Process and apparatus for reducing nitrogen oxide emissions in genset systems

• US 20070262586A1
• Filed: 05/08/2007
• Published: 11/15/2007
• Est. Priority Date: 05/09/2006
• Status: Active Grant

• Current Assignee: GE Hybrid Technologies, LLC
• Original Assignee: Azure Dynamics Incorporated
• Inventors: Collins, Heidi, Bouchon, Nicolas, Bouvier, Mathieu
• Granted Patent: US 7,728,448 B2
• Time in Patent Office: Days
• US Class Current: 290/1.A
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: F02D 2250/36 Control for minimising NOx emissions
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A process and apparatus for reducing nitrogen oxide emissions in a genset comprising an engine and a generator and a shaft coupled to the engine and generator. The apparatus directs the generator to reduce load on the shaft while directing the engine to seek a steady state shaft speed for a desired energy transfer to the shaft when a shaft speed correction signal representing a shaft speed correction to reach the desired energy transfer meets a criterion.

Claims

1. An apparatus for reducing nitrogen oxide emissions in a genset comprising an engine and a generator and a shaft coupled to the engine and the generator, the apparatus comprising:

a generator controller operably configured to control power transfer between the generator and the shaft;

an engine controller operably configured to control energy transfer between the engine and the shaft;

a system controller responsive to a shaft speed correction (SSC) signal representing a shaft speed correction to reach a desired energy transfer to the shaft, for causing said generator controller to cause the generator to reduce load on the shaft while causing said engine controller to cause the engine to seek a steady state shaft speed associated with said desired energy transfer to the shaft, when said shaft speed correction (SSC) signal meets a criterion.

2. The apparatus of claim 1 wherein said system controller is operably configured to cause said generator controller to reduce load on the shaft while causing said engine controller to direct the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a value.

3. The apparatus of claim 1 wherein said system controller is operably configured to cause said generator controller to reduce load on the shaft while causing said engine controller to direct the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a pre-defined value.

4. The apparatus of claim 1 wherein said engine controller is operably configured control the engine in response to an injection quantity command (IQCM) signal and said generator controller is operably configured to control the generator in response to an energy transfer command (ETCM) signal and wherein said system controller is operable to produce said injection quantity command (IQCM) signal and said energy transfer command (ETCM) signal, in response to:

an energy transfer setpoint (ETS) signal representing an energy transfer setpoint; and

said shaft speed correction signal, wherein said shaft speed correction signal represents a difference between a shaft speed and a shaft speed setpoint associated with said energy transfer setpoint.

5. The apparatus of claim 4 wherein said system controller includes a processor operably configured to produce said generator shaft speed correction (SSC) signal in response to a shaft speed setpoint (SSS) signal representing a shaft speed for said energy transfer setpoint and in response to a shaft speed (SS) signal representing a shaft speed.

6. The apparatus of claim 5 wherein said processor is operably configured to produce said shaft speed setpoint (SSS) signal.

7. The apparatus of claim 6 further comprising a lookup table and wherein said processor is operably configured to find a shaft speed setpoint (SSS) associated with said energy transfer setpoint (ETS) in said lookup table.

8. The apparatus of claim 1 wherein said system controller comprises a processor operably configured to produce a steady state injection quantity (SSIQ) signal in response to said energy transfer setpoint (ETS) signal and operably configured to produce an injection quantity correction (IQC) signal in response to said shaft speed correction (SSC) signal.

9. The apparatus of claim 8 further comprising a lookup table and wherein said processor is operably configured to find a steady state injection quantity (SSIQ) associated with said energy transfer setpoint (ETS) signal in said lookup table.

10. The apparatus of claim 8 wherein processor is operably configured to apply a steady state response function to said shaft speed correction (SSC) signal.

11. The apparatus of claim 10 wherein said processor is operably configured to apply an integral control function to said shaft speed correction (SSC) signal.

12. The apparatus of claim 1 wherein said system controller comprises a processor operably configured to produce an energy transfer correction (ETC) signal in response to said shaft speed correction (SSC) signal.

13. The apparatus of claim 12 wherein said processor is operably configured to apply a transient response function to said shaft speed correction (SSC) signal.

14. The apparatus of claim 13 wherein said processor is operably configured to apply at least one of a proportional control function, a derivative control function and a proportional/derivative control function to said shaft speed correction (SSC) signal.

18. The apparatus of claim 1 wherein the engine control means is operably configured control the engine in response to an injection quantity command (IQCM) signal and said generator control means is operably configured to control the generator in response to an energy transfer command (ETCM) signal and wherein said system control means is operable to produce said injection quantity command (IQCM) signal and said energy transfer command (ETCM) signal, in response to:

an energy transfer setpoint (ETS) signal representing an energy transfer setpoint; and

said shaft speed correction (SSC) signal, wherein said shaft speed correction signal represents a difference between a shaft speed of said shaft and a shaft speed setpoint associated with said energy transfer setpoint;

19. The apparatus of claim 18 wherein said system control means includes means for producing said generator shaft speed correction (SSC) signal in response to a shaft speed setpoint (SSS) signal representing a shaft speed for said energy transfer setpoint and in response to a shaft speed (SS) signal representing a current shaft speed.

20. The apparatus of claim 19 wherein said means for producing said shaft speed correction signal comprises means for producing said shaft speed setpoint (SSS) signal.

21. The apparatus of claim 20 wherein said means for producing said shaft speed setpoint signal comprises a lookup table and means for finding a shaft speed setpoint (SSS) associated with said energy transfer setpoint (ETS) in said lookup table.

15. An apparatus for reducing nitrogen oxide emissions in a genset comprising an engine and a generator and a shaft coupled to the engine and generator, the apparatus comprising:

generator control means for controlling power transfer between the generator and the shaft;

engine control means for controlling energy transfer between the engine and the shaft;

system control means responsive to a shaft speed correction (SSC) signal representing a shaft speed correction to reach a desired energy transfer to the shaft, for causing said generator control means to cause the generator to reduce load on the shaft while causing said engine control means to cause the engine to seek a steady state shaft speed associated with said desired energy transfer to the shaft, when said shaft speed correction (SCC) signal meets a criterion.

16. The apparatus of claim 15 wherein said system control means is operably configured to cause said generator control means to reduce load on the shaft while causing the engine control means to direct the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a value.

17. The apparatus of claim 15 wherein said system control means is operably configured to cause said generator control means to reduce load on the shaft while causing the engine control means to direct the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a pre-defined value.

22. The apparatus of claim 15 wherein said means for producing said injection quantity command signal comprises means for producing a steady state injection quantity (SSIQ) signal in response to said energy transfer setpoint (ETS) signal and means for producing an injection quantity correction (IQC) signal in response to said shaft speed correction (SSC) signal.

23. The apparatus of claim 22 wherein said means for producing said steady state injection quantity signal comprises a lookup table and means for finding a steady state injection quantity (SSIQ) associated with said energy transfer setpoint (ETS) signal in said lookup table.

24. The apparatus of claim 22 wherein said means for producing said injection quantity correction (IQC) signal comprises means for applying a steady state response function to said shaft speed correction (SSC) signal.

25. The apparatus of claim 24 wherein said means for applying said steady state response function comprises means for applying an integral control function to said shaft speed correction (SSC) signal.

26. The apparatus of claim 15 wherein said means for producing said energy transfer command signal comprises means for producing an energy transfer correction (ETC) signal in response to said shaft speed correction (SSC) signal.

27. The apparatus of claim 26 wherein said means for producing said energy transfer correction signal comprises means for applying a transient response function to said shaft speed correction (SSC) signal.

28. The apparatus of claim 27 wherein said means for applying said transient response function apparatus comprises means for applying at least one of a proportional control function, a derivative control function and a proportional derivative control function to said shaft speed correction (SSC) signal.

29. A process for reducing nitrogen oxide emissions in a genset comprising an engine and a generator and a shaft coupled to the engine and generator, the process comprising:

causing the generator to reduce load on the shaft while causing the engine to seek a steady state shaft speed for a desired energy transfer to the shaft when a shaft speed correction (SSC) signal representing a shaft speed correction to reach said desired energy transfer meets a criterion.

30. The process of claim 29 wherein causing comprises causing the generator to reduce load on the shaft while causing the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a value.

31. The process of claim 29 wherein causing comprises causing the generator to reduce load on the shaft while causing the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal exceeds a pre-defined value.

32. The process of claim 29 wherein the genset further comprises an engine controller operable to control the engine in response to an injection quantity command (IQCM) signal and a generator controller operable to control the generator in response to an energy transfer command (ETCM) signal and wherein causing comprises producing said injection quantity command signal and said energy transfer command (ETCM) signal, in response to:

an energy transfer setpoint (ETS) signal representing an energy transfer setpoint; and

said shaft speed correction (SSC) signal, wherein said shaft speed correction (SSC) signal represents a difference between a shaft speed of said shaft and a shaft speed setpoint associated with said energy transfer setpoint;

such that said energy transfer command signal causes the generator to reduce load on the shaft while said injection quantity signal causes the engine to seek said steady state shaft speed when said shaft speed correction signal meets a criterion.

33. The process of claim 32 wherein said criterion comprises a shaft speed threshold value such that said energy transfer command (ETCM) signal causes the generator to reduce load on the shaft while said injection quantity signal directs the engine to seek said steady state shaft speed when said shaft speed correction (SSC) signal reaches said shaft speed threshold value.

34. The process of claim 33 further comprising producing said generator shaft speed correction (SSC) signal in response to a shaft speed setpoint (SSS) signal representing a shaft speed for said energy transfer setpoint (ETS) and in response to a shaft speed setpoint (SSS) signal representing said shaft speed.

35. The process of claim 34 wherein producing said shaft speed correction (SSC) signal comprises producing said shaft speed setpoint (SSS) signal.

36. The process of claim 35 wherein producing said shaft speed setpoint (SSS) signal comprises finding said shaft speed associated with said energy transfer setpoint (ETS) in a lookup table.

37. The process of claim 29 wherein producing said injection quantity command signal comprises producing a steady state injection quantity (SSIQ) signal in response to said energy transfer setpoint (ETS) signal and producing an injection quantity correction (IQC) signal in response to said shaft speed correction (SSC) signal.

38. The process of claim 37 wherein producing said steady state injection quantity (SSIQ) signal comprises finding a steady state injection quantity (SSIQ) associated with said energy transfer setpoint (ETS) signal in a lookup table.

39. The process of claim 37 wherein producing said injection quantity correction (IQC) signal comprises applying a steady state response function to said shaft speed correction (SSC) signal.

40. The process of claim 39 wherein applying said steady state response function comprises applying an integral control process to said shaft speed correction (SSC) signal.

41. The process of claim 29 wherein producing said energy transfer command (ETCM) signal comprises producing an energy transfer correction (ETC) signal in response to said shaft speed correction (SSC) signal.

42. The process of claim 41 wherein producing said energy transfer correction (ETC) signal comprises applying a transient response function to said shaft speed correction (SSC) signal.

43. The process of claim 42 wherein applying said transient response function comprises applying at least one of a proportional control function, a derivative control function and a proportional derivative control function to said shaft speed correction (SSC) signal.