WO2009035630A2

WO2009035630A2 - Boosting assist electric hybrid combination

Info

Publication number: WO2009035630A2
Application number: PCT/US2008/010610
Authority: WO
Inventors: John Shutty
Original assignee: Borgwarner Inc.
Priority date: 2007-09-12
Filing date: 2008-09-11
Publication date: 2009-03-19
Also published as: WO2009035630A3

Abstract

An electric hybrid system having an internal combustion engine and a electric motor where the electric hybrid system includes a boost device and at least one electric storage device. The boost device is operatively connected to the internal combustion engine. The at least one electric storage device is in operative electrical communication with the boost device and the electric motor for selectively providing power by way of a controller to the electric motor or the boost device. The controller selects the electric motor, the internal combustion engine or boost assist and internal combination engine combinations for powering of a vehicle or other machine based on predetermined operator demand conditions.

Description

BOOSTING ASSIST ELECTRIC HYBRID COMBINATION

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a PCT International Application of United States Provisional Patent Application No. 60/993,432 filed on September 12, 2007. The disclosure of the above application is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the use of electric energy in a hybrid electric/internal combustion engine system.

BACKGROUND OF THE INVENTION

Due to regulations and customer demands it is ideal to improve fuel economy and reduce emissions produced by internal combustion engines. One way of increasing the efficiency of the internal combustion engine is to include an electric power plant which assists the engine. While useable hybrid vehicles are manufactured today, there remains a need to improve the storage and use of power in both the electrical and internal combustion engine power plants. The goal in any hybrid system is efficient storage and use of power.

Efficient storage and use of power, allows smaller IC engines to be utilized.

This provides advantages in both fuel economy and weight.

Therefore, it is desirable to develop an electric energy use system which advantageously uses electric power for maximizing efficient use of same when powering a vehicle or other hybrid powered machine.

SUMMARY OF THE INVENTION

The present invention relates to a method of using electric energy in an electric hybrid system having an internal combustion (hereinafter "(IC)") engine and an electric motor. The internal combustion engine of the electric hybrid system includes an electric powered boost device and at least one electrical storage device. The boost device is operatively connected to the IC engine for improving power output of the IC engine. The at least one electrical storage device is in operative electrical communication with the boost device and the hybrid system for selectively providing power to at least one of the boost device and the electric motor under predetermined conditions.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a schematic view of an electric hybrid system having a boost device in accordance with an embodiment of the present invention;

Figure 2 is a schematic view of an electric hybrid system having a boost device in series with a turbocharger assembly in accordance with an embodiment of the present invention;

Figure 3 is a schematic view of an electric hybrid system having a boost device in parallel with a turbocharger assembly in accordance with an embodiment of the present invention; and

Figure 4 is a flow chart of a method for controlling an electric hybrid system in accordance with an embodiment of the present hybrid power plant invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Provided in the present invention is a method for use of electrical energy in an electrical hybrid system. The method comprises the steps of: providing an electric hybrid system, determining whether electric energy is stored and at what level, and based on operational conditions, apportioning the energy where it is most efficient for performance of the vehicle.

In the method of the present invention, referring to Figures 1-3, an electric hybrid system is provided which is generally shown at 10. The electric hybrid system 10 has a hybrid power plant generally indicated at 12 with an electric motor 13 portion. Hybrid power plant 12 includes an electric motor portion and an IC engine. A boost assembly generally indicated at 14 is operatively connected to the IC engine of the hybrid power plant 12. The boost assembly 14 includes a boost device generally indicated at 16. The hybrid system 10 also includes at least one electric storage system 18. The electric storage system 18 is in operative electric communication with the boost device 16 and the electric motor of hybrid power plant 12 for selectively providing power to the boost device 16 of the IC engine, the electric motor, or a combination thereof under predetermined conditions. A controller 17 is used for monitoring operator demands along with the electrical energy stored in the electric storage system 18 and controlling where electric energy is used during operation. By way of explanation and not limitation, the electric storage system 18 is charged from: the IC engine during operation; a transmission assembly 13 (shown in phantom); a braking assembly 15 (shown in phantom) under braking conditions, or combinations of these. This transfer of energy may include hydraulic, electrical or mechanical links. By way of explanation and not limitation, the boost device 16 includes a motor 19 coupled to a compressor 21 for rotating the compressor 21 in response to electric energy from the electric storage system 18 through switches 24 and 38. Thus, as electric current flows from the electric storage system 18 to the motor 19, the motor 19 rotates which causes the compressor 21 to rotate. The compressor 21 compresses gaseous fluid which ultimately flows to the IC engine for improving power and performance of the IC engine, as described in greater detail below. - A -

As shown in Figure 1 , the electric storage system 18 includes an alternator or generator 20 or the like. The alternator or generator 20 is powered by the IC engine, by way of a conventional belt, chain drive or gear drive or the like. Thus, the alternator 20 causes current to flow to the electric motor of hybrid power plant 12, the motor 19 of boost device 16 or to the battery 22, or a combination thereof under predetermined conditions. The electrical energy is stored in battery 22. Alternatively, a capacitor 23 can be used to store energy either alone or in conjunction with the battery 22. The electric storage system 18 includes a switch 24 which controls the flow of electric current into and out of the battery 22. Thus, if the switch 24 is closed and switch 38 is in the open position in a disconnect mode, such that the circuit is not powering the motor 19 or the hybrid power plant 12, the alternator or generator 20 charges the battery 22 or capacitor 23. Additionally, if the switch 24 is closed, the switch 38 may be used for discharging the current to power the electric motor of the hybrid power plant of the vehicle, the boost device 16, or a combination thereof. Switch 38 is a three-way switch which can be selected to power the motor 19, the electric motor in the power plant, a combination thereof or to disconnect power to both. An alternate embodiment shown in Figure 2 includes a turbocharger assembly generally indicated at 26 which has at least a turbine 28 and a compressor 30. The turbine 28 and compressor 30 are moveably coupled to one another. The compressor 30 is in operative fluid communication with an intake 32 of the IC engine. The boost device 16 is upstream of and in series with the compressor 30. It should be appreciated that the boost device 16 can also be plumbed out of the main stream flow path but in series with the compressor 30, and alternatively includes a valve so that gaseous fluid can flow through the boost device 16, directly to the intake 32, or a combination thereof. In an alternate embodiment, the boost device 16 instead of being a separate device, is a motor 19a attached to the turbocharger drive shaft. In this embodiment, motor 19a powers the compressor of the turbocharger to provide boost to the IC engine. This uses an existing compressor on the turbocharger shaft to improve IC engine performance. The same control system is used but modified to work for driving the motor 19a.

A bypass valve 25 is provided. The bypass valve 25 is open when boost device 16 is not in operation and the engine is operating under high load conditions. During boost assist the bypass valve 25 is selected to be closed or partially closed.

Alternatively, as shown in Figure 3, the boost device 16 can be in parallel with the compressor 30, such that the boost device 16 is in operative fluid communication with the intake 32 and the gaseous fluid that passes through the boost device 16 bypasses the compressor 30. A bypass channel, generally indicated at 34, includes a three-way valve 36 in order to control the flow of gaseous fluid to the boost device 16 and the compressor 30.

The three-way valve 36 is operated to block off flow to the compressor 30 but allow flow from the booster into the intake 32. This prevents back flow into the compressor 30 and ultimately out the air filter of the engine, if the booster is being used without the turbocharger. Alternatively, the three-way valve 36 is actuated to stop reverse airflow to the booster and out through the air filter. The three-way valve 36 is also positionable to allow airflow from both the compressor 30 and the booster into the intake 32 when both are operational.

The electric storage system 18 flows current to the electric motor of hybrid power plant 12, the boost device 16, or a combination thereof. As set forth above, a three-way switch 38 controls the flow of current from the electric storage device 18 to the electric motor of hybrid power plant 12, boost device 16, or combination thereof. It should be appreciated that the switch 38, in an alternate embodiment, is a variable switch which can be used to modulate the power or flow of current from the battery 22 to the hybrid power plant 12 and/or boost device 16 for providing adjustments to the level of performance. In reference to Figure 4, a method as used in a controller 17 for controlling the electric hybrid system 10 having an IC engine is generally shown at 40. At decision box 42 it is determined if the electric energy in the electric storage system 18 is greater than or equal to a predetermined minimum electric motor limit. If there is a predetermined minimum which the controller 17 determines allows use of the electric motor, the method 40 proceeds to decision box 44 and the electric motor is used for powering the vehicle in high demand or start up conditions. If the energy level in the electric storage system 18 is below the minimum storage value, then the method 40 proceeds to decision box 46. In decision box 46 the controller 17 assesses whether the stored electric energy is greater than or equal to the predetermined minimum which allows at least one, but preferably many, boost operating cycles. If this minimum is met the controller 17 at box 48 directs electric power from the electric storage device battery 22 or capacitor 23 to drive the IC engine booster for improving performance when operation demands. Any ,of the minimum storage values discussed above can be a predetermined value that is not necessarily a value when the electric storage system 18 does not have any energy, but instead can be a predetermined value when the electric storage system 18 will not perform as desired or when conservation of electric energy is desired.

The predetermined values may be preset values based on known vehicle weight, operating conditions and vehicle parameters. It is also within the scope of the present invention that the predetermined minimums may be modified, adjusted or recalculated during operation based on operating conditions such as: learned operator tendencies or inputs, environmental operating factors, such as hilly conditions or city versus highway driving or even sensed changes in vehicle weight.

If in decision box 46 it is determined that the energy level in the electric storage system 18 is below the required minimum storage value for driving the booster, the method 40 proceeds to decision box 50 and the internal combustion engine is used to drive the alternator or generator 20 which drives the motor 19 of the boost device 16 for improving engine performance. As an example of a method for recharging the electric system, the following is given. It is determined if the IC engine is operating under low energy demand conditions. First, by way explanation and not limitation, the IC engine operates under low energy demand conditions when the IC engine is idling, operating under low load steady state conditions, or the like. If it is determined that the IC engine is operating under low energy demand conditions, the electric storage device is charged. The electric storage system 18 is charged when the IC engine is operating under low energy demand conditions because the energy that would be used to charge the energy storage device is not being required by the operator such that energy can be provided without loss of performance to the operator. By way of explanation and not limitation, the electric storage system 18 can be charged by the IC engine, during braking by the transmission, brake system, or the like. Thus, the electric hybrid system 10 stores energy that the IC engine produces which is not otherwise used and uses it at other times to operate the hybrid power plant 12 more efficiently. When the electric storage system 18 is being charged, the alternator or generator 20 is using IC engine power to charge the battery 22 or the capacitor 23.

If it is determined that the IC engine is not operating under low energy demand conditions, it is determined whether the IC engine is operating under acceleration conditions. By way of explanation and not limitation, the IC engine is operating under acceleration conditions when the vehicle is accelerating, the hybrid power plant 12 RPMs are increasing, or the like. If it is determined that the hybrid power plant 12 is operating under acceleration conditions, the electric storage system 18 provides power to the electric motor of hybrid power plant 12 as required.

By way of explanation and not limitation, the IC engine is operating under high energy demand conditions when the IC engine must produce a greater amount of power than that required under normal acceleration conditions where IC boost is desired. This value can be a predetermined value based upon the operation of the vehicle or a sensed condition based on user input. If it is determined that the IC engine is operating under high energy demand conditions, the battery 22 provides power to the boost device 16 of the IC engine. When boost device 16 provides power to the IC engine, the electric storage system 18 powers the motor 19 of boost device 16 with electric current, and the boost device provides additional compressed gaseous fluid so that the IC engine can provide the necessary power more efficiently when compared to if the boost device 16 did not provide additional power to the IC engine.

Thus, in operation the electric power management system of the present invention preferentially uses powering of the electric motor for launch of the vehicle. When the electric power reserve is depleted to a predetermined level from repeated launch of vehicle using the electric motor, and there is a lack of sufficient opportunities for replenishing, an electric power reserve mode is used to facilitate conservation of the remaining electric power. In this mode, a fraction of the normal electric power, which would normally be directed to the electric motor of the power plant of the hybrid for start up, is directed to the motor for powering the boost device 16 of the IC engine. The boosted IC engine is then used for initial launch. This allows electric assist of the booster to be used for a number of additional launches even if no additional charging of the battery 22 occurs. There is also a fail safe mode if substantially all the electric reserves are depleted. In the fail safe mode, the alternator or generator 20 is used for powering the booster. While this mode is not preferred, it still provides improved performance, but to the detriment of more fuel consumption.

This system allows for efficient use of electric power to provide the best performance for launch of the vehicle when sufficient minimum resources in the electric storage system 18, for instance, greater than or equal to 50% capacity. If the stored electric power is less than the predetermined minimum, for instance, less than 50%, the system uses the next most efficient use of power which is using electric power to provide boost for the internal combustion engine and use the boosted engine for startups. This allows improved startup performance yet conserves stored electric energy since many more startups can be accomplished using less electric energy than using the electric motor power plant of the hybrid system.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

CLAIMS What is claimed is:

1. A method of using electric power in an operator controlled hybrid electric power system for a machine comprising: a) providing an electric motor coupled for powering a machine; a source of stored electric energy; an internal combustion engine having an electrical charging device; and an electrically operated booster for boosting power to said IC engine; which are operably coupled for driving a machine with electric power, internal combustion power, or both; b) providing a controller for selectively controlling electric energy use depending on sensed operator demands and sensed available electric resources; c) said controller selectively first using stored electric energy for operation of the electric motor if sufficient stored energy is available; d) said controller selectively secondarily using electric energy for boosting the internal combustion engine if stored electric energy is below a predetermined level in order to conserve electric energy; and e) said controller selectively using the electric charging device to power the booster during conditions of lack of sufficient stored electric energy for powering the electric motor or booster with stored energy.

2. The method of claim 1 , wherein using stored electric power for powering the electric motor is preferentially used during start up and high demand acceleration conditions.

3. The method of claim 1 , wherein the step of selectively secondarily using electric energy further comprises using a plurality of fractions of stored electric power, when the source of stored electric energy is below a predetermined electric storage level, for powering the booster while running the internal combustion engine.

4. The method of claim 3, wherein the internal combustion engine and the booster are used for powering of a vehicle during launches or other high demand conditions.

5. The method of claim 1 , wherein when said source of stored electrical energy is below a minimum which allows direct powering of the electric motor or the booster, the controller selects the electric charging device for powering the booster and directs the system to use the internal combustion engine during start up conditions.

6. The method of claim 6, wherein in step e the electric charging device powers the booster of the internal combustion engine during start up conditions, light demand conditions, and other conditions designated by the controller.

7. The method of claim 7, wherein the internal combustion engine is used for powering the recharging device.

8. The method of claim 1 , wherein the system is used in powering a vehicle.

9. The method of claim 1 wherein the source of stored electrical energy is replenished during braking, from the transmission or the internal combustion engine running the recharging device.

10. The method of claim 9 wherein the recharging device is an alternator or generator.

11. The method of claim 11 , wherein the levels of sufficient stored energy of step 2 and predetermined level of step d are selected and modified based on operating conditions.

12. An electric hybrid system for a vehicle having an internal combustion engine and an electric motor, said electric hybrid system comprising: an electric powered boost device operatively connected to said engine for providing boost to said engine; and an electric storage device in operative fluid communication with said boost device and said electric motor; and a controller for assessing stored electric power and operation demands and for selectively providing power to said boost device, said electric motor or requiring use of, said internal combustion engine, under predetermined conditions, and combinations thereof.

13. The electric hybrid system of claim 12, wherein when stored electric energy in the electric storage device is greater than a first predetermined level, the controller directs electric power to the electric motor upon predetermined operator high demand conditions.

14. The electric hybrid system of claim 12, wherein when stored electric energy in the electric storage device is less than said first predetermined value but greater than a second predetermined minimum, the controller directs electric power to the booster of the internal combustion engine and uses the internal combustion engine upon predetermined operator high demand conditions.

15. The electric hybrid system of claim 13, wherein said first predetermined level and a said second predetermined minimum are selected and modified based on operating conditions.

16. The electric hybrid system of claim 12 further comprising a electric charging device coupled for powering said booster; said controller using said pump for powering said booster when said electric storage is below said second predetermined minimum.

17. The electric hybrid system of claim 14, wherein said electric charger is powered by said internal combustion engine.

18. The electric hybrid system of claim 14, wherein the electric power remaining below said first predetermined level and above said second predetermined level includes enough electric energy for several applications of boost during high energy demand conditions.

19. The electric hybrid system of claim 12, wherein said electric storage device is charged when said engine is operating under low energy demand conditions by one of a group consisting of: said internal combustion engine; a transmission assembly; and a braking assembly.

20. The electric hybrid system of claim 12, wherein said electric storage is selected from the group consisting of: a battery, a capacitor and combinations thereof.

21. The electric hybrid system of claim 17, wherein the electric charger comprises an alternator or generator powered by the IC engine.

22. The electric hybrid system of claim 12 further comprising a turbocharger assembly having at least a turbine and a compressor moveably coupled to one another, wherein said compressor is in operative fluid communication with an intake of said engine.

23. The electric hybrid system of claim 21 , wherein said boost device is upstream of said compressor.

24. The electric hybrid system of claim 21 , wherein said boost device is in parallel with said compressor and in operative fluid communication with said intake of said engine

25. The electric hybrid system of claim 21 , wherein said boost device is operably connected to a shaft that moveably couples said compressor and said turbine in said turbocharger assembly.

26. The electric hybrid system of claim 11 , wherein said boost device is in direct operative fluid communication with an intake of said engine.

27. The electric hybrid system of claim 12, wherein said electric storage device provides power to said electric motor when said electric hybrid system is operating under acceleration conditions.

28. The electric hybrid system of claim 12, wherein said electric storage device provides power to said boost device when said engine is operating under high energy demand conditions and the storage capacity is below a first predetermined level and above a second predetermined level.