Voltage measurement device, voltage detection circuit, and voltage detection method

1. A voltage measurement device, comprising:

a plurality of voltage detection circuits which measure cell voltages of a plurality of cells connected in series,

wherein each of the plurality of voltage detection circuits includes:

a communication end information holding circuit which holds communication end information specifying, as at least one communication end position, at least one of the plurality of voltage detection circuits; and

a communication control circuit which controls transfer for sending a communication command received from a preceding voltage detection circuit, among the plurality of voltage detection circuits, located at a preceding stage to a next voltage detection circuit, among the plurality of voltage detection circuits, located at a next stage, according to the communication end information.

2. The voltage measurement device according to claim 1 ,

wherein the communication control circuit:

allows the transfer of the communication command, when the communication end information does not specify the voltage detection circuit which includes the communication control circuit; and

prohibits the transfer of the communication command, when the communication end information specifies the voltage detection circuit which includes the communication control circuit.

3. The voltage measurement device according to claim 1 ,

wherein the plurality of voltage detection circuits are connected in a daisy chain to enable communication bi-directionally in a first direction and a second direction which are opposite to each other, and

the communication control circuit controls whether to allow or prohibit each of the transfer of the communication command in the first direction and the transfer of the communication command in the second direction, according to the communication end information.

4. The voltage measurement device according to claim 3 ,

wherein the communication end information includes: upper communication end information specifying a first communication end position which is included in the at least one communication end position; and a lower communication end information specifying a second communication end position which is included in the at least one communication end position, and

the communication control circuit controls whether to allow or prohibit the transfer of the communication command that flows in the first direction according to the upper communication end information, and controls whether to allow or prohibit the transfer of the communication command that flows in the second direction according to the lower communication end information.

5. The voltage measurement device according to claim 4 ,

wherein the first direction is a direction in which the communication command flows from the uppermost stage to the lowermost stage when it is assumed that a voltage detection circuit corresponding to a last cell in a negative side among the plurality of cells is located at the lowermost stage and that a voltage detection circuit corresponding to a last cell in a positive side among the plurality of cells is located at the uppermost stage.

6. The voltage measurement device according to claim 4 ,

wherein the first direction is a direction in which the communication command flows from the lowermost stage to the uppermost stage when it is assumed that a voltage detection circuit corresponding to a last cell in a negative side among the plurality of cells is located at the lowermost stage and that a voltage detection circuit corresponding to a last cell in a positive side among the plurality of cells is located at the uppermost stage.

7. The voltage measurement device according to claim 4 ,

wherein the communication control circuit selectively switches the following modes:

(1) a first operation mode for controlling whether to allow or prohibit the transfer of the communication command that flows in the first direction according to the upper communication end information and controlling whether to allow or prohibit the transfer of the communication command that flows in the second direction according to the lower communication end information; and

(2) a second operation mode for controlling whether to allow or prohibit the transfer of the communication command that flows in the first direction according to the lower communication end information and controlling whether to allow or prohibit the transfer of the communication command that flows in the second direction according to the upper communication end information.

8. The voltage measurement device according to claim 1 ,

wherein the communication control circuit controls sending of a reply to the preceding voltage detection circuit when the communication command is received from the preceding voltage detection circuit.

9. The voltage measurement device according to claim 8 , further comprising:

a controller which is connected to a lowermost voltage detection circuit and an uppermost voltage detection circuit among the plurality of voltage detection circuits, sends the communication command, and receives the reply, the lower most voltage detection circuit being located at a lowermost stage, the uppermost voltage detection circuit being located at an uppermost stage.

10. The voltage measurement device according to claim 8 ,

wherein, when the communication command received from the preceding voltage detection circuit is a broadcast communication command, the communication control circuit performs, according to the communication end information, control whether to allow or prohibit sending of a reply to the broadcast communication command to the preceding voltage detection circuit.

11. The voltage measurement device according to claim 10 ,

wherein the communication control circuit:

prohibits the sending of the reply to the broadcast communication command when the communication end information does not specify the voltage detection circuit which includes the communication control circuit; and

allows sending of the reply to the broadcast communication command when the communication end information specifies the voltage detection circuit which includes the communication control circuit.

12. The voltage measurement device according to claim 8 ,

wherein the communication control circuit performs control to cause a dummy reply to be sent to the next voltage detection circuit when the voltage detection circuit which includes the communication control circuit is a target of the communication command received from the preceding voltage detection circuit.

13. The voltage measurement device according to claim 12 ,

wherein, when receiving the dummy reply from the preceding voltage detection circuit, the communication control circuit:

prohibits sending of the dummy reply to the next voltage detection circuit when the communication end information specifies the voltage detection circuit which includes the communication control device; and

allows sending of the dummy reply to the next voltage detection circuit when the communication end information does not specify the voltage detection circuit which includes the communication control device.

14. The voltage measurement device according to claim 8 ,

wherein, when the voltage detection circuit which includes the communication control device is located after the voltage detection circuit which is a target of the communication command received from the preceding voltage detection circuit, the communication control circuit performs control to cause a dummy reply to be sent to either the preceding voltage detection circuit or the next voltage detection circuit.

15. The voltage measurement device according to claim 1 , further comprising:

a battery pack having the plurality of cells connected in series.

16. A voltage detection circuit included in a plurality of voltage detection circuits included in a voltage measurement device which measures cell voltages of a plurality of cells connected in series, the voltage detection circuit comprising:

a communication end information holding circuit which holds communication end information specifying, as at least one communication end position, at least one of the plurality of voltage detection circuits; and

a communication control circuit which controls transfer for sending a communication command received from a preceding voltage detection circuit, among the plurality of voltage detection circuits, located at a preceding stage to a next voltage detection circuit, among the plurality of voltage detection circuits, located at a next stage, according to the communication end information.

17. A voltage detection method performed in a plurality of voltage detection circuits included in a voltage measurement device which measures cell voltages of a plurality of cells connected in series,

wherein each of the plurality of voltage detection circuits:

obtains a cell voltage from at least one of the plurality of cells, as battery information; and

controls transfer for sending a communication command received from a preceding voltage detection circuit, among the plurality of voltage detection circuits, located at a preceding stage to a next voltage detection circuit, among the plurality of voltage detection circuits, located at a next stage, according to communication end information specifying, as at least one communication end position, at least one of the plurality of voltage detection circuits.