Electrically drivable motor vehicle with two anti-parallel power branches

• US 8,952,651 B2
• Filed: 04/29/2010
• Issued: 02/10/2015
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler AG (Mercedes-Benz Group AG)
• Inventors: Herges, Peter, Hofmann, Michael, Huber, Joerg, Weigel, Dennis, Willikens, Axel
• Primary Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US13/318,052
• Publication Number:
  US 20120056477A1
• Time in Patent Office: 1,748 Days
• Field of Search: 320/104
• US Class Current: 320/104
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An electrically drivable motor vehicle with at least two parallel connectable vehicle batteries is provided with an electronic circuit arrangement. The electronic circuit arrangement includes a number of electronic load interrupter switches corresponding to the number of vehicle batteries, via which the vehicle batteries can be connected through individually or together to an electrical consumer. The load interrupter switches respectively comprise two power branches arranged anti-parallel to each other.

Claims

1. An electrically drivable motor vehicle, comprising:

at least two parallel connectable vehicle batteries; and

an electronic circuit arrangement comprising a number of electronic load interrupter switches corresponding to the at least two parallel connectable vehicle batteries, wherein the at least two parallel connectable vehicle batteries can be connected individually or jointly to an electrical consumer via the electronic circuit arrangement, wherein the load interrupter switches respectively comprise two power branches arranged anti-parallel to each other,

wherein at least one of the load interrupter switches comprises a third power branch arranged parallel to the two power branches arranged anti-parallel to each other,

wherein the two power branches arranged anti-parallel to each other respectively comprise an IGBT and a blocking diode, and the third power branch comprises a field effect transistor unit comprising at least one field effect transistor and a relay unit comprising at least one relay arranged in series with the at least one field effect transistor.

2. The electrically drivable motor vehicle according to claim 1, wherein the field effect transistor unit comprises a plurality of field effect transistors and the relay unit comprises a plurality of relays, wherein each relay is electrically conductively connectable via a connection to one of the at least two parallel connectable vehicle batteries, and each relay is electrically conductively connectable via a further connection to a connection of each field effect transistor, and wherein each field effect transistor is electrically conductively connectable via its further connection to the electrical consumer.

3. A method for operating a circuit arrangement with at least two electronic load interrupter switches for an electrically drivable motor vehicle, comprising:

connecting at least two electronic load interrupter switches to an electrical consumer in high load operation, wherein internal resistances of at least two vehicle batteries and the electrical consumer form a star connection,

wherein the at least two load interrupter switches include IGBTs that are respectively assigned to the at least two vehicle batteries, wherein a first one of the at least two vehicle batteries is a main battery and a second one of the at least two vehicle batteries is a subsidiary battery, and wherein for a period of time, the IGBTs of the load interrupter switch of the main battery are permanently connected through to the electrical consumer and the IGBTs of the load interrupter switch of the subsidiary battery are connected through to the electrical consumer in dependence upon requirements.

4. The method for operating a circuit arrangement according to claim 3, further comprising:

alternately connecting, in partial load operation, the individual vehicle batteries to the electrical consumer via corresponding load interrupter switches so that the at least two vehicle batteries are discharged evenly.

5. The method for operating a circuit arrangement according to claim 4, further comprising:

controlling a changeover between partial load operation and high load operation in dependence upon a difference in no-load voltages of the at least two vehicle batteries.

6. A method for operating a circuit arrangement with at least two electronic load interrupter switches for an electrically drivable motor vehicle, comprising:

connecting at least two electronic load interrupter switches to an electrical consumer in high load operation, wherein internal resistances of at least two vehicle batteries and the electrical consumer form a star connection, wherein the circuit arrangement includes a field effect transistor unit,

wherein for connection of the field effect transistor unit,

first relays of the field effect transistor unit are closed, and

subsequently a field effect transistor of the field effect transistor unit is connected, and

wherein for disconnection of the field effect transistor unit,

first the relays of the field effect transistor unit are opened, and

subsequently the field effect transistor of the field effect transistor unit is disconnected,

wherein the connection or disconnection of the field effect transistor unit is performed during a driving operation of the motor vehicle.

7. The method for operating a circuit arrangement according to claim 6, wherein the field effect transistor unit is connected as a reduction means for reducing the temperature of the load interrupter switch.

8. The method for operating a circuit arrangement according to claim 6, further comprising:

alternately connecting, in partial load operation, the individual vehicle batteries to the electrical consumer via corresponding load interrupter switches so that the at least two vehicle batteries are discharged evenly.

9. The method for operating a circuit arrangement according to claim 8, further comprising:

controlling a changeover between partial load operation and high load operation in dependence upon a difference in no-load voltages of the at least two vehicle batteries.