JP2014182088A - Battery monitoring device - Google Patents

Abstract

A battery monitoring device capable of improving fault tolerance is provided.
SOLUTION: One or N adjacent battery cells 10 are used as detection cells, a cell voltage detection circuit 21 that detects a cell voltage for each detection cell, and two or more adjacent detection cells are used as detection blocks, and each detection block is detected. A block voltage detection circuit 22 that detects a block voltage of the cell, a disconnection detection means 23a that detects a disconnection of the cell voltage detection line Lc, a voltage abnormality determination means 23b that determines whether or not a voltage abnormality has occurred in the detection cell, Is provided. The voltage abnormality determination means 23b estimates the block voltage of the detection block based on the cell voltage detected by the cell voltage detection circuit 21 when the disconnection of the cell voltage detection line Lc is detected by the disconnection detection means 23a. A value is calculated, and based on the difference between the estimated value and the detection value of the block voltage detection circuit 22, it is determined whether or not a voltage abnormality has occurred in the detection cell connected to the disconnected cell voltage detection line Lc.
[Selection] Figure 3

Description

  The present invention relates to a battery monitoring device that monitors a voltage state of an assembled battery configured by connecting a plurality of battery cells in series.

  Conventionally, in a battery monitoring device that detects battery cell voltage abnormality such as overcharge or overdischarge based on the detection result of the cell voltage of each battery cell, one that detects disconnection of a voltage detection line that detects the cell voltage has been proposed. (For example, refer to Patent Document 1). The disconnection of the voltage detection line can be determined based on the detection result of the cell voltage when both ends of the battery cell are short-circuited and the detection result of the cell voltage when not short-circuited.

JP 2008-175804 A

  By the way, in patent document 1, when a battery detection device breaks a voltage detection line, since the cell voltage of each battery cell cannot be detected, power supply from the assembled battery and charging of the assembled battery are prohibited or restricted. I am doing so.

  In this case, even if the voltage state of each battery cell is within a normal voltage range and no problem occurs even if the assembled battery is used, the use of the assembled battery is uniformly prohibited or restricted. Thus, the battery monitoring device of the prior art has a problem that it lacks fault tolerance.

  An object of this invention is to provide the battery monitoring apparatus which can aim at the improvement of fault tolerance in view of the said point.

  The present invention is directed to a battery monitoring device that monitors a voltage state of an assembled battery (1) configured by connecting a plurality of battery cells (10) in series.

  In order to achieve the above object, according to the first aspect of the present invention, a cell voltage detection circuit for detecting a cell voltage for each detection cell, using one or adjacent N (= positive integer) battery cells as detection cells. 21), two or more adjacent detection cells as detection blocks, a block voltage detection circuit (22) for detecting a block voltage for each detection block, and a cell voltage between the electrode terminal of the detection cell and the cell voltage detection circuit Disconnection detection means (23a) for detecting disconnection of the detection line (Lc), and voltage abnormality determination means (23b) for determining whether or not a voltage abnormality that causes the cell voltage of the detection cell to be outside a predetermined appropriate voltage range has occurred. The voltage abnormality determination means estimates the block voltage of the detection block based on the cell voltage detected by the cell voltage detection circuit when the disconnection of the cell voltage detection line is detected by the disconnection detection means. And whether or not a voltage abnormality has occurred in the detection cell connected to the disconnected cell voltage detection line based on the difference between the estimated value of the block voltage and the block voltage detected by the block voltage detection circuit. It is characterized by judging.

  According to this, even if the cell voltage detection line is disconnected, it is possible to detect a voltage abnormality in the detection cell connected to the disconnected cell voltage detection line. You can continue to use the battery. Therefore, the fault tolerance of the battery monitoring device can be improved.

  In addition, the code | symbol in the parenthesis of each means described in this column and the claim shows an example of a correspondence relationship with the specific means described in the embodiment described later.

It is a schematic block diagram of the battery monitoring apparatus which concerns on 1st Embodiment. It is a flowchart which shows the flow of the control processing which the control apparatus which concerns on 1st Embodiment performs. It is a flowchart which shows the flow of the principal part of the control processing which the control apparatus which concerns on 1st Embodiment performs. It is a schematic block diagram of the battery monitoring apparatus which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
Describing the first embodiment, in this embodiment, the battery monitoring device 2 of the present invention is applied to the assembled battery 1 mounted on a vehicle such as a hybrid vehicle or an electric vehicle.

  The assembled battery 1 constitutes an in-vehicle high-voltage battery that supplies power to various on-vehicle electric devices mainly using a driving device that generates a driving force for traveling the vehicle. The assembled battery 1 and various electric devices of the present embodiment are connected via an SMR (system main relay) (not shown) that switches the connection between the assembled battery 1 and the electric device between a conductive state and a cut-off state. When the SMR is turned off, it becomes impossible to supply power from the assembled battery 1 or charge the assembled battery 1. Accordingly, the SMR functions as a use prohibiting unit that prohibits the use of the assembled battery 1.

  As shown in FIG. 1, the assembled battery 1 is obtained by electrically connecting a plurality (for example, 100) of battery cells 10 made of a secondary battery such as a lithium ion battery in series. The assembled battery 1 of the present embodiment includes a plurality of battery blocks CB in which each battery cell 10 that is the minimum unit of charge / discharge is grouped in a predetermined number of units (in this example, five units). For convenience, FIG. 1 shows two representative battery blocks CBi and CBi + 1 among the plurality of battery blocks.

  The battery monitoring device 2 is a device that monitors the voltage state of the assembled battery 1, and includes a cell voltage detection circuit 21, a block voltage detection circuit 22, and a control device 23 as main components.

  The cell voltage detection circuit 21 is a circuit that detects a voltage for each detection cell using one or N adjacent (= positive integer: number smaller than the total number of) battery cells 10 as a detection cell. The cell terminals are connected to electrode terminals at both ends of each detection cell via a cell voltage detection line Lc. Specifically, the cell voltage detection circuit 21 of the present embodiment is configured to detect a voltage (cell voltage) for each battery cell 10 using one battery cell 10 as a detection cell.

  The cell voltage detection circuit 21 of the present embodiment includes a plurality of monitoring ICs (monitoring units) 211 provided corresponding to the battery blocks CB. Each monitoring IC 211 is an integrated circuit that detects the voltage of the detection cell of the corresponding battery block CB in accordance with a control signal from the control device 23 described later. Each monitoring IC 211 is configured to operate by power feeding from the corresponding battery block CB.

  Each monitoring IC 211 in this embodiment is connected to the control device 23 via an insulating part (not shown) such as a photocoupler. This insulating part is an insulating means for ensuring insulation between the assembled battery 1 side (high voltage system) and the control device 23 side (low voltage system). The signal transmission between each monitoring IC 211 and the control device 23 may be configured to be performed by a daisy chain method.

  Each monitoring IC 211 of this embodiment includes a cell voltage detection unit 211a that detects a voltage for each detection cell of the corresponding battery block CB, a short-circuit unit 211b for detecting disconnection, and the like.

  Specifically, the cell voltage detection unit 211a is an AD conversion type voltage detection circuit that samples the voltage of the detection cell at a predetermined period, converts the voltage into a digital signal, and outputs the digital signal. A multiplexer, an operational amplifier, and an AD converter (not shown) Etc. Note that the multiplexer is switching means for selectively connecting either one of the detection cells to a pair of input terminals of the operational amplifier. The operational amplifier is a differential amplifier circuit that outputs an analog signal corresponding to the potential difference between the two terminals of the detection cell selected by the multiplexer. The analog signal output from the operational amplifier is converted into a digital signal by the AD converter. The

  Moreover, the short circuit part 211b is a short circuit which short-circuits the electrode terminal of the both ends of each detection cell at the time of the disconnection detection process of the control apparatus 23 mentioned later, The short circuit switch which short-circuits the electrode terminal of both ends of each detection cell, predetermined | prescribed It is comprised by the serial connection body of the resistor which has resistance value. The operation of the short-circuit switch is controlled according to a control signal from the control device 23.

  The block voltage detection circuit 22 is a circuit for detecting a voltage for each detection block using two or more adjacent detection cells as detection blocks, and electrode terminals at both ends of each detection block via a plurality of block voltage detection lines Lb. It is connected to the. Specifically, the block voltage detection circuit 22 is configured to detect the voltage in units of the battery block CB with the battery block CB as a detection block.

  The block voltage detection circuit 22 of the present embodiment is composed of a flying capacitor type voltage detection circuit, and detects a capacitor (not shown), an input unit for inputting the voltage across the detection block to the capacitor, and a voltage stored in the capacitor. It consists of a detector and the like.

  Here, the block voltage detection circuit 22 can be realized with a simpler circuit configuration than the cell voltage detection circuit 21 because the number of monitoring of the battery voltage of the assembled battery 1 is smaller than that of the cell voltage detection circuit 21. The capacitor serves as an insulating means for ensuring insulation between the assembled battery 1 side (high voltage system) and the control device 23 side (low voltage system).

  Then, the control apparatus 23 which comprises the electronic control part of the battery monitoring apparatus 2 is demonstrated. The control device 23 according to the present embodiment includes a CPU, a microcomputer including various memories constituting a storage unit, and peripheral devices thereof, and is configured to execute various processes according to a control program stored in the memory. Yes.

  The control device 23 controls charging / discharging of the voltage detection circuits 21 and 22 and the assembled battery 1, and based on the detection results of the voltage detection circuits 21 and 22, the voltage abnormality of each detection cell and the cell voltage detection line Lc. It is configured to detect various abnormalities such as disconnection.

  The control device 23 of the present embodiment is configured to output a control signal instructing voltage detection to each of the voltage detection circuits 21 and 22 and obtain detection results (voltage values) of the voltage detection circuits 21 and 22. ing.

  In addition, the control device 23 of the present embodiment is configured to execute a disconnection detection process for detecting disconnection of each cell voltage detection line Lc. Specifically, the control device 23 determines whether or not each cell voltage detection line Lc is generated based on the detection result of the cell voltage detection unit 211a when the short circuit switch of the short circuit unit 211b is turned on / off. . For example, in the control device 23, when the detection result of the cell voltage detection unit 211a when the short circuit switch of the short circuit unit 211b is switched on / off is within the voltage range at the time of disconnection, the cell connected to the detection cell It may be determined that the voltage detection line Lc is disconnected.

  Furthermore, the control device 23 according to the present embodiment has a voltage abnormality (overdischarge or overcharge) that causes the cell voltage of each detection cell to be out of the appropriate voltage range based on the detection results of the voltage detection circuits 21 and 22. An overcharge / discharge determination process is performed to determine whether or not there is.

  Specifically, when the cell voltage detection line Lc is not disconnected, the control device 23 of the present embodiment sets the cell voltage of each detection cell detected by the cell voltage detection circuit 21 to an appropriate voltage range (for example, 0 .7V to 4.1) is determined. For example, in the control device 23, it is determined as overdischarge when the cell voltage of the detection cell is below the appropriate voltage range, and is determined as overcharge when it is above the appropriate voltage range.

  Here, in the disconnection detection process, when the disconnection of the cell voltage detection line Lc is detected, the cell voltage of the detection cell connected to the disconnected cell voltage detection line Lc cannot be detected by the cell voltage detection circuit 21. The charge / discharge determination process cannot be executed.

  Therefore, the control device 23 according to the present embodiment changes the content of the overcharge / discharge determination process depending on whether the cell voltage detection line Lc is disconnected. When the disconnection of the cell voltage detection line Lc is detected, the control device 23 of this embodiment detects the disconnected cell voltage based on the detection result of the cell voltage detection circuit 21 and the detection result of the block voltage detection circuit 22. It is determined whether or not a voltage abnormality has occurred in the detection cell connected to the line Lc. The specific content of the overdischarge determination process when the disconnection of the cell voltage detection line Lc is detected will be described later.

  Here, in this embodiment, the configuration for executing the disconnection detection process in the control device 23 constitutes the disconnection detection means 23a, and the configuration for executing the overdischarge determination process in the control device 23 constitutes the voltage abnormality determination means 23b. Yes.

  Next, an example of a series of control processes executed by the control device 23 of the battery monitoring device 2 will be described using the flowchart shown in FIG. The control routine shown in FIG. 2 is executed according to a command signal from a host control device that controls the entire vehicle, or a control schedule defined in the control device 23.

  First, a detection process for detecting the cell voltage Vc of each detection cell is executed (S10). In this process, a control signal instructing the detection of the cell voltage Vc is output to each monitoring IC 211 constituting the cell voltage detection circuit 21, and the detection result of the cell voltage Vc of each detection cell is acquired from each monitoring IC 211.

  Then, the detection process which detects the block voltage Vb of each detection block is performed (S20). In this process, a control signal that instructs the block voltage detection circuit 22 to detect the block voltage Vb is output, and the detection result of the block voltage Vb of each detection block is acquired from the block voltage detection circuit 22.

  Then, the disconnection detection process of each cell voltage detection line Lc is performed (S30). In this process, a control signal is output to each monitoring IC 211 to instruct on / off switching of the short circuit switch and detection of the cell voltage Vc when the on / off of the short circuit switch is switched. And the cell voltage Vc of each detection cell at the time of switching on / off of a short circuit switch from each monitoring IC211 is acquired, and it is determined whether the acquired cell voltage Vc is in the voltage range at the time of a disconnection. As a result of this determination processing, when the cell voltage Vc falls within the voltage range at the time of disconnection, it is determined that the cell voltage detection line Lc connected to the detection cell is disconnected.

  Subsequently, it is determined whether or not the disconnection of each cell voltage detection line Lc is detected in the disconnection detection process (S40). As a result, when it is determined that the disconnection of each cell voltage detection line Lc has not been detected, the cell voltage detection circuit 21 can detect the cell voltage Vc of each detection cell. A determination process is executed (S50). In this process, it is determined whether or not the cell voltage of each detection cell detected by the cell voltage detection circuit 21 is within an appropriate voltage range (0.7 V to 4.1 in this example). It is determined that the voltage is abnormal. In addition, it determines with overdischarge when the cell voltage of a detection cell is less than the appropriate voltage range, and determines with overcharge when it exceeds the appropriate voltage range.

  On the other hand, when it is determined in step S40 that the disconnection of the cell voltage detection line Lc has been detected, the cell voltage Vc of the detection cell connected to the disconnected cell voltage detection line Lc is supplied to the cell voltage detection circuit 21. Therefore, the overcharge / discharge determination process at the time of disconnection is executed (S60).

  In this process, the detection cell connected to the normal cell voltage detection line Lc that is not disconnected is subjected to the same process as the above-described normal overcharge / discharge determination process and connected to the disconnected cell voltage detection line Lc. For the detected cells, a process different from the normal overcharge / discharge determination process is executed.

  Hereinafter, the overcharge / discharge determination processing of the detection cell connected to the disconnected cell voltage detection line Lc will be described with reference to the flowchart of FIG.

  First, in a detection block including a detection cell connected to the disconnected cell voltage detection line Lc, an average value Vavg of cell voltages of the detection cells excluding the detection cell connected to the disconnected cell voltage detection line Lc is calculated ( S61). The average cell voltage Vavg of each detection cell excluding the detection cell connected to the disconnected cell voltage detection line Lc is the average cell voltage of each detection cell connected to the non-disconnected cell voltage detection line Lc. The value Vavg.

  Then, an estimated value Vest of the block voltage of the detection block including the detection cell connected to the disconnected cell voltage detection line Lc is calculated from the average value Vavg calculated in step S61 (S62). In the present embodiment, a value obtained by multiplying the average value Vavg calculated in the process of step S61 by the number of detection cells constituting the detection block is calculated as an estimated value Vest of the block voltage.

  Here, when the cell voltage of the detection cell connected to the disconnected cell voltage detection line Lc is overdischarged, the estimated value Vest of the detection block is higher than the block voltage Vb detected by the block voltage detection circuit 22. Increased (Vest> Vb).

  The subtracted value (Vest−Vb) obtained by subtracting the block voltage Vb from the estimated value Vest of the detection block is the cell voltage of the detection cell connected to the disconnected cell voltage detection line Lc and the average value Vavg of each detection cell. It makes a difference.

  For this reason, by comparing a subtraction value (Vest−Vb) obtained by subtracting the block voltage Vb from the estimated value Vest of the detection block and the overdischarge determination threshold, the detection cell connected to the disconnected cell voltage detection line Lc is compared. It can be determined whether or not an overdischarge has occurred. The overdischarge determination threshold value may be set to a value obtained by subtracting the lower limit value (0.7 in this example) of the appropriate voltage range from the average value Vavg of each detection cell.

  On the other hand, when the cell voltage of the detection cell connected to the disconnected cell voltage detection line Lc is overcharged, the estimated value Vest of the detection block is smaller than the block voltage Vb detected by the block voltage detection circuit 22. (Vest <Vb).

  The subtracted value (Vb−Vest) obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is the cell voltage of the detection cell connected to the disconnected cell voltage detection line Lc and the average value Vavg of each detection cell. It makes a difference.

  For this reason, the subtraction value (Vb−Vest) obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is compared with the overcharge determination threshold value, thereby detecting the detection cell connected to the disconnected cell voltage detection line Lc. It can be determined whether or not an overdischarge has occurred. The overcharge determination threshold value may be set to a value obtained by subtracting the average value Vavg of each detection cell from the upper limit value (4.1 in this example) of the appropriate voltage range.

  In view of these, in the present embodiment, based on the difference between the block voltage estimated value Vest and the block voltage Vb detected by the block voltage detection circuit 22, the detection cell connected to the disconnected cell voltage detection line Lc is applied. It is determined whether a voltage abnormality has occurred.

  Specifically, first, it is determined whether or not a subtraction value (Vest−Vb) obtained by subtracting the block voltage Vb from the estimated value Vest of the detection block is larger than the overdischarge determination threshold (= Vavg−0.7) ( S63).

  As a result, when it is determined that the subtraction value obtained by subtracting the block voltage Vb from the estimated value Vest of the detection block is larger than the overdischarge determination threshold, the voltage abnormality of the detection cell connected to the disconnected cell voltage detection line Lc The flag is set to overdischarge (S64).

  Here, the voltage abnormality flag is used to notify the host controller of the prohibition of use of the assembled battery 1 (for example, SMR off) when a voltage abnormality occurs in the detection cell connected to the disconnected cell voltage detection line Lc. Flag. Therefore, the use of the assembled battery 1 is prohibited by setting the voltage abnormality flag to overcharge in step S64.

  On the other hand, if it is determined that the subtraction value is equal to or less than the overdischarge determination threshold, the subtraction value obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is an overcharge determination threshold (= 4.1-Vavg). ) Is determined (S65).

  As a result, if it is determined that the subtraction value obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is larger than the overdischarge determination threshold, the voltage abnormality of the detection cell connected to the disconnected cell voltage detection line Lc The flag is set to overcharge (S66). Thereby, use of the assembled battery 1 is prohibited.

  On the other hand, if the subtraction value obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is determined to be equal to or less than the overcharge determination threshold, the abnormal voltage flag of the detection cell connected to the disconnected cell voltage detection line Lc is set. Set normally (S67). In this case, the use of the assembled battery 1 can be continued even when the cell voltage detection line Lc is disconnected.

  In the present embodiment described above, when the disconnection of the cell voltage detection line Lc is detected, the block voltage estimated value Vest of the detection block is calculated based on the cell voltage Vc detected by the cell voltage detection circuit 21. Then, based on the difference between the estimated value Vest of the block voltage and the block voltage Vb detected by the block voltage detection circuit 22, whether or not a voltage abnormality has occurred in the detection cell connected to the disconnected cell voltage detection line Lc. It is set as the structure which determines.

  According to this, even when the cell voltage detection line Lc is disconnected, the voltage abnormality of the detection cell connected to the disconnected cell voltage detection line Lc can be detected, and the battery abnormality of the detection cell has not occurred. Can continue to use the battery pack 1. Therefore, the fault tolerance of the battery monitoring device can be improved.

(Second Embodiment)
Next, a second embodiment will be described. In the present embodiment, description of the same or equivalent parts as in the first embodiment will be omitted or simplified.

  In the present embodiment, as shown in FIG. 4, the assembled battery 1 is composed of a plurality of battery blocks CB grouped in units of six battery cells 10, and the cell voltage detection circuit 21 includes two adjacent battery cells. 10 is a detection cell, and a circuit for detecting the voltage of each detection cell is used. For convenience, FIG. 4 shows a representative battery block CBi among a plurality of battery blocks.

  In the control device 23 of the present embodiment, it is determined whether or not a voltage abnormality such as overdischarge and overcharge has occurred in each of the two adjacent battery cells 10 based on the detection results of the voltage detection circuits 21 and 22. An overcharge / discharge determination process is executed.

  Specifically, when the cell voltage detection line Lc is not disconnected, the control device 23 of the present embodiment sets the cell voltage of each detection cell detected by the cell voltage detection circuit 21 to an appropriate voltage range (for example, 1 .4V to 8.2) is determined. For example, in the control device 23, it is determined as overdischarge when the cell voltage of the detection cell is below the appropriate voltage range, and is determined as overcharge when it is above the appropriate voltage range.

  When a disconnection of the cell voltage detection line Lc is detected, whether or not a voltage abnormality has occurred in the detection cell connected to the disconnected cell voltage detection line Lc based on the detection results of the voltage detection circuits 21 and 22. Determine whether.

  In this process, for example, in the detection block including the detection cell connected to the disconnected cell voltage detection line Lc, the average value Vavg of the cell voltages of each detection cell excluding the detection cell connected to the disconnected cell voltage detection line Lc. Is calculated. Then, the subtraction value (Vb−Vest) obtained by subtracting the estimated value Vest of the detection block from the block voltage Vb is compared with the overdischarge determination threshold value and the overcharge determination threshold value, and connected to the disconnected cell voltage detection line Lc. It is determined whether a voltage abnormality has occurred in the detection cell.

  Here, in the present embodiment, since two adjacent battery cells 10 are used as detection cells, the cell voltage of each detection cell is approximately twice that of the detection cell described in the first embodiment. For this reason, the overdischarge determination threshold value may be set to a value obtained by subtracting the lower limit value (for example, 0.7) of the appropriate voltage range from 0.5 × Vavg which is half of the average value Vavg of each detection cell. The overcharge determination threshold value may be set to a value obtained by subtracting 0.5 × Vavg, which is half of the average value Vavg of each detection cell, from the upper limit value (for example, 4.1) of the appropriate voltage range.

  Other configurations and operations are the same as those in the first embodiment. Therefore, according to the present embodiment, similarly to the first embodiment, even if the cell voltage detection line Lc is disconnected, it is possible to detect the voltage abnormality of the detection cell connected to the disconnected cell voltage detection line Lc. When the battery abnormality of the detection cell does not occur, the use of the assembled battery 1 can be continued.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, In the range described in the claim, it can change suitably. For example, various modifications are possible as follows.

  (1) In each of the above-described embodiments, the example in which the detection cell in the cell voltage detection circuit 21 is one or two adjacent battery cells 10 and the detection block in the block voltage detection circuit 22 is the battery block CB has been described. However, it is not limited to this. If the detection block in the block voltage detection circuit 22 is two or more adjacent detection cells, for example, the detection cell in the cell voltage detection circuit 21 may be three or more battery cells 10.

  (2) In each of the above-described embodiments, among the detection cells constituting the detection block, the block is determined based on the average voltage of the detection cells connected to the cell voltage detection line Lc that is not disconnected and the number of detection block cells. Although the example which calculates the estimated value Vest of a voltage was demonstrated, it is not limited to this. For example, among the detection cells constituting the detection block, among the detection cells connected to the cell voltage detection line Lc that is not disconnected, the block is determined based on the cell voltage of one representative detection cell and the number of detection block cells. The estimated voltage Vest may be calculated.

  (3) Although it is desirable to determine both overdischarge and overcharge by the control device 23 as in the above-described embodiments, either overdischarge or overcharge may be determined.

  (4) In each of the above-described embodiments, an example has been described in which when the control device 23 detects a voltage abnormality of the detection cell, a voltage abnormality flag that sets the prohibition of the use of the assembled battery 1 to the host control device is set. However, it is not limited to this. For example, when the control device 23 detects a voltage abnormality of each detection cell, the SMR may be directly turned off to prohibit the use of the assembled battery 1. Further, when the control device 23 detects a voltage abnormality of each detection cell, it may be notified only to the host control device.

  (5) In each of the above-described embodiments, the example in which the cell voltage detection circuit 21 is configured by a plurality of monitoring ICs 211 has been described. However, the present invention is not limited to this. For example, the cell voltage detection circuit 21 may be configured by a single integrated circuit or other than the integrated circuit Or may be configured.

  (6) In each of the above-described embodiments, the example in which the block voltage detection circuit 22 is configured by a flying capacitor type voltage detection circuit that detects a block voltage using a capacitor has been described. However, the present invention is not limited to this. For example, the block voltage detection circuit 22 may be configured by a voltage detection circuit other than the flying capacitor method.

  (7) In each of the above-described embodiments, the example in which the battery monitoring device 2 of the present invention is applied to the assembled battery 1 mounted on the vehicle has been described. However, the embodiment may be applied to the assembled battery 1 used other than the vehicle. .

  (8) The above-described embodiments are not irrelevant to each other, and can be appropriately combined unless the combination is clearly impossible.

  (9) In each of the above-described embodiments, the elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Needless to say.

  (10) In each of the above-described embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, the specific number is clearly specified when clearly indicated as essential. It is not limited to the specific number except when limited to.

  (11) In each of the above-described embodiments, when referring to the shape, positional relationship, etc. of the component, etc., unless otherwise specified, and in principle limited to a specific shape, positional relationship, etc. It is not limited to shape, positional relationship, and the like.

DESCRIPTION OF SYMBOLS 1 assembled battery 10 battery cell 21 cell voltage detection circuit 22 block voltage detection circuit 23 control apparatus 23a disconnection detection means 23b voltage abnormality determination means

Claims (5)

A battery monitoring device for monitoring a voltage state of an assembled battery (1) configured by connecting a plurality of battery cells (10) in series,
A cell voltage detection circuit (21) for detecting a cell voltage for each of the detection cells, using one or adjacent N (= positive integer) battery cells as detection cells;
A block voltage detection circuit (22) for detecting a block voltage for each detection block, using two or more adjacent detection cells as detection blocks;
Disconnection detecting means (23a) for detecting disconnection of a cell voltage detection line (Lc) between the electrode terminal of the detection cell and the cell voltage detection circuit;
Voltage abnormality determining means (23b) for determining whether or not a voltage abnormality that causes the cell voltage of the detection cell to be outside a predetermined appropriate voltage range has occurred,
The voltage abnormality determination means estimates the block voltage of the detection block based on the cell voltage detected by the cell voltage detection circuit when the disconnection of the cell voltage detection line is detected by the disconnection detection means. The voltage abnormality is calculated in the detection cell connected to the disconnected cell voltage detection line based on a difference between the estimated value of the block voltage and the block voltage detected by the block voltage detection circuit. A battery monitoring device for determining whether or not a battery has occurred.   The voltage abnormality determination unit is configured to disconnect the cell voltage detection line when the subtraction value obtained by subtracting the block voltage detected by the block voltage detection circuit from the estimated value of the block voltage is larger than an overdischarge determination threshold. The battery monitoring apparatus according to claim 1, wherein the detection cell connected to the battery is determined to be overdischarged.   The voltage abnormality determination unit is configured to disconnect the cell voltage detection line when a subtraction value obtained by subtracting an estimated value of the block voltage from the block voltage detected by the block voltage detection circuit is larger than an overcharge determination threshold. The battery monitoring device according to claim 1, wherein the detection cell connected to the battery is determined to be overcharged.   The voltage abnormality determination means includes: an average voltage of cell voltages of the detection cells excluding the detection cells connected to the disconnected cell voltage detection line among the detection cells constituting the detection block; and the detection block 4. The battery monitoring device according to claim 1, wherein an estimated value of the block voltage is calculated from the number of the detection cells constituting the battery.   5. The battery monitoring according to claim 1, wherein the voltage abnormality determination unit is configured to prohibit use of the assembled battery when the battery abnormality is detected. 6. apparatus.

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