JP2009037962A - Abnormality detection device and abnormality detection method of secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent erroneous detection of abnormality of a battery block unit based on a voltage difference, in a secondary battery composed as a battery pack with a plurality of battery cells serially connected to one another. <P>SOLUTION: The secondary battery 10 being a battery pack is composed of a plurality of battery blocks 14 each having at least one battery cell 12. A voltage sensor 20 detects an output voltage Vb(i) of each battery block 14. A battery ECU 100 calculates a voltage difference of each battery block 14 from that of another battery block, and when the calculated voltage difference is set above a predetermined voltage, the battery ECU detects abnormality of the battery block 14 having caused the voltage difference. The battery ECU 100 prevents erroneous detection by suspending the abnormality detection based on the voltage difference when it is determined that the secondary battery 10 is in the operation region (low residual charge state region) where the percentage change of its output voltage with respect to the change of State of Charge (SOC) is large. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an abnormality detection device and an abnormality detection method for a secondary battery, and more particularly, to an abnormality detection for a secondary battery configured by an assembled battery in which a plurality of battery cells are connected in series.

  In order to ensure the output voltage, an assembled battery in which a plurality of secondary batteries (battery cells) are connected in series is used. Such an assembled battery requires a configuration for detecting a battery cell in which an abnormality has occurred from a plurality of battery cells connected in series.

  In order to perform such an abnormality detection, Japanese Patent Application Laid-Open No. 2002-334726 (Patent Document 1) discloses, in particular, the voltage of each cell and all the cells by measuring the voltage of each cell constituting the assembled battery. An abnormal detection of an assembled battery is disclosed in which an abnormal cell is detected based on an average voltage, an abnormality determination threshold value, and a correction value for correcting the average voltage or the abnormality determination threshold value.

  JP 2000-150002 A (Patent Document 2) and JP 2003-257504 A (Patent Document 3) divide a plurality of battery cells connected in series constituting an assembled battery into battery blocks or modules. And the structure which detects the overdischarged abnormal cell based on the voltage for every block or module detected by the said voltmeter by providing the voltmeter for every said battery block or module is disclosed.

  In particular, according to the overdischarge cell detection device for an assembled battery according to Patent Document 2, the voltage difference detection means between the modules is further provided with an ammeter for detecting the current flowing through the assembled battery, and the change in voltage causes the change in current value. It is disclosed that the occurrence of an overdischarge cell is distinguished from the occurrence of a difference in internal resistance of the cell by detecting whether it is independent of the cell.

Further, in Patent Document 3, a voltmeter and a thermometer are provided for each battery block, and the current value of the assembled battery is measured with an ammeter, whereby the electromotive voltage detection unit detects the SOC of the battery by integrating the current value. By detecting the electromotive voltage, the internal resistance and the polarization voltage are detected from the battery and temperature, and the estimated voltage of each battery block is obtained from the electromotive voltage, the internal resistance, and the polarization voltage by the voltage estimation unit. It is disclosed that the presence or absence of overdischarge is determined from the difference from the actual voltage measured with a voltmeter.
JP 2002-334726 A JP 2000-150002 A JP 2003-257504 A

  In the above-described abnormality detection of the secondary battery, there is a problem that an abnormality is erroneously detected based on a voltage measurement value or the like although no abnormality such as overdischarge actually occurs. That is, it is necessary to prevent erroneous detection.

  Generally, a secondary battery has a characteristic that an output voltage changes with a change in remaining capacity, but this change characteristic varies depending on the type of secondary battery. In particular, there is a secondary battery having such characteristics that the rate of change of the output voltage with respect to the change of the remaining capacity varies greatly depending on the level of the remaining capacity. Therefore, in an assembled battery configured using a secondary battery having such characteristics, when an abnormality is detected based on a voltage difference between blocks, a normal battery is detected due to a voltage difference caused by a variation in remaining capacity. There is a risk of erroneously detecting an abnormality in the block.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a plurality of batteries in a secondary battery configured as an assembled battery in which a plurality of battery cells are connected in series. It is to prevent erroneous detection of abnormality in battery block unit abnormality detection based on the block output voltage.

  An abnormality detection device for a secondary battery according to the present invention is an abnormality detection device for a secondary battery having a plurality of battery blocks each composed of at least one battery cell. A calculation unit, an abnormality detection unit, and an abnormality detection stop unit are provided. The secondary battery has a first operation region in which a change rate of the output voltage with respect to a change in the remaining capacity is relatively large and a change rate of the output voltage with respect to the remaining capacity is smaller than that in the first region. 2 operating regions. The plurality of voltage detectors detect output voltages of the plurality of battery blocks, respectively. A voltage difference calculation part calculates the voltage difference between blocks about a some battery block based on the detection value by a some voltage detection part. The abnormality detection unit detects an abnormality of the battery block in which the voltage difference is generated when the voltage difference calculated by the voltage calculation unit exceeds a predetermined determination value. The abnormality detection stop unit forcibly stops the abnormality detection by the abnormality detection unit when the secondary battery is in the first operation region.

  An abnormality detection method for a secondary battery according to the present invention is an abnormality detection method for a secondary battery having a plurality of battery blocks each composed of at least one battery cell. The voltage change characteristic has a first operation region in which the change rate of the output voltage is relatively large with respect to the change in the remaining capacity, and a second operation region in which the change rate is smaller than that of the first region. Then, the abnormality detection method includes a step of acquiring each output voltage of the plurality of battery blocks based on outputs of the plurality of voltage detection units provided corresponding to the plurality of battery blocks, A step of calculating a voltage difference between the blocks for a plurality of battery blocks based on each output voltage, and the voltage difference is generated when the voltage difference calculated by the voltage calculation unit exceeds a predetermined determination value. Detecting an abnormality of the battery block that is present, and disabling abnormality detection when the secondary battery is in the first operating region.

  According to the secondary battery abnormality detection device and abnormality detection method described above, the abnormality detection based on the voltage difference between the battery blocks is forced in the operation region (low remaining capacity region) in which the change rate of the output voltage with respect to the change in the remaining capacity is large. Can be canceled. As a result, paying attention to the fact that a voltage difference occurs due to the remaining capacity variation between the battery blocks even in a normal state in the low remaining capacity region, the battery block abnormality is erroneously detected based on such a voltage difference. Can be prevented.

  Preferably, the abnormality detection device further includes a battery state estimation unit that calculates an estimated value of the remaining capacity of the secondary battery based on the state quantity of the secondary battery. Then, the abnormality detection stop unit determines that the secondary battery is in the first operation region when the estimated remaining capacity value estimated by the battery state estimation unit is equal to or less than a predetermined value. Or an abnormality detection apparatus is further provided with the battery state estimation part which estimates each open circuit voltage of a some battery block based on the state quantity of a secondary battery. Then, the abnormality detection stop unit causes the secondary battery to enter the first operation region when the maximum voltage among the estimated open voltages of the plurality of battery blocks estimated by the battery state estimation unit is equal to or lower than a predetermined voltage. Judge that there is. Alternatively, the abnormality detection stop unit causes the secondary battery to enter the first operation region when the maximum voltage among the output voltages of the plurality of battery blocks detected by the plurality of voltage detection units is equal to or lower than a predetermined voltage. Judge that there is.

  Preferably, in the abnormality detection method, the invalidating step is performed when the estimated value of the remaining capacity of the entire secondary battery or the estimated value of the remaining capacity of each of the plurality of battery blocks is equal to or less than a predetermined value. It is determined that the secondary battery is in the first operating region. Alternatively, the invalidating step determines that the secondary battery is in the first operation region when the highest voltage among the estimated open circuit voltages of the plurality of battery blocks is equal to or lower than a predetermined voltage. Alternatively, the invalidating step determines that the secondary battery is in the first operation region when the highest voltage among the output voltages of the plurality of battery blocks is equal to or lower than a predetermined voltage.

  Thus, based on the estimated remaining capacity (SOC value) or the open circuit voltage of the secondary battery, and the maximum value of the output voltage between the battery blocks, the operating region where the rate of change of the output voltage with respect to the change of the remaining capacity is large ( It can be easily determined whether or not it is in the low remaining capacity region.

  More preferably, the abnormality detection device further includes a plurality of temperature detection units that respectively detect the temperatures of the plurality of battery blocks. The predetermined value or the predetermined voltage used for determining whether or not the secondary battery is in the first operating region is variably set according to the detection values by the plurality of temperature detection units. Alternatively, in the abnormality detection method, in the invalidating step, the predetermined voltage or the predetermined value is variably set according to the temperature detection values of the plurality of battery blocks.

  This reflects whether the change characteristic of the output voltage with respect to the remaining capacity changes depending on the temperature of the secondary battery, and whether the change rate of the output voltage with respect to the change of the remaining capacity is in an operating region (low remaining capacity region). Can be determined more accurately. As a result, it is possible to enhance the effect of preventing abnormal abnormality detection.

  Preferably, the secondary battery is mounted on a hybrid vehicle. The abnormality detection stop unit is configured to detect when the secondary battery is in the first operation region, when a failure occurs in a predetermined part of the hybrid vehicle, or when the remaining fuel level of the hybrid vehicle is determined. Even when the amount is below the fixed amount, the abnormality detection by the abnormality detection unit is forcibly stopped. Alternatively, the abnormality detection method further includes a step of invalidating the abnormality detection when a failure occurs in a predetermined part of the hybrid vehicle or when the remaining fuel amount of the hybrid vehicle is equal to or less than a predetermined amount.

  Thereby, since the abnormality detection in a special case such as when a predetermined part fails or when the remaining amount of fuel is extremely small is not executed, erroneous detection of abnormality can be prevented more reliably.

  According to the present invention, in the secondary battery configured as an assembled battery in which a plurality of battery cells are connected in series, it is possible to prevent erroneous detection of abnormality in battery block unit abnormality detection based on the output voltage of the plurality of battery blocks. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

  FIG. 1 is a circuit diagram showing an overall configuration of a battery system to which abnormality detection of a secondary battery according to an embodiment of the present invention is applied.

  Referring to FIG. 1, secondary battery 10 is configured as an assembled battery in which a plurality of battery cells 12 are connected in series. The plurality of battery cells 12 are divided into a plurality of battery blocks 14. Each battery block 14 includes a single battery cell 12 or a plurality of battery cells 12 connected in series (not shown). In addition, when the battery block 14 is configured by a plurality of battery cells 12, each battery block 14 is preferably configured by the same number of battery cells 12. When the number of battery cells 12 differs between the battery blocks 14, it is necessary to correct the output voltage for each battery block 14 described below by reflecting the difference in the number.

  Each battery block 14 is provided with a voltage sensor 20 and a temperature sensor 22. In addition, a current sensor 24 for measuring input / output current from the secondary battery 10 to the load 50 is disposed.

  A battery ECU 100 constituted by an electronic control unit (ECU) is configured by a battery current Ib detected by the current sensor 24, a battery temperature Tb (i) for each battery block 14 detected by the temperature sensor 22, and a voltage sensor 20. The detected output voltage Vb (i) for each battery block 14 is received. The symbol (i) in the battery temperature Tb (i) and the output voltage Vb (i) indicates the detected value of the i-th battery block (i: an integer from 1 to N, where N is the number of battery blocks 14 ).

  The battery ECU 100 has a function of detecting abnormality of the secondary battery 10 based on detection values obtained by the voltage sensor 20, the temperature sensor 22 and the current sensor 24. The abnormality detection function of the battery ECU 100 constitutes an abnormality detection device for a secondary battery according to the present invention. Further, the battery ECU 100 executes a predetermined program stored in advance, thereby realizing the abnormality detection method for the secondary battery according to the present invention.

  FIG. 2 is a schematic block diagram illustrating the configuration of the secondary battery abnormality detection device according to the embodiment of the present invention.

  Referring to FIG. 2, secondary battery abnormality detection device 105 according to the embodiment of the present invention includes an inter-block voltage difference calculation unit 110, an abnormality detection unit 120, an abnormality detection stop unit 130, and a battery state estimation unit. 140.

  Based on the output voltage Vb (i) for each battery block 14 detected by the voltage sensor 20, the inter-block voltage difference calculation unit 110 calculates the voltage difference ΔVb (i) with respect to the other battery blocks for each battery block 14. calculate. For example, the inter-block voltage difference calculation unit 110 calculates the voltage difference ΔVb (i) for each battery block 14 according to the output voltage difference between the adjacent battery blocks 14. The voltage difference ΔVb (i) may be calculated by further reflecting the battery current Ib and the battery temperature Tb (i) at that time in addition to the output voltage Vb (i) of the battery block 14. Good. For example, the battery current Ib and / or the battery temperature Tb (i) is used so that the voltage difference ΔVb (i) is not excessively calculated in the operation region of the secondary battery 10 that is easily affected by the internal resistance. Thus, it is preferable to calculate the voltage difference ΔVb (i) by appropriately correcting the difference in the output voltage Vb (i).

  The abnormality detection unit 120 compares the voltage difference ΔVb (i) of each battery block 14 calculated by the inter-block voltage difference calculation unit 110 with a predetermined determination value. Then, an abnormality such as overdischarge is detected for the battery block 14 in which the voltage difference ΔVb (i) exceeds the determination value. At this time, the abnormality detection unit 120 turns on the abnormality detection flag FL (i) corresponding to the battery block.

  Based on the output voltage Vb (i), the battery temperature Tb (i), and the battery current Ib for each battery block 14, the battery state estimation unit 140 is configured for the entire secondary battery 10 or for each battery block 14 in addition to this. A remaining capacity estimation value (SOC: State of Charge) is calculated. The SOC is calculated to a value between 0 and 100%, for example, with the fully charged state being 100% and the fully discharged state being 0%.

  Alternatively, the battery state estimation unit 140 may estimate the open circuit voltage (OCV) for each battery block 14 by estimating the internal resistance based on the output voltage Vb (i), the battery temperature Tb (i), and the battery current Ib for each battery block 14. ) And the estimated voltage OCV # (i) is calculated.

  Here, the change characteristic of the output voltage with respect to the remaining capacity of the secondary battery 10 will be described with reference to FIG.

  Referring to FIG. 3, change rate (ΔVb / ΔSOC) of output voltage Vb with respect to the change in remaining capacity (SOC) in secondary battery 10, that is, the slope of the tangent to the characteristic line in FIG. 3, depends on the SOC region. Are very different. Such a change characteristic remarkably occurs when the secondary battery 10, that is, each battery cell 12, is a nickel metal hydride battery.

  Specifically, in the nickel metal hydride battery, in the low remaining capacity region 200, the Vb change rate with respect to the SOC change is considerably larger than that in the normal remaining capacity region 210. For this reason, in the low remaining capacity region 200, the output voltage Vb (i) rapidly decreases even in the battery block 14 in which no abnormality has occurred due to the difference in remaining capacity between the battery blocks 14. There is a possibility that 14 abnormalities are erroneously detected. That is, in FIG. 3, the low remaining capacity region 200 corresponds to the “first operation region” in the present invention, and the normal remaining capacity region 210 corresponds to the “second operation region” in the present invention.

  Referring again to FIG. 2, abnormality detection stop unit 130 outputs a stop signal STP for forcibly stopping abnormality detection in abnormality detection unit 120 based on the SOC calculated by battery state estimation unit 140. . That is, when the stop signal STP is generated by the abnormality detection stop unit 130, the abnormality detection unit 120 calculates the voltage difference ΔVb (i) calculated by the inter-block voltage difference calculation unit 110 in any battery block 14. Even when the value exceeds the determination value, the corresponding abnormality detection flag FL (i) is not turned on. That is, while the stop signal STP is generated, each abnormality detection flag FL (i) is forcibly fixed to OFF.

  When abnormality detection flag FL (i) is turned on, battery ECU 100 performs a predetermined abnormality process described later. This abnormality process includes fail-safe processing such as limiting output power from the secondary battery 10.

  On the other hand, as shown in FIG. 4, battery ECU 100 is generally configured to perform output restriction in accordance with the remaining capacity (SOC). That is, the allowable output from the secondary battery is variably set according to the SOC estimated by the battery state estimation unit 140, and the allowable output is significantly limited in the low remaining capacity region 200 than in the normal remaining capacity region 210. The output power is preferably limited to zero.

  As described above, in the low remaining capacity region 200, the output power is significantly limited, so that it is less necessary to perform abnormality detection and accompanying fail-safe processing (including allowable output limitation). Therefore, as described above, it is understood that even if the abnormality detection in the abnormality detection unit 120 is forcibly stopped, an adverse effect is hardly caused.

  Therefore, according to the secondary battery abnormality detection device 105 according to the present embodiment, abnormality detection based on the voltage difference ΔVb (i) between the battery blocks 14 is forced in such a low remaining capacity region 200. By stopping, it is possible to prevent erroneous detection of abnormality.

  The abnormality detection stop unit 130 is configured such that when the SOC of the entire secondary battery 10 estimated by the battery state estimation unit 140 is equal to or lower than a predetermined value, or the highest value of the SOC for each battery block 14 is equal to or lower than a predetermined value. In this case, it can be determined that the secondary battery 10 is in the low remaining capacity region 200 and the stop signal STP is output.

  Or abnormality detection stop part 130 is good also as composition which outputs stop signal STP, when the highest voltage of output voltage Vb (i) of each battery block 14 is below a predetermined voltage. Further, based on the open circuit voltage OCV # (i) for each battery block 14 estimated by the battery state estimation unit 140, when the maximum voltage of the estimated OCV is equal to or lower than a predetermined voltage, the secondary battery 10 has a low remaining capacity. It may be configured to output the stop signal STP by determining that the area 200 exists.

  Further, the above-described determination value (SOC) and determination voltage used for determining whether or not the secondary battery 10 is in the low remaining capacity region 200, that is, whether or not the stop signal STP needs to be output are the battery temperature Tb (i ) May be variably set. In this case, the secondary battery 10 is in the low remaining capacity region 200 where the abnormality detection should be stopped, reflecting that the change characteristic of the output voltage with respect to the remaining capacity and the charge / discharge current changes depending on the temperature of the secondary battery. It can be judged more accurately. As a result, it is possible to enhance the effect of preventing abnormal abnormality detection.

  FIG. 5 is a flowchart for explaining the processing procedure of secondary battery abnormality detection according to the embodiment of the present invention. Battery ECU 100 can realize abnormality detection of the secondary battery according to the embodiment of the present invention by executing a predetermined program stored in advance for executing the series of processes shown in FIG.

  Referring to FIG. 5, battery ECU 100 detects output voltage Vb (i) and battery temperature Tb (i) of each battery block 14 detected by voltage sensor 20, temperature sensor 22 and current sensor 24 in step S100, and The battery current Ib is acquired. In step S110, a voltage difference ΔVb (i) between each battery block 14 and another battery block is calculated. The process by step S110 is the same as the process by the voltage difference calculation part 110 between blocks of FIG. 2 mentioned above.

  Further, in step S120, battery ECU 100 determines whether or not voltage difference ΔVb (i) of each battery block 14 obtained in step S110 exceeds a predetermined determination value Vmax. In order to prevent erroneous detection, step S120 is determined as YES when ΔVb (i)> Vmax continues for a predetermined time (for example, about 2 to 4 seconds). Basically, the determination of step S120 as YES is equivalent to the fact that the battery block 14 in which ΔVb (i)> Vmax is detected as being abnormal.

  Battery ECU 100 further executes step S130 when YES is determined in step S120. In step S130, it is determined whether or not the secondary battery 10 is in the low remaining capacity region 200 where the abnormality detection should be stopped by the same processing as the abnormality detection stopping unit 130 in FIG.

  Then, the battery ECU 100 determines that the voltage difference ΔVb (i) exceeding the determination value Vmax is generated in any of the battery blocks 14 when the determination in step S130 is NO, and the secondary battery 10 enters the low remaining capacity region 200. If not, an abnormality of the battery block 14 is detected in step S140. Then, fail-safe processing is executed as necessary. As the fail-safe process, for example, a request for charging the secondary battery 10 is generated by replacing the estimated SOC value with the SOC value at the lower control limit.

  On the other hand, the battery ECU 100 invalidates the abnormality detection by skipping step S140 when the determination in step S130 is YES. Thereby, even if the voltage difference ΔVb (i) exceeding the determination value Vmax is generated in any of the battery blocks 14 (YES in S120), no abnormality is detected. That is, the YES determination in step S130 is equivalent to the output of the stop signal STP by the abnormality detection stop unit 130 in FIG.

  Battery ECU 100 determines in step S150 whether an abnormality has been detected over a plurality of trips. One trip indicates a period from when a switch (typically, an ignition key switch or the like) that is turned on / off at the start / end of operation is turned on until it is turned off. Step S150 is determined to be YES when, for example, the abnormality is detected in step S140 for two consecutive trips. When the determination in step S150 is YES, battery ECU 100 determines in step S160 that a battery failure has occurred. As a result, a diagnostic code indicating that a battery failure has occurred is generated and notified to the driver. Further, a fail-safe process for limiting (or prohibiting) the output power from the secondary battery is also executed as necessary.

  On the other hand, even when an abnormality is detected in step S140, if this is the first detection, step S150 is NO, so the battery failure determination in step S160 is skipped. In this case, information indicating that an abnormality has been detected in the trip is stored and used for the determination in step S150 in the subsequent trip.

  As described above, according to the abnormality detection of the secondary battery according to the embodiment of the present invention, between the battery blocks 14 in the operation region (low remaining capacity region 200) where the change rate of the output voltage with respect to the change in the remaining capacity is large. The abnormality detection based on the output voltage difference can be forcibly stopped. As a result, in the low remaining capacity region 200, paying attention to the fact that a voltage difference occurs due to the remaining capacity variation between the battery blocks even under normal conditions, the battery block abnormality is erroneously detected based on such a voltage difference. Can be prevented.

[Modification]
FIG. 6 is a schematic block diagram illustrating the configuration of a secondary battery abnormality detection device according to a modification of the embodiment of the present invention.

  Compared with FIG. 2 in FIG. 2, in abnormality detection device 105 # for the secondary battery according to the modification of the embodiment, abnormality detection stop unit 130 includes component failure information in the hybrid vehicle on which secondary battery 10 is mounted. In addition, information indicating the remaining amount of fuel in a fuel tank (not shown) is further received. Then, the abnormality detection stop unit 130, when the condition described with reference to FIG. 2 is satisfied, when a failure occurs in a predetermined part of the hybrid vehicle or when the remaining amount of fuel is equal to or less than a predetermined amount, The stop signal STP is also output when the state (fuel remaining amount≈0).

  The configuration of other parts in FIG. 6 and the operation of each block are the same as those in FIG. 2, and therefore detailed description will not be repeated.

  FIG. 7 is a flowchart for explaining the processing procedure of the secondary battery abnormality detection method according to the modification of the embodiment of the present invention to be compared with FIG.

  Referring to FIG. 7, in detection of abnormality of the secondary battery according to the modification of the embodiment, battery ECU 100 further executes steps S <b> 200 and S <b> 210 in addition to the processing in the flowchart shown in FIG. 5. Since the other steps shown in FIG. 7 are the same as those in FIG. 5, detailed description will not be repeated.

  In step S200, battery ECU 100 determines whether or not failure information indicating that the predetermined component has a failure is input. Here, the predetermined components include components necessary for charging the secondary battery among components mounted on the hybrid vehicle, such as an engine, an electric motor for starting the engine, a fuel pump, a transmission, and the like.

  In step S210, battery ECU 100 determines whether or not the remaining amount of fuel is equal to or less than a predetermined value and the hybrid vehicle on which secondary battery 10 is mounted is in a so-called out-of-gas state.

  Battery ECU 100 determines that any one of steps S130, S200, and S210 is YES even when voltage difference ΔVb (i) exceeding determination value Vmax is occurring in any battery block 14 (when YES is determined in S120). Then, the abnormality detection is invalidated by skipping step S140. That is, the secondary battery 10 is in the low remaining capacity region 200 even when there is a failure in a predetermined part (when YES is determined in S200) or when the hybrid vehicle is out of gas (when YES is determined in S210). At the same time (when YES is determined in S130), the abnormality detection based on the output voltage difference between the battery blocks 14 is forcibly stopped.

  As described above, according to the abnormality detection of the secondary battery according to the modification of the embodiment, the abnormality detection is not performed in a special case such as when a predetermined part is broken or the remaining amount of fuel is extremely small. Thus, erroneous detection of abnormality can be prevented more reliably.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a circuit diagram showing an overall configuration of a battery system to which abnormality detection of a secondary battery according to an embodiment of the present invention is applied. It is a schematic block diagram explaining the structure of the abnormality detection apparatus of the secondary battery by embodiment of this invention. It is a conceptual diagram explaining the change characteristic of the output voltage with respect to the remaining capacity of a secondary battery. It is a conceptual diagram which shows the example of output electric power restrictions with respect to the remaining capacity of a secondary battery. It is a flowchart explaining the process sequence of the abnormality detection method of the secondary battery by embodiment of this invention. It is a schematic block diagram explaining the structure of the abnormality detection apparatus of the secondary battery by the modification of embodiment of this invention. It is a flowchart explaining the process sequence of the abnormality detection method of the secondary battery by the modification of embodiment of this invention.

Explanation of symbols

  10 Secondary battery, 12 Battery cell, 14 Battery block, 20 Voltage sensor, 22 Temperature sensor, 24 Current sensor, 50 Load, 100 Battery ECU, 105, 105 # Abnormality detection device, 110 Inter-block voltage difference calculation unit, 120 Abnormality Detection unit, 140 remaining capacity estimation unit, 200 low remaining capacity region, 210 normal remaining capacity region, FL (i) abnormality detection flag, Ib battery current, OCV # (i) estimated OCV, STP stop signal, Tb (i) battery Temperature (each battery block), Vb (i) output voltage (each battery block), Vmax determination value, ΔVb (i) voltage difference (between battery blocks).

Claims (12)

An abnormality detection device for a secondary battery having a plurality of battery blocks each composed of at least one battery cell,
The secondary battery has a first operating region in which a change rate of the output voltage with respect to a change in the remaining capacity is relatively large in a change characteristic of an output voltage with respect to a remaining capacity, and the change rate is higher than that in the first region. Has a small second operating area,
The abnormality detection device is:
A plurality of voltage detectors for respectively detecting output voltages of the plurality of battery blocks;
Based on detection values by the plurality of voltage detection units, a voltage difference calculation unit that calculates a voltage difference between the blocks for the plurality of battery blocks; and
When the voltage difference calculated by the voltage calculation unit exceeds a predetermined determination value, an abnormality detection unit that detects an abnormality of the battery block in which the voltage difference occurs;
An abnormality detection device for a secondary battery, comprising: an abnormality detection stop unit for forcibly stopping abnormality detection by the abnormality detection unit when the secondary battery is in the first operation region. A battery state estimation unit that calculates an estimated value of the remaining capacity of the secondary battery based on the state quantity of the secondary battery;
2. The abnormality detection stop unit determines that the secondary battery is in the first operation region when a remaining capacity estimation value estimated by the battery state estimation unit is equal to or less than a predetermined value. Secondary battery abnormality detection device. A battery state estimating unit for estimating an open circuit voltage of each of the plurality of battery blocks based on a state quantity of the secondary battery;
The abnormality detection stop unit is configured such that when the highest voltage among the estimated open circuit voltages of the plurality of battery blocks estimated by the battery state estimation unit is equal to or lower than a predetermined voltage, the secondary battery is the first battery. The abnormality detection device for a secondary battery according to claim 1, wherein the abnormality detection device determines that the region is in an operation region.   The abnormality detection stop unit is configured such that when the highest voltage among the output voltages of the plurality of battery blocks detected by the plurality of voltage detection units is equal to or lower than a predetermined voltage, the secondary battery is the first battery. The abnormality detection device for a secondary battery according to claim 1, wherein the abnormality detection device determines that the region is in an operation region. A plurality of temperature detectors for detecting temperatures of the plurality of battery blocks,
The predetermined value or the predetermined voltage used for determining whether or not the secondary battery is in the first operation region is variably set according to detection values by the plurality of temperature detection units. The abnormality detection apparatus of the secondary battery of any one of 2-4. The secondary battery is mounted on a hybrid vehicle,
The abnormality detection stop unit is provided when a failure occurs in a predetermined part of the hybrid vehicle, or when a fuel remaining in the hybrid vehicle is detected, in addition to the determination that the secondary battery is in the first operation region. 2. The abnormality detection device for a secondary battery according to claim 1, wherein abnormality detection by the abnormality detection unit is forcibly stopped even when the amount is equal to or less than a predetermined amount. A method for detecting an abnormality in a secondary battery having a plurality of battery blocks each comprising at least one battery cell,
The secondary battery has a first operating region in which a change rate of the output voltage with respect to a change in the remaining capacity is relatively large in a change characteristic of an output voltage with respect to a remaining capacity, and the change rate is higher than that in the first region. Has a small second operating area,
Acquiring each output voltage of the plurality of battery blocks based on outputs of a plurality of voltage detection units provided corresponding to the plurality of battery blocks, respectively.
Calculating a voltage difference between the blocks of the plurality of battery blocks based on output voltages of the plurality of battery blocks; and
Detecting the abnormality of the battery block in which the voltage difference occurs when the voltage difference calculated by the voltage calculation unit exceeds a predetermined determination value;
An abnormality detection method for a secondary battery, comprising: disabling abnormality detection when the secondary battery is in the first operation region.   In the invalidating step, when the estimated remaining capacity of the entire secondary battery or the highest estimated value of the remaining capacity of each of the plurality of battery blocks is equal to or less than a predetermined value, the secondary battery The abnormality detection method for a secondary battery according to claim 7, wherein the abnormality is determined to be in one operation region.   The disabling step determines that the secondary battery is in the first operating region when the highest voltage among the estimated open circuit voltages of the plurality of battery blocks is equal to or lower than a predetermined voltage. Item 8. A secondary battery abnormality detection method according to Item 7.   The invalidating step determines that the secondary battery is in the first operating region when a maximum voltage among output voltages of the plurality of battery blocks is equal to or lower than a predetermined voltage. The abnormality detection method of the secondary battery of 7.   The secondary battery according to any one of claims 8 to 10, wherein, in the invalidating step, the predetermined voltage or the predetermined value is variably set according to a temperature detection value of the plurality of battery blocks. Anomaly detection method. The secondary battery is mounted on a hybrid vehicle,
8. The method according to claim 7, further comprising a step of invalidating the abnormality detection when a failure occurs in a predetermined part of the hybrid vehicle or when a remaining fuel amount of the hybrid vehicle is equal to or less than a predetermined amount. Secondary battery abnormality detection method.

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