Method and device for charging an energy store of a vehicle

• US 9,493,079 B2
• Filed: 08/28/2012
• Issued: 11/15/2016
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Stichowski, Torsten, Ott, Bernhard, Keller, Michael
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): Robbins, Jerry D
• Application Number:
  US14/342,180
• Publication Number:
  US 20140225567A1
• Time in Patent Office: 1,540 Days
• Field of Search: 320/109
• US Class Current: 1/1
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2240/525 Temperature of converter or components thereof
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2240/529 Current
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

When an energy store of a vehicle is charged via a charging device, a voltage (U) which is made available by the charging device, at a terminal of the vehicle, is measured. A charging current (I) which is made available by the charging device and which charges the energy store is regulated as a function of this voltage (U) in order to limit the power loss during charging.

Claims

1. A method for charging an energy store of a vehicle by a charging device, the method comprising:

measuring a charging voltage (U) provided by the charging device across a connection; and

regulating a charging current (I) provided by the charging device and which charges the energy store as a function of the charging voltage (U) of the charging device in order to limit the power loss during charging,

wherein the charging voltage (U) of the charging device across the connection is measured as an open-circuit voltage in the no-load state,

wherein the charging current (I) is regulated as a function of a difference (dU) between the open-circuit voltage and the charger voltage (U) of the charging device which is currently measured across the connection, and

wherein the charging current (I) is regulated to keep a ratio of the difference (dU) and the open-circuit voltage at a predetermined value.

2. The method of claim 1, wherein the charging voltage of the charging device, which is measured across the connection, is an AC voltage (U).

3. The method of claim 1, wherein measurement of the open-circuit voltage is repeated at predetermined time intervals to take into account fluctuations in the charging voltage (U) of the charging device which is provided by the charging device.

4. The method of claim 1, wherein the charging current (I) is adjusted to 0 when the charging voltage (U) of the charging device, which is measured across the connection, falls below a predetermined voltage threshold value.

5. The method of claim 1, the method further comprising:

generating a current pulse of the charging current (I);

detecting a profile of the charging voltage (U) of the charging device across the connection as the current pulse flows;

determining a line resistance as a function of the profile of the charging voltage (U) of the charging device and as a function of the current pulse; and

regulating the charging current (I) as a function of the line resistance.

8. The device of claim 7, wherein the device carries out the method of claim 1.

6. A method for charging an energy store of a vehicle, the method comprising:

determining a power loss during charging of the energy store; and

establishing a charging current (I) during charging of the energy store as a function of the power loss,

wherein a charging voltage (U) of a charging device across a connection with the energy store, is measured as an open-circuit voltage in the no-load state,

wherein the charging current (I) is regulated as a function of a difference (dU) between the open-circuit voltage and the charging voltage (U) of the charging device which is currently measured across the connection, and

wherein the charging current (I) is regulated to keep a ratio of the difference (dU) and the open-circuit voltage at a predetermined value.

7. A device for charging an energy store of a vehicle by a charging device;

the device comprising;

a controller;

a voltmeter; and

a current regulator,

wherein the voltmeter measures a charging voltage (U) provided by the charging device across a connection of the vehicle,

wherein the controller and the current regulator regulate a charging current which is provided by the charging device and charges the energy store as a function of the measured charging voltage (U) provided by the charging device to limit a power loss during charging,

wherein the charging voltage (U) provided by the charging device across a connection, is measured as an open-circuit voltage in the no-load state,

wherein a charging current (I) is regulated as a function of a difference (dU) between the open-circuit voltage and the charging voltage (U) provided by the charging device which is currently measured across the connection, and

wherein the charging current (I) is regulated to keep a ratio of the difference (dU) and the open-circuit voltage at a predetermined value.

9. A vehicle comprising a device as claimed in claim 7.

10. A device for charging an energy store of a vehicle, the device comprising:

a controller; and

a current regulator,

wherein the device determines a power loss during charging of the energy store by the controller, and establishes a charging current (I) during charging of the energy store as a function of the power loss using the controller and the current regulator,

wherein a charging voltage (U) provided by the charging device across a connection, is measured as an open-circuit voltage in the no-load state,

wherein the charging current (I) is regulated as a function of a difference (dU) between the open-circuit voltage and the charging voltage (U) of the charging device which is currently measured across the connection, and

wherein the charging current (I) is regulated to keep a ratio of the difference (dU) and the open-circuit voltage at a predetermined value.