Battery system for vehicle, on-vehicle battery module, and cell controller

• US 8,401,728 B2
• Filed: 01/19/2012
• Issued: 03/19/2013
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd. (Hitachi, Ltd.)
• Inventors: Kubo, Kenji, Kudo, Akihiko, Kikuchi, Mutsumi, Emori, Akihiko
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US13/353,906
• Publication Number:
  US 20120133370A1
• Time in Patent Office: 425 Days
• Field of Search: None
• US Class Current: 701/29.1
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/388 involving voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A battery system for vehicle comprises a battery unit that is constituted with a plurality of serially connected cell groups each include a plurality of serially connected battery cells, integrated circuits that are each disposed in correspondence to one of the cell groups of the battery unit and each measure terminal voltages at the battery cells in the corresponding cell group, and a signal transmission path through which one of the integrated circuits is connected to another one of the integrated circuits or to a circuit other than that of the integrated circuits.

Claims

1. A battery system, comprising:

a battery unit that is constituted with a plurality of cell groups, which are electrically connected in series, each include a plurality of battery cells, which are electrically connected in series;

integrated circuits that are each provided in correspondence to one of the cell groups of the battery unit and each input terminal voltages at the battery cells in the corresponding cell group to measure each of the terminal voltages at the battery cells, wherein;

the integrated circuits each comprise;

a selection circuit that selects terminal voltages of a battery cell that is a measurement target from among the terminal voltages at the individual battery cells in the corresponding cell group;

a differential amplifier that amplifies a difference of the selected terminal voltages to be outputted;

an analog/digital converter that converts an output of the differential amplifier to a digital value;

a pull-up circuit that is provided for diagnosing the selection circuit and pulls up a potential at an output terminal of the selection circuit to a high potential;

a pull-down circuit that is provided for diagnosing the selection circuit and pulls down a potential at an output terminal of the selection circuit to a low potential.

2. A battery system according to claim 1, wherein:

the integrated circuits each further comprise a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter.

3. A battery system according to claim 1, wherein:

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter.

4. A battery system according to claim 1, wherein:

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.

5. A battery system according to claim 1, wherein:

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter; and

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.

6. A battery system according to claim 1, wherein:

the integrated circuits each further comprise a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter; and

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter.

7. A battery system according to claim 1, wherein:

the integrated circuits each further comprise a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter;

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter; and

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.

8. An integrated circuit that is provided in correspondence to a cell group including a plurality of battery cells which are electrically connected in series, comprising:

a selection circuit that selects terminal voltages of a battery cell that is a measurement target from among the terminal voltages at the individual battery cells in the cell group;

a differential amplifier that amplifies a difference of the selected terminal voltages to be outputted;

an analog/digital converter that converts an output of the differential amplifier to a digital value;

a pull-up circuit that is provided for diagnosing the selection circuit and pulls up a potential at an output terminal of the selection circuit to a high potential;

a pull-down circuit that is provided for diagnosing the selection circuit and pulls down a potential at an output terminal of the selection circuit to a low potential.

9. An integrated circuit according to claim 8, further comprising:

a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter.

10. An integrated circuit according to claim 8, wherein:

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter.

11. An integrated circuit according to claim 8, wherein:

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.

12. An integrated circuit according to claim 8, wherein:

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter; and

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.

13. An integrated circuit according to claim 8, further comprising:

a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter, wherein;

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter.

14. An integrated circuit according to claim 8, further comprising:

a diagnosis circuit that diagnoses whether or not the selection circuit has an abnormality based upon an output of the selection circuit that is pulled up by the pull-up circuit and is input via the differential amplifier and the analog/digital converter or an output of the selection circuit that is pulled down by the pull-down circuit and is input via the differential amplifier and the analog/digital converter, wherein;

the pull-up circuit and the pull-down circuit operate in correspondence to a measurement period when the terminal voltages at one of the battery cells in the corresponding cell group are measured with the selection circuit, the differential amplifier and the analog/digital converter; and

the pull-up circuit and the pull-down circuit are provided for each of two output terminals of the selection circuit.