BATTERY CONTROL SYSTEM AND VEHICLE CONTROL SYSTEM

• US 20160176308A1
• Filed: 07/25/2014
• Published: 06/23/2016
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.), Nissan Motor Co., Ltd.
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.), Nissan Motor Co., Ltd.
• Inventors: MORIKAWA, Hiroshi, AOSHIMA, Yoshinori, TAKADA, Masayuki, TSURU, Kenichiro, HASHIMOTO, Hiroaki, TAKAHASHI, Yasuyuki, KIYOTA, Shigeyuki, TANAKA, Yoshiyuki, IGUCHI, Toyoki
• Granted Patent: US 10,005,373 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 2240/80 Time limits
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/16 Regulation of the charging current or voltage by variation of field
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery control system connected to a battery, which controls charge/discharge at the battery, includes: a current detection unit that measures a current value by detecting a charge/discharge current flowing through the battery; a voltage detection unit that detects a voltage at the battery; a temperature detection unit that detects a temperature at the battery; a temperature history recording unit that records temperature history pertaining to the temperature detected by the temperature detection unit; and a charge/discharge restriction unit that restricts the charge/discharge current in a low-temperature state based upon the temperature history recorded by the temperature history recording unit.

Claims

1. A battery control system connected to a battery, which controls charge/discharge at the battery, comprising:

a current detection unit that measures a current value by detecting a charge/discharge current flowing through the battery;

a voltage detection unit that detects a voltage at the battery;

a temperature detection unit that detects a temperature at the battery;

a temperature history recording unit that records temperature history pertaining to the temperature detected by the temperature detection unit; and

a charge/discharge restriction unit that restricts the charge/discharge current in a low-temperature state based upon the temperature history recorded by the temperature history recording unit.

2. The battery control system according to claim 1, wherein:

the charge/discharge restriction unit makes a decision as to whether or not to restrict the charge/discharge current by determining, based upon the temperature history, a highest temperature at the battery as the battery is charged/discharged continuously or intermittently over a length of time equal to or greater than a predetermined continuous time length and comparing the highest temperature with a predetermined threshold value.

3. The battery control system according to claim 2, wherein:

the continuous time length is set in correspondence to a length of time to elapse until the temperature at the battery enters a state of equilibrium during charge/discharge.

4. The battery control system according to claim 2, wherein:

a plurality of varying time lengths are set for the continuous time length; and

the threshold value takes a greater value in correspondence to the continuous time length as the continuous time length increases.

5. The battery control system according to claim 2, wherein:

a first threshold value and a second threshold value lower than the first threshold value are set to be used as the threshold value; and

the charge/discharge restriction unit imposes a first charge/discharge restriction so as to restrict the charge/discharge current if the highest temperature is lower than the first threshold value and imposes a second charge/discharge restriction so as to further restrict the charge/discharge current if the highest temperature is lower than the second threshold value.

6. The battery control system according to claim 5, wherein:

the charge/discharge restriction unit, having imposed the first charge/discharge restriction, clears the first charge/discharge restriction when the highest temperature subsequently exceeds the first threshold value, and having imposed the second charge/discharge restriction, sustains the second charge/discharge restriction even if the highest temperature subsequently exceeds the second threshold value.

7. The battery control system according to claim 6, wherein:

the charge/discharge restriction unit clears the second charge/discharge restriction once a length of elapsed time having elapsed since the second charge/discharge restriction came into effect or a total length of time over which the second charge/discharge restriction has been in effect exceeds a predetermined restriction clearance time.

8. The battery control system according to claim 7, wherein:

the battery control system is connected to an in-vehicle communication network; and

the charge/discharge restriction unit obtains information pertaining to the length of elapsed time or the total length of time via the communication network.

9. The battery control system according to claim 1, further comprising:

an effective current value calculation unit that calculates, based upon the current value measured by the current detection unit, an effective current value in a predetermined time window, wherein;

when the effective current value calculated by the effective current value calculation unit is less than a predetermined reference value, the temperature history recording unit does not record the temperature history.

10. A vehicle control system, comprising:

a battery control system connected to a battery, which controls charge/discharge at the battery; and

a vehicle control unit connected with the battery control system, wherein;

the battery control system includes a current detection unit that detects a charge/discharge current flowing through the battery, a voltage detection unit that detects a voltage at the battery, a temperature detection unit that detects a temperature at the battery and a temperature history recording unit that records a temperature history pertaining to the temperature detected by the temperature detection unit; and

the vehicle control unit issues, based upon the temperature history recorded by the temperature history recording unit, an instruction for the battery control system so as to restrict the charge/discharge current in a low-temperature state.