Battery control device and battery system

• US 9,252,624 B2
• Filed: 06/10/2011
• Issued: 02/02/2016
• Est. Priority Date: 06/10/2011
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Ohkawa, Keiichiro, Nakao, Ryouhei, Kawahara, Youhei
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US14/124,590
• Publication Number:
  US 20140111164A1
• Time in Patent Office: 1,698 Days
• Field of Search: 320/104, 320/132, 320/134, 320/152, 320/165, 903/903
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/40 DC to AC 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 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• 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: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• 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: H01M 10/441 for several batteries or cells simultaneously or sequentially
• 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 7/00714 in response to battery charging or discharging current
• 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 7/14 : for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• 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 90/14 : Plug-in electric vehicles

Abstract

An object of the invention is to provide a battery control apparatus capable of accurately obtaining permissible charging or discharging power in keeping with variation of the internal resistance of a battery. The battery control apparatus of this invention includes an internal resistance table in which the internal resistance value of single cells corresponding to the temperature and state of charge thereof are described in association with each of charging or discharging duration time of the single cells. The battery control apparatus calculates a permissible charging current or a permissible discharging current by using the internal resistance value described in the internal resistance table and controls the charging or discharging of the single cells in accordance with the current value thus obtained.

Claims

1. A battery control device comprising:

a control unit which controls a battery pack having a plurality of single cells connected therein;

a voltage measurement unit which measures voltage between terminals of the single cells or the battery pack;

a current measurement unit which measures a current flowing through the single cells or the battery pack;

a temperature measurement unit which measures a temperature of the single cells or the battery pack, and

a storage unit which stores internal resistance characteristic information indicative of correspondence relation between the temperature, state of charge, and either internal resistance value of the single cells or duration time during which the single cells are charged or discharged, wherein

the internal resistance characteristic information describes the correspondence relation regarding each of the duration time;

wherein

the control unit acquires the state of charge of the single cells by using the result of the measurement by the voltage measurement unit and by the current measurement unit;

wherein

using the duration time that differs between an operation mode in to which to supply power to an electric vehicle and an operation mode in which to supply power to a hybrid vehicle, the control unit acquires the internal resistance value corresponding to the temperature, state of charge, and duration time of the single cells from the internal resistance characteristic information, and wherein

the control unit uses an upper or lower voltage, an open circuit voltage, and the internal resistance value of the single cells to calculate a charging current or a discharging current of the single cells, the control unit further performing a control to charge or discharge the single cells in accordance with the charging current or the discharging current.

2. A battery control device according to claim 1, wherein

the control unit switches the battery pack to either an operation mode in which to supply power to an electric vehicle or an operation mode in which to supply power to a hybrid vehicle, and wherein

when the battery pack is operated in the operation mode in which to supply power to the electric vehicle, the control unit calculates the charging current or the discharging current of the single cells by using the internal resistance value corresponding to the duration time during which the single cells are charged or discharged.

3. A battery control device according to claim 1, wherein

the control unit switches the battery pack to either an operation mode in which to supply power to an electric vehicle or an operation mode in which to supply power to a hybrid vehicle, and wherein

when the battery pack is operated in the operation mode in which to supply power to the hybrid vehicle, the control unit calculates the charging current or the discharging current of the single cells by fixedly using the internal resistance value corresponding to one of the duration time.

4. A battery control device according to claim 1, wherein

the control unit switches the battery pack to either an operation mode in which to supply power to an electric vehicle or an operation mode in which to supply power to a hybrid vehicle, and wherein

when the battery pack is operated in the operation mode in which to supply power to the hybrid vehicle, the control unit calculates the charging current or the discharging current of the single cells by using the internal resistance value corresponding to duration time shorter than the duration time in effect when the battery pack is operated in the operation mode in which to supply power to the electric vehicle.

5. A battery control device according to claim 1, wherein

the control unit calculates the charging current or the discharging current of the single cells by using the upper voltage or the lower voltage, the open circuit voltage, the internal resistance values of the single cells, and state of health of the single cells.

6. A battery control device according to claim 1,

wherein

the control unit calculates the charging current or the discharging current of the single cells using the internal resistance value obtained corresponding to the highest of the temperatures of the single cells, the control unit further calculating the charging current or the discharging current of the single cells by using the internal resistance value obtained corresponding to the lowest of the temperature of the single cells, the control unit further controlling the charging or discharging of the single cells by using the smaller of the two charging currents or of the two discharging currents of the single cells thus obtained.

7. A battery control device according to claim 1, wherein

the control unit controls the charging or discharging of the single cells using the smallest of the charging current or of the discharging current of the single cells.

8. A battery control device according to claim 1, wherein

the storage unit stores SOC characteristic information indicative of correspondence relation between the open circuit voltage and the state of charge of the single cells, and wherein

the control unit acquires the current state of charge of the single cells using the open circuit voltage of the single cells and the SOC characteristic information.

9. A battery system comprising:

a battery control device according to claim 1, and

a battery pack having a plurality of single cells connected therein, wherein

the battery control device controls either the single cells or the battery pack.