System and method for battery charging

Patent metadata

Field	Value
Publication number	US-10744892-B2
Application number	US-201715813772-A
Country	US
Kind code	B2
Filing date	Nov 15, 2017
Priority date	Nov 15, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

Methods and systems are provided for expediting charging of a battery before entry into a zero emissions zone. In one example, the battery is charged with a ratio of motor torque drawn from a first electric motor of an electric turbocharger and a second electric motor of an HEV driveline. The ratio is coordinated with adjustments to an exhaust waste-gate and an intake throttle so as to maintain operator torque demand and propel the vehicle while charging the battery.

First claim

The invention claimed is:

1. A method, comprising:
while propelling a hybrid vehicle using engine torque, based on input from a navigation system, responsive to actual or imminent entry of the hybrid vehicle into a low emissions geographic zone where vehicle propulsion using engine operation is not allowed and the hybrid vehicle is required to be operated in an electric mode,
providing an operator demanded torque by generating increased engine torque greater than the operator demanded torque to charge a battery while adjusting each of a turbocharger waste-gate opening, an amount of motor torque from a first electric motor coupled to a turbocharger shaft, and an amount of motor torque of a second electric motor coupled to a vehicle driveline, wherein at decreased engine speeds below a threshold, the first electric motor is operated to provide positive motor torque to the turbocharger shaft.

2. The method of claim 1 , further comprising selecting a ratio of motor torque of the first electric motor and second electric motor based on the operator demanded torque, the ratio of motor torque from the second electric motor increased as the operator demanded torque increases.

3. The method of claim 2 , further comprising, when the operator demanded torque increases above a threshold, charging the battery using negative motor torque from the second electric motor while propelling the vehicle using engine torque in excess of the operator demanded torque, the excess engine torque generated while providing positive motor torque from the first electric motor to the turbocharger shaft.

4. The method of claim 2 , wherein, as the ratio of motor torque from the first electric motor increases, the turbocharger waste-gate opening is reduced beyond a position based on the operator demanded torque.

5. The method of claim 2 , further comprising adjusting an intake throttle opening based on each of the turbocharger waste-gate opening, the operator demanded torque, and the amount of motor torque from the first electric motor.

6. The method of claim 2 , wherein the ratio of motor torque is further selected based on an amount and a rate of charge transfer to the battery required before entry into the low emissions geographic zone.

7. The method of claim 6 , wherein charging includes a threshold state of charge, the threshold state of charge based on a duration and a distance of vehicle operation until and within the low emissions geographic zone, wherein a rate of charge transfer during charging the battery via the first electric motor and the second electric motor is higher than a rate of charge transfer to the battery during regenerative braking.

8. The method of claim 2 , wherein at increased engine speeds above the threshold, the first electric motor is operated to provide negative motor torque to the turbocharger shaft.

9. The method of claim 8 , further including:
while operating in a low engine speed-load condition, selecting the second electric motor for charging the battery while maintaining wheel torque via an engine with the first electric motor disabled;
while operating in a first high engine speed-load condition, selecting each of the first and the second electric motors for charging the battery while maintaining wheel torque via the engine; and
while operating in a second high engine speed-load condition, higher than the first high engine speed-load condition, selecting the first electric motor for charging the battery while maintaining wheel torque via the engine with the second electric motor disabled.

10. The method of claim 9 , further comprising, while operating in the first high engine speed-load condition, adjusting a split ratio of motor torque provided by the first electric motor relative to motor torque provided by the second electric motor for charging the battery based on one or more of boost pressure, a temperature of the first electric motor and the second electric motor relative to corresponding temperature thresholds, and a motor speed of the first electric motor and the second electric motor relative to corresponding speed thresholds.

11. A method, comprising:
while propelling a hybrid vehicle using engine torque, responsive to actual or imminent entry of the hybrid vehicle into a low emissions zone where vehicle propulsion using engine operation is not allowed and the hybrid vehicle is required to be operated in an electric mode,
providing an operator demanded torque by adjusting a waste-gate opening while charging a battery using a controlled ratio of motor torque from a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, wherein the ratio of motor torque is further selected based on an amount and a rate of charge transfer to the battery required before entry into the low emissions zone.

12. The method of claim 11 , further comprising selecting the ratio of motor torque based on the operator demanded torque, the ratio of motor torque from the second electric motor increased as the operator demanded torque increases.

13. The method of claim 12 , further comprising, when the operator demanded torque increases above a threshold, charging the battery using negative motor torque from the second electric motor while propelling the vehicle using engine torque in excess of the operator demanded torque, the excess engine torque generated while providing positive motor torque from the first electric motor to the turbocharger shaft.

14. The method of claim 12 , wherein, as the ratio of motor torque from the first electric motor increases, the waste-gate opening is reduced beyond a position based on the operator demanded torque.

15. The method of claim 12 , further comprising adjusting an intake throttle opening based on each of the waste-gate opening, the operator demanded torque, and the motor torque from the first electric motor.

16. A method, comprising:
while propelling a hybrid vehicle using engine torque, based on input from a navigation system, responsive to actual or imminent entry of the hybrid vehicle into a low emissions geographic zone where vehicle propulsion using engine operation is not allowed and the hybrid vehicle is required to be operated in an electric mode,
providing an operator demanded torque by adjusting a waste-gate opening while charging a battery using a controlled ratio of motor torque from a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, wherein charging includes a threshold state of charge, the threshold state of charge based on a duration and a distance of vehicle operation until and within the low emissions geographic zone, wherein a rate of charge transfer during charging the battery via the first electric motor and the second electric motor is higher than a rate of charge transfer to the battery during regenerative braking.

17. The method of claim 16 , further comprising selecting the ratio of motor torque based on engine speed.

18. The method of claim 17 , wherein the selecting includes:
while operating in a low engine speed-load condition, selecting the second electric motor for charging the battery while maintaining wheel torque via an engine with the first electric motor disabled;
while operating in a first high engine speed-load condition, selecting each of the first and the second electric motors for charging the battery while maintaining wheel torque via the engine; and
while operating in a second high engine speed-load condition, higher than the first high engine speed-load condition, selecting th

Assignees

• Ford Global Tech Llc

Inventors

• Bell David
• Buckland Julia Helen
• Kelly Tyler
• Stolzenfeld Timothy
• Xiao Baitao

Classifications

• Y02T10/62

  Hybrid vehicles · CPC title

• Y02T90/14

  Plug-in electric vehicles · CPC title

• B60L2240/441

  Speed · CPC title

• B60L7/10

  Dynamic electric regenerative braking (B60L7/22 takes precedence) · CPC title

• B60L50/16

  with provision for separate direct mechanical propulsion · CPC title