motor-generator to increase torque produced by the powertrain under the torque increase condition.

4. The method of claim 3, wherein increased torque produced in the powertrain prevents lugging of the internal combustion engine.

5. The method of claim 3, further comprising charging energy to the energy storage device from the motor-generator through the inverter gate to apply a torque load to the internal combustion engine under the torque decrease condition.

6. The method of claim 5, wherein applying the torque load to the internal combustion engine prevents an overspeed condition of the internal combustion engine.

7. The method of claim 1, wherein the step of operating the inverter gate to accelerate the internal combustion engine comprises discharging energy from the energy storage device to the motor-generator to achieve the second engine speed.

8. The method of claim 7, further comprising charging the energy storage device from the motor-generator through the inverter gate at the second engine speed.

9. A powertrain for a machine comprising:

an internal combustion engine operable at a plurality of engine speeds;

a motor-generator physically coupled in series to the internal combustion engine, the motor-generator capable of operating as either a motor or a generator;

a powertrain load physically coupled in series to the motor-generator and the internal combustion engine;

an energy storage device electrically coupled to the motor-generator through an inverter gate; and

a controller communicating with the inverter gate, the controller programmed to register a change in the powertrain load and to determine if the change represents a torque change condition or a speed change condition, the controller further programmed to operate the inverter gate to maintain a first engine speed of the internal combustion engine under the torque change condition and to accelerate the internal combustion engine under the speed change condition.

10. The powertrain of claim 9, wherein the inverter gate discharges power from the energy storage device to the motor-generator during the torque change condition to increase torque transmitted in the powertrain.

11. The powertrain of claim 10, wherein the inverter gate charges power to the energy storage device from the motor-generator during the torque change condition to apply a torque load to the internal combustion engine.

12. The powertrain of claim 11, wherein the inverter gate discharges power from the energy storage device to the motor-generator during the speed change condition to accelerate the internal combustion engine to a second engine speed.

13. The powertrain of claim 12, wherein the inverter gate charges power to the energy storage device from the motor-generator once the internal combustion engine is at the second engine speed.

14. The powertrain of claim 9, wherein the energy storage device is selected from a group consisting of a capacitor and a battery.

15. The powertrain of claim 9, wherein the powertrain load is a hydraulic pump.