JP6877912B2 - Battery monitoring system - Google Patents

Description

The present invention relates to a voltage monitoring device and an assembled battery monitoring system.

Vehicles such as electric vehicles and hybrid vehicles have an electric motor and a power source, and the electric power stored in the power source drives the electric vehicle. As such a power source, an assembled battery having a plurality of battery blocks configured by connecting a plurality of battery cells in series is used, and as a voltage monitoring device for monitoring the voltage of each battery block, a device using a flying capacitor is used. It is known (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-301224

However, when a conventional voltage monitoring device is provided for each battery block, a microcomputer including an AD converter for detecting the voltage of the flying capacitor is arranged for each battery block, which hinders cost reduction. There is.

The present invention has been made in view of the above, and an object of the present invention is to provide, for example, a voltage monitoring device and an assembled battery monitoring system capable of reducing costs.

The voltage monitoring device according to one aspect of the embodiment is a voltage monitoring device provided for each battery block of an assembled battery having a plurality of battery blocks, and includes a threshold voltage output unit, a comparator, and an output unit. The threshold voltage output unit outputs a threshold voltage. The comparator compares the voltage corresponding to the voltage of the battery block with the threshold voltage, and detects the overvoltage of the battery block. The output unit outputs the detection result of the overvoltage by the comparator.

According to the voltage monitoring device and the assembled battery monitoring system according to one aspect of the embodiment, for example, cost reduction can be achieved.

FIG. 1 is a diagram showing a configuration example of a vehicle-mounted system including the assembled battery monitoring system according to the embodiment. FIG. 2 is a diagram showing a configuration example of a satellite board including a block monitoring unit. FIG. 3 is a diagram showing a configuration example of the overvoltage detection unit. FIG. 4 is a diagram showing an example of changes in the voltage dividing voltage, the detection signal, and the detection result signal when the block voltage changes from the normal state to the overvoltage. FIG. 5 is a diagram showing an example of changes in the threshold voltage, the adjustment signal, and the detection signal when the self-diagnosis process is executed by the battery condition monitoring unit. FIG. 6 is a diagram showing state changes of the power supply voltage, the voltage dividing voltage, and the abnormality detection signal before and after the occurrence of the abnormality in which the power supply voltage rises. FIG. 7 is a diagram showing a specific configuration example of the overvoltage detection unit. FIG. 8 is a diagram showing a configuration example of performing self-diagnosis processing in the configuration of the battery status monitoring unit. FIG. 9 is a flowchart showing the flow of the self-diagnosis process performed by the battery condition monitoring unit. FIG. 10 is a diagram showing a configuration example of the high voltage detection unit. FIG. 11 is a diagram for explaining the relationship between the operating state of the current cutoff device included in the battery cell, the charge / discharge state of the battery cell, and the voltage across the current cutoff device. FIG. 12 is a diagram showing a specific configuration example of the high voltage detection unit. FIG. 13 is a diagram showing changes in the CID voltage, each output voltage, and the detection result signal due to the occurrence of CID expiration when the battery block is discharged. FIG. 14 is a diagram showing changes in the CID voltage, each output voltage, and the detection result signal due to the occurrence of CID expiration during charging of the battery block. FIG. 15 is a diagram showing the CID voltage, the current flowing through the resistor of the output unit, and the on / off state of the photocoupler. FIG. 16 is a diagram showing another configuration example of the high voltage detection unit.

Hereinafter, the voltage monitoring device and the assembled battery monitoring system according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to these embodiments.

[1. Vehicle mounting system configuration]
FIG. 1 is a diagram showing a configuration example of a vehicle-mounted system including the assembled battery monitoring system according to the embodiment. The vehicle mounting system 100 is mounted on a vehicle such as a hybrid electric vehicle (HEV), an electric vehicle (EV), and a fuel cell vehicle (FCV) (not shown), for example.

The vehicle mounting system 100 includes an assembled battery 1, an assembled battery monitoring system 2, a vehicle control device 3, an electric motor 4, a power converter 5, and a relay 6.

The assembled battery 1 is, for example, a lithium ion secondary battery, a nickel hydrogen secondary battery, or the like, and is insulated from a vehicle body (not shown). The assembled battery 1 is configured by connecting a plurality of battery blocks 10 in series. Each battery block 10 includes a plurality of battery cells 11 connected in series. Each battery cell 11 is provided with a current interrupt device (not shown) that mechanically interrupts the current path when the internal pressure rises.

The assembled battery monitoring system 2 monitors the charging state of the assembled battery 1 and notifies the vehicle control device 3. The assembled battery monitoring system 2 includes a plurality of satellite boards 21 and a battery condition monitoring unit 23. Each satellite board 21 has a block monitoring unit 22 (an example of a voltage monitoring device), and is individually provided for each battery block 10. The plurality of satellite substrates 21 are arranged at positions separated from each other, for example.

The block monitoring unit 22 detects the voltage of the battery block 10 and the battery cell 11, detects the overvoltage of the battery block 10 and the disconnection of the battery block 10, and notifies the battery status monitoring unit 23 of these detection results. To do. The configuration and operation of the block monitoring unit 22 will be described in detail later.

Further, the battery condition monitoring unit 23 is, for example, an electronic control unit (ECU). The battery condition monitoring unit 23 determines the charging state of the assembled battery 1 based on the information acquired from the plurality of block monitoring units 22. The battery condition monitoring unit 23 notifies the vehicle control device 3 of the charging state of the assembled battery 1, or turns off the relay 6 based on the charging state of the assembled battery 1 to stop charging / discharging the assembled battery 1. can do.

For example, the battery status monitoring unit 23 determines that there is an abnormality in the assembled battery 1 or the block monitoring unit 22 when the voltage of the assembled battery 1 is larger than the allowable value, turns off the relay 6, and charges / discharges the assembled battery 1. Can be stopped. Further, when the block monitoring unit 22 detects an abnormality in the battery block 10, the battery condition monitoring unit 23 can turn off the relay 6 to stop charging / discharging the assembled battery 1.

The vehicle control device 3 controls the vehicle by charging / discharging the assembled battery 1 according to the charging state of the assembled battery 1. For example, the vehicle control device 3 converts the voltage charged in the assembled battery 1 into a power converter 5 from a direct current to an alternating voltage, and supplies the converted voltage to the motor 4 to drive the motor 4. As a result, the assembled battery 1 is discharged.

Further, the vehicle control device 3 converts the voltage generated by the regenerative braking of the motor 4 into a voltage of AC to DC by the power converter 5 and supplies the voltage to the assembled battery 1. As a result, the assembled battery 1 is charged. In this way, the vehicle control device 3 monitors the voltage of the assembled battery 1 based on the charging state of the assembled battery 1 acquired from the assembled battery monitoring system 2, and executes control according to the monitoring result.

[2. Block monitoring unit 22]
FIG. 2 is a diagram showing a configuration example of the satellite board 21 including the block monitoring unit 22. As shown in FIG. 2, the satellite board 21 is provided for each battery block 10, and includes a plurality of cell connection terminals T1, communication terminals T2, output terminals T3 and T5, input terminals T4, and a block monitoring unit. 22 and.

The block monitoring unit 22 includes a plurality of fuses 30, a power supply voltage generation unit 31, a cell monitor IC (Integrated Circuit) 32, a communication unit 33, an overvoltage detection unit 34, and a high voltage detection unit 35.

The power supply voltage generation unit 31 generates a power supply voltage Vc based on the voltage Vbr between the positive electrode and the negative electrode of the battery block 10 (hereinafter, may be referred to as a block voltage Vbr). The power supply voltage Vc (<Vbr) is output from the power supply voltage generation unit 31 to the cell monitor IC 32, the communication unit 33, the overvoltage detection unit 34, and the high voltage detection unit 35. The cell monitor IC 32, the communication unit 33, the overvoltage detection unit 34, and the high voltage detection unit 35 are operated by the power supply voltage Vc.

The positive electrode and the negative electrode of each battery cell 11 are connected to different cell connection terminals T1, and the cell monitor IC 32 (an example of the cell voltage detection unit) is connected to the positive electrode and the negative electrode of each battery cell 11 via a plurality of fuses 30. Be connected. When a large current flows between the cell connection terminal T1 and the cell monitor IC 32, the fuse 30 is blown and the cell monitor IC 32 is protected.

The cell monitor IC 32 detects the voltage of each battery cell 11 constituting the battery block 10 (hereinafter, may be referred to as the cell voltage Vce) and the block voltage Vbr. For example, the cell monitor IC 32 can detect the cell voltage Vce and the block voltage Vbr from the battery condition monitoring unit 23 in response to the voltage detection request, and notify the battery condition monitoring unit 23 of the detection result.

The communication unit 33 is an insulating communication interface, and is provided between the communication terminal T2 and the cell monitor IC 32. The communication unit 33 transmits and receives a communication signal S1 to and from the battery condition monitoring unit 23. The communication unit 33 can communicate between the battery condition monitoring unit 23 and the cell monitor IC 32 while maintaining the insulation between the cell monitor IC 32 and the battery condition monitoring unit 23.

The overvoltage detection unit 34 determines whether or not the voltage of the battery block 10 has become overvoltage, and outputs a detection result signal S2 indicating the determination result to the battery condition monitoring unit 23 via the output terminal T3. The overvoltage detection unit 34 compares the voltage corresponding to the block voltage Vbr with the threshold voltage Vath, and detects the overvoltage of the battery block 10 based on the comparison result. As described above, by providing the overvoltage detection unit 34 in addition to the cell monitor IC 32, the voltage of the battery block 10 can be monitored more appropriately.

Further, the overvoltage detection unit 34 can change the threshold voltage Vath based on the threshold adjustment request signal S3 input from the battery condition monitoring unit 23 to the input terminal T4. As a result, the threshold voltage Vath can be adjusted from the battery condition monitoring unit 23. The configuration of the overvoltage detection unit 34 will be described in detail later.

The high voltage detection unit 35 determines whether or not a disconnection of the battery block 10 such as “CID out” or “bus bar disconnection” has occurred, and transmits a detection result signal S4 indicating such a determination result via the output terminal T5. It can be output to the battery status monitoring unit 23. In addition, "CID out" is a state in which the current cutoff device (not shown) provided in the battery cell is activated and the current path of the battery cell 11 is cut off. Further, "bus bar disconnection" is a state in which the bus bar (not shown) connecting the battery cells 11 is disconnected from the battery cells 11.

The high voltage detection unit 35 has a rectifying bridge circuit, and detects a disconnection of the battery block 10 based on the output voltage of the rectifying bridge circuit. Therefore, the high voltage detection unit 35 can accurately detect the disconnection of the battery block 10 at both the time of discharging and the time of charging of the battery block 10.

As described above, by providing the high voltage detection unit 35 in addition to the cell monitor IC 32, the battery block 10 can be monitored more appropriately. Further, by detecting the disconnection of the battery cell by the high voltage detection unit 35, the cost can be reduced as compared with the case where the disconnection of the battery cell is detected by the flying capacitor. The configuration of the high voltage detection unit 35 will be described in detail later.

[3. Configuration example of overvoltage detection unit 34]
FIG. 3 is a diagram showing a configuration example of the overvoltage detection unit 34. The overvoltage detection unit 34 shown in FIG. 3 includes a voltage dividing circuit 41, a threshold voltage output unit 42, a comparator 43, an output unit 44, an input unit 45, a threshold voltage adjusting unit 46, and a power supply voltage monitoring unit 47. To be equipped.

The voltage divider circuit 41 generates a voltage corresponding to the block voltage Vbr. Specifically, the voltage dividing circuit 41 has resistors R1 and R2, and generates a voltage dividing voltage Va (= R2 / (R1 + R2)) which is a voltage obtained by dividing the block voltage Vbr. The configuration may be such that a voltage proportional to the block voltage Vbr can be output to the comparator 43, and is not limited to the voltage dividing circuit 41 shown in FIG.

The threshold voltage output unit 42 generates and outputs the threshold voltage Vath. Such a threshold voltage Vath is a voltage higher than the voltage dividing voltage Va when the block voltage Vbr is in the normal range.

The threshold voltage output unit 42 has, for example, a voltage dividing circuit similar to the voltage dividing circuit 41, and generates a voltage obtained by dividing the power supply voltage Vc as the threshold voltage Vath. The threshold voltage output unit 42 may be configured by, for example, a series circuit of a resistor and a Zener diode.

The comparator 43 compares the voltage dividing voltage Va with the threshold voltage Vath, and outputs a detection signal Scmp indicating the comparison result. Specifically, the comparator 43 outputs a high level detection signal Scmp indicating that the battery block 10 is overvoltage when the voltage dividing voltage Va is equal to or higher than the threshold voltage Vath. On the other hand, the comparator 43 outputs a Low level detection signal Scmp indicating that the battery block 10 is not overvoltage when the voltage dividing voltage Va is less than the threshold voltage Vath.

In this way, since the overvoltage detection unit 34 determines whether or not the battery block 10 is overvoltage by the comparator 43, the overvoltage detection unit 34 is lower than the case where the overvoltage is detected by the flying capacitor and the microcomputer. It can be configured by cost.

The output unit 44 is an insulating output unit, and is provided between the output terminal T3 and the output of the comparator 43. The output unit 44 outputs the detection result signal S2 corresponding to the detection signal Scmp to the battery condition monitoring unit 23. The output unit 44 can output the detection result signal S2 corresponding to the detection signal Scm to the battery condition monitoring unit 23 while maintaining the insulation between the overvoltage detection unit 34 and the battery condition monitoring unit 23.

FIG. 4 is a diagram showing an example of changes in the voltage dividing voltage Va, the detection signal Scmp, and the detection result signal S2 when the block voltage Vbr changes from the normal state to the overvoltage. As shown in FIG. 4, when the voltage dividing voltage Va becomes equal to or higher than the threshold voltage Vath due to overcharging of the battery block 10 or the like (time t1), the detection signal Scm changes from the Low level to the High level. Therefore, the detection result signal S2 indicating the overvoltage is output from the output unit 44 to the battery condition monitoring unit 23.

Returning to FIG. 3, the description of the overvoltage detection unit 34 will be continued. The input unit 45 of the overvoltage detection unit 34 is an insulating input unit, and is provided between the input terminal T4 and the output of the threshold voltage adjustment unit 46. The input unit 45 receives the threshold value adjustment request signal S3 requesting the adjustment of the threshold voltage Vath from the battery condition monitoring unit 23 via the input terminal T4.

The input unit 45 outputs the adjustment signal Ad corresponding to the received threshold value adjustment request signal S3 to the threshold voltage adjustment unit 46. The input unit 45 can perform communication between the battery condition monitoring unit 23 and the overvoltage detection unit 34 while maintaining the insulation between the battery condition monitoring unit 23 and the overvoltage detection unit 34.

The threshold voltage adjusting unit 46 adjusts the threshold voltage Vath based on the adjustment signal Ad output from the input unit 45. The threshold value adjustment request signal S3 and the adjustment signal Ad are, for example, pulse signals having a duty ratio, but it is sufficient that the threshold voltage Vath can be adjusted, and the threshold value adjustment request signal S3 and the adjustment signal Ad are limited to pulse signals having a duty ratio. Not done.

The threshold voltage adjusting unit 46 can adjust the threshold voltage Vath based on the duty ratio of the adjustment signal Ad. In this case, for example, a capacitor is connected to the output end of the threshold voltage output unit 42, and the electric charge of the capacitor is discharged at the duty ratio of the adjustment signal Ad to reduce the voltage of the capacitor. As a result, the threshold voltage Vath is adjusted.

By adjusting the threshold value adjustment request signal S3, the battery condition monitoring unit 23 can execute a self-diagnosis process of whether or not the cell monitor IC 32 and the overvoltage detection unit 34 are operating normally, such as a failure of the satellite board 21. Can be detected accurately.

For example, the battery condition monitoring unit 23 can adjust the threshold value adjustment request signal S3 so that the threshold voltage Vath becomes a voltage slightly higher than the voltage dividing voltage Va based on the detection result by the cell monitor IC 32. By such adjustment, when the detection result signal S2 indicating that there is an abnormality is output from the output unit 44 to the battery condition monitoring unit 23, the battery condition monitoring unit 23 detects that the cell monitor IC 32 or the overvoltage detection unit 34 has an abnormality. be able to.

Further, the battery condition monitoring unit 23 can adjust the threshold value adjustment request signal S3 so that the threshold voltage Vath becomes a voltage slightly lower than the voltage dividing voltage Va based on the detection result by the cell monitor IC 32. When the detection result signal S2 indicating that there is an abnormality is not output from the output unit 44 to the battery condition monitoring unit 23 by such adjustment, the battery condition monitoring unit 23 detects that the cell monitor IC 32 or the overvoltage detection unit 34 has an abnormality. Can be done.

FIG. 5 is a diagram showing an example of changes in the threshold voltage Vath, the adjustment signal Ad, and the detection signal Scmp when the self-diagnosis process is executed by the battery condition monitoring unit 23. In FIG. 5, the magnitude of the adjustment signal Ad indicates the detail ratio, and it is assumed that the cell monitor IC 32 is operating normally.

As shown in FIG. 5, before the self-diagnosis process is executed (before the time t10), the detail ratio of the adjustment signal Ad is zero, and the threshold voltage Vath is not adjusted by the threshold voltage adjusting unit 46. In this state, the threshold voltage Vath is somewhat higher than the voltage dividing voltage Va, and the detection signal Scmp is at the Low level.

After that, when the self-diagnosis process is executed at time t10, the battery condition monitoring unit 23 generates a threshold adjustment request signal S3 having a detail ratio of Duty 1 based on the block voltage Vbr according to the detection result of the cell monitor IC 32.

At this time, the detail ratio of the adjustment signal Ad output from the input unit 45 is Duty 1, and the threshold voltage Vath is adjusted by the threshold voltage adjusting unit 46, and the threshold voltage Vath drops to a level slightly higher than the voltage dividing voltage Va. In this state, since the threshold voltage Vath is higher than the voltage dividing voltage Va, the detection signal Scmp is at the Low level.

On the other hand, for example, it is assumed that the voltage dividing circuit 41 fails and the voltage dividing voltage Va becomes a voltage Va'higher than usual. In this case, the threshold voltage Vath falls below the voltage Va'at time t11. Therefore, the detection signal Scmp becomes a high level as shown in "Scmp'", and the detection result signal S2 indicating the overvoltage is output from the output unit 44 to the battery condition monitoring unit 23.

Therefore, the battery condition monitoring unit 23 can detect a failure of the voltage dividing circuit 41, that is, an abnormality of the overvoltage detecting unit 34, based on the detection result signal S2 output from the overvoltage detecting unit 34.

Further, even when the voltage dividing circuit 41 is normal, the threshold voltage Vath also becomes lower than usual when the threshold voltage Vath becomes lower than usual due to a failure of the threshold voltage output unit 42 or the threshold voltage adjusting unit 46. the divided voltage Va may fall below. Also in this case, based on the detection result signal S2 output from the overvoltage detection unit 34, a failure of the threshold voltage output unit 42 or the threshold voltage adjustment unit 46, that is, an abnormality of the overvoltage detection unit 34 can be detected.

When the battery condition monitoring unit 23 determines that the overvoltage detection unit 34 is normal, the battery status monitoring unit 23 raises the detail ratio of the threshold value adjustment request signal S3 from Duty1 to Duty2 at time t12. As a result, the threshold voltage Vath is adjusted by the threshold voltage adjusting unit 46 by the adjustment signal Ad of the Duty 2, and the threshold voltage Vath drops to a level slightly lower than the voltage dividing voltage Va. In this state, since the threshold voltage Vath is lower than the voltage dividing voltage Va, the detection signal Scmp is at the High level, and the detection result signal S2 indicating the overvoltage is output from the output unit 44 to the battery condition monitoring unit 23.

On the other hand, for example, it is assumed that the voltage dividing circuit 41 has failed and the voltage dividing voltage Va is lower than usual. In this case, the threshold voltage Vath is set to voltage Va "in the period from time t13 to t15. Exceed. Therefore, the detection signal Scmp remains at the Low level as shown in "Scmp", and the detection result signal S2 indicating the overvoltage is not output from the output unit 44 to the battery condition monitoring unit 23. Therefore, the battery condition monitoring unit 23 can detect a failure of the voltage dividing circuit 41, that is, an abnormality of the overvoltage detecting unit 34, based on the detection result signal S2.

Further, even when the voltage dividing circuit 41 is normal, the threshold voltage Vath also becomes higher than usual when the threshold voltage Vath becomes higher than usual due to a failure of the threshold voltage output unit 42 or the threshold voltage adjusting unit 46. it may exceed the divided voltage Va. In this case as well, the abnormality of the overvoltage detection unit 34 can be detected in the same manner.

Even if the overvoltage detection unit 34 is normal, if the cell monitor IC 32 is not operating normally and the block voltage Vbr cannot be detected normally, it is appropriate according to the threshold adjustment request signal S3 as in the above case. Detection result signal S2 may not be output. In such a case, the cell monitor IC 32 can detect an abnormality such as a failure.

Returning to FIG. 3, the description of the overvoltage detection unit 34 will be continued. The power supply voltage monitoring unit 47 of the overvoltage detection unit 34 can detect an abnormality in which the power supply voltage Vc rises. When the power supply voltage Vc rises above the threshold voltage Vct, the power supply voltage monitoring unit 47 determines that the power supply voltage Vc is abnormal.

When it is determined that the power supply voltage Vc is abnormal, the power supply voltage monitoring unit 47 outputs a high level abnormality detection signal Sub to the output unit 44, and outputs a detection result signal S2 indicating an abnormality from the output unit 44 to the battery status monitoring unit. Output to 23. By sharing the detection result signal S2 indicating an abnormality with the detection result signal S2 indicating an overvoltage, the configuration of the output unit 44 can be simplified.

When the magnitude of the threshold voltage Vath changes depending on the magnitude of the power supply voltage Vc, when an abnormality in which the power supply voltage Vc rises occurs, the threshold voltage Vath also rises. Therefore, when the battery block 10 becomes overvoltage, it may take time for the voltage dividing voltage Va to reach the threshold voltage Vath or higher, or the voltage dividing voltage Va may not reach the threshold voltage Vath or higher. In such a case, the detection of the overvoltage may be delayed or the overvoltage may not be detected, so that the battery block 10 may be further overcharged.

Therefore, when the power supply voltage Vc rises above the threshold voltage Vct, the power supply voltage monitoring unit 47 determines that the power supply voltage Vc is abnormal, and outputs the detection result signal S2 indicating the abnormality from the output unit 44 to the battery status monitoring unit 23. To output to. As a result, the battery condition monitoring unit 23 can, for example, turn off the relay 6 (see FIG. 1) to stop charging / discharging the assembled battery 1, and delays the suppression of overcharging of the battery block 10. Can be prevented.

FIG. 6 is a diagram showing state changes of the power supply voltage Vc, the voltage dividing voltage Va, and the abnormality detection signal Sab before and after the occurrence of an abnormality in which the power supply voltage Vc rises. As shown in FIG. 6, when a failure occurs in the power supply voltage generation unit 31 at time t20, the power supply voltage Vc rises, and the threshold voltage Vath rises as the power supply voltage Vc rises.

Then, when the power supply voltage Vc becomes equal to or higher than the threshold voltage Vct (time t21), the power supply voltage monitoring unit 47 outputs a high level abnormality detection signal Sab indicating that the power supply voltage Vc is abnormal to the output unit 44. .. As a result, the detection result signal S2 indicating an abnormality is output from the output unit 44 to the battery condition monitoring unit 23.

As described above, the overvoltage detection unit 34 has the power supply voltage monitoring unit 47, and even if the detection of the overvoltage is delayed due to the abnormality of the power supply voltage Vc or the overvoltage cannot be detected, the battery is used. The block 10 can be appropriately protected.

[4. Specific configuration example of the overvoltage detection unit 34]
FIG. 7 is a diagram showing a specific configuration example of the overvoltage detection unit 34. As shown in FIG. 7, the threshold voltage output unit 42 includes resistors R3 to R5 and a capacitor C1. The power supply voltage Vc is divided by the resistors R3 and R4, the divided voltage is input to the capacitor C1 via the resistor R5, and the voltage across the capacitor C1 is output as the threshold voltage Vath.

When the threshold adjustment request signal S3 is not input to the input terminal T4, that is, when the duty ratio of the threshold adjustment request signal S3 is zero, the threshold voltage output unit 42 sets the divided voltage of the power supply voltage Vc to the threshold voltage. Output as Threshold (= R4 / (R3 + R4)).

On the other hand, when the threshold voltage output unit 42 receives the threshold adjustment request signal S3 input to the input terminal T4, the threshold voltage adjustment unit 46 reduces the voltage across the capacitor C1 according to the threshold adjustment request signal S3. Therefore, the voltage after such a decrease becomes the threshold voltage Vath.

The output unit 44 includes resistors R6 to R8 and R18, a capacitor C2, transistors Q1 and Q2, and a photocoupler PC1. The transistor Q1 is an NPN type transistor, and the transistor Q2 is a PNP type transistor.

As shown in FIG. 7, the resistor R6 and the transistor Q1 form a first grounded emitter circuit, and the resistor R7 and the transistor Q2 form a second grounded emitter circuit. Then, the collector of the transistor Q1 is input to the base of the transistor Q2.

With this configuration, when the detection signal Scmp output from the comparator 43 is at the Low level, the transistor Q1 is off and the transistor Q2 is off. Therefore, when the detection signal Scmp is at the Low level, the photocoupler PC1 is off and the terminals T3a and T3b constituting the output terminal T3 are not connected, so that the detection result signal S2 indicating an overvoltage is an output terminal. No output from T3.

On the other hand, when the detection signal Scmp output from the comparator 43 is at the High level, the transistor Q1 is on and the transistor Q2 is on. Therefore, when the detection signal Scmp is at the High level, the photocoupler PC1 is on and the terminals T3a and T3b are connected, so that the detection result signal S2 indicating an overvoltage is output from the output terminal T3.

In this way, since the detection result signal S2 is output from the output terminal T3 by the photocoupler PC1, communication between the battery condition monitoring unit 23 and the overvoltage detection unit 34 can be performed while improving the insulation property. The resistor R6 and the capacitor C2 form a filter for removing noise. This makes it possible to prevent the photocoupler PC1 from being turned on due to the influence of noise or the like.

The input unit 45 has a photocoupler PC2 and resistors R9 and R10. The diode of the photocoupler PC2 is connected between the terminals T4a and T4b constituting the input terminal T4. Therefore, the photocoupler PC2 is turned on when a current flows between the terminals T4a and T4b, and the photocoupler PC2 is turned off when no current flows between the terminals T4a and T4b.

In the case of the configuration of the overvoltage detection unit 34 shown in FIG. 7, the threshold value adjustment request signal S3 is a pulse signal whose duty ratio is adjusted by the battery condition monitoring unit 23. The resistor R9 is connected between the collector of the transistor of the photocoupler PC2 and the power supply voltage Vc, and the resistor R10 is connected between the emitter of the transistor of the photocoupler PC2 and the ground.

The resistance value of the resistor R9 is sufficiently smaller than the resistance value of the resistor R10. Therefore, when the photocoupler PC2 is on, the adjustment signal Ad becomes the High level, and when the photocoupler PC2 is off, the adjustment signal Ad becomes the Low level. As a result, the input unit 45 outputs the adjustment signal Ad having the same duty ratio as the duty ratio of the threshold value adjustment request signal S3.

The threshold voltage adjusting unit 46 includes a resistor R11 and a transistor Q3. The adjustment signal Ad is input to the gate of the transistor Q3. When the adjustment signal Ad is off (Low level), the transistor Q3 is turned off and the capacitor C1 is not connected to the ground via the resistor R11.

On the other hand, when the adjustment signal Ad is on (High level), the transistor Q3 is turned on, and the capacitor C1 is connected to the ground via the resistor R11 and the transistor Q3. Therefore, when the duty ratio of the adjustment signal Ad is not zero, the voltage of the capacitor C1 decreases and the threshold voltage Vath decreases, and the higher the duty ratio of the adjustment signal Ad, the lower the threshold voltage Vath can be.

The power supply voltage monitoring unit 47 includes a resistor R12, a comparator 48, and a transistor Q4. The power supply voltage Vc is input to the non-inverting input terminal of the comparator 48, and the threshold voltage Vct is input to the inverting input terminal of the comparator 48. The threshold voltage Vct is generated from the block voltage Vbr. For example, by connecting the block voltage Vbr to the Zener diode via a resistor, the Zener of the Zener diode can be set to the threshold voltage Vct.

When the power supply voltage Vc is less than the threshold voltage Vct, the comparator 48 outputs a Low level signal. Therefore, the transistor Q4 is off, and the high level abnormality detection signal Sab is output. Therefore, when there is no abnormality in the overvoltage, the photocoupler PC1 is off. On the other hand, when the power supply voltage Vc is equal to or higher than the threshold voltage Vct, the comparator 48 outputs a High level signal. Therefore, the transistor Q4 is on, the low level abnormality detection signal Sab is output, and the photocoupler PC1 is on.

[5. Battery condition monitoring unit 23]
Next, the configuration and operation of the battery condition monitoring unit 23 that performs the above-mentioned self-diagnosis process will be described in more detail. FIG. 8 is a diagram showing a configuration example in which the self-diagnosis process is performed among the configurations of the battery status monitoring unit 23, and the configuration for performing other functions is omitted.

As shown in FIG. 8, the battery condition monitoring unit 23 includes a communication terminal T10, an input terminal T11, an output terminal T12, a communication unit 60, a block voltage value request unit 61, a block voltage value acquisition unit 62, and the like. A threshold voltage adjustment request unit 63 and an abnormality determination unit 64 are provided.

The battery status monitoring unit 23 includes, for example, a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and various circuits. By reading and executing the program stored in the ROM, the CPU of the microcomputer serves as a communication unit 60, a block voltage value request unit 61, a block voltage value acquisition unit 62, a threshold voltage adjustment request unit 63, and an abnormality determination unit 64. Function.

Further, at least one or all of the communication unit 60, the block voltage value request unit 61, the block voltage value acquisition unit 62, the threshold voltage adjustment request unit 63, and the abnormality determination unit 64 are ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable). It can also be configured with hardware such as Gate Array).

The communication unit 60 transmits / receives information or a request to / from the cell monitor IC 32 via the communication terminal T10, for example, in a serial data format or a parallel data format. The block voltage value request unit 61 outputs a voltage detection request from the communication unit 60 to the cell monitor IC 32. As a result, the cell monitor IC 32 is made to detect the voltage of the battery cell 11 or the voltage of the battery block 10.

The block voltage value acquisition unit 62 acquires information on the voltage value of each battery cell 11 or the voltage value of the battery block 10 transmitted from the cell monitor IC 32 in response to the voltage detection request. When the block voltage value acquisition unit 62 acquires the voltage value of each battery cell 11 from the cell monitor IC 32, the block voltage value acquisition unit 62 integrates the voltage values of all the battery cells 11 constituting the battery block 10 to provide information on the voltage value of the battery block 10. To get.

The threshold voltage adjustment request unit 63 generates a threshold adjustment request signal S3 having a duty ratio corresponding to the voltage value of the battery block 10 based on the voltage value of the battery block 10 acquired by the block voltage value acquisition unit 62. Output to the overvoltage detection unit 34 via the output terminal T12.

The threshold voltage adjustment request unit 63 generates, for example, a threshold adjustment request signal S3 having a duty ratio corresponding to the block voltage Vbr corresponding to each overvoltage detection unit 34, and generates a threshold adjustment request signal S3 for each overvoltage detection unit 34. It can be output from the output terminal T12. The output terminal T12 is provided for each overvoltage detection unit 34, whereby the threshold adjustment request signal S3 can be output for each overvoltage detection unit 34.

Further, the threshold voltage adjustment request unit 63 generates a common threshold adjustment request signal S3 for the plurality of overvoltage detection units 34, and outputs the common threshold adjustment request signal S3 from the output terminals T12 to the plurality of overvoltage detection units 34. Can be output to. In this case, the threshold voltage adjustment request unit 63 can generate a threshold adjustment request signal S3 having a duty ratio corresponding to an average value, a minimum value, or a maximum value of a plurality of block voltages Vbr as a common threshold adjustment request signal S3. ..

Further, although the output terminal T12 may be provided for each overvoltage detection unit 34, the output terminal T12 can be shared with a plurality of overvoltage detection units 34. For example, the input terminals T4 of the plurality of overvoltage detection units 34 may be cascade-connected, and one end and the other end of the cascade-connected input terminals T4 may be connected to the output terminal T12. As a result, the number of output terminals T12 can be reduced, and the battery condition monitoring unit 23 can be downsized.

The threshold voltage adjustment requesting unit 63 includes a first duty ratio output unit 65 and a second duty ratio output unit 66. The first duty ratio output unit 65 generates a duty ratio threshold adjustment request signal S3 so as to be a voltage slightly higher than the block voltage Vbr corresponding to each overvoltage detection unit 34, and overvoltages via the output terminal T12. Output to the detection unit 34.

When the first duty ratio output unit 65 generates a common threshold adjustment request signal S3 for the plurality of overvoltage detection units 34, the threshold voltage Vath is slightly higher than the maximum value of the plurality of block voltages Vbr. It is also possible to generate a threshold adjustment request signal S3 having a duty ratio such that the voltage becomes.

Further, the second duty ratio output unit 66 generates a duty ratio threshold adjustment request signal S3 so as to be a voltage slightly lower than the block voltage Vbr corresponding to each overvoltage detection unit 34, and via the output terminal T12. Is output to the overvoltage detection unit 34.

When the second duty ratio output unit 66 generates a common threshold adjustment request signal S3 for the plurality of overvoltage detection units 34, the threshold voltage Vath is slightly lower than the minimum value of the plurality of block voltage Vbr. It is also possible to generate a threshold adjustment request signal S3 having a duty ratio such that the voltage becomes about the same.

When the abnormality determination unit 64 outputs the detection result signal S2 from the first duty ratio output unit 65 to the overvoltage detection unit 34, the threshold adjustment request signal S3 output from the overvoltage detection unit 34 indicates that there is an abnormality. , The cell monitor IC 32 or the overvoltage detection unit 34 determines that there is an abnormality. Further, when the detection result signal S2 from the second duty ratio output unit 66 is output to the overvoltage detection unit 34, the abnormality determination unit 64 determines that the threshold adjustment request signal S3 output from the overvoltage detection unit 34 has no abnormality. When shown, it is determined that the cell monitor IC 32 or the overvoltage detection unit 34 is abnormal.

The input terminal T11 is provided for each overvoltage detection unit 34, and includes two terminals for connecting the terminals T3a and T3b constituting the output terminal T3, respectively. As a result, the detection result signal S2 can be input to each overvoltage detection unit 34.

The abnormality determination unit 64 has a detection unit (not shown) for detecting the continuity state between the terminals T3a and T3b constituting the output terminal T3, and the detection result for each overvoltage detection unit 34 by such a detection unit. The state of the signal S2 is determined, and an overvoltage abnormality or a power supply voltage abnormality is detected for each overvoltage detection unit 34. The conduction state between the terminals T3a and T3b can be determined, for example, by applying a voltage between the terminals T3a and T3b and whether or not a current flows at that time.

Further, the input terminal T11 can be shared with the plurality of overvoltage detection units 34. For example, the output terminals T3 of the plurality of overvoltage detection units 34 can be connected in parallel to the input terminals T11. As a result, the number of input terminals T11 can be reduced while making it possible to detect that an overvoltage abnormality or a power supply voltage abnormality has occurred in any one of the plurality of overvoltage detection units 34, and the battery condition monitoring unit 23 can be made smaller. Can be achieved.

FIG. 9 is a flowchart showing the flow of the self-diagnosis process performed by the battery condition monitoring unit 23. The cell monitor IC 32 will be described as normal.

As shown in FIG. 9, the battery condition monitoring unit 23 determines whether or not it is the self-diagnosis start timing of the overvoltage detection unit 34 (step S10). When it is determined that it is the self-diagnosis start timing of the overvoltage detection unit 34 (step S10; Yes), the battery condition monitoring unit 23 makes a voltage detection request to the cell monitor IC 32 and acquires the block voltage Vbr information (step S11). ..

Next, the battery condition monitoring unit 23 generates a duty ratio threshold adjustment request signal S3 so that the voltage becomes slightly higher than the block voltage Vbr acquired in step S11, and the overvoltage detection unit via the output terminal T12. Output to 34 (step S12). After that, the battery condition monitoring unit 23 determines whether or not the detection result signal S2 indicates normality (step S13).

When it is determined that the detection result signal S2 indicates normality (step S13; Yes), the battery condition monitoring unit 23 generates a duty ratio threshold adjustment request signal S3 such that the voltage is slightly lower than the block voltage Vbr. Then, it is output to the overvoltage detection unit 34 via the output terminal T12 (step S14). After that, the battery condition monitoring unit 23 determines whether or not the detection result signal S2 indicates an abnormality (step S15).

When it is determined that the detection result signal S2 indicates an abnormality (step S15; Yes), the battery condition monitoring unit 23 determines that the overvoltage detection unit 34 is normal (step S16). On the other hand, when it is determined in step S13 that the detection result signal S2 does not show normality (step S13; No), or when it is determined that the detection result signal S2 does not show abnormality (step S15; No), in step S15. The battery condition monitoring unit 23 determines that the overvoltage detection unit 34 is abnormal (step S17).

When it is determined that it is not the self-diagnosis start timing (step S10; No), when the process of step S16 or step S17 is completed, the process shown in FIG. 9 is repeated from step S10.

[6. High voltage detector 35]
Next, the high voltage detection unit 35 will be described. FIG. 10 is a diagram showing a configuration example of the high voltage detection unit 35.

As shown in FIG. 10, the high voltage detection unit 35 includes a rectifying bridge circuit 51 and a disconnection detection unit 52. The rectifying bridge circuit 51 is connected between the negative electrode and the positive electrode of the battery block 10 and rectifies and outputs the block voltage Vbr.

The disconnection detection unit 52 describes the detection result signal S4 (hereinafter, the detection result signal S4 indicating the disconnection) indicating that the battery block 10 is disconnected when the output voltage Vre of the rectifying bridge circuit 51 is equal to or higher than the predetermined voltage Vret. ) Is output. On the other hand, when the output voltage Vre of the rectifier bridge circuit 51 is less than the predetermined voltage Vreth, the detection result signal S4 indicating disconnection is not output.

As will be described in detail later, the disconnection detection unit 52 has, for example, a configuration having a plurality of voltage limiting circuits, and when the output voltage difference between these limiting voltage circuits is equal to or greater than a predetermined value, the output voltage Vre is predetermined. Assuming that the voltage is Vret or higher, the detection result signal S4 indicating a disconnection can be output.

Further, the disconnection detection unit 52 may have, for example, a configuration having a voltage dividing circuit for dividing the output voltage Vre and a comparator. In this case, when the voltage dividing voltage of the output voltage Vre is equal to or higher than the predetermined voltage, the disconnection detection unit 52 can output the detection result signal S4 indicating the disconnection, assuming that the output voltage Vre is equal to or higher than the predetermined voltage Vreth. ..

FIG. 11 is a diagram for explaining the relationship between the operating state of the current cutoff device (CID) of the battery cell 11, the charge / discharge state of the battery cell 11, and the voltage across the current cutoff device. In FIG. 11, the case where the CID expires is described as "CID expired", and the case where the CID expires does not occur is described as "CID normal". Further, the voltage across the current cutoff device when the CID is cut off is assumed to be ± 300 V as an example.

As shown in FIG. 11, when the CID is cut off during the discharge of the battery block 10, the voltage Vpid (hereinafter referred to as the CID voltage Vside) at the location where the CID is cut off becomes + 300 V, and the CID is charged while the battery block 10 is being charged. When a break occurs, the CID voltage Vside becomes -300V.

As described above, both poles of the battery block 10 are connected to the rectifying bridge circuit 51, and the block voltage Vbr is rectified by the rectifying bridge circuit 51 and output from the rectifying bridge circuit 51. Therefore, the same positive voltage is output from the rectifying bridge circuit 51 regardless of whether the CID voltage Vside is + 300V or −300V.

Therefore, by monitoring the output voltage Vre of the rectifying bridge circuit 51, even if the CID is cut off when the battery block 10 is charged or the cell current is cut off when the battery block 10 is charged. , The CID outage can be detected with high accuracy.

Further, when the bus bar is disconnected, a positive high voltage or a negative high voltage is generated between the battery blocks 10 from which the bus bar is disconnected, as in the case where the CID is exhausted. Therefore, the output voltage Vre of the rectifying bridge circuit 51 should be monitored. Therefore, it is possible to accurately detect the detachment of the bus bar regardless of whether the battery block 10 is charged or discharged.

Further, as shown in FIG. 2, the high voltage detection unit 35 is connected to both ends (negative electrode and positive electrode) of the battery block 10 without passing through the fuse 30. Therefore, for example, even when an overcurrent flows between the cell monitor IC 32 and the battery block 10 due to the disconnection of the battery block 10 and the fuse 30 is blown, the disconnection of the battery block 10 can be detected.

Therefore, the fuse 30 is blown due to the disconnection of the battery block 10, the voltage of the battery block 10 cannot be detected by the cell monitor IC 32 and the overvoltage detection unit 34, and the voltage information cannot be notified to the battery status monitoring unit 23. Also, the disconnection of the battery block 10 can be detected.

[7. Specific configuration example of the high voltage detection unit 35]
FIG. 12 is a diagram showing a specific configuration example of the high voltage detection unit 35. As shown in FIG. 12, the rectifying bridge circuit 51 is composed of a diode bridge circuit in which four diodes D10 to D13 are bridge-connected.

The disconnection detection unit 52 includes a first voltage limiting circuit 53, a second voltage limiting circuit 54, a determination unit 55, and an output unit 56.

When the output voltage Vre is equal to or less than the first voltage V1, the first voltage limiting circuit 53 outputs a voltage corresponding to the output voltage Vre as the output voltage Vcp1, and the output voltage Vre of the rectifying bridge circuit 51 is the first voltage V1. When it is higher, the output voltage Vcp1 is limited to the first voltage V1 for output. The "voltage corresponding to the output voltage Vre" is the same voltage as the output voltage Vre, assuming that the voltage between the input and output of the first voltage limiting circuit 53 can be ignored.

The first voltage V1 is set to a voltage higher than the block voltage Vbr when the battery block 10 is normal. For example, when the normal value of the block voltage Vbr is 110 V or less, the first voltage V1 is set to, for example, 130 V.

Therefore, when the block voltage Vbr is a normal value, the voltage corresponding to the block voltage Vbr is output from the first voltage limiting circuit 53 as the output voltage Vcp1. On the other hand, when the block voltage Vbr becomes higher than the normal value due to disconnection of the battery block 10, the first voltage V1 is output from the first voltage limiting circuit 53 as the output voltage Vcp1.

The first voltage limiting circuit 53 includes a resistor R20, a capacitor C10, and a Zener diode ZD1. One end of the resistor R20 is connected to the output of the rectifying bridge circuit 51, and a capacitor C10 and a Zener diode ZD1 are connected in parallel between the other end of the resistor R20 and the ground. The RC filter is composed of the resistor R20 and the capacitor C10.

The Zener voltage of the Zener diode ZD1 is set to the first voltage V1, and when the output voltage Vre is lower than the first voltage V1, the voltage corresponding to the output voltage Vre is output as the output voltage Vcp1.

On the other hand, when the output voltage Vre of the rectifying bridge circuit 51 is higher than the first voltage V1, the voltage at the other end of the resistor R20 is clamped by the Zener diode ZD1. As a result, when the output voltage Vre exceeds the first voltage V1, the output voltage Vcp1 of the first voltage limiting circuit 53 becomes the first voltage V1, and the voltage applied to the second voltage limiting circuit 54 and the determination unit 55 is first. The voltage can be limited to V1 or less.

Therefore, it is possible to avoid applying a high voltage to the second voltage limiting circuit 54 and the determination unit 55, and the rated voltage of each element constituting the second voltage limiting circuit 54 and the determination unit 55 is compared with the case where a high voltage is applied. Can be suppressed, and cost reduction and miniaturization can be achieved.

When the output voltage Vcp1 is lower than the first voltage V1 and is equal to or lower than the second voltage V2 (<V1), the second voltage limiting circuit 54 outputs a voltage corresponding to the output voltage Vcp1 as the output voltage Vcp2. The "voltage corresponding to the output voltage Vcp1" is the same voltage as the output voltage Vcp1 when the voltage between the input and output of the second voltage limiting circuit 54 can be ignored.

On the other hand, when the output voltage Vcp1 of the first voltage limiting circuit 53 is higher than the second voltage V2, the second voltage limiting circuit 54 limits the output voltage Vcp2 to the second voltage V2 and outputs the voltage.

The second voltage V2 is set to a voltage higher than the block voltage Vbr when the battery block 10 is normal, and is set to a voltage lower than the first voltage V1. For example, when the normal value of the block voltage Vbr is 110 V or less, the second voltage V2 is set to, for example, 120 V.

The second voltage limiting circuit 54 includes a resistor R21, a capacitor C11, and a Zener diode ZD2, and is configured in the same manner as the first voltage limiting circuit 53. However, when the Zener voltage of the Zener diode ZD2 is set to the second voltage V2 and the output voltage Vcp1 of the first voltage limiting circuit 53 is the second voltage V2 or less, the voltage corresponding to the output voltage Vre is the output voltage. It is output as Vcp2.

On the other hand, when the output voltage Vcp1 of the first voltage limiting circuit 53 exceeds the second voltage V2, the voltage at the other end of the resistor R21 is clamped by the Zener diode ZD2. As a result, when the output voltage Vcp1 of the first voltage limiting circuit 53 exceeds the second voltage V2, the output voltage Vcp2 of the second voltage limiting circuit 54 becomes the second voltage V2, which is lower than the first voltage V1.

Therefore, when the block voltage Vbr becomes high due to disconnection of the battery block 10, the first voltage V1 is output as the output voltage Vcp1 from the first voltage limiting circuit 53, and the second voltage V2 is output from the second voltage limiting circuit 54. Is output as the output voltage Vcp2. As described above, when the battery block 10 is disconnected, a voltage difference ΔV (= V1-V2) is generated between the output voltage Vcp1 and the output voltage Vcp2.

Therefore, the determination unit 55 determines whether or not the battery block 10 is disconnected based on the difference between the output voltage Vcp1 and the output voltage Vcp2. For example, the determination unit 55 determines that the battery block 10 is disconnected when the difference between the output voltage Vcp1 and the output voltage Vcp2 is equal to or greater than a predetermined value ΔVcp (<ΔV). On the other hand, when the difference between the output voltage Vcp1 and the output voltage Vcp2 is less than the predetermined value ΔVcp, the determination unit 55 determines that the battery block 10 is not disconnected.

The determination unit 55 includes, for example, an input resistance R22 and a transistor Q10. The output voltage Vcp1 of the first voltage limiting circuit 53 is input to the emitter of the transistor Q10, and the output voltage Vcp2 of the second voltage limiting circuit 54 is input to the base of the transistor Q10 via the input resistor R22.

Therefore, when the voltage difference between the output voltage Vcp1 and the output voltage Vcp2 becomes equal to or higher than the threshold voltage of the transistor Q10, the transistor Q10 is turned on and it is determined that the battery block 10 is disconnected. Therefore, in the case of the circuit shown in FIG. 12, the predetermined value ΔVcp is a voltage equal to or higher than the threshold voltage of the transistor Q10. On the other hand, when the voltage difference between the output voltage Vcp1 and the output voltage Vcp2 is less than the threshold voltage of the transistor Q10, the transistor Q10 is off and it is determined that the battery block 10 is not disconnected.

The output unit 56 is an insulating output unit, and is provided between the output of the determination unit 55 and the output terminal T5. The output unit 56 outputs the detection result signal S4 according to the determination result of the determination unit 55 to the battery condition monitoring unit 23. The output unit 56 can output the detection result signal S4 according to the determination result of the determination unit 55 to the battery condition monitoring unit 23 while maintaining the insulation between the high voltage detection unit 35 and the battery condition monitoring unit 23. it can.

The output unit 56 includes a resistor R23 and a photocoupler PC3. The diode side of the photocoupler PC3 is connected in series with the resistor R23, and the terminals T5a and T5b constituting the output terminal T5 are connected to the transistor side of the photocoupler PC3.

When the transistor Q10 is off, the photocoupler PC3 is off, the terminals T5a and T5b are not connected, and the detection result signal S4 indicating disconnection is not output from the output terminal T5. On the other hand, when the transistor Q10 is on, the photocoupler PC3 is on, the terminals T5a and T5b are connected, and the detection result signal S4 indicating disconnection is output from the output terminal T5.

The battery condition monitoring unit 23 detects the continuity state of the input terminal T15 (not shown) having two terminals connected to the terminals T5a and T5b, respectively, and the two terminals of the input terminal T15 (not shown). (Not shown). The battery condition monitoring unit 23 can determine the state of the detection result signal S4 for each high voltage detection unit 35 by such a detection unit, and can detect the disconnection of the battery block 10 for each high voltage detection unit 35. The conduction state between the terminals T5a and T5b can be determined, for example, by applying a voltage between the terminals T5a and T5b and whether or not a current flows at that time.

Further, the battery condition monitoring unit 23 can be configured to connect the output terminals T5 of the plurality of high voltage detection units 35 in parallel to the input terminals T15 (not shown). As a result, the number of input terminals T15 can be reduced while making it possible to detect that the battery block 10 has been disconnected in any one of the plurality of high voltage detection units 35, and the battery condition monitoring unit 23 can be made smaller. Can be achieved. The output terminals T5 of the plurality of high voltage detection units 35 may be connected to the input terminal T11 in parallel with the output terminal T3.

As described above, the disconnection detection unit 52 shown in FIG. 12 is provided with two voltage limiting circuits having a voltage limit higher than the normal value of the block voltage Vbr and different limiting voltages from each other, and the difference between the outputs of these voltage limiting circuits. Based on the above, it can be determined whether or not the battery block 10 is broken. Therefore, for example, the disconnection detection unit 52 can be configured relatively easily and inexpensively using only a resistor, a Zener diode, a capacitor, and a transistor.

The determination unit 55 shown in FIG. 12 detects that the voltage difference between the output voltage Vcp1 and the output voltage Vcp2 is equal to or greater than a predetermined value by the transistor Q10, but the configuration is not limited to this.

For example, the output voltage Vcp1 may be input to the resistor R23 side of the series circuit of the resistor R23 and the photocoupler PC3 (see FIG. 12), and the output voltage Vcp2 may be input to the photocoupler PC3 side of the series circuit. As a result, a current corresponding to the voltage difference ΔV between the output voltage Vcp1 and the output voltage Vcp2 flows in the series circuit of the resistor R23 and the photocoupler PC3.

Further, in this case, the voltage difference between the output voltage Vcp1 and the output voltage Vcp2 at which the photocoupler PC3 is turned on can be adjusted by adding one or more diodes in series to the series circuit of the resistor R23 and the photocoupler PC3. .. In this case, the forward direction of the diode is the same as the forward direction of the photocoupler PC3.

FIG. 13 is a diagram showing changes in the CID voltage Vside, output voltages Vre, Vcp1, Vcp2, and detection result signal S4 due to the occurrence of CID expiration when the battery block 10 is discharged.

As shown in FIG. 13, when the CID is cut off when the battery block 10 is discharged (time t31), the CID voltage Vside and the output voltages Vre, Vcp1 and Vcp2 increase. Then, when the output voltage Vcp1 of the first voltage limiting circuit 53 becomes higher than the second voltage V2 (time t32), the output voltage Vcp2 of the second voltage limiting circuit 54 is limited to the second voltage V2.

After that, when the output voltage Vcp1 of the first voltage limiting circuit 53 rises and the voltage difference between the output voltage Vcp1 and the output voltage Vcp2 becomes a predetermined value ΔVcp or more (time t33), the determination unit 55 determines the battery block 10 It is determined that there is a disconnection, and the output unit 56 outputs the detection result signal S4 indicating the disconnection from the output terminal T5.

FIG. 14 is a diagram showing changes in the CID voltage Vside, output voltages Vre, Vcp1, Vcp2, and detection result signal S4 due to the occurrence of CID expiration during charging of the battery block 10.

As shown in FIG. 14, when the CID is cut off when the battery block 10 is charged (time t31), the CID voltage Vside becomes a negative voltage, but the output voltage Vre output from the rectifying bridge circuit 51 is shown in FIG. It is a positive voltage as in the case shown. Therefore, as in the case shown in FIG. 13, the determination unit 55 determines that the battery block 10 is disconnected, and the output unit 56 can output the detection result signal S4 indicating the disconnection from the output terminal T5.

Here, the relationship between the current Ia flowing through the resistor R23 of the output unit 56 and the diode of the photocoupler PC3 and the on / off of the photocoupler PC3 will be described. FIG. 15 is a diagram showing an on / off state of the CID voltage Vside, the current Ia, and the photocoupler PC3.

As shown in FIG. 15, when the CID voltage Vcid becomes equal to or higher than the predetermined voltage Vcidth, the current Ia becomes equal to or higher than the threshold value Ith, the photocoupler PC3 is turned on, and the detection result signal S4 indicating disconnection is the output terminal T5. Is output from. The predetermined voltage Vcithth is a voltage corresponding to the predetermined voltage Vreth, and when the internal loss of the rectifying bridge circuit 51 is ignored, for example, Vcidth = Vreth.

As described above, the high voltage detection unit 35 has the rectifying bridge circuit 51, and detects the disconnection of the battery block 10 based on the output voltage Vre of the rectifying bridge circuit 51. Therefore, the disconnection of the battery block 10 can be detected with the same configuration regardless of whether the battery block 10 is in the charged state or the discharged state.

In the high voltage detection unit 35 shown in FIG. 12, the input side of the second voltage limiting circuit 54 is connected to the output side of the first voltage limiting circuit 53, but the high voltage detection unit 35 is limited to the configuration shown in FIG. Not done. FIG. 16 is a diagram showing another configuration example of the high voltage detection unit 35. In the high voltage detection unit 35 shown in FIG. 16, the input side of the second voltage limiting circuit 54 is connected to the output side of the rectifying bridge circuit 51.

In the high voltage detection unit 35 shown in FIG. 16, the input side of the first voltage limiting circuit 53 and the input side of the second voltage limiting circuit 54 are connected to the output side of the rectifying bridge circuit 51, respectively. Therefore, even if the rise of the output voltage Vcp1 is delayed by the capacitor C10, the delay of the rise of the output voltage Vcp2 due to such a delay can be suppressed. Therefore, the disconnection of the battery block 10 can be quickly detected.

As described above, the block monitoring unit 22 (an example of the voltage monitoring device) according to the embodiment is provided for each battery block 10 of the assembled battery 1 having the plurality of battery blocks 10. The block monitoring unit 22 includes a threshold voltage output unit 42, a comparator 43, and an output unit 44. The threshold voltage output unit 42 outputs the threshold voltage Vath. The comparator 43 compares the divided voltage Va of the block voltage Vbr (voltage of the battery block) with the threshold voltage Vath, and detects the overvoltage of the battery block 10. The output unit 44 outputs the detection result of the overvoltage by the comparator 43. In this way, since the block monitoring unit 22 determines whether or not the battery block 10 is overvoltage by the comparator 43, the block monitoring unit 22 is lower than the case where the overvoltage is detected by the flying capacitor and the microcomputer. It can be configured by cost.

Further, the block monitoring unit 22 includes an input unit 45 and a threshold voltage adjusting unit 46. The input unit 45 inputs the threshold value adjustment request signal S3 that requests the adjustment of the threshold voltage Vath. The threshold voltage adjusting unit 46 adjusts the threshold voltage Vath based on the threshold adjustment request signal S3 input to the input unit 45. In this way, since the block monitoring unit 22 can change the threshold voltage Vath from the outside of the block monitoring unit 22, it is possible to accurately detect the overvoltage of the battery block 10 and the failure of the block monitoring unit 22.

Further, the threshold adjustment request signal S3 is a pulse signal having a duty ratio corresponding to the block voltage Vbr, and the threshold voltage adjustment unit 46 adjusts the threshold voltage Vath based on the duty ratio of the threshold adjustment request signal S3. By converting the threshold value adjustment request signal S3 into a pulse signal, a threshold value adjustment request for adjusting the threshold voltage voltage in multiple stages can be made from the battery status monitoring unit 23 to the block monitoring unit 22 with a simple configuration while maintaining insulation. Can be sent.

Further, the block monitoring unit 22 includes a power supply voltage generation unit 31 and a power supply voltage monitoring unit 47. The power supply voltage generation unit 31 generates a power supply voltage Vc based on the block voltage Vbr. The threshold voltage output unit 42 outputs a voltage proportional to the power supply voltage Vc as the threshold voltage Vath. The power supply voltage monitoring unit 47 detects an abnormality in the power supply voltage Vc based on the rise in the power supply voltage Vc. The output unit 44 outputs the detection result of the abnormality of the power supply voltage Vc by the power supply voltage monitoring unit 47. As a result, it is possible to suppress overcharging of the battery block 10 even when the detection of the overvoltage is delayed when the magnitude of the threshold voltage Vath changes depending on the magnitude of the power supply voltage Vc. ..

Further, the output unit 44 includes a photocoupler PC2. The photocoupler PC2 turns ON / OFF according to the detection result of the overvoltage by the comparator 43, and outputs the detection result of the overvoltage by the comparator 43. As a result, for example, while maintaining insulation between the block monitoring unit 22 and the outside (for example, the battery condition monitoring unit 23), the overvoltage detection result can be sent to the outside (for example, the battery condition monitoring unit 23) with a simple configuration. Can be output.

Further, the assembled battery monitoring system 2 according to the embodiment includes a plurality of block monitoring units 22, and also includes a battery status monitoring unit 23 that communicates with the plurality of block monitoring units 22. The battery condition monitoring unit 23 stops charging / discharging of the assembled battery 1 based on the detection result of the overvoltage in the block monitoring unit 22. As a result, while providing the block monitoring unit 22 for each battery block 10, charging / discharging of the assembled battery 1 can be stopped based on the detection result of the overvoltage in the block monitoring unit 22.

Further, the assembled battery monitoring system 2 according to the embodiment includes a cell monitor IC 32 (an example of a cell voltage detection unit). The cell monitor IC 32 detects a block voltage Vbr or a plurality of cell voltages Vce (voltages of a plurality of battery cells constituting the battery block 10). Based on the voltage detected by the cell monitor IC 32, the battery status monitoring unit 23 sets a threshold value in the threshold voltage adjusting unit 46 so that the voltage is lower than the threshold voltage Vath output by the threshold voltage output unit 42 and higher than the block voltage Vbr. The request for adjusting the voltage Vath is output as the threshold adjustment request signal S3. After that, when the overvoltage detection result is output from the block monitoring unit 22, the battery status monitoring unit 23 determines that the block monitoring unit 22 has an abnormality. As a result, the failure of the block monitoring unit 22 can be detected with high accuracy.

Further, the battery condition monitoring unit 23 requests the threshold voltage adjusting unit 46 to adjust the threshold voltage Vath so as to be lower than the block voltage Vbr based on the voltage detected by the cell monitor IC 32. Output as. After that, when the overvoltage detection result is output from the block monitoring unit 22, the battery status monitoring unit 23 determines that the block monitoring unit 22 has an abnormality. As a result, the failure of the block monitoring unit 22 can be detected with high accuracy.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 set battery 2 sets battery monitoring system 10 battery block 11 battery cell 21 satellite board 22 block monitoring unit 23 battery condition monitoring unit 30 fuse 31 power supply voltage generator 32 cell monitor IC
34 Overvoltage detector 35 High voltage detector 41 Voltage divider circuit 42 Threshold voltage output unit 43 Comparator 44 Output unit 45 Input unit 46 Threshold voltage adjustment unit 47 Power supply voltage monitoring unit

Claims (6)

A voltage monitoring device provided for each battery block of an assembled battery having a plurality of battery blocks.
The threshold voltage output unit that outputs the threshold voltage and
A comparator that compares the divided voltage obtained by dividing the voltage of the battery block with the threshold voltage and detects the overvoltage of the battery block.
An output unit that outputs the detection result of the overvoltage by the comparator and
An input unit for inputting a threshold value adjustment request signal for adjusting the threshold voltage, and an input unit for inputting the threshold value adjustment request signal.
Based on the threshold value adjustment request signal inputted to the input unit, and a Ru voltage monitoring apparatus includes a threshold voltage adjustment section for adjusting the threshold voltage,
A cell voltage detection unit that detects the voltage of the battery block or the voltage of a plurality of battery cells constituting the battery block, and
A battery condition monitoring unit that communicates between the voltage monitoring device and the cell voltage detecting unit,
With
The battery condition monitoring unit
Based on the voltage detected by the cell voltage detection unit, the threshold voltage is applied to the threshold voltage adjusting unit so that the voltage is lower than the threshold voltage output by the threshold voltage output unit and higher than the divided voltage. The request to be adjusted is output as the threshold adjustment request signal,
When the overvoltage detection result is output from the voltage monitoring device after the threshold adjustment request signal is output, it is determined that the voltage monitoring device has an abnormality.
An assembled battery monitoring system characterized by this . A voltage monitoring device provided for each battery block of an assembled battery having a plurality of battery blocks.
The threshold voltage output unit that outputs the threshold voltage and
A comparator that compares the divided voltage obtained by dividing the voltage of the battery block with the threshold voltage and detects the overvoltage of the battery block.
An output unit that outputs the detection result of the overvoltage by the comparator and
An input unit for inputting a threshold value adjustment request signal for adjusting the threshold voltage, and an input unit for inputting the threshold value adjustment request signal.
Based on the threshold value adjustment request signal inputted to the input unit, and a Ru voltage monitoring apparatus includes a threshold voltage adjustment section for adjusting the threshold voltage,
A cell voltage detection unit that detects the voltage of the battery block or the voltage of a plurality of battery cells constituting the battery block, and
A battery condition monitoring unit that communicates between the voltage monitoring device and the cell voltage detecting unit,
With
The battery condition monitoring unit
Based on the voltage detected by the cell voltage detection unit, a request for the threshold voltage adjusting unit to adjust the threshold voltage so as to be lower than the divided voltage is output as the threshold adjustment request signal.
When the overvoltage detection result is not output from the voltage monitoring device after the threshold adjustment request signal is output, it is determined that the voltage monitoring device has an abnormality.
An assembled battery monitoring system characterized by this . The threshold value adjustment request signal is a pulse signal having a duty ratio corresponding to the voltage of the battery block.
The threshold voltage adjusting unit is
The assembled battery monitoring system according to claim 1 or 2, wherein the threshold voltage is adjusted based on the detail ratio of the pulse signal. A power supply voltage generator that lowers the voltage of the battery block to generate a power supply voltage,
A power supply voltage monitoring unit that detects an abnormality in the power supply voltage based on the rise in the power supply voltage is provided.
The threshold voltage output unit is
A voltage that decreases in proportion to the power supply voltage is output as the threshold voltage.
The output unit
The assembled battery monitoring system according to any one of claims 1 to 3, wherein the power supply voltage monitoring unit outputs the detection result of the abnormality. The output unit
The assembled battery monitoring system according to any one of claims 1 to 4, further comprising a photocoupler that turns ON / OFF according to the overvoltage detection result and outputs the overvoltage detection result. Before Symbol battery state monitoring unit,
Any of claims 1 to 5 , wherein communication is performed with the plurality of voltage monitoring devices, and charging / discharging of the assembled battery is stopped based on the detection result of the overvoltage by the voltage monitoring device. The assembled battery monitoring system described in one.

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