System for supplying voltage to electrical loads of a motor vehicle

• US 8,324,754 B2
• Filed: 02/03/2009
• Issued: 12/04/2012
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Broesse, Andreas, Polenov, Dieter, Proebstle, Hartmut, Hafkemeyer, Marcus
• Primary Examiner(s): Barnie, Rexford N
• Assistant Examiner(s): Fauth, Justen
• Application Number:
  US12/364,794
• Publication Number:
  US 20100001581A1
• Time in Patent Office: 1,400 Days
• Field of Search: None
• US Class Current: 307/9.1
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A system is provided for supplying voltage to electrical loads in the onboard electrical system of a motor vehicle, in which system the onboard electrical system includes at least two onboard electrical system regions. The first onboard electrical system region has an electric generator, a vehicle battery, and one or more first electrical loads, and the second onboard electrical system region has a double-layer capacitor or a so-called supercap, and one or more second electrical loads. A blocking apparatus, in particular a semiconductor diode or a circuit breaker, is provided between the two onboard electrical system regions. The blocking apparatus permits current to flow from the first onboard electrical system region to the second onboard electrical system region and largely prevents current from flowing in reverse from the second onboard electrical system region to the first onboard electrical system region. The output voltage of the electrical generator is increased and the supercap is charged when a first threshold value of the electrical voltage is undershot in the second onboard electrical system region.

Claims

1. A system for supplying voltage to electrical loads in an onboard vehicle electrical system, the system comprising:

a first onboard electrical system region of the onboard vehicle electrical system, the first region having an electric generator, a vehicle battery, and one or more first electrical loads;

a second onboard electrical system region of the onboard vehicle electrical system, the second region having an energy accumulator and one or more second electrical loads;

a current blocking apparatus operatively configured between the first and second regions for permitting current to flow from the first region into the second region and largely preventing current from flowing in reverse from the second region into the first region; and

wherein an output voltage of the electric generator is raised and the energy accumulator in the second region is charged by the electric generator in the first region, as a result of and in response to, a first threshold value of the electric voltage being undershot in the second region.

2. The system according to claim 1, wherein the energy accumulator comprises a capacitor and the current blocking device comprises a semiconductor diode or a power switch.

3. The system according to claim 2, wherein at least one of a time duration and an increased amount of the electric voltage in the second region is a function of energy consumption of at least one of said one or more second electrical loads and a capacitance of the capacitor in the second region.

4. The system according to claim 3, wherein the time duration and/or the increased amount of the electric voltage in the second region is proportional to the energy consumption of the one or more second electrical loads and/or the capacitance of the capacitor.

5. The system according to claim 2, wherein, after operating the vehicle, the capacitor is separated from the second region and, during operation of the vehicle, the capacitor is recharged to a voltage of the onboard vehicle electrical system and then electrically coupled to the second region.

6. The system according to claim 5, wherein the capacitor is one of a double-layer capacitor and a supercap.

7. The system according to claim 5, further comprising a separate control/power unit operatively configured to precharge and/or couple or separate the capacitor to/from the onboard vehicle electrical system.

8. The system according to claim 7, wherein the separate control/power unit is operatively configured to diagnose the capacitor during precharging.

9. The system according to claim 8, wherein the diagnosis of the capacitor during precharging determines at least one of a capacitance and a resistance of the capacitor.

10. The system according to claim 2, wherein the capacitor is one of a double-layer capacitor and a supercap.

11. The system according to claim 1, wherein operation of the first electrical loads require an operating voltage in a first voltage range and operation of the second electrical loads require an operating voltage in a second voltage range, said second voltage range being narrower than said first voltage range.

12. The system according to claim 11, wherein the first electrical loads operating in the first voltage range are non-sensitive first electrical loads and are largely provided in the first region, and the second electrical loads operating in the second voltage range are sensitive electrical loads largely provided in the second region of the onboard vehicle electrical system.

13. The system according to claim 11, wherein a voltage range predominant in the first region during operation of the motor vehicle comprises a voltage range of approximately 10 to 16 volts, and a voltage range predominant in the second region during operation of the motor vehicle comprises a voltage range of approximately 11 to 13 volts.

14. The system according to claim 1, wherein a voltage range predominant in the first region during operation of the motor vehicle comprises a voltage range of approximately 10 to 16 volts, and a voltage range predominant in the second region during operation of the motor vehicle comprises a voltage range of approximately 11 to 13 volts.

15. The system according to claim 1, wherein the energy accumulator is a battery.