Battery Management System

• US 20090174369A1
• Filed: 03/09/2009
• Published: 07/09/2009
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Vehicle Energy Japan, Inc.
• Original Assignee: Hitachi Vehicle Energy, Ltd. (Hitachi, Ltd.)
• Inventors: AOSHIMA, Yoshinori, SHIDA, Masami, TAKAHASHI, Hirotaka, KAWAHARA, Youhei, EMORI, Akihiko, YAMAUCHI, Shuko
• Granted Patent: US 8,004,239 B2
• Time in Patent Office: Days
• US Class Current: 320/150
• CPC Class Codes: B60L 2240/545 Temperature
• 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 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery management system which can output a battery state enabling optimum charge and discharge control to be performed even when a temperature variation occurs among individual single cells. A plurality of temperature sensors measure temperature values of a battery. A measurement unit measures a voltage and a current of the battery. A maximum/minimum temperature selection unit in a calculation unit determines a maximum temperature and a minimum temperature from the temperature values measured by the temperature sensors. An available power calculation unit calculates respective values of maximum available charge and discharge powers or maximum available charge and discharge currents of the battery corresponding to the maximum temperature and the minimum temperature based on the voltage and the current of the battery. A selection unit selects and outputs smaller maximum available charge and discharge powers or smaller maximum available charge and discharge currents from the respective values of the maximum available charge and discharge powers or the maximum available charge and discharge currents of the battery corresponding to the maximum temperature and the minimum temperature, which are calculated by the calculation unit.

Claims

1. A battery management system comprising:

a plurality of temperature measuring means for measuring temperature values of a battery capable of charging and discharging electricity;

voltage and current measuring means for measuring a voltage and a current of said battery;

calculation means for determining a maximum temperature and a minimum temperature of said battery from the temperature values measured by said temperature measuring means, and calculating respective values of maximum available charge and discharge powers or maximum available charge and discharge currents of said battery corresponding to the maximum temperature and the minimum temperature based on the voltage and the current of said battery measured by said voltage and current measuring means; and

selection means for selecting smaller maximum available charge and discharge powers or smaller maximum available charge and discharge currents from the respective values of the maximum available charge and discharge powers or the maximum available charge and discharge currents of said battery corresponding to the maximum temperature and the minimum temperature, which are calculated by said calculation means.

2. The battery management system according to claim 1, further comprising limiter means for limiting the values of the maximum available charge and discharge powers or the maximum available charge and discharge currents, which are calculated by said calculation means, to be reduced when the voltage of said battery measured by said voltage and current measuring means is near an upper limit voltage or a lower limit voltage.

3. A battery management system comprising:

a plurality of temperature measuring means for measuring temperature values of a battery capable of charging and discharging electricity;

voltage and current measuring means for measuring a voltage and a current of said battery and voltages of a plurality of single cells constituting said battery;

calculation means for determining a maximum voltage and a minimum voltage among the single cells in said battery from the voltage values of the single cells in said battery measured by said voltage and current measuring means, and calculating respective values of maximum available charge and discharge powers or maximum available charge and discharge currents of said battery corresponding to the maximum voltage and the minimum voltage based on the voltage and the current of said battery measured by said voltage and current measuring means; and

selection means for selecting smaller maximum available charge and discharge powers or smaller maximum available charge and discharge currents from the respective values of the maximum available charge and discharge powers or the maximum available charge and discharge currents of said battery corresponding to the maximum voltage and the minimum voltage, which are calculated by said calculation means.

4. The battery management system according to claim 3, further comprising limiter means for limiting the values of the maximum available charge and discharge powers or the maximum available charge and discharge currents, which are calculated by said calculation means, to be reduced when the voltage of said battery measured by said voltage and current measuring means is near an upper limit voltage or a lower limit voltage.

5. A battery management system comprising:

a plurality of temperature measuring means for measuring temperature values of a battery capable of charging and discharging electricity;

voltage and current measuring means for measuring a voltage and a current of said battery and voltages of a plurality of single cells constituting said battery;

calculation means for determining a maximum temperature and a minimum temperature of said battery from the temperature values measured by said temperature measuring means, calculating respective values of maximum available charge and discharge powers or maximum available charge and discharge currents of said battery corresponding to the maximum temperature and the minimum temperature based on the voltage and the current of said battery measured by said voltage and current measuring means, determining a maximum voltage and a minimum voltage among the single cells in said battery from the voltage values of the single cells in said battery measured by said voltage and current measuring means, and calculating respective values of maximum available charge and discharge powers or maximum available charge and discharge currents of said battery corresponding to the maximum voltage and the minimum voltage based on the voltage and the current of said battery measured by said voltage and current measuring means; and

selection means for selecting smallest maximum available charge and discharge powers or smallest maximum available charge and discharge currents from the respective values of the maximum available charge and discharge powers or the maximum available charge and discharge currents of said battery corresponding to the maximum temperature, the minimum temperature, the maximum voltage and the minimum voltage, which are calculated by said calculation means.