Method for controlling the torque of a hybrid drive unit and hybrid drive unit

• US 20070278021A1
• Filed: 04/25/2007
• Published: 12/06/2007
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Pott, Ekkehard, Holz, Matthias, Zillmer, Michael, Prochazka, David
• Granted Patent: US 8,250,864 B2
• Time in Patent Office: Days
• US Class Current: 180/65.285
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2260/12 of combustion engines
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60Y 2400/435 Supercharger or turbochargers
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method is for controlling the torque of a hybrid drive unit, which includes a combustion engine and at least one electric machine capable of being operated alternatively as a motor or as a generator. The electric machine, when operated as a motor, is powered by an energy storage device and supplies a positive electric motor torque which together with a combustion engine torque of the combustion engine produces a total drive torque of the hybrid drive unit. A hybrid drive unit includes a respective torque control. In the event that a desired torque is greater than a consumption-optimized combustion engine maximum torque, the electric machine is operated as a motor having an electric motor torque. An electric motor maximum torque is specified as a function of at least one state parameter of the energy storage device.

Claims

1. A method for controlling torque of a hybrid drive unit including a combustion engine and at least one electric machine operable alternatively as a motor or a generator, comprising:

powering the electric machine by an energy storage device to operate the electric machine as a motor and supplying a positive electric motor torque together with a combustion engine torque of the combustion engine to produce a total drive torque of the hybrid drive unit; and

if a desired torque is greater than a consumption-optimized combustion engine maximum torque, operating the electric machine as a motor having an electric motor torque;

wherein an electric motor maximum torque is predetermined as a function of at least one state parameter of the energy storage device.

2. The method according to claim 1, wherein a maximum producible total drive torque of the hybrid drive unit, at least in one predetermined rotational speed range, matches a consumption-independent combustion engine maximum torque of the combustion engine.

3. The method according to claim 2, wherein the predetermined rotational speed range includes rotational speeds above 1,600 rpm.

4. The method according to claim 2, wherein the predetermined rotational speed range includes rotational speeds above 1,800 rpm.

5. The method according to claim 2, wherein the predetermined rotational speed range includes rotational speeds above 2,000 rpm.

6. The method according to claim 1, wherein the electric motor maximum torque is predetermined as a function of the at least one state parameter such that the electric motor maximum torque decreases with decreasing at least one of (a) charging and (b) discharging capacity of the energy storage device.

7. The method according to claim 1, wherein the at least one state parameter of the energy storage device includes at least one of (a) a charge state, (b) an aging state, (c) an energy storage device temperature and (d) a structure-borne noise excitation of the energy storage device.

8. The method according to claim 6, wherein the electric motor maximum torque lowers with at least one of (a) a decreasing charge state of the energy storage device, (b) an increasing aging state of the energy storage device, (c) in the event of one of (i) very high and (ii) very low energy storage device temperatures and (d) strong structure-borne noise excitation.

9. The method according to claim 1, wherein the combustion engine is operated having a combustion engine torque greater than the consumption-optimized combustion engine maximum torque if the desired torque is greater than a sum of the consumption-optimized combustion engine maximum torque and the electric motor maximum torque.

10. The method according to claim 9, further comprising adjusting at least one operating parameter of the combustion engine with respect to an efficiency-optimized setting to operate the combustion engine having a combustion engine torque greater than the consumption-optimized combustion engine maximum torque.

11. The method according to claim 10, wherein the at least one operating parameter of the combustion engine includes at least one of (a) ignition angle, (b) injection quantity, (c) injection point, (d) air ratio, (e) valve timing, (f) charge-influencing parameters and (g) a transmission ratio of a variable compressor.

12. A hybrid drive unit, comprising:

a combustion engine;

at least one electric machine configured to operate alternatively as a motor or as a generator;

an energy storage device configured to power the electric machine to operate the electric machine as a motor to supply a positive electric motor torque together with a combustion engine torque of the combustion engine to produce a total drive torque of the hybrid drive unit; and

a torque control device configured to operate the electric machine as a motor having an electric motor torque if a desired torque is greater than a consumption-optimized combustion engine torque;

wherein an electric motor maximum torque is a function of at least one parameter of the energy storage device.

13. The hybrid drive unit according to claim 12, wherein the combustion engine includes a compressed charge air supply device.

14. The hybrid drive unit according to claim 12, wherein the combustion engine includes at least one of (a) a turbocharger and (b) a compressor.

16. A torque control device, comprising:

an arrangement configured to perform a method for controlling torque of a hybrid drive unit including a combustion engine and at least one electric machine operable alternatively as a motor or a generator, the method including;

powering the electric machine by an energy storage device to operate the electric machine as a motor and supplying a positive electric motor torque together with a combustion engine torque of the combustion engine to produce a total drive torque of the hybrid drive unit; and

if a desired torque is greater than a consumption-optimized combustion engine maximum torque, operating the electric machine as a motor having an electric motor torque;

wherein an electric motor maximum torque is predetermined as a function of at least one state parameter of the energy storage device.