Battery System for Vehicle

• US 20120025769A1
• Filed: 02/18/2010
• Published: 02/02/2012
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd. (Hitachi, Ltd.)
• Inventors: Kikuchi, Mutsumi, Kudo, Akihiko, Aoshima, Yoshinori, Shibahara, Gosuke, Kubo, Kenji, Uemura, Yasuo
• Granted Patent: US 9,035,611 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• 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 50/50 using propulsion power supplied by batteries or fuel cells
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• 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: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• 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

A battery system for a vehicle is provided with discharge circuits (R1, 129A through 129D, 128A through 128D) that discharge battery cells (BC1 through BC4) via measurement lines of those battery cells (BC1 through BC4). A control circuit transmits to an integrated circuit (3A) a first discharge command that causes discharge of the odd numbered battery cells (BC1 and BC3) of a cell group (GB1), a first transmission command that causes transmission to the control circuit of the terminal voltages of only the odd numbered battery cells (BC1 and BC3) measured during execution of the first discharge command, a second discharge command that causes discharge of the even numbered battery cells (BC2 and BC4) of the cell group (GB1), and a second transmission command that causes transmission to the control circuit of the terminal voltages of only the even numbered battery cells (BC2 and BC4) measured during execution of the second discharge command; and, based on the these various terminal voltages transmitted from the integrated circuit (3A), the control circuit diagnoses abnormalities in the system that includes the battery cells, the measurement lines, and the discharge circuits.

Claims

1. A battery system for a vehicle, comprising:

a battery unit in which a plurality of cell groups are electrically connected in series, with a plurality of battery cells being electrically connected in series in each cell group;

integrated circuits provided for the cell groups respectively, each of which measures the terminal voltage of each battery cell included in its cell group via a measurement line, and outputs battery cell information; and

a control circuit that monitors states of the battery cells based on battery cell informations from the integrated circuits;

wherein each of the integrated circuits comprises a measurement circuit that measures respective terminal voltages of battery cells in its cell group, and discharge circuits provided for each battery cell, each of which discharges its battery cell via measurement lines for that battery cell;

and the control circuit transmits to each of the integrated circuits;

a first discharge command that causes odd numbered battery cells of its cell group to be discharged;

a first transmission command that causes terminal voltages of only the odd numbered battery cells, measured during execution of the first discharge command, to be sent to the control circuit;

a second discharge command that causes even numbered battery cells of its cell group to be discharged; and

a second transmission command that causes terminal voltages of only the even numbered battery cells, measured during execution of the second discharge command, to be sent to the control circuit;

and diagnoses abnormality of a system including the battery cells, the measurement lines, and the discharge circuits based on the terminal voltages sent from each of the integrated circuits.

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

each of the discharge circuits comprises a semiconductor switching element that performs ON/OFF of discharge, and a detection circuit that detects the switching state of the semiconductor switching element; and

the control circuit diagnoses whether disconnection of one or more of the measurement lines, abnormality of states of charge of one or more of the battery cells, or abnormality of one or more of the discharge circuits has occurred, based on the terminal voltages of the odd numbered battery cells, the terminal voltages of the even numbered battery cells, and the switching states.

3. A battery system for a vehicle according to claim 1, further comprising a serial communication system that comprises a first transmission path in which the plurality of integrated circuits are connected in series, a second transmission path for transmitting signals from the control circuit to a highest ranking one of the integrated circuits that are connected in series, and a third transmission path for transmitting signals from a lowest ranking one of the integrated circuits that are connected in series to the control circuit;

and wherein transmission of the first discharge command, the second discharge command, the first transmission command and the second transmission command from the control circuit to the plurality of integrated circuits, and sending of the terminal voltages from the plurality of integrated circuits to the control circuit, are performed via the serial communication system.

6. A battery system for a vehicle according to claim 1, wherein detection by the detection circuits is performed in each cycle of a predetermined detection cycle.

7. A battery system for a vehicle according to claim 6, wherein:

the measurement circuits measure the terminal voltages on a predetermined measurement cycle; and

the predetermined detection cycle has a same (coincident) period as the measurement cycle.

8. A battery system for a vehicle according to claim 2, further comprising a serial communication system that comprises a first transmission path in which the plurality of integrated circuits are connected in series, a second transmission path for transmitting signals from the control circuit to a highest ranking one of the integrated circuits that are connected in series, and a third transmission path for transmitting signals from a lowest ranking one of the integrated circuits that are connected in series to the control circuit;

and wherein transmission of the first discharge command, the second discharge command, the first transmission command and the second transmission command from the control circuit to the plurality of integrated circuits, and sending of the terminal voltages from the plurality of integrated circuits to the control circuit, are performed via the serial communication system.

9. A battery system for a vehicle according to claim 2, wherein detection by the detection circuits is performed in each cycle of a predetermined detection cycle.

10. A battery system for a vehicle according to claim 3, wherein detection by the detection circuits is performed in each cycle of a predetermined detection cycle.

4. A battery system for a vehicle, comprising:

a battery unit in which a plurality of cell groups are electrically connected in series, with a plurality of battery cells being electrically connected in series in each cell group;

integrated circuits provided for the cell groups respectively, each of which measures the terminal voltage of each battery cell included in its cell group via a measurement line, and outputs battery cell information; and

a control circuit that monitors the states of the battery cells based on battery cell information from the integrated circuits;

wherein each of the integrated circuits comprises;

a measurement circuit that measures respective terminal voltages of the battery cells in its cell group;

discharge circuits provided for each battery cell, each of which includes a semiconductor switching element for flowing a discharge current via measurement lines for that battery cell; and

detection circuits that detect switching states of the semiconductor switching elements;

and wherein the control circuit transmits to the integrated circuits discharge commands that command discharge operation by the discharge circuits, and diagnoses whether disconnection of one or more of the measurement lines, abnormality of states of charge of one or more of the battery cells, or abnormality of one or more of the of the discharge circuits has occurred, based on the terminal voltages measured during execution of the discharge commands and on the switching states.

5. A battery system for a vehicle according to claim 4, wherein the control circuit transmits to each of the integrated circuits:

a first discharge command that causes odd numbered battery cells of its cell group to be discharged;

a first transmission command that causes terminal voltages only of the odd numbered battery cells, measured during execution of the first discharge command, to be sent to the control circuit;

a second discharge command that causes even numbered battery cells of its cell group to be discharged; and

a second transmission command that causes terminal voltages of only the even numbered battery cells, measured during execution of the second discharge command, to be sent to the control circuit;

and diagnoses whether disconnection of one or more of the measurement lines, abnormality of the states of charge of one or more of the battery cells, or abnormality of one or more of the of the discharge circuits has occurred, based on the terminal voltages sent from each of the integrated circuits.

11. A battery system for a vehicle according to claim 4, wherein detection by the detection circuits is performed in each cycle of a predetermined detection cycle.

12. A battery system for a vehicle according to claim 5, wherein detection by the detection circuits is performed in each cycle of a predetermined detection cycle.