Power supply circuit for a motor vehicle electric system

• US 20060137918A1
• Filed: 12/13/2003
• Published: 06/29/2006
• Est. Priority Date: 02/07/2003
• Status: Abandoned Application

• Current Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Kronewitter, Matthias, Heni, Anton, Heni, Irmgard, Dinser, Wolfgang
• Application Number:
  US10/544,789
• Publication Number:
  US 20060137918A1
• Time in Patent Office: Days
• US Class Current: 180/65.100
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• 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

The present invention discloses a power supply circuit for a motor vehicle electric system having a starter generator (1), a power electronics system (LE), at least one battery (B), at least one dynamic energy accumulator (3) and a DC/DC converter (2). The power supply circuit has a first connection branch which is provided with the DC/DC converter (2) and is connected to a terminal of the dynamic energy accumulator (3) and a second connection branch which is connected to a terminal of the battery (B). Both connection branches can be disconnected from the starter generator (1) by means of controllable switches (S1, S2). A control device (5) actuates the switches (S1, S2) in the first and second connection branches and the DC/DC converter (2) in response to a charge state of the battery (B) and of the energy accumulator (3) and an operating state of the motor vehicle in such a way that recuperation energy which is present in the energy accumulator (3) is stored, drive support is provided by energy from the energy accumulator (3) as soon as the latter is charged, and until then from the battery (B), and for a rapid start energy is used from the energy accumulator (3) and the battery is charged according to its charge state as required, and after a recuperation the vehicle electric system is fed via the battery (B).

Claims

1. A power supply circuit for a motor vehicle electric system having:

a starter generator (1),

a power electronics system (LE),

at least one battery (B),

at least one dynamic energy accumulator (3) and a DC/DC converter (2), wherein the starter generator (1) can be connected to the vehicle electric system via a first connection branch in which the DC/DC converter (2) is arranged, characterized in that the starter generator (1) can be connected to the vehicle electric system via a second connection branch,

wherein both the first and the second connection branches each have, at their side connected to the starter generator (1), a switch (S1, S2) by means of which the connection branch can be disconnected,

the battery (B) is connected on the vehicle electric system side between the second connection branch and ground,

the energy accumulator (3) is connected between the switch (S2) in the first connection branch and the DC/DC converter (2) between ground and the first connection branch, and

a control device (5) is formed which actuates switches (S1, S2) in the first and the second connection branches and the DC/DC converter (2) in response to a charge state of the battery (B) and of the energy accumulator (3) and an operating state of the motor vehicle in such a way that

recuperation energy which is present in the energy accumulator (3) is stored and recuperation energy which is present is optionally used to charge the battery (B) if the energy accumulator (3) is fully charged,

drive support is provided by energy from the energy accumulator (3) as soon as the energy accumulator (3) is charged after an initial start, and drive support is provided from the battery (B) up to this time,

for a rapid start energy is used from the energy accumulator (3),

the battery is charged according to its charge state as required, and

after a recuperation the vehicle electric system is fed via the battery (B).

2. The power supply circuit for a motor vehicle electric system as claimed in claim 1, characterized in that a monitoring device (4) is also formed which monitors the charge state of the battery (B) and of the energy accumulator (3) and transfers the monitoring result to the control device (5).

3. The power supply circuit for a motor vehicle electric system as claimed in claim 1, characterized in that the switches (S1, S2) are embodied as controllable semiconductor switches.

4. The power supply circuit for a motor vehicle as claimed in claim 1, characterized in that the dynamic energy accumulator (4) is embodied as a capacitor.

5. The power supply circuit for a motor vehicle as claimed in claim 4, characterized in that the capacitor is embodied as a supercap or ultracap.

6. The power supply circuit for a motor vehicle electric system as claimed in claim 2, characterized in that the switches (S1, S2) are controllable semiconductor switches.