Voltage balance circuit, voltage detecting circuit, voltage balancing method, and voltage detecting method

• US 20080018301A1
• Filed: 09/27/2007
• Published: 01/24/2008
• Est. Priority Date: 10/01/2001
• Status: Active Grant

• Current Assignee: Sanken Electric Company Limited
• Original Assignee: Sanken Electric Company Limited
• Inventors: Morita, Koichi
• Granted Patent: US 7,583,057 B2
• Time in Patent Office: Days
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0018 using separate charge circuits

Abstract

When a control section (39) turns on a switch (31, 33, 35), a capacitor (37) is connected to a secondary battery (B1) in parallel. Accordingly, voltage between both ends of each capacitor (37, 38) reaches voltage between both polarities of each secondary battery (B1, B2). Thereafter, when the control section (39) turns off the switch (31, 33, 35) and turns on a switch (32, 34, 36), each capacitor (37, 38) is connected to the secondary battery (B2, B3) in parallel. The capacitor (37, 38) is charged/discharged to balance voltage between both polarities of the secondary battery (B1 to B3).

Claims

1. A voltage balance circuit that balances voltage between both polarities of each storage circuit of a plurality of storage circuits (B1, B2, B3) connected to one another in series, comprising:

a capacitor (37, 38);

a first connecting section (31, 33, 35) that connects said capacitor in parallel to a storage circuit selected from said plurality of storage circuits (B1, B2, B3) connected to one another in series to charge/discharge said capacitor (37, 38) from said selected storage circuit (B1, B2, B3); and

a second connecting section (32, 34, 36) that connects said charged/discharged capacitor (37, 38) in parallel to another selected storage circuit (B1, B2, B3) different from said selected storage circuit (B1, B2, B3) to charge/discharge said another selected capacitor (B1, B2, B3) from said charged/discharged capacitor (37,38); and

said first connecting section and said second connecting section having a first switch and a second switch that are connected to each other in series between one electrode of said each storage circuit (B1, B2, B3) and the other electrode, and a connecting node between the first switch and the second switch being connected to each other in series between one electrode of said each storage circuit (B1, B2, B3) and the other electrode connected by said capacitor (37, 38).

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. A voltage detection circuit that detects a voltage between both polarities of each storage circuit of a plurality of storage circuits (B1, B2, B3) connected to one another in series, comprising:

a first capacitor (67, 68, 69);

a second capacitor (72);

a charging section (62, 64, 66, 71) that selects one storage circuit (B1, B2, B3) from said plurality of storage circuits (B1, B2, B3) to charge said first capacitor (67, 68, 69) by voltage of one electrode of said selected storage circuit (B1, B2, B3);

a voltage applying section (61, 63, 65, 70) that connects said first capacitor (67, 68, 69) to said second capacitor (72) in series to apply voltage of the other electrode of said selected storage circuit (B1, B2, B3) to said first capacitor (67, 68, 69) and said second capacitor (72) connected to each other in series; and

a pair of measuring terminals connected to both ends of said second capacitor (72) to detect voltage between both polarities of said selected storage circuit (B1, B2, B3).

7. The voltage detection circuit according to claim 6, further comprising a control section (39) that repeats processing that charges said first capacitor (67, 68, 69) in connection with said selected storage circuit (B1, B2, B3) and processing that applies voltage of the other electrode of said selected storage circuit (B1, B2, B3) to said first capacitor (67, 68, 69) and said second capacitor (72) connected to each other in series.

8. The voltage detection circuit according to claim 6, wherein said charging section (62, 64, 66, 71) includes a plurality of first switches (62, 64, 66) each having one end connected to one electrode of said each storage circuits (B1, B2, B3) and the other end connected to one electrode of said each first capacitors (67, 68, 69), a charging switch (71) having one end connected to the other electrode of said plurality of first capacitors (67, 68, 69) in common and the other end connected to a node that sets a reference electric potential, and a control section (39) that turns on said first switch (62, 64, 66) having one end connected to said selected storage circuit (B1, B2, B3) and said charging switch (71).

9. The voltage detection circuit according to claim 6, wherein one electrode of said second capacitor (72) is connected to the other end of said charging switch (71), and said voltage applying section (61, 63, 65, 70) includes a plurality of second switches (61, 63, 65) each having one end connected to the other electrode of said each storage circuit (B1, B2, B3) and the other end connected to one electrode of said each first capacitor (67, 68, 69), a voltage applying switch (70) having one end connected to the other electrode of said plurality of first capacitors (67, 68, 69) and the other end connected to the other electrode of said second capacitor (72), and a control section (39) that turns off said plurality of first switches (62, 64, 66) and said charging switch (71) and turns on said second switch (61, 63, 65) having one end connected to the selected storage circuit (B1, B2, B3) and said voltage applying switch (70) when voltage of the other electrode of said selected storage circuit (B1, B2, B3) is applied to said first capacitor (67, 68, 69) and said second capacitor (72) connected to each other in series.

10. The voltage detection circuit according to claim 6, wherein said each storage circuit includes one or multiple secondary batteries (B1, B2, B3).

11. The voltage detection circuit according to claim 6, wherein said each storage circuit includes one or multiple capacitors (C1, C2, C3).

12. A voltage detection circuit that detects voltage between both polarities of each storage circuit of a plurality of storage circuits (B1, B2, B3) connected to one another in series, comprising:

a terminal voltage detecting section (62, 64, 66) that selects one storage circuit (B1, B2, B3) from said plurality of storage circuits (B1, B2, B3) connected to one another in series to detect voltage of one electrode of the selected storage circuit;

a pair of measuring terminals (both ends of 71) capable of measuring voltage; and

a voltage detecting section (67 to 69, 71) that detects voltage of the other electrode of said selected storage circuit (B1, B2;

B3) to show a differential voltage between the voltage of the other electrode and the voltage detected by said terminal voltage detecting section (62, 64, 66) to said pair of measuring terminals (both ends of 71) as voltage between both polarities of the selected storage circuit (B1, B2, B3).

13. The voltage detection circuit according to claim 12, wherein said terminal voltage detecting section includes a plurality of first switches (62, 64, 66) each having one end connected to one electrode of said each storage circuits (B1, B2, B3), one of said pair of measuring terminals (both ends of 71) is connected to a node that sets a reference electric potential, and said voltage detecting section (67 to 69, 71) includes a plurality of second switches (61, 63, 65) each connected between the other end of said each first switch (62, 64, 66) and the other electrode of said each storage circuit (B1, B2, B3), a plurality of capacitors (67 to 69), corresponding to said respective storage circuits (B1, B2, B3), each having one electrode connected to a node between each said first switch (62, 64, 66) and each said second switch (61, 63, 65) and the other electrode connected to the other measuring terminal of said pair of measuring terminals (both ends of 71) in common, a third switch (71) connected between said pair of measuring terminals, and a control section (39) that turns on said first switch (62, 64, 66) connected to said selected storage circuit (B1, B2, B3) and said third switch (71) to charge said capacitor (67, 68, 69) corresponding to said selected storage circuit (B1, B2, B3) and turns off said first switch (62, 64, 66) and said third switch (71) and thereafter turning on the second switch (61, 63, 65) connected to said selected storage circuit (B1, B2, B3) at the time of showing the differential voltage to said pair of measuring terminals (both ends of 71).

14. The voltage detection circuit according to claim 12, wherein the plurality of storage circuits (B1, B2, B3) connected to one another in series is sequentially scanned to show the differential voltage to said pair of measuring terminals (both ends of 71) for each storage circuit (B1, B2, B3) in order to measure voltage between both polarities of said each storage circuit (B1, B2, B3) from said terminal voltage detecting section (62, 64, 66) and said voltage detecting section (67 to 69, 71).

15. The voltage detection circuit according to claim 12, wherein said each storage circuit includes one or multiple secondary batteries (B1, B2, B3).

16. The voltage detection circuit according to claim 12, wherein said each storage circuit includes one or multiple capacitors (C1, C2, C3).

17. (canceled)

18. A voltage detection method of detecting voltage between both polarities of each storage circuit of a plurality of storage circuits (B1, B2, B3) connected to one another in series, comprising the steps of:

selecting one storage circuit from said plurality of storage circuits (B1, B2, B3) to charge a first capacitor (67, 68, 69) by voltage of one electrode of said selected storage circuit (B1, B2, B3);

connecting the first capacitor (67, 68, 69) and a second capacitor (72) to each other in series to apply voltage of the other electrode of said selected storage circuit (B1, B2, B3) to said first capacitor (67, 68, 69) and said second capacitor (72) connected to each other in series; and

detecting the voltage applied to both ends of said second capacitor (72) as voltage between both polarties of said selected storage circuit (B1, B2, B3).

19. A voltage detection method of detecting a voltage between both polarities of the respective storage circuits of a plurality of storage circuits (B1, B2, B3) connected to one another in series, comprising the steps of:

selecting one storage circuit (B1, B2, B3) from said plurality of storage circuits (B1, B2, B3) connected to one another in series to detect voltage of one electrode of the selected storage circuit;

detecting voltage of the other electrode of said selected storage circuit (B1, B2, B3) to show a differential voltage between the voltage of the other electrode and the detected voltage to a pair of measuring terminals (both ends of 71) as voltage between both polarities of the selected storage circuit (B1, B2, B3); and

detecting voltage between both polarities of each storage circuit (B1, B2, B3) at both ends of said pair of measuring terminals.