JP6402597B2 - Battery monitoring device, power storage device, and disconnection diagnosis method - Google Patents

Description

  The technique disclosed by this specification is related with the monitoring apparatus of an assembled battery.

  Conventionally, comprising a plurality of switches connected in parallel to each cell of an assembled battery in which a plurality of cells are connected in series via a wire, and a voltage detection circuit that detects the voltage of each cell via the wire, A monitoring device for monitoring the voltage of each cell is known (see Patent Document 1). In this monitoring device, when the electric wire connecting each cell and the voltage detection circuit is disconnected, the voltage of the cell cannot be monitored, and therefore, disconnection diagnosis processing for diagnosing the presence or absence of the disconnection of the electric wire is performed. In the disconnection diagnosis processing, after each switch is closed and the corresponding cell is discharged, or while discharging the corresponding cell, the voltage of the cell is acquired, and the disconnection is determined based on the comparison result obtained by comparing the acquired voltage with the threshold value. Diagnose presence or absence. Conventionally, the disconnection diagnosis processing has been repeatedly executed at a predetermined cycle, for example.

JP 2010-268681 A

  However, since the disconnection diagnosis process involves cell discharge, the current consumption of the cell increases when it is repeatedly executed in a predetermined cycle.

  The present specification discloses a technique capable of solving at least a part of the problems described above.

(1) An assembled battery monitoring device disclosed in the present specification is an assembled battery monitoring device in which a plurality of cells are connected in series, and includes a plurality of switches connected in parallel to each cell via electric wires. A discharge circuit; a voltage detection circuit that detects a voltage of each cell via the electric wire; and a control unit, wherein the control unit is configured to enable the voltage detection circuit to operate when the plurality of switches are open. The detected open voltage of at least one of the cells is equal to or higher than a predetermined first threshold, and the open voltage of each of the at least one of the cells is equal to or lower than a second threshold smaller than the first threshold. If at least one of the switches satisfies the diagnostic condition, and if it is determined that the diagnostic condition is satisfied, the at least one switch is changed from the open state to the closed state. And diagnosing the presence or absence of breakage of the wire, when not determined that the diagnosis condition is satisfied, not to diagnose the presence or absence of breakage of the wire while maintaining the plurality of switches in the open state. In this assembled battery monitoring device, when the open voltage of at least one cell detected when a plurality of switches are in the open state satisfies the diagnostic condition, at least one switch is closed and the cell is discharged. Then, diagnose the presence or absence of wire breakage. Therefore, the number of times of diagnosis can be reduced and current consumption can be suppressed as compared with the case where the diagnosis of the presence or absence of the disconnection of the electric wire is repeatedly executed at a predetermined cycle.

(2) In the assembled battery monitoring apparatus, in the diagnosis of the presence or absence of disconnection of the electric wire, the voltage detected by the voltage detection circuit when the at least one switch is changed from the open state to the closed state and the closed state is detected. It is good also as a structure which diagnoses the presence or absence of the disconnection of the said electric wire using. According to this assembled battery monitoring apparatus, since the presence or absence of a wire breakage is diagnosed using the voltage detected by the voltage detection circuit when at least one switch is in the closed state, the wire breakage using the open voltage is detected. Compared to diagnosing the presence / absence, it is possible to accurately diagnose the presence / absence of wire breakage.

(3) In the assembled battery monitoring apparatus, the diagnosis condition includes that an open voltage of the at least one cell is equal to or higher than the first threshold, and the control unit is adjacent to the plurality of cells. When the first cell among the first cell and the second cell arranged in the same condition satisfies the diagnostic condition, the switch corresponding to the first cell is set to the open state, and the second cell The switch corresponding to the second cell is in the open state, and the voltage detection circuit detects the close voltage of the second cell in the closed state. The switch corresponding to the first cell is set to the closed state, and the voltage detection circuit detects the close voltage of the first cell when the switch is in the closed state. Carried out earlier than the Rukoto, it may be configured. According to this assembled battery monitoring device, the electric wire between the first cell and the second cell is disconnected, and as a result, the open voltage of the first cell becomes equal to or higher than the first threshold value. If it is, the close voltage of the second cell is a constant voltage of approximately 0V. Therefore, the presence or absence of the disconnection of an electric wire can be diagnosed early by detecting before the closing voltage of the 1st cell which changes with the actual voltage value of a 1st cell and a 2nd cell.

(4) In the assembled battery monitoring apparatus, the diagnostic condition includes that an open voltage of the at least one cell is equal to or lower than the second threshold value, and the control unit is adjacent to the plurality of cells. When the first cell among the first cell and the second cell arranged in the same condition satisfies the diagnostic condition, the switch corresponding to the second cell is set to the open state, and the first cell The switch corresponding to the first cell is in the open state, and the voltage detection circuit detects the close voltage of the first cell in the closed state. The switch corresponding to the second cell is set to the closed state, and the voltage detection circuit detects the close voltage of the second cell in the closed state. Carried out earlier than the Rukoto, it may be configured. According to this assembled battery monitoring apparatus, the electric wire between the first cell and the second cell is disconnected, and as a result, the open voltage of the first cell becomes equal to or lower than the second threshold value. If it is, the close voltage of the first cell is a constant voltage of approximately 0V. Therefore, the presence or absence of the disconnection of an electric wire can be diagnosed early by detecting before the closing voltage of the 2nd cell which changes with the actual voltage value of a 1st cell and a 2nd cell.

(5) In the assembled battery monitoring apparatus, the assembled battery may include three or more cells, and the first cells and the second cells are alternately arranged. According to this assembled battery monitoring apparatus, in an assembled battery including three or more cells, it is possible to reliably diagnose the presence or absence of a broken wire.

(6) In the assembled battery monitoring apparatus, the first threshold value may be an overcharge threshold value, and the second threshold value may be an overdischarge threshold value. According to this assembled battery monitoring apparatus, it is possible to diagnose the presence or absence of a broken wire using the overcharge threshold and the overdischarge threshold.

(7) A power storage device including an assembled battery in which a plurality of cells are connected in series, and the assembled battery monitoring device may be used.

  The technology disclosed in the present specification can be realized in various forms. For example, the function of the assembled battery monitoring device abnormality diagnosis method, assembled battery monitoring device or abnormality diagnosis method is realized. The present invention can be realized in various modes, such as a computer program for recording, a recording medium on which the computer program is recorded.

Block diagram showing the electrical configuration of the monitoring device 300 Flow chart showing abnormality diagnosis processing Flow chart showing disconnection diagnosis processing Flow chart showing the first diagnosis process Flow chart showing the second diagnosis process The block diagram which shows the electrical constitution of the monitoring apparatus 300 which the disconnection generate | occur | produced in the wiring 320

A. Embodiment:
A-1. Configuration of Battery Pack FIG. 1 is an explanatory diagram schematically showing a configuration of a battery pack 100 according to an embodiment. The battery pack 100 is provided in an electric vehicle (EV), for example, and supplies power to a load such as a motor that drives the EV. Further, the battery pack 100 is charged by, for example, a charger installed at a charging stand. The battery pack 100 is an example of a power storage device.

  The battery pack 100 includes an assembled battery 200 and a monitoring device 300. The assembled battery 200 includes four cells (also referred to as “single cells”) 210 to 240 connected in series. Each cell 210-240 is, for example, a lithium ion battery. However, each of cells 210 to 240 is not limited to a lithium ion battery, but may be a power storage element, and may be a capacitor.

  Hereinafter, the cell 210 is referred to as a first cell. The cell 220 is referred to as a second cell. The cell 230 is referred to as a third cell. The cell 240 is referred to as a fourth cell. The first cell 210 and the third cell 230 are collectively referred to as an odd cell CA. The second cell 220 and the fourth cell 240 are collectively referred to as an even cell CB. The odd cell CA is an example of one of the first cell and the second cell, and the even cell CB is an example of the other of the first cell and the second cell.

  The monitoring device 300 includes a monitoring unit 400 and a discharge unit 500. The monitoring unit 400 includes a central processing unit (hereinafter referred to as “CPU”) 410, a memory 420, and a voltage detection circuit 430. The memory 420 is composed of, for example, a RAM or a ROM, and stores various programs. CPU 410 controls the operation of each part of battery pack 100 in accordance with the program read from memory 420.

  The voltage detection circuit 430 is connected to both terminals of each of the cells 210 to 240 via the wirings 310 to 350, and individually detects the terminal voltage V of each of the cells 210 to 240. When the voltage detection circuit 430 receives a detection command signal from the CPU 410, the voltage detection circuit 430 outputs a voltage detection signal corresponding to the detected terminal voltage V of each cell 210 to 240 to the CPU 410. The wirings 310 to 350 are examples of electric wires.

  Hereinafter, the terminal voltage V of the first cell 210 is referred to as a first voltage V1. The terminal voltage V of the second cell 220 is referred to as a second voltage V2. The terminal voltage V of the third cell 230 is referred to as a third voltage V3. The terminal voltage V of the fourth cell 240 is referred to as a fourth voltage V4.

  The discharge unit 500 includes discharge circuits 510 to 540 provided between the wirings 310 to 350 that connect the cells 210 to 240 and the voltage detection circuit 430. The discharge circuits 510 to 540 are connected in parallel to the corresponding cells 210 to 240 via wirings 310 to 350, respectively. Each of the discharge circuits 510 to 540 is configured by connecting a resistor R and a switch Q in series.

  Opening and closing of the switches Q of the discharge circuits 510 to 540 is controlled by the CPU 410 of the monitoring unit 400. The CPU 410 transmits an open command signal and a close command signal to the switches Q of the discharge circuits 510 to 540 to control the opening and closing of the switches Q. When the switch Q of the discharge circuits 510 to 540 is closed by the close command signal from the CPU 410, a current flows through the wirings 310 to 350 and the resistor R, and corresponds to the discharge circuits 510 to 540. Cells 210-240 are discharged.

  Hereinafter, the switch Q of the discharge circuit 510 is referred to as a first switch Q1. The switch Q of the discharge circuit 520 is referred to as a second switch Q2. The switch Q of the discharge circuit 530 is referred to as a third switch Q3. The switch Q of the discharge circuit 540 is referred to as a fourth switch Q4. The switch Q may be a semiconductor switch element such as a field effect transistor or a mechanical switch.

A-2. Abnormality Diagnosis Processing Next, a specific flow of the abnormality diagnosis processing will be described with reference to FIGS. In the abnormality diagnosis process according to the present embodiment, each cell 210 to 240 and the voltage detection circuit are detected when an abnormality such as overcharge or overdischarge of each cell 210 to 240 is determined and an abnormality such as overcharge or overdischarge is detected. The presence or absence of disconnection of the wirings 310 to 350 connecting the 430 is diagnosed.

  In the abnormality diagnosis process of the present embodiment, open voltages VA1 to VA4 that are terminal voltages V1 to V4 of the cells 210 to 240 detected by the voltage detection circuit 430 when the switches Q1 to Q4 are opened (open) are used. Then, the abnormality of each cell 210-240 is determined. Here, “open voltage” means the terminal voltage V of each cell 210 to 240 detected when the corresponding switch Q is in the open state. Then, when it is detected that an abnormality has occurred in at least one cell 210 to 240, a disconnection diagnosis process for diagnosing disconnection of the wirings 310 to 350 is executed.

  As shown in FIG. 2, when the abnormality diagnosis process is started, the CPU 410 initializes the disconnection detection counter DC stored in the memory 420 to “0” (S100). The CPU 410 transmits an open command signal to the switches Q1 to Q4 (S110), and acquires the open voltages VA1 to VA4 of the cells 210 to 240 when the switches Q1 to Q4 are in the open state (S120). The disconnection detection counter DC will be described later.

  The memory 420 stores an overcharge threshold ZS for determining overcharge of each cell 210 to 240 and an overdischarge threshold HS for determining overdischarge. The CPU 410 compares the acquired open voltages VA1 to VA4 with the overcharge threshold ZS (S130). For example, as shown in FIG. 6, when the wiring 320 is disconnected, the open voltage VA2 of the second cell 220 to which the disconnected wiring 320 is connected to the negative electrode side becomes larger than the actual second voltage V2, It tends to be over the overcharge threshold ZS. The overcharge threshold value ZS is an example of a first threshold value.

  When the at least one open voltage VA1 to VA4 is equal to or higher than the overcharge threshold ZS (S130: YES), the CPU 410 has detected an overcharge abnormality in at least one cell 210 to 240, that is, an overcharge cell (FIG. 6). Then, it is determined that the second cell 220) is included, and disconnection diagnosis processing is executed (S150).

  When all the open voltages VA1 to VA4 are less than the overcharge threshold ZS (S130: NO), the CPU 410 compares the acquired open voltages VA1 to VA4 with the overdischarge threshold HS (S140). For example, as shown in FIG. 6, when the wiring 320 is disconnected, the open voltage VA2 of the first cell 210 to which the disconnected wiring 320 is connected to the positive electrode side becomes smaller than the actual first voltage V1, It tends to be below the overdischarge threshold HS. The overdischarge threshold value HS is an example of a second threshold value.

  When the at least one open voltage VA1 to VA4 is equal to or lower than the overdischarge threshold HS (S140: YES), the CPU 410 has detected an overdischarge abnormality in at least one cell 210 to 240, that is, an overdischarge cell (FIG. 6). Then, it is determined that the first cell 210) is included, and disconnection diagnosis processing is executed (S150).

  On the other hand, when all the open voltages VA1 to VA4 are less than the overcharge threshold ZS and greater than the overdischarge threshold HS (S130: NO, S140: NO), the CPU 410 indicates that the cells 210 to 240 are normal, It is determined that no disconnection has occurred in the wirings 310 to 350, and the abnormality diagnosis process is terminated without executing the disconnection diagnosis process.

  In the disconnection diagnosis processing, the switches Q1 to Q4 are changed from the open state to the closed state, and the closed voltages VB1 to VB4 that are the terminal voltages V1 to V4 of the cells 210 to 240 detected by the voltage detection circuit 430 when the switches Q1 to Q4 are closed are used. Then, the presence or absence of disconnection of the wirings 310 to 350 is diagnosed. Here, the “close voltage” means the terminal voltage V of each of the cells 210 to 240 detected when the corresponding switch Q is in the closed state. Specifically, each of the close voltages VB1 to VB4 is compared with a predetermined reference value, and a disconnection detection counter DC indicating the number of close voltages VB1 to VB4 determined to be abnormal is used to determine the wiring 310 to 350. Diagnose the disconnection.

  As illustrated in FIG. 3, when starting the disconnection diagnosis process, the CPU 410 determines whether the cells 210 to 240 include an overcharged cell (S300). CPU410 specifies the overcharge cell contained in the cells 210-240, when the overcharge cell is contained in the cells 210-240 (S300: YES) (S310).

  CPU410 determines whether or not the identified overcharged cell is included in even-numbered cell CB (S320). CPU410 performs a 1st diagnostic process before the 2nd diagnostic process mentioned later (S350), when the specified overcharge cell is contained in the even-numbered cell CB (S320: YES). For example, as shown in FIG. 6, when the overcharged cell is the second cell 220, since the overcharged cell is included in the even-numbered cell CB, the first diagnosis process is executed first. In addition, when the identified overcharged cell is included in the odd-numbered cell CA (S320: NO), the CPU 410 executes the second diagnosis process first (S360).

  On the other hand, CPU410 specifies the overdischarge cell contained in cells 210-240, when an overcharge cell is not contained in cells 210-240 and an overdischarge cell is contained (S300: NO) (S330). . The CPU 410 determines whether or not the identified overdischarge cell is included in the even-numbered cell CB (S340). When the identified overdischarge cell is included in the even-numbered cell CB (S340: YES), the CPU 410 executes the second diagnosis process before the first diagnosis process (S360). Further, when the identified overdischarge cell is included in the odd-numbered cell CA (S340: NO), the CPU 410 executes the first diagnosis process first (S350). For example, as shown in FIG. 6, when the overdischarge cell is the first cell 210, since the overcharge cell is included in the odd-numbered cell CA, the first diagnosis process is executed first.

  In the first diagnosis process, it is determined whether or not the close voltages VB1 and VB3 of the odd-numbered cell CA are abnormal. As shown in FIG. 4, when starting the first diagnosis process, the CPU 410 transmits a close command signal to the first switch Q1 and the third switch Q3 corresponding to the odd-numbered cell CA, and the first switch Q1 and the third switch Q3 is changed from the open state to the closed state (S500). As a result, the odd-numbered cell CA is discharged. Further, the CPU 410 transmits an open command signal to the second switch Q2 and the fourth switch Q4 corresponding to the even cell CB, and sets the second switch Q2 and the fourth switch Q4 to the open state (S510). The CPU 410 acquires the close voltages VB1 and VB3 of the odd-numbered cell CA when the first switch Q1 and the third switch Q3 are in the closed state (S520).

  The memory 420 stores an upper limit reference value UK and a lower limit reference value DK, which are reference values for diagnosing disconnection of the wirings 310 to 350. For example, the upper limit reference value UK is set to a value larger than the overcharge threshold value ZS, and the lower limit reference value DK is set to a value smaller than the overdischarge threshold value HS. The CPU 410 compares the acquired close voltages VB1 and VB3 with the upper limit reference value UK and the lower limit reference value DK (S530). For example, as illustrated in FIG. 6, when the wiring 320 is disconnected, the closing voltage VB1 of the second cell 220 acquired using the voltage detection circuit 430 is approximately 0 V, which is lower than the lower limit reference value DK.

  When the close voltages VB1 and VB3 are equal to or higher than the upper limit reference value UK or lower than the lower limit reference value DK (S530: YES), the CPU 410 determines that the close voltages VB1 and VB3 are abnormal. The CPU 410 increases the disconnection detection counter DC by the number of close voltages VB1 and VB3 determined to be abnormal (S540), and ends the first diagnosis process.

  On the other hand, when each of the close voltages VB1 and VB3 is less than the upper limit reference value UK and greater than the lower limit reference value DK (S530: NO), the CPU 410 determines that the close voltages VB1 and VB3 of the odd cell CA are normal. In this case, the CPU 410 ends the first diagnosis process without increasing the disconnection detection counter DC.

  In the second diagnosis process, it is determined whether or not the close voltages VB2 and VB4 of the even cell CB are abnormal. As shown in FIG. 5, when starting the second diagnosis process, the CPU 410 transmits a close command signal to the second switch Q2 and the fourth switch Q4 corresponding to the even cell CB, and the second switch Q2 and the fourth switch Q4 is changed from the open state to the closed state (S600). As a result, the even cell CB is discharged. In addition, the CPU 410 transmits an open command signal to the first switch Q1 and the third switch Q3 corresponding to the odd-numbered cell CA, and sets the first switch Q1 and the third switch Q3 to an open state (S610). The CPU 410 acquires the close voltages VB2 and VB4 of the even cells CB when the second switch Q2 and the fourth switch Q4 are in the closed state (S620).

  The CPU 410 compares the acquired close voltages VB2 and VB4 with the upper limit reference value UK and the lower limit reference value DK (S630). For example, as shown in FIG. 6, when the wiring 320 is disconnected, the close voltage VB1 of the first cell 210 acquired using the voltage detection circuit 430 is the actual first voltage V1 and second voltage V2. Depending on the magnitudes of the first voltage V1 and the second voltage V2, it is equal to or higher than the upper limit reference value UK.

  When the close voltages VB2 and VB4 are equal to or higher than the upper limit reference value UK or lower than the lower limit reference value DK (S630: YES), the CPU 410 determines that the close voltages VB2 and VB4 are abnormal. The CPU 410 increases the disconnection detection counter DC by the number of the close voltages VB2 and VB4 determined to be abnormal (S640), and ends the second diagnosis process.

  On the other hand, when each of the close voltages VB2 and VB4 is less than the upper limit reference value UK and greater than the lower limit reference value DK (S630: NO), the CPU 410 determines that the close voltages VB2 and VB4 of the odd cell CA are normal. In this case, the CPU 410 ends the second diagnosis process without increasing the disconnection detection counter DC.

  As shown in FIG. 3, in the disconnection diagnosis process, when the CPU 410 ends the first diagnosis process (S350), the CPU 410 determines whether or not the disconnection detection counter DC is equal to or greater than a predetermined value (S370). CPU410 complete | finishes a disconnection diagnostic process, when the disconnection detection counter DC is beyond a regulation value (S370: YES). On the other hand, when the disconnection detection counter DC is less than the specified value (S370: NO), the second diagnosis process is executed (S380), and the disconnection diagnosis process is terminated. Note that the first diagnosis process of S400 is the same process as the first diagnosis process of S350, and redundant description is omitted.

  Further, when the second diagnosis process is finished (S360), the CPU 410 determines whether or not the disconnection detection counter DC is equal to or greater than a specified value (S390). CPU410 complete | finishes a disconnection diagnostic process, when the disconnection detection counter DC is more than a regulation value (S390: YES). On the other hand, when the disconnection detection counter DC is less than the specified value (S390: NO), the first diagnosis process is executed (S400), and the disconnection diagnosis process is terminated. Note that the first diagnosis process of S400 is the same process as the first diagnosis process of S350, and redundant description is omitted.

  As shown in FIG. 2, in the abnormality diagnosis process, when the CPU 410 ends the disconnection diagnosis process (S150), the CPU 410 determines whether or not the disconnection detection counter DC is equal to or greater than a specified value (S160). When the disconnection detection counter DC is equal to or greater than the specified value (S160: YES), the CPU 410 diagnoses that the disconnection has occurred in the wirings 310 to 350 (S170). In this case, the CPU 410 performs necessary processing such as notifying the occurrence of disconnection, and ends the abnormality diagnosis processing.

  On the other hand, if the disconnection detection counter DC is less than the specified value (S160: NO), it is diagnosed that an abnormality has occurred in the cells 210-240. The CPU 410 determines whether the cells 210 to 240 include overcharged cells or overdischarged cells (S180). When the cells 210 to 240 include overcharged cells (S180: YES), the CPU 410 diagnoses that the cells 210 to 240 are overcharged (S190). In this case, the CPU 410 performs necessary processing such as discharging overcharged cells 210 to 240 using the switches Q1 to Q4, and ends the abnormality diagnosis processing.

  In addition, when the cells 210 to 240 include an overdischarge cell (S180: NO), the CPU 410 diagnoses that an overdischarge has occurred in the cells 210 to 240 (S200). In this case, the CPU 410 executes necessary processes such as discharging the cells 210 to 240 using the switches Q1 to Q4, such as prompting charging of the assembled battery 200 by notification or the like, and ends the abnormality diagnosis process.

  As described above, in this embodiment, the open voltages VA1 to VA4 detected when the switches Q1 to Q4 are in the open state are not less than the overcharge threshold ZS and not more than the overdischarge threshold HS. When a diagnostic condition including the above is satisfied, a disconnection diagnostic process involving the discharge of the cells 210 to 240 is executed. Therefore, the number of times of the disconnection diagnosis process can be reduced and the current consumption of the cells 210 to 240 can be suppressed as compared with the case where the disconnection diagnosis process is repeatedly executed at a predetermined cycle.

  In the present embodiment, it is determined whether or not the open voltages VA1 to VA4 satisfy the diagnosis condition, and it is detected whether or not the wires 310 to 350 are disconnected. Since the open voltages VA1 to VA4 are detected without discharge of the cells 210 to 240, even if the determination as to whether or not the open voltages VA1 to VA4 satisfy the diagnostic condition is repeatedly executed at a predetermined cycle, the cells The current consumption of 210 to 240 does not increase.

  In the present embodiment, the disconnection diagnosis processing is executed when the open voltages VA1 to VA4 satisfy the diagnosis condition including being over the overcharge threshold ZS and over the overdischarge threshold HS. When the disconnection of the wirings 310 to 350 occurs, the open voltages VA1 to VA4 detected by the voltage detection circuit 430 via the wirings 310 to 350 also fluctuate and are likely to be over the overcharge threshold ZS or overdischarge threshold HS. Whether the wirings 310 to 350 are disconnected by including the conditions of significant increase or decrease in voltage such as being overcharge threshold ZS or overdischarge threshold HS or less as diagnostic conditions It is possible to accurately estimate whether or not.

  In the present embodiment, in the disconnection diagnosis process, the disconnection of the wirings 310 to 350 is diagnosed using the close voltages VB1 to VB4, so that the disconnection of the wirings 310 to 350 is diagnosed using the open voltages VA1 to VA4. The disconnection of the wirings 310 to 350 can be accurately diagnosed.

  In the present embodiment, when the even cell CB includes a cell having an overcharge abnormality, the first diagnosis process for diagnosing the abnormality of the close voltage VB1, VB3 of the odd cell CA is performed as the close voltage VB2, VB4 of the even cell CB. This is executed before the second diagnosis process for diagnosing the abnormality. Thereby, the disconnection of the wirings 310 to 350 can be reliably diagnosed. When the disconnection of the wirings 310 to 350 is diagnosed by the first diagnosis process, the abnormality diagnosis process is terminated without executing the second diagnosis process. Thereby, the disconnection diagnosis process can be simplified and the time required for the disconnection diagnosis process can be shortened.

  Similarly, when the odd-numbered cell CA includes a cell having an overcharge abnormality, the second diagnostic process is executed before the first diagnostic process. When the even-numbered cell CB includes a cell having an overdischarge abnormality, the second diagnosis process is executed before the first diagnosis process. When the odd-numbered cell CA includes a cell having an abnormal overdischarge, the first diagnosis process is executed before the second diagnosis process.

C. Variation:
The technology disclosed in the present specification is not limited to the above-described embodiment, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are possible. For example, in the above-described embodiment, the monitoring device 300 includes one CPU 410. However, the configuration of the monitoring device 300 is not limited to this, and includes a configuration including a plurality of CPUs, an ASIC (Application Specific Integrated Circuit), and the like. A configuration including a hard circuit or a configuration including both a hard circuit and a CPU may be used.

  In the above embodiment, the battery pack 100 includes one monitoring device 300, but may include a plurality of monitoring devices 300. Moreover, you may provide the some assembled battery 200 and the some monitoring apparatus 300. FIG.

  Moreover, in the said embodiment, the example which the 1st threshold value was the overcharge threshold value ZS and the 2nd threshold value was the overdischarge threshold value HS was shown as diagnostic conditions which perform a disconnection diagnostic process. However, the present invention is not limited to this. For example, the first threshold value and the second threshold value may be set to values different from the overcharge threshold value ZS and the overdischarge threshold value HS.

  Specifically, the use range of the terminal voltage V is determined for each of the cells 210 to 240, and the overcharge threshold ZS is normally set to a voltage higher than the upper limit value of the use range. The first threshold value may be set to a voltage lower than the overcharge threshold value ZS, and may be set to an upper limit value of the use range of the terminal voltage V, for example. Thereby, compared with the case where the 1st threshold value is set to the overcharge threshold value ZS, abnormalities, such as an overcharge of each cell 210-240, can be detected early.

  Similarly, the overdischarge threshold value HS is normally set to a voltage lower than the lower limit value of the usage range of the terminal voltage V of each cell 210-240. The second threshold value may be set to a voltage higher than the overdischarge threshold value HS, for example, may be set to a lower limit value of the usage range of the terminal voltage V. Thereby, compared with the case where the 2nd threshold is set to the overdischarge threshold HS, abnormalities, such as overdischarge of each cell 210-240, can be detected early.

  In addition, when the monitoring unit 400 includes a plurality of voltage detection circuits 430, a disconnection occurs when an abnormality relating to voltage detection occurs, such as when the voltage detected by each voltage detection circuit 430 exceeds a specified difference value. You may make it perform a diagnostic process.

  Moreover, in the said embodiment, the example which compares all the open voltages VA1-VA4 which the voltage detection circuit 430 detects with the overcharge threshold value ZS and the overdischarge threshold value HS was shown. However, the present invention is not limited to this. For example, when the cells 210 to 240 connected to the wirings 310 to 350 in which disconnection has occurred are expected, only the open voltages VA1 to VA4 of the cells 210 to 240 are set to the overcharge threshold ZS. It may be compared with the overdischarge threshold HS.

  Moreover, in the said embodiment, the example which compares open voltage VA1-VA4 with both overcharge threshold value ZS and overdischarge threshold value HS was shown. However, the present invention is not limited to this, and it may be compared with only one of them.

DESCRIPTION OF SYMBOLS 100: Battery pack 200: Battery pack 210-240: Cell 300: Monitoring apparatus 310-350: Wiring 400: Monitoring part 410: CPU 420: Memory 430: Voltage detection circuit 500: Discharge part 510-540: Discharge circuit CA: Odd number Cell CB: Even cell DC: Disconnection detection counter Q1 to Q4: Switch R: Resistance V: Terminal voltage VA: Open voltage VB: Close voltage

Claims (8)

A battery pack monitoring device in which a plurality of cells are connected in series,
A discharge circuit including a plurality of switches connected in parallel to each cell via electric wires;
A voltage detection circuit for detecting the voltage of each cell via the electric wire;
A control unit,
The controller is
A first threshold value, wherein an open voltage of at least one of the cells detected by the voltage detection circuit when the plurality of switches are in an open state is equal to or higher than a predetermined upper limit value of the use range of the terminal voltage of the cell. and not less than, that open voltage of the at least one of said each cell, the rather smaller than the first threshold value, and is less than the lower limit of the use range of the terminal voltage of the cell is below a second threshold value And whether or not a diagnostic condition including at least one of the conditions is satisfied,
When it is determined that the diagnostic condition is satisfied, at least one of the switches is changed from the open state to the closed state to diagnose the presence or absence of the wire breakage,
An assembled battery monitoring device that maintains the plurality of switches in the open state and does not diagnose the presence or absence of disconnection of the electric wires when it is not determined that the diagnostic condition is satisfied. The assembled battery monitoring device according to claim 1,
In the diagnosis of the presence or absence of disconnection of the electric wire, the at least one switch is changed from the open state to the closed state, and the presence or absence of the disconnection of the electric wire is diagnosed using the voltage detected by the voltage detection circuit in the closed state. A battery pack monitoring device. The assembled battery monitoring device according to claim 2,
The diagnostic condition includes an open voltage of the at least one cell being equal to or higher than the first threshold;
The controller is
Among the first cells and the second cells arranged adjacent to each other in the plurality of cells, when the first cell satisfies the diagnostic condition, the switch corresponding to the first cell is in the open state. The switch corresponding to the second cell is set to the closed state, and the voltage detection circuit detects the close voltage of the second cell in the closed state. The switch is set to the open state, the switch corresponding to the first cell is set to the closed state, and the voltage detection circuit detects the close voltage of the first cell in the closed state. The assembled battery monitoring device is performed first. The assembled battery monitoring device according to claim 2,
The diagnostic condition includes an open voltage of the at least one cell being equal to or lower than the second threshold;
The controller is
Among the first cells and the second cells arranged adjacent to each other in the plurality of cells, when the first cell satisfies the diagnostic condition, the switch corresponding to the second cell is in the open state. The switch corresponding to the first cell is set to the closed state, and the voltage detection circuit detects the close voltage of the first cell in the closed state. The switch is set to the open state, the switch corresponding to the second cell is set to the closed state, and the voltage detection circuit detects the close voltage of the second cell in the closed state. The assembled battery monitoring device is performed first. The assembled battery monitoring device according to claim 3 or 4,
The assembled battery includes three or more cells, and the assembled battery monitoring device in which the first cells and the second cells are alternately arranged. The assembled battery monitoring device according to any one of claims 1 to 5,
The first threshold is an overcharge threshold;
The assembled battery monitoring device, wherein the second threshold is an overdischarge threshold. A power storage device,
An assembled battery in which a plurality of cells are connected in series;
A battery pack comprising: the assembled battery monitoring device according to claim 1. A discharge circuit including a plurality of switches connected in parallel to each cell of an assembled battery in which a plurality of cells are connected in series via an electric wire;
A voltage detection circuit for detecting a voltage of each cell via the electric wire, and a disconnection diagnosis method for a monitoring apparatus for an assembled battery,
A first threshold value, wherein an open voltage of at least one of the cells detected by the voltage detection circuit when the plurality of switches are in an open state is equal to or higher than a predetermined upper limit value of the use range of the terminal voltage of the cell. and not less than, that open voltage of the at least one of said each cell, the rather smaller than the first threshold value, and is less than the lower limit of the use range of the terminal voltage of the cell is below a second threshold value And a determination step for determining whether or not a diagnostic condition including at least one of the conditions is satisfied,
When it is determined that the diagnosis condition is satisfied in the determination step, the at least one switch is changed from the open state to the closed state to diagnose the presence or absence of the wire breakage,
A disconnection diagnosis method comprising: a diagnosis step of maintaining the plurality of switches in the open state and not diagnosing the presence or absence of disconnection of the electric wire when it is not determined that the diagnosis condition is satisfied in the determination step.

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