CONTROL APPARATUS FOR SECONDARY BATTERY AND CONTROL METHOD FOR SECONDARY BATTERY

• US 20120217933A1
• Filed: 05/02/2012
• Published: 08/30/2012
• Est. Priority Date: 12/15/2009
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: ABE, Hiroyuki, HATTA, Tetsuya
• Granted Patent: US 8,796,994 B2
• Time in Patent Office: Days
• US Class Current: 320/128
• CPC Class Codes: H01M 10/3909 Sodium-sulfur cells
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/6571 Resistive heaters arrangements for heating the battery by its resistance to the internal current H01M10/637
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks

Abstract

Provided are a control apparatus for a secondary battery and a control method for a secondary battery, which suppress decreases in released power and absorbed power. When a power storage device is requested to release power, a limit for power supply to a power consuming body is set relatively higher, and when the power storage device is requested to absorb power, the limit for power supply to the power consuming body is set relatively lower. When the power storage device is requested to release power, a command value PD for released power is calculated by adding supplied power PS to a requested value PE for released power. When the power storage device is requested to absorb power, a command value PC for charged power is calculated by subtracting the supplied power PS from a requested value PA for absorbed power.

Claims

1. A control apparatus for a secondary battery, comprising:

a request acquiring part that acquires a request for power release/absorption and a requested value for released/absorbed power;

a discharged/charged power calculator that calculates discharged/charged power of said secondary battery;

a command value outputting part that outputs a calculated value of the discharged/charged power calculated by said discharged/charged power calculator as a command value for discharged/charged power;

a bidirectional converter that controls discharge/charge of said secondary battery such that the discharged/charged power is the command value outputted by said command value outputting part;

a power consuming body that consumes power;

a limit-contents deciding part that decides contents of a limit for power supply to said power consuming body; and

a supply controller that controls power supply to said power consuming body in accordance with the decision made by said limit-contents deciding part, wherein

said limit-contents deciding part sets the limit for power supply relatively higher when a request for power release is acquired by said request acquiring part, and sets the limit for power supply relatively lower when a request for power absorption is acquired by said request acquiring part.

2. The control apparatus for a secondary battery according to claim 1, wherein

said discharged/charged power calculator adds the power supplied to said power consuming body to the requested value for released power acquired by said request acquiring part, to calculate discharged power, and subtracts the power supplied to said power consuming body from the requested value for absorbed power acquired by said request acquiring part, to calculate charged power.

3. The control apparatus for a secondary battery according to claim 1, wherein

said power consuming body is a heater that heats said secondary battery,

a temperature sensor that measures a temperature of said secondary battery is further provided in said control apparatus for a secondary battery, and

said limit-contents deciding part permits power supply to said heater regardless of the request acquired by said request acquiring part when the measured value of the temperature measured by said temperature sensor is lower than a first lower limit, permits power supply to said heater upon acquirement of the request for power absorption by said request acquiring part and prohibits power supply to said heater upon acquirement of the request for power release by said request acquiring part when the measured value of the temperature measured by said temperature sensor is higher than the first lower limit and lower than a second lower limit.

4. The control apparatus for a secondary battery according to claim 3, wherein said supply controller controls power supply to said heater such that the measured value of the temperature measured by said temperature sensor is a set value when power supply to said heater is permitted by said limit-contents deciding part.

5. The control apparatus for a secondary battery according to claim 3, wherein

a plurality of said temperature sensors and said heaters are provided,

a priority deciding part that decides priority for power supply to each of said plurality of heaters is further provided in said control apparatus for a secondary battery,

said priority deciding part increases priority for power supply to the heater with decrease in measured value of the temperature measured by said temperature sensor, and

said limit-contents deciding part permits power supply in an order from said heater with higher priority for power supply to said heater with lower priority for power supply, the priority having been decided by said priority deciding part, such that overall supplied power, as a sum of power supplied to each of said plurality of heaters, is not higher than the requested value for absorbed power acquired by said request acquiring part.

6. The control apparatus for a secondary battery according to claim 3, wherein

said limit-contents deciding part repeatedly updates contents of a limit for power supply to said power consuming body at intervals, and

a first lower limit and a second lower limit which are applied at the time of an increase in measured value of the temperature measured by said temperature sensor are displaced to higher values than a first lower limit and a second lower limit which are applied at the time of a decrease in measured value.

7. The control apparatus for a secondary battery according to claim 3, wherein said limit-contents deciding part prohibits power supply to said heater regardless of the request acquired by said request acquiring part when the measured value of the temperature measured by said temperature sensor is higher than an upper limit.

8. The control apparatus for a secondary battery according to claim 1, wherein

said power consuming body is a heater that heats said secondary battery,

a temperature sensor that measures a temperature of said secondary battery and a predicted value calculator that calculates a predicted value of the temperature of said secondary battery from a history of the measured value of the temperature measured by said temperature sensor and a history of the supplied power to said power consuming body are further provided in said control apparatus for a secondary battery, and

said limit-contents deciding part permits power supply to said heater upon acquirement of the request for power absorption by said request acquiring part and prohibits power supply to said heater upon acquirement of the request for power release by said request acquiring part when the predicted value of the temperature calculated by said predicted value calculator is lower than a lower limit.

9. The control apparatus for a secondary battery according to claim 8, wherein said supply controller controls power supply to said heater such that the measured value of the temperature measured by said temperature sensor is a set value when power supply to said heater is permitted by said limit-contents deciding part.

10. The control apparatus for a secondary battery according to claim 8, wherein

a plurality of said temperature sensors and said heaters are provided,

a priority deciding part that decides priority for power supply to each of said plurality of heaters is further provided in said control apparatus for a secondary battery,

said priority deciding part increases priority for power supply to the heater with decrease in measured value of the temperature measured by said temperature sensor, and

said limit-contents deciding part permits power supply in an order from said heater with higher priority for power supply to said heater with lower priority for power supply, the priority having been decided by said priority deciding part, such that overall supplied power, as a sum of power supplied to each of said plurality of heaters, is not higher than the requested value for absorbed power acquired by said request acquiring part.

11. The control apparatus for a secondary battery according to claim 8, wherein

said limit-contents deciding part repeatedly updates contents of a limit for power supply to said power consuming body at intervals, and

a lower limit which is applied at the time of an increase in predicted value of the temperature calculated by said predicted value calculator is displaced to a higher value than a lower limit which is applied at the time of a decrease in predicted value.

12. The control apparatus for a secondary battery according to claim 8, wherein said limit-contents deciding part prohibits power supply to said heater regardless of the request acquired by said request acquiring part when the predicted value of the temperature calculated by said predicted value calculator is higher than an upper limit.

13. A control method for a secondary battery, comprising:

(a) a step of acquiring a request for power release/absorption and a requested value for released/absorbed power;

(b) a step of calculating discharged/charged power of said secondary battery;

(c) a step of outputting a calculated value of the discharged/charged power calculated in said step (b) as a command value for discharged/charged power;

(d) a step of controlling discharge/charge of said secondary battery such that the discharged/charged power is the command value outputted in said step (c);

(e) a step of deciding contents of a limit for power supply to the power consuming body; and

(f) a step of controlling power supply to said power consuming body in accordance with the decision made in said step (e), wherein

said step (e) sets the limit for power supply relatively higher when a request for power release is acquired in said step (a), and sets the limit for power supply relatively lower when a request for power absorption is acquired in said step (a).

14. A control method for a secondary battery according to claim 13, wherein

said step (b) adds the power supplied to said power consuming body to the requested value for released power acquired in said step (a), to calculate discharged power, and subtracts the power supplied to said power consuming body from the requested value for absorbed power acquired in said step (a), to calculate charged power.