JP6491965B2 - Inspection method and inspection apparatus for battery monitoring unit - Google Patents

Description

  The present invention relates to an inspection method and an inspection apparatus for a battery monitoring unit that monitors a power storage module in which a plurality of unit batteries (cells) are connected in series, and in particular, it is necessary to provide inspection components and circuits exclusively in the battery monitoring unit. There is no inspection method and inspection apparatus.

  Conventionally, as a battery used in an electric vehicle, a hybrid vehicle, or the like, an energy storage module (also referred to as “battery pack” or “battery pack”) in which a plurality of unit cells are connected in series may be used.

  A plurality of cells included in such a power storage module needs to maintain a uniform cell voltage in order to improve stability and life and obtain high output. For example, the cell voltage of each cell can be made uniform by discharging another cell having a relatively high cell voltage with respect to the cell having the lowest cell voltage and lowering the voltage.

  A battery equalization circuit (also referred to as a “balancer circuit”) connected to each cell in order to implement such a battery equalization function (also referred to as “balancer function”) starts and ends cell discharge. And a discharge resistor connected in series with the switching element, and is incorporated in a battery monitoring unit for monitoring the power storage module.

  However, if an abnormality occurs in each balancer circuit, specifically an on failure (short circuit) or off failure (disconnection), problems may arise in the use of the power storage module. It is also necessary to make it detectable. However, if another abnormality detection circuit or the like is added for that purpose, the cost increases.

  In view of this, there has been proposed an abnormality diagnosis apparatus and method that can accurately determine the presence / absence and cause of an abnormality of a balancer circuit with a simple circuit configuration (see, for example, Patent Document 1).

  Furthermore, a cell monitoring device for a power storage module that can detect the abnormality of each balancer circuit one by one instead of one by one has been proposed (for example, see Patent Document 2).

Japanese Patent No. 5101748 JP 2014-085302 A

  However, in the above-described conventional technology, it is necessary to provide a resistor (detection resistor) necessary for detecting an abnormality of each balancer circuit in the battery monitoring unit that monitors the power storage module.

  However, these detection resistors not only have a function other than the abnormality detection of each balancer circuit, but may have some adverse effects on the voltage detection accuracy of each cell in the power storage module during normal use. Moreover, since it is built in all the battery monitoring units, it results in an increase in product cost.

  In view of such problems of the prior art, an object of the present invention is to provide an inspection method and an inspection apparatus for a battery monitoring unit capable of detecting an abnormality of each balancer circuit without providing an abnormality detection resistor or the like in the battery monitoring unit. Is to provide.

  In order to achieve the above object, the battery monitoring unit inspection method of the present invention is connected to a power storage module in which a plurality of unit cells are connected in series, and is connected in parallel to each of the unit cells so that discharge and discharge can be stopped. A battery monitoring unit inspection method for monitoring the power storage module, the inspection target equalizing circuit being the inspection target in the equalization circuit, and the equalizing circuit adjacent to the inspection target equalizing circuit. The adjacent equalization circuit is referred to as each, and the same number of power supplies connected in series as the unit battery included in the power storage module, wiring connected between these power supplies and both ends of each of the power supplies, The battery monitoring unit is connected to an inspection device including a discharge state detecting means provided on at least one of the pair of wires connected to each power source. And measuring the discharge state of the inspection target equalization circuit using the corresponding discharge state detection means while the discharge by the adjacent equalization circuit is stopped and during the discharge by the inspection target equalization circuit The discharge state detection means corresponding to the discharge state of the inspection target equalization circuit during the first measurement step and the discharge stop by the adjacent equalization circuit and the discharge stop by the inspection target equalization circuit A second measurement step that uses and measures, and a discrimination step that discriminates an abnormality in the inspection object equalization circuit based on each measurement result in the first measurement step and the second measurement step, To do.

  Here, the equalization circuit includes, for example, a switching element that controls the start and end of discharge of the unit battery (cell) and a discharge resistor connected in series to the unit battery, and can discharge and stop discharge of the unit battery. . Examples of switching elements include, but are not limited to, FETs (field effect transistors), other semiconductor switching elements, contactors (electromagnetic contactors), and switching means for controlling current inside the IC. When the inspection target equalization circuit is at either end of the series connection, there is only one adjacent equalization circuit, but in other cases, there are two adjacent equalization circuits.

  The discharge state detection means is means for detecting whether or not the discharge and discharge stop by the equalization circuit are normally performed, for example, current detection of a voltage drop element such as a resistor or a Hall element. Examples include an element (current detection circuit), but are not limited thereto. When using a current detection element, the discharge current flowing through the equalization circuit can be directly measured. When using a voltage drop element, measure the voltage drop caused by the discharge current as the voltage across the voltage drop element, or measure the voltage across the equalization circuit that changes in conjunction with the voltage drop. Current can be measured indirectly. “Based on each measurement result” means, for example, based on the value (state) or change (difference, ratio) of each measurement result. Note that the first measurement process and the second measurement process do not necessarily have to be performed first.

  According to the inspection method of the battery monitoring unit having such a configuration, the battery monitoring unit does not include a discharge state detection means (for example, a voltage drop element or a current detection element) necessary for detecting an abnormality. As a result, the voltage detection accuracy of each unit battery in the power storage module during normal use is not adversely affected, and the product cost is not increased.

  In the battery monitoring unit inspection method of the present invention, the discharge state detection means is a voltage drop element, and in the first measurement step, the voltage across the inspection target equalizing circuit is measured, and the second measurement is performed. In the process, the voltage across the inspection target equalization circuit may be measured.

  Further, in the inspection method for a battery monitoring unit according to the present invention, the discharge state detection means is a current detection element, and in the first measurement step, the current flowing through the inspection target equalizing circuit is measured, and the second measurement is performed. In the step, the current flowing through the inspection object equalizing circuit may be measured.

  Alternatively, in order to achieve the above object, the battery monitoring unit inspection apparatus according to the present invention is connected to a power storage module in which a plurality of unit cells are connected in series, and is connected in parallel to the unit cells to discharge and stop discharging. An inspection device for a battery monitoring unit that has an equalization circuit capable of monitoring the power storage module, wherein the inspection target in the equalization circuit is an inspection target equalization circuit and the equalization adjacent thereto Each circuit is called an adjacent equalization circuit, and the same number of power supplies connected in series as the unit cells included in the power storage module, and wiring connected between these power supplies and at both ends of each power supply A discharge state detecting means provided on at least one of the pair of wires connected to each power source, and communication with the battery monitoring unit. And controlling the equalization circuit respectively, and the discharge state detection means corresponding to the discharge state of the inspection target equalization circuit while the discharge by the adjacent equalization circuit is stopped and during the discharge by the inspection target equalization circuit And the discharge state of the inspection object equalization circuit corresponding to the discharge state while the discharge is stopped by the adjacent equalization circuit and the discharge is stopped by the inspection object equalization circuit. And a control unit that discriminates an abnormality in the inspection target equalizing circuit based on a second measurement result measured using the state detection means.

  Here, the discharge state detection means is means for detecting whether or not the discharge and discharge stop by the equalization circuit are normally performed. For example, the current such as a voltage drop element such as a resistor or a Hall element is used. Although a detection element (current detection circuit) etc. are mentioned, it is not restricted to these. When using a current detection element, each detection output may be input to the control unit. When using a voltage drop element, for example, a voltage measurement circuit (function) is further provided, and the voltage measurement circuit is connected to both ends of each voltage drop element so that the voltage measurement result is input to the control unit. Alternatively, the control unit may be able to acquire the voltage across the equalization circuit via communication with the battery monitoring unit.

  According to the inspection apparatus for a battery monitoring unit having such a configuration, the battery monitoring unit does not include a discharge state detection means (for example, a voltage drop element or a current detection element) necessary for detecting an abnormality. As a result, the voltage detection accuracy of each unit battery in the power storage module during normal use is not adversely affected, and the product cost is not increased.

  According to the inspection method and inspection apparatus for the battery monitoring unit of the present invention, the battery monitoring unit does not include a discharge state detection means (for example, a voltage drop element or a current detection element) necessary for detecting an abnormality. As a result, the voltage detection accuracy of each unit battery in the power storage module during normal use is not adversely affected, and the product cost is not increased.

It is the schematic which shows the whole structure at the time of connecting the battery monitoring unit 20 in order to test | inspect using the test | inspection machine 100 which concerns on 1st Embodiment of this invention. 2 is a schematic view illustrating a state in which the battery monitoring unit 20 is connected to the battery pack 10. FIG. It is the schematic which shows the whole structure at the time of connecting the battery monitoring unit 20 in order to test | inspect using the test | inspection machine 100A which concerns on the modification of 1st Embodiment of this invention. It is the schematic which shows the whole structure at the time of connecting the battery monitoring unit 20 in order to test | inspect using the test | inspection machine 200 which concerns on 2nd Embodiment of this invention. It is the schematic which shows the whole structure at the time of connecting the battery monitoring unit 20 in order to test | inspect using the test | inspection machine 200A which concerns on the modification 1 of 2nd Embodiment of this invention. It is the schematic which shows the whole structure at the time of connecting the battery monitoring unit 20 in order to test | inspect using the test | inspection machine 200B which concerns on the modification 2 of 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
1.1 Configuration of the First Embodiment FIG. 1 is a schematic diagram showing the overall configuration when the battery monitoring unit 20 is connected to perform an inspection using the inspection machine 100 according to the first embodiment of the present invention. . FIG. 2 is a schematic view illustrating a state in which the battery monitoring unit 20 is connected to the battery pack 10.

  As shown in FIG. 1, the inspection of the battery monitoring unit 20 using the inspection machine 100 is performed by electrically connecting the inspection machine side connector 101 and the battery monitoring unit side connector 21 to electrically connect the inspection machine 100 and the battery monitoring unit 20. This is done while connected. When the battery monitoring unit 20 shipped after inspection is in actual use (for example, when attached to a battery mounted on an automobile), as shown in FIG. By connecting the side connector 11, the battery pack 10 is electrically connected. The battery pack side connector 11 and the inspection machine side connector 101 have the same shape.

  First, the battery pack 10 will be described. The battery pack 10 is an example of a power storage module used for an electric vehicle, a hybrid vehicle, or the like, and is an assembled battery in which four cells 1 to 4 are connected in series as shown in FIG. The number of cells used is not limited to four, but may be two, three, or five or more. Each of the cells 1 to 4 is a secondary battery such as a lithium ion battery. However, each of the cells 1 to 4 is not limited to a single battery, but may be a power storage element, and may be a capacitor or the like. Note that when a lithium ion secondary battery is used, the cell voltage is about 2.5 to 4.2 V in a normal state in which no abnormality such as disconnection, overdischarge, or overcharge occurs. However, the voltage is not limited to this.

  In the battery pack 10, the cells 1 to 4 connected in series and both ends of the cells 1 to 4 and the terminals of the battery pack side connector 11 are respectively connected by a total of five wires W0 to W4. Yes. When the battery pack side connector 11 and the battery monitoring unit side connector 21 are connected in actual use, monitoring of each cell voltage of the cells 1 to 4 and the balancer function by the battery monitoring unit 20 become effective.

  In addition, as shown in FIG. 1, the inspection machine 100 includes the same number of cells 1 to 4 included in the battery pack 10, that is, four constant voltage power sources P <b> 1 to P <b> 4 connected in series. These power supplies P1 to P4 are not necessarily variable in voltage. Between the power sources P1 to P4 and both ends of these power sources P1 to P4 and the terminals of the inspection machine side connector 101 are respectively connected by a total of five wires Ws0 to Ws4. Further, detection resistors Rs0 to Rs4 are inserted into these wirings Ws0 to Ws4 as voltage drop elements necessary for voltage detection by the battery monitoring unit 20, respectively.

  In addition, since this inspection machine 100 is not provided with a control part etc., it can be said that it is an inspection jig at the time of inspecting the battery monitoring unit 20.

  On the other hand, as shown in FIGS. 1 and 2, the battery monitoring unit 20 includes a balancer circuit 31 that is connected in parallel to the power supplies P1 to P4 or the cells 1 to 4 when connected to the inspection machine 100 or the battery pack 10. To 34 and a battery monitoring unit 22 for monitoring each voltage of the power supplies P1 to P4 or the cells 1 to 4.

  The balancer circuits 31 to 34 are series circuits in which switching elements S1 to S4 and discharge resistors R1 to R4 are respectively connected in series. The switching elements S <b> 1 to S <b> 4 are on / off controlled by a control signal from the battery monitoring unit 22. For example, in the balancer circuit 31, the switching element S1 and the discharge resistor R1 are connected in series. When the switching element S1 is turned on, the cell 1 can be discharged through the switching element S1 and the discharge resistor R1. The same applies to the other balancer circuits 32-34. As described above, the cell voltages of the cells 1 to 4 can be made uniform by performing on / off control of the switching elements S1 to S4 from the battery monitoring unit 22, respectively.

  Examples of the switching elements S1 to S4 include FETs (field effect transistors), but are not limited thereto. In addition to other semiconductor switching elements and contactors (electromagnetic contactors), switching means for controlling current in the IC may be used.

  The battery monitoring unit 22 is an example of a control unit, and includes a CPU (central processing unit) 23, a memory 24, and a voltage measurement circuit 25. Various programs (including a switch failure detection program) for controlling the operation of the battery monitoring unit 22 are stored in the memory 24, and the CPU 23 executes each unit of the battery monitoring unit 22 according to the program read from the memory 24. To control. The memory 24 has a RAM and a ROM. The medium for storing the various programs may be a non-volatile memory such as a CD-ROM, a hard disk device, or a flash memory in addition to the RAM.

  When the battery monitoring unit 20 and the battery pack 10 are connected (see FIG. 2), the voltage measuring circuit 25 is connected to the cells 1 to 4 via the wires W0 to W4, and between the wires W0 to W4. Are individually measured and the measurement result is given to the CPU 23. On the other hand, when the battery monitoring unit 20 and the inspection machine 100 are connected (see FIG. 1), they are connected to the power sources P1 to P4 via the wires Ws0 to Ws4, and the voltage between the wires Ws0 to Ws4 is set. Individual measurement is performed and the measurement result is given to the CPU 23.

  Hereinafter, when the battery monitoring unit 20 and the inspection machine 100 are connected (see FIG. 1), the voltage measured by the voltage measurement circuit 25 is referred to as “measurement voltage”. Specifically, a voltage between the wiring Ws0 and the wiring Ws1 is referred to as a measurement voltage Es1, and corresponds to the switching element S1. A voltage between the wiring Ws1 and the wiring Ws2 is referred to as a measurement voltage Es2, and corresponds to the switching element S2. A voltage between the wiring Ws2 and the wiring Ws3 is called a measurement voltage Es3 and corresponds to the switching element S3. The voltage between the wiring Ws3 and the wiring Ws4 is referred to as a measurement voltage Es4 and corresponds to the switching element S4. The measurable range of the voltage measuring circuit 25 may be 0 to 5V.

  In addition, the battery monitoring unit 20 is provided with a communication interface with the outside (for example, the communication unit 26 of the second embodiment described later), and this is connected to a personal computer or the like, and the power source P1 to P1 of the inspection machine 100 is connected from the personal computer. The battery monitoring unit 20 may be inspected by controlling the set voltage of P4. In that case, you may make it display the test result (normal, on failure, off failure), etc. of the balancer circuits 31-34 of the battery monitoring unit 20 on the screen of a personal computer.

1.2 Inspection Method for Battery Monitoring Unit 20 According to First Embodiment Hereinafter, a basic inspection method for inspecting / determining whether the switching element S2 (or the balancer circuit 32) is abnormal and causing the abnormality will be described as an example. As described above, when the switching element S2 (or the balancer circuit 32) among the switching elements S1 to S4 is set as an inspection target (corresponding to the “inspection target equalization circuit” of the present application), the switching elements S1, S3 ( Alternatively, it is necessary to turn off the balancer circuits 31, 33) (corresponding to the “adjacent equalization circuit” of the present application). In addition, in the case of either one of the switching elements S1 to S4 (S1 or S4), there is only one adjacent switching element. For example, it is because only the switching element S2 is adjacent to the switching element S1.

  First, the battery monitoring unit 22 turns off the switching elements S1 and S3 adjacent to the switching element S2 to be inspected and turns on the switching element S2. Thereafter, the measurement voltage Es <b> 2 corresponding to the power supply P <b> 2 is measured by the voltage measurement circuit 25 and the measurement result is stored in the memory 24.

  After a predetermined time, the battery monitoring unit 22 turns off the switching element S2 while the switching elements S1 and S3 are off, and then measures the measurement voltage Es2 corresponding to the power source P2 by the voltage measurement circuit 25 again. Save in the memory 24.

  Based on the two measurement results stored in the memory 24 in this way, for example, whether the value or change (difference) of each measurement result is greater than or equal to a predetermined threshold value or within a predetermined range. Whether or not the switching element S2 is abnormal can be determined and the cause of the abnormality.

(1) When the switching element S2 is normal When a control signal for turning on the switching element S2 is output from the battery monitoring unit 22 and the switching element S2 is turned on, the positive side of the power supply P2 → the detection resistor Rs2 → the balancer circuit 32 ( Discharge resistor R2 and switching element S2) → detection resistor Rs1 → power source P2 discharges along the negative path of power source P2. Then, since a voltage drop occurs along the current direction in the detection resistor Rs2 and the detection resistor Rs1, a voltage obtained by subtracting these voltage drop equivalents from the set voltage of the power supply P2 becomes the measurement voltage Es2.

  On the other hand, when a control signal for turning off the switching element S2 is output from the battery monitoring unit 22 and the switching element S2 is turned off, the power supply P2 is not discharged, and thus no voltage drop occurs in the detection resistor Rs2 and the detection resistor Rs1. Therefore, the measurement voltage Es2 is equal to the set voltage of the power supply P2.

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, the measured voltage Es2 is equal to or higher than a predetermined threshold value than the set voltage of the power supply P2 (corresponding to a voltage drop in the detection resistor Rs2 and the detection resistor Rs1). When the switching element S2 is turned off and the measured voltage Es2 is equal to the set voltage of the power supply P2, it can be determined that the switching element S2 to be inspected is normal.

  For example, if the designed discharge current is 100 mA and the detection resistors Rs0 to Rs4 are all 10Ω, the voltage drop is 1 V per detection resistor. It is preferable to determine the threshold value with some allowance in consideration of these values and detection errors. Further, for example, even when the measured voltage Es2 and the set voltage of the power source P2 are compared, the determination is not based on whether or not they are strictly equal, but whether or not they are within a range having some width in consideration of detection errors and the like. It is preferable. This determination method is the same in the following description, but the repetition at each portion is omitted.

(2) When switching element S2 is on-failed (short circuit)
Regardless of the control signal of the switching element S2 output from the battery monitoring unit 22, the switching element S2 is in the ON state. Therefore, the measurement voltage Es1 is lower than the set voltage of the power supply P2 by a predetermined threshold or more (corresponding to a voltage drop in the detection resistor Rs2 and the detection resistor Rs1).

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, and when the switching element S2 is turned off, if the measured voltage Es2 is lower than the set voltage of the power supply P2 by a predetermined threshold or more, the inspection object It can be determined that there is a high possibility that the switching element S2 is on-failure.

(3) When switching element S2 has an off failure (disconnection)
Regardless of the control signal of the switching element S2 output from the battery monitoring unit 22, the switching element S2 is in the off state. Therefore, the measurement voltage Es1 is equal to the set voltage of the power supply P2.

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, and when the switching element S2 is turned off, the switching element to be inspected when the measured voltage Es2 is equal to the set voltage of the power source P2. It can be determined that there is a high possibility that S2 has an off-failure.

1.3 Another Inspection Method for Battery Monitoring Unit 20 According to the First Embodiment Hereinafter, another inspection method for inspecting / determining the presence / absence of the switching element S2 (or balancer circuit 32) and the cause of the abnormality will be described.

  First, the battery monitoring unit 22 turns off the switching elements S1 and S3 adjacent to the switching element S2 to be inspected and turns on the switching element S2. Thereafter, the measurement voltage Es1 corresponding to the power supply P1 and the measurement voltage Es3 corresponding to the power supply P3 are respectively measured by the voltage measurement circuit 25, and the measurement results are stored in the memory 24.

  After a predetermined time, the battery monitoring unit 22 turns off the switching element S2 while the switching elements S1 and S3 remain off, and then again measures the measurement voltage Es1 corresponding to the power supply P1 and the measurement voltage Es3 corresponding to the power supply P3. Each measurement is performed by the circuit 25 and these results are also stored in the memory 24.

  Based on the two measurement results stored in the memory 24 in this way, for example, whether the value or change (difference) of each measurement result is greater than or equal to a predetermined threshold value or within a predetermined range. Whether or not the switching element S2 is abnormal can be determined and the cause of the abnormality.

(1) When the switching element S2 is normal When a control signal for turning on the switching element S2 is output from the battery monitoring unit 22 and the switching element S2 is turned on, the positive side of the power supply P2 → the detection resistor Rs2 → the balancer circuit 32 ( Discharge resistor R2 and switching element S2) → detection resistor Rs1 → power source P2 discharges along the negative path of power source P2. Then, a voltage drop occurs along the current direction in the detection resistor Rs2 and the detection resistor Rs1, so that the potential on the right side decreases in the detection resistor Rs2, and the potential on the right side increases in the detection resistor Rs1.

  The measurement voltage Es1 is supposed to be equal to the set voltage of the power supply P1 because the switching element S1 is off. However, since the potential on the right side of the detection resistor Rs1 has increased as described above, the measurement voltage Es1 becomes higher than the set voltage of the power supply P1 by the increase. Similarly, the measurement voltage Es3 should originally be equal to the set voltage of the power supply P3 because the switching element S3 is turned off, but because the potential on the right side of the detection resistor Rs2 is lowered as described above. The measured voltage Es3 becomes higher than the set voltage of the power source P3 by the amount of the decrease.

  On the other hand, when a control signal for turning off the switching element S2 is output from the battery monitoring unit 22 and the switching element S2 is turned off, the power supply P2 is not discharged, and thus no voltage drop occurs in the detection resistor Rs2 and the detection resistor Rs1. Therefore, the measurement voltage Es1 is equal to the set voltage of the power supply P1, and the measurement voltage Es3 is also equal to the set voltage of the power supply P3.

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, the measured voltage Es1 is higher than the set voltage of the power source P1, and the measured voltage Es3 is also higher than the set voltage of the power source P3. When the element S2 is turned off, when the measured voltage Es1 is equal to the set voltage of the power supply P1 and the measured voltage Es3 is also equal to the set voltage of the power supply P3, it can be determined that the switching element S2 to be inspected is normal.

(2) When switching element S2 is on-failed (short circuit)
When the control signal for turning on the switching element S2 is output from the battery monitoring unit 22, the switching element S2 is in an on state although it has failed. Therefore, similarly to (1) the first half, the measurement voltage Es1 is higher than the set voltage of the power supply P1, and the measurement voltage Es3 is also higher than the set voltage of the power supply P3.

  On the other hand, when a control signal for turning off the switching element S2 is output from the battery monitoring unit 22, the switching element S2 remains on because of a failure. Therefore, (1) Unlike the latter half, the measured voltage Es1 is higher than the set voltage of the power supply P1, and the measured voltage Es3 is also higher than the set voltage of the power supply P3.

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, the measured voltage Es1 is higher than the set voltage of the power source P1, and the measured voltage Es3 is also higher than the set voltage of the power source P3. Even when the element S2 is turned off, if the measured voltage Es1 is higher than the set voltage of the power supply P1 and the measured voltage Es3 is also higher than the set voltage of the power supply P3, the switching element S2 to be inspected is on-failed. It can be determined that the possibility is high.

(3) When switching element S2 has an off failure (disconnection)
When the control signal for turning on the switching element S2 is output from the battery monitoring unit 22, the switching element S2 remains in an off state due to a failure. Therefore, (1) Unlike the first half, the measurement voltage Es1 is equal to the set voltage of the power supply P1, and the measurement voltage Es3 is also equal to the set voltage of the power supply P3.

  On the other hand, when the control signal for turning off the switching element S2 is output from the battery monitoring unit 22, the switching element S2 is in an off state although it has failed. Therefore, (1) As in the latter half, the measurement voltage Es1 is equal to the set voltage of the power supply P1, and the measurement voltage Es3 is also equal to the set voltage of the power supply P3.

  Therefore, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, the measured voltage Es1 is equal to the set voltage of the power supply P1, and the measured voltage Es3 is also equal to the set voltage of the power supply P3. Even when the element S2 is turned off, if the measured voltage Es1 is equal to the set voltage of the power supply P1 and the measured voltage Es3 is also equal to the set voltage of the power supply P3, the switching element S2 to be inspected is in an off failure. It can be determined that the possibility is high.

  With respect to the other switching elements S1, S3, S4 (or other balancer circuits 31, 33, 34), the presence / absence of an abnormality and the cause of the abnormality can be similarly inspected / discriminated.

  According to the configuration of the first embodiment described above, the voltage drop elements (detection resistors Rs0 to Rs4) necessary for detecting the abnormality of the switching elements S1 to S4 (or balancer circuits 31 to 34) in the battery monitoring unit 20 are described. ) Is built in the inspection machine 100 instead of the battery monitoring unit 20. Therefore, the battery monitoring unit 20 that is shipped after the inspection does not include voltage drop elements (detection resistors Rs0 to Rs4) that are originally unnecessary. As a result, the voltage detection accuracy of each cell in the battery pack 10 during normal use is not adversely affected, and the product cost is not increased.

  If the technique described in Patent Document 2 is applied, it is possible to more efficiently inspect and determine the presence / absence and cause of abnormality of the switching elements S1 to S4.

<Modification of First Embodiment>
FIG. 3 is a schematic diagram showing an overall configuration when the battery monitoring unit 20 is connected in order to perform inspection using the inspection machine 100A according to the modification of the first embodiment of the present invention.

  In the inspection machine 100 according to the first embodiment described above, the detection resistors Rs0 to Rs4 are inserted into all the wirings W0 to W4, respectively. However, for example, in order to inspect / determine whether or not the switching element S2 is abnormal and the cause of the abnormality, the pair of wiring Ws1 connected to the power supply P2 corresponding thereto and the detection resistance Rs1 and the detection resistance Rs2 inserted in the wiring Ws2 It is sufficient that at least one of the above exists. Assuming that only the detection resistor Rs2 exists, when the switching element S2 is turned on and the power supply P2 is discharged, a voltage drop occurs in the detection resistor Rs2, which means that the measured voltage Es3 is higher than the set voltage of the power supply P3. It is because it can be confirmed only by no. The same applies to the other switching elements S1, S3, and S4.

  Therefore, for example, as shown in FIG. 3, a switch failure detection program written in advance in the memory 24 of the battery monitoring unit 20 even if the inspection machine 100A in which the detection resistors Rs1 and Rs3 are omitted from the inspection machine 100 is used instead. It is possible to inspect and discriminate the presence / absence of abnormality and the cause of abnormality of all the switching elements S1 to S4 with a slight correction.

  According to the configuration of the modified example of the first embodiment described above, in addition to the operational effects of the first embodiment, there is an effect that the cost of the inspection machine 100 can be slightly reduced.

Second Embodiment
2.1 Configuration of Second Embodiment FIG. 4 is a schematic diagram showing an overall configuration when the battery monitoring unit 20 is connected to perform an inspection using the inspection machine 200 according to the second embodiment of the present invention. . The same components as those in the first embodiment and the modifications thereof are denoted by the same reference numerals, and the differences will be mainly described below.

  As shown in FIG. 4, the inspection of the battery monitoring unit 20 using the inspection machine 200 is performed by electrically connecting the inspection machine side connector 201 and the battery monitoring unit side connector 21 to electrically connect the inspection machine 200 and the battery monitoring unit 20. This is done while connected. When the battery monitoring unit 20 shipped after inspection is actually used, the battery monitoring unit 20 is electrically connected to the battery pack 10 by connecting the battery monitoring unit side connector 21 and the battery pack side connector 11 as shown in FIG. The connection to is the same as in the case of the first embodiment and its modifications.

  The battery monitoring unit 22 of the battery monitoring unit 20 further includes a communication unit 26 that performs communication with the outside.

  On the other hand, in the inspection machine 200, as shown in FIG. 4, instead of the detection resistors Rs0 to Rs4 in the first embodiment, a hall element is used as a current detection element (current detection circuit) necessary for current detection of the wirings Ws0 to Ws4. H0 to H4 are inserted. These Hall elements H0 to H4 are voltage output types, and the negative side output is grounded (not shown). The current detection element is not limited to the Hall element. For example, current detection may be performed by a magnetic element.

  Further, a current detection signal of the Hall elements H0 to H4 is input, and a communication / control unit 202 that performs communication with the communication unit 26 of the battery monitoring unit 22 of the battery monitoring unit 20 and stores various data is provided. Yes. The communication / control unit 202 and the communication unit 26 are connected by a communication line W so as to be able to communicate with each other. However, the communication line W is not required at least for the battery pack 10 as shown in FIG.

2.2 Method for Inspecting Battery Monitoring Unit 20 According to Second Embodiment Next, the most basic method for inspecting and determining the presence / absence and cause of abnormality of the switching element S2 (or balancer circuit 32) is described as an example.

  First, the communication / control unit 202 instructs the CPU 23 of the battery monitoring unit 22 via the communication unit 26 to turn off the switching elements S1 and S3 adjacent to the switching element S2 to be inspected and to turn on the switching element S2. Let At this time, the presence / absence of the current of the wiring Ws1 appears in the current detection signal of the Hall element H1, and the presence / absence of the current of the wiring Ws2 appears in the current detection signal of the Hall element H2, so these current detection results are stored.

  After a predetermined time, the battery monitoring unit 22 instructs the CPU 23 of the battery monitoring unit 22 via the communication unit 26 via the communication / control unit 202 to turn off the switching element S2 while the switching elements S1 and S3 remain off. The current detection results by the Hall element H1 and the Hall element H2 are also stored.

  Based on the current detection results stored in this manner, the presence / absence of abnormality of the switching element S2 and the cause of abnormality can be determined as follows.

  That is, when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, a current exceeding a predetermined threshold value flows through the Hall element H1 and the Hall element H2, and the switching element S2 is turned off. Sometimes, if no current flows through the Hall element H1 and the Hall element H2, it can be determined that the switching element S2 to be inspected is normal. For example, if the designed discharge current is 100 mA, the threshold value may be determined in consideration of this value.

  In addition, if a current equal to or higher than a predetermined threshold flows through the Hall element H1 and the Hall element H2 when the switching element S2 is turned on / off in a state where the switching elements S1 and S3 are turned off, it is an inspection target. It can be determined that there is a high possibility that the switching element S2 is on-failed.

  On the other hand, if no current flows through the Hall element H1 and the Hall element H2 when the switching element S2 is turned on / off in a state where the switching elements S1 and S3 are turned off, the switching element S2 to be inspected is It can be determined that there is a high possibility of an off-failure.

  According to the configuration of the second embodiment described above, the current detection elements (Hall elements H0 to H4) necessary for detecting the abnormality of the switching elements S1 to S4 (or the balancer circuits 31 to 34) in the battery monitoring unit 20 are described. ) Is built in the inspection machine 200 instead of the battery monitoring unit 20. Therefore, the battery monitoring unit 20 shipped after the inspection does not include current detection elements (Hall elements H0 to H4). As a result, the voltage detection accuracy of each cell in the battery pack 10 during normal use is not adversely affected, and the product cost is not increased.

<Modification Example 1 of Second Embodiment>
FIG. 5 is a schematic diagram showing an overall configuration when the battery monitoring unit 20 is connected in order to perform inspection using the inspection machine 200A according to Modification 1 of the second embodiment of the present invention. Note that the same reference numerals are assigned to the same components as those in the first embodiment, its modification, and the second embodiment, and differences from the second embodiment will be mainly described below.

  This modification 1 replaces the hall elements H0 to H4 with detection resistors Rs0 to Rs4 (see the inspection device 100 of the first embodiment) in the inspection device 200 of the second embodiment, and the communication / control unit 202. Is replaced with a communication / control unit 202A further equipped with a voltage measurement function (a part of the switch failure detection program is also corrected), and wiring between each end of the detection resistors Rs0 to Rs4 and the communication / control unit 202A is also added. It is.

  According to the configuration of the first modification, for example, the measurement results (predetermined voltages of both ends of the detection resistor Rs2 and the detection resistor Rs1 when the switching device S2 is turned on while the switching devices S1 and S3 are turned off). Of the detection resistance Rs2 and the detection resistance Rs1 when the switching element S2 is turned off while the switching elements S1 and S3 are turned off. Based on the measurement results of the voltages at both ends (whether a voltage drop equal to or greater than a predetermined threshold has occurred, or whether a voltage drop has occurred), the presence / absence of abnormality of the switching element S2 and the cause of abnormality can be determined.

<Modification 2 of the second embodiment>
FIG. 6 is a schematic diagram showing an overall configuration when the battery monitoring unit 20 is connected to perform inspection using the inspection machine 200B according to the second modification of the second embodiment of the present invention. The same reference numerals are given to the same constituent members as those in the first embodiment and its modification, the second embodiment and its modification 1, and differences from the second embodiment will be mainly described below. .

  This modification 2 replaces the hall elements H0 to H4 with the detection resistors Rs0 to Rs4 (see the inspection device 100 of the first embodiment) in the inspection device 200 of the second embodiment, and the communication / control unit 202. A part of the switch failure detection program is also corrected, and the communication / control unit 202B that can arbitrarily acquire the measurement voltages Es1 to Es4 from the battery monitoring unit 22 of the battery monitoring unit 20 via the communication unit 26 is used. .

  According to the configuration of the second modification, for example, the measurement voltage Es2 when the switching element S2 is turned on while the switching elements S1 and S3 are turned off, and the switching element S1 and S3 are turned off. Based on the measured voltage Es2 when the switching element S2 is turned off, the presence / absence of the abnormality of the switching element S2 and the cause of the abnormality can be determined as in the first embodiment.

<Other embodiments>
In the inspection machine 200 of the second embodiment, as in the modification of the first embodiment, for example, even if the Hall element H1 and the Hall element H3 are omitted, the switch failure detection program for the communication / control unit 202 is slightly modified. For example, the presence / absence and cause of abnormality of all the switching elements S1 to S4 can be inspected and determined.

  Further, in the inspection machine 200A of the first modification of the second embodiment and the inspection machine 200B of the second modification, as in the modification of the first embodiment, for example, even if the detection resistor Rs1 and the detection resistor Rs3 are omitted, If the switch failure detection programs for the communication / control units 202A and 202B are slightly modified, the presence / absence and cause of abnormality of all the switching elements S1 to S4 can be inspected / discriminated.

  Alternatively, as in the first embodiment and its modifications, the CPU 23 in the battery monitoring unit 20 is the main subject of inspection, and instead of referring to the measured voltage by the voltage measuring circuit 25, it communicates with the communication / control unit 202. It is also possible to obtain current detection results of the Hall elements H0 to H4, and to inspect and determine the presence / absence and cause of abnormality of all the switching elements S1 to S4 based on the result.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-mentioned embodiment is only a mere illustration in all points, and should not be interpreted limitedly. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

1 to 4 cells 10 battery pack 11 battery pack side connector 20 battery monitoring unit 21 battery monitoring unit side connector 22 battery monitoring unit 23 CPU
24 Memory 25 Voltage Measurement Circuit 26 Communication Units 31-34 Balancer Circuit 100 Inspection Machine 101 Inspection Machine Side Connector 100A Inspection Machine 200 Inspection Machine 200A Inspection Machine 200B Inspection Machine 201 Inspection Machine Side Connector 202 Communication / Control Unit 202A Communication / Control Unit 202B Communication / control part P1-P4 Power supply R1-R4 Discharge resistance Rs0-Rs4 Detection resistance S1-S4 Switching element W Communication line W0-W4 Wiring Ws0-Ws4 Wiring

Claims (4)

An equalization circuit that is connected to a power storage module (10) in which a plurality of unit cells (1 to 4) are connected in series, and is connected in parallel to the unit cells (1 to 4) to discharge and stop discharge ( 31 to 34), and the battery monitoring unit (20) for monitoring the power storage module (10),
Among the equalization circuits (31 to 34), the inspection target is referred to as an inspection target equalization circuit, and the equalization circuit adjacent thereto is referred to as an adjacent equalization circuit, respectively.
The same number of power supplies (P1 to P4) connected in series as the unit batteries (1 to 4) included in the power storage module (10), and between these power supplies (P1 to P4) and the power supplies (P1 to P4) ) Discharge state detection means provided on at least one of the wires (Ws0 to Ws4) connected to both ends of the whole and the pair of wires (Ws0 to Ws4) connected to the power sources (P1 to P4), respectively. A connection step of connecting the battery monitoring unit (20) with an inspection device (100, 100A, 200, 200A, 200B) comprising (Rs0 to Rs4, H0 to H4);
A first measurement step of measuring the discharge state of the inspection target equalization circuit using the corresponding discharge state detection means while the discharge by the adjacent equalization circuit is stopped and during the discharge by the inspection target equalization circuit When,
The discharge state of the inspection object equalization circuit is measured using the corresponding discharge state detection means while the discharge is stopped by the adjacent equalization circuit and the discharge is stopped by the inspection object equalization circuit. Measuring process,
An inspection method for the battery monitoring unit (20), comprising: a determination step of determining an abnormality of the inspection target equalizing circuit based on each measurement result in the first measurement step and the second measurement step. . In the inspection method of the battery monitoring unit (20) according to claim 1,
The discharge state detection means (Rs0 to Rs4, H0 to H4) are voltage drop elements (Rs0 to Rs4),
In the first measurement step, the voltage across the inspection target equalizing circuit is measured,
In the second measuring step, the voltage across the test target equalizing circuit is measured, and the battery monitoring unit (20) inspection method In the inspection method of the battery monitoring unit (20) according to claim 1,
The discharge state detection means (Rs0 to Rs4, H0 to H4) are current detection elements (H0 to H4),
In the first measurement step, a current flowing through the inspection object equalization circuit is measured,
In the second measurement step, the current flowing through the inspection target equalizing circuit is measured, and the inspection method for the battery monitoring unit (20) An equalization circuit that is connected to a power storage module (10) in which a plurality of unit cells (1 to 4) are connected in series, and is connected in parallel to the unit cells (1 to 4) to discharge and stop discharge ( 31 to 34) and an inspection device (200, 200A, 200B) of the battery monitoring unit (20) for monitoring the power storage module (10),
Among the equalization circuits (31 to 34), the inspection target is referred to as an inspection target equalization circuit, and the equalization circuit adjacent thereto is referred to as an adjacent equalization circuit, respectively.
The same number of unit-connected power supplies (P1 to P4) as the unit batteries (1 to 4) included in the power storage module (10);
Wires (Ws0 to Ws4) connected between the power sources (P1 to P4) and to both ends of the power sources (P1 to P4),
Discharge state detection means (Rs0 to Rs4, H0 to H4) provided on at least one of the pair of wirings (Ws0 to Ws4) connected to the power sources (P1 to P4);
The equalization circuits (31 to 34) are respectively controlled through communication with the battery monitoring unit (20), and the discharge is stopped by the adjacent equalization circuit and the discharge is performed by the inspection target equalization circuit. The first measurement result obtained by measuring the discharge state of the inspection target equalization circuit using the corresponding discharge state detection means, the discharge being stopped by the adjacent equalization circuit, and the discharge being stopped by the inspection target equalization circuit And a controller (202) for determining abnormality of the inspection object equalization circuit based on a second measurement result obtained by measuring the discharge state of the inspection object equalization circuit using the corresponding discharge state detection means. 202A, 202B), an inspection device (200, 200A, 200B) for the battery monitoring unit (20).

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