Method for state of charge compensation of a battery and method for charging a battery

• US 9,577,444 B2
• Filed: 09/18/2014
• Issued: 02/21/2017
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Inventors: Gleiter, Andreas, Wilhelm, Joerg Christoph, Korn, Christian
• Primary Examiner(s): DIAO, M BAYE
• Application Number:
  US14/489,872
• Publication Number:
  US 20150084595A1
• Time in Patent Office: 887 Days
• Field of Search: 320/127
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The disclosure relates to a method for state of charge compensation of a battery having a plurality of battery units. The method comprises the steps of calculating a depth of discharge of each battery unit after the battery units have been charged, calculating an available charge of each battery unit before the battery units are charged, calculating a state of charge compensation requirement value on the basis of the calculated depth of discharge and the calculated available charge for each battery unit, and discharging each battery unit on the basis of the calculated state of charge compensation requirement value. The disclosure also relates to a method for charging a battery which has a plurality of battery units. Also specified are a computer program and a battery management system set up to perform the method, and a battery and a motor vehicle having a drive system connected to such a battery.

Claims

1. A method for state of charge compensation of a battery having a plurality of battery units, the method comprising:

calculating, with a depth of discharge unit operatively connected to each battery unit, a depth of discharge of each battery unit after the plurality of battery units has been charged;

calculating, with an available charge unit operatively connected to each battery unit, an available charge of each battery unit before the plurality of battery units is charged;

calculating, with a state of charge unit operatively connected to the depth of discharge unit and the available charge unit, a state of charge compensation requirement value based on the calculated depth of discharge and the calculated available charge of each battery unit; and

discharging, with a discharge unit operatively connected to each battery unit, each battery unit based on the calculated state of charge compensation requirement value.

2. The method according to claim 1, the calculating of the depth of discharge with the depth of discharge unit further comprising:

calculating a state of charge of each battery unit;

calculating a battery unit with maximum state of charge; and

calculating a charge difference value of each battery unit with respect to the battery unit with maximum state of charge.

3. The method according to claim 2, the calculating of the depth of discharge with the depth of discharge unit further comprising:

calculating a charge current of the battery;

calculating an open terminal voltage of the battery; and

calculating the state of charge of each battery unit based on the calculated charge current and the calculated open terminal voltage.

4. The method according to claim 1, the calculating of the state of charge with the available charge unit further comprising:

calculating a state of charge of each battery unit;

calculating a battery unit with minimum state of charge; and

calculating a charge difference value of each battery unit with respect to the battery unit with minimum state of charge.

5. The method according to claim 4, the calculating of the state of charge with the available charge unit further comprising:

calculating a charge current of the battery;

calculating an open terminal voltage of the battery; and

calculating the state of charge of each battery unit based on the calculated charge current and the calculated open terminal voltage.

6. A battery management system of a battery having a plurality of battery units, the battery management system comprising:

a depth of discharge unit configured to calculate a depth of discharge of each battery unit after the plurality of battery units has been charged;

an available charge unit configured to calculate an available charge of each battery unit before the plurality of battery units is charged;

a state of charge unit configured to calculate a state of charge compensation requirement value based on the calculated depth of charge and the calculated available charge of each battery unit; and

a discharge unit configured to discharge each battery unit based on the calculated state of charge compensation requirement value.

7. A battery having a plurality of battery units and a battery management system according to claim 6.

8. A motor vehicle comprising:

a drive system; and

a battery comprising;

a plurality of battery units; and

a battery management system comprising;

a depth of discharge unit configured to calculate a depth of discharge of each battery unit after the plurality of battery units has been charged;

an available charge unit configured to calculate an available charge of each battery unit before the plurality of battery units is charged;

a state of charge unit configured to calculate a state of charge compensation requirement value based on the calculated depth of charge and the calculated available charge of each battery unit; and

a discharge unit configured to discharge each battery unit based on the calculated state of charge compensation requirement value.