Battery module voltage control device, battery module, and power supply system

• US 10,381,862 B2
• Filed: 11/29/2018
• Issued: 08/13/2019
• Est. Priority Date: 06/02/2016
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Mori, Michiya
• Primary Examiner(s): Grant, Robert
• Assistant Examiner(s): Trischler, John T
• Application Number:
  US16/203,971
• Publication Number:
  US 20190097452A1
• Time in Patent Office: 257 Days
• Field of Search: 320162
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/305 in the event of power-supply fluctuations
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 3/002 Flicker reduction, e.g. compensation of flicker introduced by non-linear load
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 9/00 Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power supply system including a battery module and a converter unit. The system includes a bidirectional DC-DC converter as a component of a battery module voltage control device that is connected between a load and a secondary battery and that changes a discharge voltage of the secondary battery and outputs the discharge voltage to the load. Moreover, a voltage control unit, which can include a control unit and the bidirectional DC-DC converter, changes the discharge voltage of the secondary battery to an output voltage target value to be outputted to the load.

Claims

1. A battery module voltage control device comprising:

a voltage control unit connected between a load and a secondary battery and configured to control a discharge voltage of the secondary battery to an output voltage target value for a voltage to be outputted to the load, and to output the discharge voltage to the load; and

an output current value acquisition unit configured to acquire a value of an output current of a converter unit that is configured to perform constant voltage control for outputting a predetermined constant voltage to the load when the value of the output current is equal to or lower than a predetermined value,

wherein the voltage control unit is configured to set the output voltage target value such that, when the acquired value of the output current is equal to or higher than a first threshold that is lower than the predetermined value, the output voltage target value increases with increase of the output current until the output voltage target value exceeds a value of the predetermined constant voltage of the converter unit, and, when the acquired value of the output current is between the first threshold and a second threshold, which is greater than the first threshold and lower than the predetermined value, the output voltage target value exceeds the value of the predetermined constant voltage of the converter unit.

2. The battery module voltage control device according to claim 1, wherein the voltage control unit comprises the output current value acquisition unit.

3. The battery module voltage control device according to claim 1, wherein the voltage control unit is configured to stop voltage control of the converter unit when the acquired value of the output current is equal to or lower than a third threshold that is lower than the first threshold.

4. The battery module voltage control device according to claim 1, wherein the voltage control unit is configured to hold a relationship between the value of the output current and the output voltage target value in a programmable state.

5. The battery module voltage control device according to claim 1, wherein the voltage control unit is configured to charge the secondary battery with output power of the converter unit when the acquired value of the output current is less than the first threshold.

6. The battery module voltage control device according to claim 1,

wherein the voltage control unit comprises a load-connection side that is OR-connected to the converter unit by an OR connection switching element, and

wherein the voltage control unit is configured to temporarily cut off the OR connection switching element when the acquired value of the output current of the converter unit is equal to or less than a fourth threshold that is lower than a critical current value corresponding to the constant voltage of the converter unit in a relationship between the value of the output current and the output voltage target value.

7. A battery module comprising:

a secondary battery;

a voltage control unit connected between a load and the secondary battery and configured to control a discharge voltage of the secondary battery to an output voltage target value for a voltage to be outputted to the load, and to output the discharge voltage to the load; and

an output current value acquisition unit configured to acquire a value of an output current of a converter unit that is configured to perform constant voltage control for outputting a predetermined constant voltage to the load when the value of the output current is equal to or lower than a predetermined value,

wherein the voltage control unit is configured to set the output voltage target value such that, when the acquired value of the output current is equal to or higher than a first threshold that is lower than the predetermined value, the output voltage target value increases with increase of the output current until the output voltage target value exceeds a value of the predetermined constant voltage of the converter unit, and, when the acquired value of the output current is between the first threshold and a second threshold, which is greater than the first threshold and lower than the predetermined value, the output voltage target value exceeds the value of the predetermined constant voltage of the converter unit.

8. The battery module according to claim 7, wherein the voltage control unit comprises the output current value acquisition unit.

9. The battery module according to claim 7, wherein the voltage control unit is configured to stop voltage control of the converter unit when the acquired value of the output current is equal to or lower than a third threshold that is lower than the first threshold.

10. The battery module according to claim 7, wherein the voltage control unit is configured to hold a relationship between the value of the output current and the output voltage target value in a programmable state.

11. The battery module according to claim 7, wherein the voltage control unit is configured to charge the secondary battery with output power of the converter unit when the acquired value of the output current is less than the first threshold.

12. The battery module according to claim 7,

wherein the voltage control unit comprises a load-connection side that is OR-connected to the converter unit by an OR connection switching element, and

wherein the voltage control unit is configured to temporarily cut off the OR connection switching element when the acquired value of the output current of the converter unit is equal to or less than a fourth threshold that is lower than a critical current value corresponding to the constant voltage of the converter unit in a relationship between the value of the output current and the output voltage target value.

13. A power supply system comprising:

a converter unit configured to perform constant voltage control for outputting a predetermined constant voltage to a load when an output current is equal to or lower than a predetermined value;

a secondary battery;

a voltage control unit connected between the load and the secondary battery and configured to control a discharge voltage of the secondary battery to an output voltage target value for a voltage to be outputted to the load, and to output the discharge voltage to the load; and

an output current value acquisition unit configured to acquire a value of an output current value of the converter unit,

wherein the voltage control unit is configured to set the output voltage target value such that, when the acquired value of the output current is equal to or higher than a first threshold that is lower than the predetermined value, the output voltage target value increases with increase of the output current until the output voltage target value exceeds a value of the predetermined constant voltage of the converter unit, and, when the acquired value of the output current is between the first threshold and a second threshold, which is greater than the first threshold and lower than the predetermined value, the output voltage target value exceeds the value of the predetermined constant voltage of the converter unit.

14. The power supply system according to claim 13, wherein the voltage control unit comprises the output current value acquisition unit.

15. The power supply system according to claim 13, wherein the voltage control unit is configured to stop voltage control of the converter unit when the acquired value of the output current is equal to or lower than a third threshold that is lower than the first threshold.

16. The power supply system according to claim 13, wherein the voltage control unit is configured to hold a relationship between the value of the output current and the output voltage target value in a programmable state.

17. The power supply system according to claim 13, wherein the converter unit comprises a plurality of convertors connected in parallel and each having a current share function based on a current share signal.

18. The power supply system according to claim 17, wherein the output current value acquisition unit is configured to acquire the value of the output current of the converter unit based on the current share signal from the converter unit.

19. The power supply system according to claim 13, wherein the voltage control unit is configured to charge the secondary battery with output power of the converter unit when the acquired value of the output current is less than the first threshold.

20. The power supply system according to claim 13,

wherein the voltage control unit comprises a load-connection side that is OR-connected to the converter unit by an OR connection switching element, and

wherein the voltage control unit is configured to temporarily cut off the OR connection switching element when the acquired value of the output current of the converter unit is equal to or less than a fourth threshold that is lower than a critical current value corresponding to the constant voltage of the converter unit in a relationship between the value of the output current and the output voltage target value.