Automotive electrical system configuration using a two bus structure

• US 7,075,273 B2
• Filed: 08/24/2004
• Issued: 07/11/2006
• Est. Priority Date: 08/24/2004
• Status: Expired due to Fees

• Current Assignee: Temic Automotive of North America, Incorporated (Continental AG)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: O'Gorman, Patrick A., Stephens, Dennis L., Remboski, Donald J.
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US10/925,558
• Publication Number:
  US 20060043938A1
• Time in Patent Office: 686 Days
• Field of Search: 322/7, 322/26, 322/27, 322/28, 322/99, 290/40, 290/40.C, 290/40.F
• US Class Current: 322/28
• CPC Class Codes: B60Q 11/005 for lighting devices, e.g. indicating if lamps are burning or not
• CPC Class Codes: B60Q 2400/30 Daytime running lights [DRL], e.g. circuits or arrangements therefor
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 31/44 Testing lamps
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/102 for limiting effects of transients
• CPC Class Codes: H02P 9/105 for increasing the stability

Abstract

Disclosed herein are a variety of different electrical system topologies intended to mitigate the impact of large intermittent loads on a 12 volt vehicle power distribution system. In some embodiments the intermittent load is disconnected from the remainder of the system and the voltage supplied to this load is allowed to fluctuate. In other embodiments, the voltage to critical loads is regulated independently of the voltage supplied to the remainder of the system. The different topologies described can be grouped into three categories, each corresponding to a different solution technique. One approach is to regulate the voltage to the critical loads. A second approach is to isolate the intermittent load that causes the drop in system voltage. The third approach is to use a different type of alternator that has a faster response than the conventional Lundell wound field machine.

Claims

1. An automotive electrical system comprising:

a main bus;

a secondary bus;

a multidirectional electronic power converter connecting the main bus and the secondary bus;

an energy storage device connected to the secondary bus;

an electrical energy generating device connected to the main bus;

at least one critical load connected to one of the main bus and the secondary bus; and

at least one high current load connected to one of the main bus and the secondary bus wherein the high current load is connected to the bus not connected to the critical load;

wherein the multidirectional electronic power converter is configured to maintain a substantially constant voltage on the bus connected to the critical load in response to a voltage dip on the bus connected to the high current load due to a high current transient.

2. The automotive electrical system of claim 1 wherein the energy generating device is a switched reluctance generator and wherein the voltage regulator is a switched reluctance controller.

3. The automotive electrical system of claim 2 further comprising a feedback path connecting a voltage supplied to the critical load to a switched reluctance controller controlling the switched reluctance generator.

4. The automotive electrical system of claim 1 wherein the critical load is connected to the main bus and the high current load is connected to the secondary bus.

5. The automotive electrical system of claim 4 further comprising a smart junction box connected between the main bus and the critical load, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

6. The automotive electrical system of claim 4 further comprising a supercapacitor coupled to the main bus by a second multidirectional electronic power converter configured to deliver energy to the main bus in response to the voltage dip caused by the high current transient.

7. The automotive electrical system of claim 4 wherein the multidirectional electronic power converter is a bidirectional DC-DC converter.

8. The automotive electrical system of claim 7 further comprising a supercapacitor coupled to the main bus by a second bidirectional DC-DC converter configured to deliver energy to the main bus in response to the voltage dip caused by the high current transient.

9. The automotive electrical system of claim 4 wherein the multidirectional electronic power converter is a tri-directional DC-DC converter having a first input connected to the main bus, a second input connected to the secondary bus, and a third input connected to a supercapacitor.

10. The automotive electrical system of claim 9 further comprising a current sensor configured to measure output current of the energy generating device and input the current into a control circuit of the tri-directional DC-DC converter.

11. The automotive electrical system of claim 9 wherein the tri-directional DC-DC converter is interconnected with a voltage regulator configured to control the output voltage of the energy generating device.

12. The automotive electrical system of claim 10 wherein the tri-directional DC-DC converter is interconnected with a voltage regulator configured to control the output voltage of the energy generating device.

13. The automotive electrical system of claim 1 wherein the critical load is connected to the secondary bus and the high current load is connected to the main bus.

14. The automotive electrical system of claim 13 further comprising a smart junction box connected between the secondary bus and the critical load, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

15. The automotive electrical system of claim 13 further comprising a supercapacitor coupled to the main bus by a second multidirectional electronic power converter configured to deliver energy to the main bus in response to the voltage dip caused by the high current transient.

16. The automotive electrical system of claim 13 wherein the multidirectional electronic power converter is a bidirectional DC-DC converter.

17. The automotive electrical system of claim 16 further comprising a supercapacitor coupled to the main bus by a second bidirectional DC-DC converter configured to deliver energy to the main bus in response to the voltage dip caused by the high current transient.

18. The automotive electrical system of claim 1 wherein the high current load is interconnected with a voltage regulator configured to control the output voltage of the electrical energy generating device.

19. The automotive electrical system of claim 18 further comprising a boost converter coupled between the main bus and the critical load and configured to maintain sufficient input voltage to the critical load in response to a voltage dip on the main pus caused by the high current transient.

20. The automotive electrical system of claim 18 further comprising a smart junction box connected between the main bus and the critical load, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

21. The automotive electrical system of claim 19 further comprising a smart junction box connected between the main bus and the critical load, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

22. A method of providing electrical power in an automotive electrical system comprising:

generating electrical energy;

delivering the generated electrical energy to a first bus;

connecting a second bus to the first bus using a multidirectional DC-DC converter;

storing electrical energy in a battery connected the second bus;

connecting at least one critical load to one of the first bus and the second bus; and

connecting at least one high current load to one of the first bus and the second bus, wherein the high current load is connected to the bus not connected to the critical load;

wherein the multidirectional DC-DC converter is configured to maintain a substantially constant voltage on the bus connected to the critical load in response to a voltage dip on the bus connected to the high current load due to a high current transient.

23. The method of claim 22 further comprising controlling the at least one critical load using a smart junction box.

24. The method of claim 22 further comprising providing a feedback path between the high current load and a voltage regulator for controlling the step of generating electrical energy.

25. The method of claim 22 further comprising:

connecting at least one critical load to the main bus using an electronic boost converter, wherein the electronic boost converter is configured to increase voltage supplied to the critical load in response to a voltage dip on the main bus caused by a high current transient of the high current load.

26. An automotive electrical system comprising:

a main bus;

an energy storage device connected to the main bus;

a bidirectional DC-DC converter having a first input connected to the main bus and a second input connected to an electrical energy generating device;

at least one critical load connected to the main bus; and

at least one high current load connected to the second input of the bidirectional DC-DC converter;

wherein the bidirectional DC-DC converter is configured to maintain a substantially constant voltage on the main bus in response to a high current transient caused by the high current load and wherein the high current load is interconnected with a voltage regulator configured to control the output voltage of the electrical energy generating device.

27. The automotive electrical system of claim 26 further comprising a boost converter coupled between the main bus and the critical load and configured to maintain sufficient input voltage to the critical load in response to a voltage dip on the main bus caused by the high current transient.

28. The automotive electrical system of claim 26 further comprising a smart junction box connected between the main bus and the critical load, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

29. The automotive electrical system of claim 27 further comprising a smart junction box connected between the main bus and the boost converter, wherein the smart junction box includes a microcontroller for controlling one or more loads connected thereto.

30. The automotive electrical system of claim 26 wherein the electrical energy generating device is a switched reluctance generator and wherein the voltage regulator is a switched reluctance controller.

31. The automotive electrical system of claim 30 further comprising a feedback path connecting a voltage supplied to the critical load to a switched reluctance controller controlling the switched reluctance generator.

32. The automotive electrical system of claim 27 wherein the electrical energy generating device is a switched reluctance generator and wherein the voltage regulator is a switched reluctance controller.

33. The automotive electrical system of claim 32 further comprising a feedback path connecting a voltage supplied to the critical load to a switched reluctance controller controlling the switched reluctance generator.

34. The automotive electrical system of claim 28 wherein the electrical energy generating device is a switched reluctance generator.

35. The automotive electrical system of claim 34 further comprising a feedback path connecting a voltage supplied to the critical load to a switched reluctance controller controlling the switched reluctance generator.