Battery system

• US 9,205,756 B2
• Filed: 12/19/2013
• Issued: 12/08/2015
• Est. Priority Date: 12/25/2012
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ito, Akira
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US14/134,535
• Publication Number:
  US 20140176079A1
• Time in Patent Office: 719 Days
• Field of Search: 320/104, 320/128, 320/138, 320/152, 307/43, 307/48, 307/65, 307/66, 307/80
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• 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 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

The controller calculates a first limit based on received information about the battery packs and the schedule for charging and discharging plan, and supplies the first limit which serves as a control command to a master battery management unit (BMU), a master BMU receives the first limit. The master BMU sets and distributes the second limit to each one of local battery management function blocks in the battery packs. As a result, each BMU receives the second limit respectively. Then, the each BMU supplies the third limit to a bidirectional power source circuit, respectively, based on failure information FAIL and capacity information SOC of the battery in the battery pack.

Claims

1. A battery system comprising:

a plurality of battery packs;

a DC line to which the battery packs are connected; and

a controller which sends control commands to the battery packs, wherein each one of the battery packs includes;

a battery;

a bidirectional power supply circuit which charges and discharges the battery; and

a battery management unit which detects failure causing information of the battery, including an over charge, an over discharge or an over temperature, before the system reaches a serious failure and state of charge of the battery, and wherein one battery pack selected from the battery packs has the battery management unit which has a central management function block to perform a master function, and wherein each one of remaining battery packs, which does not perform the master function, out of the battery packs has the battery management unit which is configured to receive the control command from the controller through the battery management unit for master function, and wherein the battery management unit for master function is configured to send battery pack information relating to the failure causing information of the plurality of the battery packs and the state of charge of the battery packs to the controller, and wherein the controller is configured to supply information relating to a first limit, which is the control command, to the battery management unit for master function based on the battery pack information received and control plan for the whole system controlled by the controller, and wherein the information relating to the first limit includes information for limiting magnitude of charging or discharging of the battery in the battery packs, and wherein the battery management unit for master function is configured to receive the information relating to the first limit and to distribute information relating to second limits to each one of local management function blocks in the battery packs based on the first limit, and wherein each one of the local management function blocks in the battery packs is configured to receive distribution of the information relating to the second limit and to supply information relating to a third limit to the bidirectional power supply circuit in corresponding one of the battery packs based on the failure causing information or state of charge of the battery of corresponding one of the battery packs.

2. The battery system in claim 1, wherein

the first limit is larger than each one of the second limits, and each one of the second limits is equal to or larger than corresponding one of the third limits.

3. The battery system in claim 1, wherein

the central management function block in the battery management unit for master function is configured to distribute information relating to the second limits by evenly dividing the first limit by a total number of the battery packs.

4. The battery system in claim 1, wherein

the central management function block in the battery management unit for master function is configured to distribute information relating to the second limits according to values of state of charge of the battery packs.

5. The battery system in claim 1, wherein

the local management function block in the battery management unit is configured to supply the third limit based on the failure causing information of the battery of corresponding one of the battery packs.

6. The battery system in claim 1, wherein

the local management function block in the battery management unit is configured to calculate a charge limit and a discharge limit based on temperature and voltage in the battery, and wherein

the local management function block in the battery management unit is configured to supply the third limit which is adjusted within a range between the discharge limit and the charge limit.

7. The battery system in claim 6, wherein

the local management function block in the battery management unit is configured to adjust the third limit, wherein

the local management function block adjusts the third limit to 0 (zero) or a reduced value regardless of the second limit in response to detecting of at least one of an over charge, an over discharge and an over temperature in the battery in the battery pack, and wherein

the local management function block adjusts the third limit to the charge limit or the discharge limit regardless of the second limit when the second limit is not within the range between the discharge limit and the charge limit.

8. The battery system in claim 1, wherein

the controller has a scheduling function block which plans a charging and discharging schedule which minimizes power consumption from a commercial power based on information showing an estimation of power demand on loads at least including a DC load on the DC line, and the battery pack information relating to a state of charge of the battery packs 1 from the battery management unit for master function, and wherein

the controller sets the first limit based on the schedule planned and supplies the first limit to the battery management unit for master function.

9. The battery system in claim 8, further comprising

an AC line which is connected to the DC line via an AC/DC converter and is connected to the commercial power.

10. The battery system in claim 1, further comprising

a DC-side power source which is connected to the DC line.