Battery fault diagnosis apparatus and method for determining FDC value by applying weight

Abstract

The present invention relates to a battery fault diagnosis apparatus and to a method for determining a fault detection counter (FDC) value by applying a weight. The battery fault diagnosis apparatus of the present invention may comprise: a measurement unit for generating measurement data of a cell voltage for each of a plurality of battery cells included in a battery pack; an FDC determination unit for increasing an FDC value with an increasing slope or decreasing the FDC value with a decreasing slope on the basis of a result of comparing the measurement data with a predetermined threshold voltage value; a weight determination unit for determining a target weight to be applied to the increasing slope or the decreasing slope, on the basis of an FDC value at a time point at which the increasing slope or the decreasing slope is applied, and a magnitude of a voltage deviation obtained by subtracting the threshold voltage value from the measurement data; and a DTC setting unit for setting a DTC value corresponding to the FDC value to a first value indicating that the battery pack is abnormal, when the FDC value reaches a predetermined upper threshold value, and setting the DTC value to a second value indicating that the battery pack is normal, when the FDC value reaches a predetermined lower threshold value.

Description

Battery fault diagnosis device and method for determining FDC values ​​by applying weights

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0011465, filed January 25, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present disclosure relates to a battery fault diagnosis device and a method for determining a FDC (Fault Detection Counter) value.

[0004] According to the ISO-14229 standard protocol definition, in the case of FDC (Fault Detection Counter) Read to determine DTC (Diagnostic Trouble Code), depending on the given diagnosis, the FDC tends to increase or decrease regularly in accordance with the test period with a predefined step up or step down size when the diagnosis occurs or is released within the range of 0x80 to 0x7F.

[0005] However, in order to establish the diagnosis condition by reaching 0x7F only with a set step-up or step-down size from the normal state of FDC=0, the number of step-ups must be repeated a lot. In addition, in order to establish the diagnosis release condition by reaching 0x80 only with a set step-up or step-down size from the normal state, the number of step-downs must be repeated a lot. Therefore, there is a problem that the waiting time for the diagnosis condition to be established or the diagnosis release condition to be established may be long.

[0006] Recently, there is a need for rapid response to battery failure in order to diagnose battery thermal events or isolation events.

[0007] The present invention aims to provide a battery fault diagnosis device and a method for determining an FDC (Fault Detection Counter) value by applying weights to determine the FDC value.

[0008] According to one aspect of the invention, a battery fault diagnosis device is provided, which generates fault detection count (FDC) information from a lower threshold value to an upper threshold value for a battery to diagnose a fault of the battery, the device including: a measuring unit connected to a battery pack to generate measurement data of cell voltages of each of a plurality of battery cells included in the battery pack; an FDC determination unit to increase an FDC value with an increasing slope or to decrease an FDC value with a decreasing slope based on a result of comparing the measurement data with a predetermined threshold voltage value; a weight determination unit to determine a target weight applied to the increasing slope or the decreasing slope based on a magnitude of a voltage deviation obtained by subtracting the threshold voltage value from the FDC value at the time of applying the increasing slope or the decreasing slope; and a DTC setting unit to set a DTC value corresponding to the FDC to a first value indicating that the battery pack is abnormal when the FDC value reaches a predetermined upper threshold value, and to set the DTC value to a second value indicating that the battery pack is normal when the FDC value reaches a predetermined lower threshold value.

[0009] The FDC decision unit may, when the voltage deviation exceeds 0, select the increasing slope from among the increasing slopes and the decreasing slopes, and determine a value obtained by applying a first target weight determined by the weight decision unit to a pre-stored predetermined increasing reference slope as the increasing slope; and, when the voltage deviation is less than 0, select the decreasing slope from among the increasing slopes and the decreasing slopes, and determine a value obtained by applying a second target weight determined by the weight decision unit to a pre-stored predetermined decreasing reference slope as the decreasing slope.

[0010] If the FDC value at the time of application is less than or equal to the lower limit of a predetermined weighted application range between the upper limit threshold value and the lower limit threshold value or greater than or equal to the upper limit of the weighted application range, the weight determination unit may determine the target weight as 1.

[0011] If the FDC value at the point of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the weight determination unit determines one of a plurality of reference weights as the target weight based on the size of the voltage deviation, and the plurality of reference weights may have a larger value as the ratio of the voltage deviation to the threshold voltage value increases.

[0012] When the FDC value at the point of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit, the FDC determination unit may determine the FDC value as an upper limit value of the weighted application range.

[0013] When the FDC value at the point of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined reduced deviation upper limit, the FDC determination unit may determine the FDC value as the lower limit value of the weighted application range.

[0014] A method for determining an FDC value by applying a weight according to another feature of the invention is a method for determining an FDC value by applying a weight in a device that diagnoses a fault of a battery by generating FDC (Fault Detection Counter) information from a lower threshold value to an upper threshold value for the battery, the method comprising the steps of: generating measurement data representing cell voltages of each of a plurality of battery cells included in a battery pack; determining a target weight to be applied to the increasing slope or the decreasing slope based on an FDC value at a time point at which an increasing slope or a decreasing slope of the FDC value is applied and a magnitude of a voltage deviation obtained by subtracting the threshold voltage value from the measurement data; increasing the FDC value with the increasing slope or decreasing the FDC value with the decreasing slope based on a result of comparing the measurement data with a predetermined threshold voltage value; and setting a DTC value corresponding to the FDC to a first value indicating that the battery pack is abnormal when the FDC value reaches a predetermined upper threshold value, and setting the DTC value to a second value indicating that the battery pack is normal when the FDC value reaches a predetermined lower threshold value.

[0015] The method may further include a step of selecting one of the increasing slope and the decreasing slope based on whether the voltage deviation exceeds 0 or whether the voltage deviation is less than 0, a step of determining the increasing slope by applying a first target weight determined by the weight determination unit to a previously stored predetermined increasing reference slope, and a step of determining the decreasing slope by applying a second target weight determined by the weight determination unit to a previously stored predetermined decreasing reference slope.

[0016] The method may further include a step of determining the target weight as 1 when the FDC value at the time of application is equal to or less than the lower limit of a predetermined weighted application range between the upper limit threshold value and the lower limit threshold value or equal to or greater than the upper limit of the weighted application range.

[0017] If the FDC value at the point of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the method further includes a step of determining one of a plurality of reference weights as the target weight based on the magnitude of the voltage deviation, wherein the plurality of reference weights may have a larger value as the ratio of the voltage deviation to the threshold voltage value increases.

[0018] The method may further include a step of determining the FDC value as the upper limit value of the weighted application range when the FDC value at the point of application is within a predetermined weighted application range between the upper limit threshold value and the lower limit threshold value, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit.

[0019] The method may further include a step of determining the FDC value as the lower limit value of the weighted application range when the FDC value at the point of application is within a predetermined weighted application range between the upper limit threshold value and the lower limit threshold value, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined reduced deviation upper limit.

[0020] According to the present invention, by defining a weight for a specific diagnosis using battery measurement data, the intensity for an area that affects a DTC diagnosis condition or a diagnosis release condition and an area that does not affect the DTC diagnosis condition or a diagnosis release condition can be adjusted to quickly reach a diagnosis or diagnosis release.

[0021] According to the present invention, the counter step size can be varied depending on the size of the deviation between the measured data and the threshold value, so that the more serious the problem that has occurred in the battery, the faster the diagnosis condition can be reached.

[0022] According to the present invention, it is possible to prevent excessive time from being taken to release a diagnosis after a diagnostic condition occurs, thereby promoting convenience in the use of a vehicle or the like.

[0023] FIG. 1 is a schematic drawing of a battery system including a battery fault diagnosis device according to one embodiment.

[0024] Figure 2 is a graph to explain the unweighted increasing slope.

[0025] Figure 3 is a graph to explain the unweighted decreasing slope.

[0026] Figure 4 is a drawing for explaining the weighted application range in the graph shown in Figure 2.

[0027] Figure 5 is an example diagram of a weight coefficient map according to one embodiment.

[0028] FIG. 6 is a graph illustrating an operation of determining an FDC value with a weighted slope according to one embodiment.

[0029] Figure 7 is a flowchart of a method for determining a weighted FDC value according to one embodiment.

[0030] Figure 8 is a detailed flowchart of step S200 illustrated in Figure 7.

[0031] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the attached drawings. The same or similar components will be given the same or similar drawing reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and / or "part" used for components in the following description are given or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0032] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0033] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0034] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0035] FIG. 1 is a schematic drawing of a battery system including a battery fault diagnosis device according to one embodiment.

[0036] Referring to FIG. 1, the battery system (1) may include a battery pack (10), a battery failure diagnosis device (20), and a relay (30, 31).

[0037] One end of the relay (30, 31) is connected to the battery pack (10), and the other end of the relay (30, 31) is connected to at least one component in an external device (2). Closing and opening of the relay (30, 31) can be controlled according to a relay control signal (RCS1, RCS2) supplied from a battery failure diagnosis device (20).

[0038] The battery system (1) can be connected to an external device (2). The external device (2) can include a load and a charging device such as an inverter or a converter. If the external device (2) is a charger, both ends (P+, P-) of the battery system (1) are connected to the charger so that power can be supplied from the charger and charged. If the external device (2) is a load, both ends (P+, P-) of the battery system (1) are connected to the load so that power supplied by the battery pack (10) can be discharged through the load.

[0039] The battery pack (10) can be implemented with two or more battery cells connected in series, two or more battery cells connected in parallel, a plurality of battery cells connected in series, or two or more battery cells connected in parallel.

[0040] A battery fault diagnosis device (20) can diagnose a battery fault by generating fault detection counter (FDC) information from a lower threshold value to an upper threshold value for the battery. The battery fault diagnosis device (20) can set a DTC (Diagnostic Trouble Code) value corresponding to the FDC value. The battery fault diagnosis device (20) can be provided in a battery management system (BMS) of a battery pack (10). When the battery system (1) is connected to a vehicle, the vehicle can transmit a request message to the battery system (1) for obtaining DTC information. The request message can be a message requesting information on a DTC belonging to a specific DTC state and an FDC (Fault Detection Counter) corresponding to the DTC. The battery system (1) can receive the request message and transmit a response message corresponding to the request message to the vehicle. The response message can include a DTC value set by the battery system (1).

[0041] The battery failure diagnosis device (20) may include a storage unit (210), a measurement unit (220), an FDC determination unit (230), a weight determination unit (240), and a DTC setting unit (250). The storage unit (210) is a configuration corresponding to the memory of the battery failure diagnosis device (20), and the FDC determination unit (230), the weight determination unit (240), and the DTC setting unit (250) may be included in a configuration corresponding to the processor of the battery failure diagnosis device (20).

[0042] The measuring unit (220) can be connected to the battery pack (10) and generate measurement data indicating the state of the battery pack (10). The measuring unit (220) can be electrically connected to the battery pack (10). The state of the battery pack (10) can include at least one of voltage, current, temperature, etc. of the battery pack (10). The measuring unit (220) can include at least one of a voltage sensor, a current sensor, and a temperature sensor. Here, the voltage sensor can measure the positive terminal voltage and / or the negative terminal voltage of the battery pack (10), the cell voltage of each of the plurality of battery cells included in the battery pack (10), etc. The current sensor can measure the current flowing in the battery pack (10) while the battery pack (10) is in a charging operation or a discharging operation. The temperature sensor can be provided at a position adjacent to the battery pack (10) and measure the temperature of the battery pack (10). The measurement data can include at least one of a voltage measured by the voltage sensor, a current measured by the current sensor, and a temperature measured by the temperature sensor.

[0043] Hereinafter, for convenience of explanation, the measurement data is explained assuming that it is the cell voltage of each of the plurality of battery cells included in the battery pack (10).

[0044] The FDC determination unit (230) can increase the FDC value with an increasing slope or decrease the FDC value with a decreasing slope based on the result of comparing the measurement data generated by the measurement unit (220) with a predetermined threshold voltage value. Here, the threshold voltage value may be a voltage value of the cell voltage, which is the measurement data, in a normal state.

[0045] The FDC decision unit (230) can increase the FDC value with an increasing slope when the measurement data is a Fail Condition. For example, if the voltage deviation (hereinafter, “voltage deviation”) obtained by subtracting a predetermined threshold voltage value from the measurement data exceeds 0, it may be a Fail Condition. For convenience of explanation, it is assumed below that the FDC decision unit (230) increases the FDC value with an increasing slope when the voltage deviation exceeds 0.

[0046] The FDC determination unit (230) can decrease the FDC value with a decreasing slope when the measurement data is a Pass Condition. For example, if the voltage deviation is less than 0, it may be a Pass Condition. For convenience of explanation, it is assumed below that the FDC determination unit (230) decreases the FDC value with a decreasing slope when the voltage deviation is less than 0.

[0047] The DTC setting unit (250) may set the DTC value corresponding to the determined FDC to a first value indicating that the battery pack (10) is abnormal when the FDC value determined by the FDC determination unit (230) reaches a predetermined upper threshold value, and may set the DTC value corresponding to the determined FDC to a second value indicating that the battery pack (10) is normal when the determined FDC value reaches a predetermined lower threshold value. The first value may indicate that a diagnosis condition (Test Fail) has been reached and thus a diagnosis of the battery pack (10) is required. The second value may indicate that a diagnosis release condition (Test Pass) has been reached and thus a diagnosis that has already occurred in the battery pack (10) can be released.

[0048] The storage unit (210) may store a predetermined upper threshold value and a predetermined lower threshold value that are compared with the FDC value. For example, the upper threshold value may be 0x7F=127, and the lower threshold value may be 0x80=-128.

[0049] If the FDC value determined by the FDC determination unit (230) reaches a predetermined upper threshold value, the DTC setting unit (250) can determine that the battery pack (10) is abnormal based on the failure test results for the measurement data. If the FDC value determined by the FDC determination unit (230) reaches a predetermined lower threshold value, the DTC setting unit (250) can determine that the battery pack (10) is normal based on the failure test results for the measurement data. The abnormal state of the battery pack (10) may be a state in which a diagnosis condition has been reached, and the normal state may be a state in which a diagnosis release condition has been reached.

[0050] The increasing slope may be the number of steps for increasing the counter value of the FDC in response to a given test time (Test Period), and the decreasing slope may be the number of steps for decreasing the counter value of the FDC in response to a given test time. For example, the increasing slope and the decreasing slope may be the number of steps for increasing or decreasing during a test time of 100 ms. Therefore, when the test time is 100 ms, the decreasing slope is X Steps / 100 ms, and the voltage deviation value is less than 0 during a period from the first time point to the second time point when 300 ms have elapsed, the FDC determination unit (230) may determine the FDC value at the second time point by decreasing the FDC value at the first time point by 3X according to the ratio of X Steps / 100 ms for 300 ms.

[0051] The weight determination unit (240) can determine the weight applied to the increasing slope and / or decreasing slope utilized by the FDC determination unit (230) based on the FDC value and the magnitude of the voltage deviation at the time when the FDC determination unit (230) applies the increasing slope or decreasing slope. Hereinafter, for convenience of explanation, a voltage deviation exceeding 0 may indicate a state in which the weight determination unit (240) determines the weight applied to the increasing slope and / or the FDC determination unit (230) can increase the FDC value with an increasing slope. Also, for convenience of explanation, a voltage deviation less than 0 may indicate a state in which the weight determination unit (240) determines the weight applied to the decreasing slope and / or the FDC determination unit (230) can decrease the FDC value with a decreasing slope.

[0052] If the voltage deviation exceeds 0, the FDC decision unit (230) may select an increasing slope among the increasing slopes and decreasing slopes, and may determine a value obtained by applying the first target weight determined by the weight decision unit (240) to a previously stored predetermined increasing reference slope as the increasing slope.

[0053] If the voltage deviation is less than 0, the FDC decision unit (230) may select a decreasing slope among the increasing slope and the decreasing slope, and may determine a value obtained by applying the second target weight determined by the weight decision unit (240) to a predetermined decreasing reference slope stored in advance as the decreasing slope.

[0054] For example, the increasing slope may be a value obtained by multiplying the increasing reference slope by the target weight, and the decreasing slope may be a value obtained by multiplying the target weight by a predetermined, stored decreasing reference slope.

[0055] The storage unit (210) may store a predetermined threshold voltage value, a predetermined increase reference slope, and a predetermined decrease reference slope that are comparison targets of the measurement data. The predetermined threshold voltage value may be, for example, 4.0 V. The predetermined increase reference slope and the predetermined decrease reference slope may have different values ​​depending on the type of the measurement data (e.g., voltage, current, temperature, etc.). For example, the increase reference slope corresponding to the cell voltage may be 9 Steps / 100 ms, and the decrease reference slope corresponding to the cell voltage may be 13 Steps / 100 ms. Hereinafter, the increase reference slope and the decrease reference slope corresponding to the cell voltage will be described according to the above-described example, but this is for the convenience of explanation and the invention is not limited thereto. In some embodiments, each of the increase reference slope and the decrease reference slope may be a value that varies depending on the diagnosis target, the project, etc. The diagnosis target here may be a target indicated by a DTC corresponding to the determined FDC value, and the project may be a target that manages a vehicle by utilizing the diagnosis target.

[0056] When the target weight is 1, the increasing slope may be a pre-stored increasing reference slope, and the decreasing slope may be a pre-stored decreasing reference slope. Hereinafter, for convenience of explanation, each of the increasing slope and the decreasing slope (e.g., the increasing slope) utilized by the FDC determination unit (230) is a value obtained by applying the target weight to the corresponding reference slope (e.g., the increasing reference slope) among the pre-stored predetermined increasing reference slope and the predetermined decreasing reference slope. Therefore, below, the fact that the weight determination unit (240) determines the target weight as 1 may indicate that no weight is applied to the increasing slope or the decreasing slope.

[0057] Figure 2 is a graph to explain the unweighted increasing slope.

[0058] Referring to Fig. 2, when the increase reference slope corresponding to the cell voltage is 9 Steps / 100ms and no weight is applied to the increase slope, the FDC value can increase by 9 every 100ms. In Fig. 2, the lower limit threshold of the FDC is described as 0x80, and the upper limit threshold of the FDC is described as 0x7F.

[0059] If the voltage deviation exceeds 0 during the fault test period, the FDC determination unit (230) can increase the FDC value from the lower limit threshold value (0x80) of the FDC with an increasing slope. If the FDC value reaches the upper limit threshold value (0x7F) of the FDC, the DTC setting unit (250) can set the DTC value to the first value at the time point (t1) when the FDC value reaches the upper limit threshold value (0x7F) of the FDC.

[0060] Figure 3 is a graph to explain the unweighted decreasing slope.

[0061] Referring to Fig. 3, when the decrease reference slope corresponding to the cell voltage is 13 Steps / 100ms and no weight is applied to the decrease slope, the FDC value can decrease by 13 per 100ms. In Fig. 3, the lower limit threshold of the FDC is described as 0x80, and the upper limit threshold of the FDC is described as 0x7F.

[0062] If the voltage deviation is less than 0 during the fault test period, the FDC determination unit (230) can decrease the FDC value from the upper limit threshold value (0x7F) with a decreasing slope (13 Steps / 100ms). If the FDC value reaches the lower limit threshold value (0x80) of the FDC, the DTC setting unit (250) can set the DTC value to a second value at the time point (t2) when the lower limit threshold value (0x80) of the FDC is reached.

[0063] Hereinafter, in one embodiment, an operation of determining an FDC value by an increasing slope or decreasing slope by applying a weight determined from a weight determining unit (240) is described.

[0064] The weight determination unit (240) may determine a target weight of 1 or more if the FDC value at the time of applying the increasing slope or decreasing slope is within a predetermined weighted application range (hereinafter, “weighted application range”) between the upper limit threshold value of the FDC and the lower limit threshold value of the FDC, and may determine the target weight as 1 if it is outside the weighted application range. Here, the weighted application range may be a range indicating a normal condition between the upper limit threshold value of the FDC and the lower limit threshold value of the FDC. The lower limit value of the weighted application range is a value greater than the aforementioned lower limit threshold value of the FDC, and the upper limit value of the weighted application range is a value less than the aforementioned upper limit threshold value of the FDC. For example, the lower limit value of the weighted application range may be 0x9B, and the upper limit value of the weighted application range may be 0x64.

[0065] Specifically, if the FDC value at the time of applying the increasing slope or decreasing slope is less than or equal to the lower limit of the weighted application range or greater than or equal to the upper limit of the weighted application range, the weight determination unit (240) may determine the target weight as 1.

[0066] However, this is for convenience of explanation and the invention is not limited thereto. In some embodiments, when the voltage deviation is less than 0 and the FDC value at the time of applying the decreasing slope is less than or equal to the lower limit of the weighted application range, or when the voltage deviation is greater than 0 and the FDC value at the time of applying the increasing slope is greater than or equal to the upper limit of the weighted application range, the weight determination unit (240) may determine the target weight as 1. In other words, when the FDC value at the time of applying the increasing slope or the decreasing slope is increased even if it is less than or equal to the lower limit of the weighted application range, or when the FDC value is decreased even if the FDC value at the time of applying the increasing slope or the decreasing slope is greater than or equal to the upper limit of the weighted application range, the weight determination unit (240) may determine that it is within the weighted application range.

[0067] Hereinafter, the operation of determining the target weight by comparing the FDC value at the time when the weight determination unit (240) applies the increasing slope or decreasing slope with the weight application range is referred to as the “first weight determination operation.”

[0068] Figure 4 is a drawing for explaining the weighted application range in the graph shown in Figure 2.

[0069] Referring to FIG. 4, the range between 0x9B and 0x64 between the lower limit threshold value of FDC (0x80) and the upper limit threshold value of FDC (0x7F) can be used as the weighted application range.

[0070] For example, if the FDC value at the first point in time is a value between the lower limit threshold value of the FDC (0x80) and the lower limit value of the weighted application range (0x9B), the weight determination unit (240) can determine the target weight from the first point in time to the second point in time after the first point in time as 1. Accordingly, if the voltage deviation corresponding to the period from the first point in time to the second point in time is less than 0, the FDC determination unit (230) can determine the decreasing slope from the first point in time to the second point in time as the decreasing reference slope.

[0071] In addition, if the FDC value at the third point in time is a value between the upper limit threshold value of the FDC (0x7F) and the upper limit value of the weighted application range (0x64), the weight determination unit (240) can determine the target weight from the third point in time to the fourth point in time after the third point in time as 1. Accordingly, if the voltage deviation corresponding to the period from the third point in time to the fourth point in time after the third point in time exceeds 0, the FDC determination unit (230) can determine the increase slope from the third point in time to the fourth point in time as the increase reference slope.

[0072] The weight determination unit (240) can determine the value of the target weight according to the size of the voltage deviation when the FDC value at the time of applying the increasing slope or decreasing slope is within the weighting application range.

[0073] Hereinafter, the operation in which the weight determination unit (240) determines the value of the target weight according to the magnitude of the voltage deviation is referred to as the "second weight determination operation." Hereinafter, the process in which the weight determination unit (240) determines the value of the target weight according to the magnitude of the voltage deviation will be described.

[0074] The storage unit (210) may store a weight factor map including a plurality of reference weights corresponding to a plurality of critical deviation sections. The weight factor map may include a plurality of increase reference weights corresponding to a plurality of increase critical deviation sections and a plurality of decrease reference slopes corresponding to a plurality of decrease critical deviation sections. If the FDC determination unit (230) selects to apply an increase weight among the increase slopes and the decrease slopes, the weight determination unit (240) may determine one of the plurality of increase reference weights corresponding to the plurality of increase critical deviation sections as a target weight. Alternatively, if the FDC determination unit (230) selects to apply a decrease weight among the increase slopes and the decrease slopes, the weight determination unit (240) may determine one of the plurality of decrease reference slopes corresponding to the plurality of decrease critical deviation sections as a target weight. Hereinafter, the plurality of critical deviation sections may represent a plurality of corresponding critical deviation sections among the plurality of increase critical deviation sections and the plurality of decrease critical deviation sections, and the plurality of reference weights may represent a plurality of corresponding reference weights among the plurality of increase reference weights and the plurality of decrease reference slopes.

[0075] The weight determination unit (240) may determine a reference weight corresponding to a critical deviation section to which the ratio of voltage deviation to the critical voltage value belongs among a plurality of critical deviation sections as a target weight. Here, the larger the critical deviation indicated by each of the plurality of critical deviation sections, the larger the multiple reference weights may be. The ratio of voltage deviation to the critical voltage value may be a value obtained by dividing the absolute value of the voltage deviation by the critical voltage value.

[0076] Figure 5 is an example diagram of a weight coefficient map according to one embodiment.

[0077] Referring to FIG. 5, multiple increase threshold deviation sections corresponding to the Fail Condition may include sections such as Level 1 where the voltage deviation ratio is 1% or more and less than 2%, Level 2 where the voltage deviation ratio is 2% or more and less than 3%, and Level 3 where the voltage deviation ratio is 3% or more and less than 3.5%. In this case, among the multiple increase threshold weights, the increase threshold weight corresponding to the increase threshold deviation section of 1% or more and less than 2% may be 1.5, the increase threshold weight corresponding to the increase threshold deviation section of 2% or more and less than 3% may be 3, and the increase threshold weight corresponding to the increase threshold deviation section of 3% or more and less than 3.5% may be 4.5. The target weight corresponding to less than 1% that does not belong to the multiple increase threshold deviation sections may be 1.

[0078] Referring to FIG. 5, a plurality of reduction threshold deviation sections corresponding to a Pass Condition may include sections such as Level 1 where the voltage deviation ratio is 1% or more and less than 4%, Level 2 where the voltage deviation ratio is 4% or more and less than 7%, and Level 3 where the voltage deviation ratio is 7% or more and less than 10%. In this case, among the plurality of reduction criteria weights, the reduction criteria weight corresponding to the reduction threshold deviation section of 1% or more and less than 4% may be 1.5, the reduction criteria weight corresponding to the reduction threshold deviation section of 4% or more and less than 7% may be 3, and the reduction criteria weight corresponding to the reduction threshold deviation section of 7% or more and less than 10% may be 4.5. The target weight corresponding to less than 1% that does not belong to the plurality of reduction threshold deviation sections may be 1.

[0079] Hereinafter, a plurality of increase criterion weights corresponding to a plurality of increase critical deviation sections, and a plurality of decrease criterion weights corresponding to a plurality of decrease critical deviation sections, are described according to the example of FIG. 5, but this is for convenience of explanation and the invention is not limited thereto. In some embodiments, the number of a plurality of increase critical deviation sections, the number of a plurality of decrease critical deviation sections, the values ​​of the critical deviations indicated by each of the plurality of increase critical deviation sections and the plurality of decrease critical deviation sections, and the values ​​of each of the plurality of increase criterion weights and the plurality of decrease criterion weights may be values ​​that vary depending on the diagnosis target, project, etc.

[0080] This is to allow for a larger target weight to be applied within a given weighted application range as the voltage deviation value increases in order to reach a faster diagnostic condition or diagnostic release condition than by increasing or decreasing the FDC value with a constant increasing or decreasing slope.

[0081] However, in cases where the voltage deviation value is very large, it is possible to respond to a large voltage deviation of the battery pack (10) by reaching the diagnosis condition or diagnosis release condition immediately without additional FDC counting operation, or by reaching an FDC value close to the diagnosis condition or diagnosis release condition.

[0082] If the voltage deviation exceeds 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit, the FDC determination unit (230) may determine the FDC value as the upper limit threshold value of the FDC. For example, if the voltage deviation exceeds 0 and exceeds 3.5% of the threshold voltage value, the FDC determination unit (230) may immediately increase the FDC value to the upper limit threshold value (0x7F). In this case, since the FDC value has reached the upper limit threshold value, the DTC setting unit (250) may set the DTC value corresponding to the FDC to a first value indicating that the battery pack (10) is abnormal.

[0083] If the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined reduced deviation upper limit, the FDC determination unit (230) may determine the FDC value as the lower limit threshold value of the FDC. For example, if the voltage deviation is less than 0 and exceeds 10% of the threshold voltage value, the FDC determination unit (230) may immediately reduce the FDC value to the lower limit threshold value (0x80). In this case, since the FDC value has reached the lower limit threshold value, the DTC setting unit (250) may set the DTC value corresponding to the FDC to a second value indicating that the battery pack (10) is normal.

[0084] Hereinafter, the upper limit of deviation may represent a corresponding upper limit of deviation among the upper limit of increase deviation and the upper limit of decrease deviation.

[0085] However, the above-described embodiment for the case where the voltage deviation value is very large and exceeds the deviation upper limit is only an example and the invention is not limited thereto. In some embodiments, when the voltage deviation exceeds the deviation upper limit, the FDC determination unit (230) may determine the FDC value as the upper limit or lower limit of the weighted application range. For example, when the voltage deviation exceeds 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit, the FDC determination unit (230) may determine the FDC value as the upper limit of the weighted application range. Alternatively, for example, when the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined decrease deviation upper limit, the FDC determination unit (230) may determine the FDC value as the lower limit of the weighted application range.

[0086] Hereinafter, the operation of the FDC decision unit (230) to determine the FDC value based on whether the voltage deviation exceeds the deviation upper limit is referred to as the “third weight determination operation.”

[0087] The first to third weight determination operations described above can be performed sequentially. For example, if the FDC value at the time of applying the increasing slope or decreasing slope is outside the weighted application range, even if the ratio of the voltage deviation exceeds a predetermined increasing deviation upper limit or a predetermined decreasing deviation upper limit, the weight determination unit (240) can determine the value of the target weight as 1. However, the embodiment is not limited thereto, and in some embodiments, if the ratio of the voltage deviation exceeds a predetermined increasing deviation upper limit or a predetermined decreasing deviation upper limit (e.g., the increasing deviation upper limit), the FDC determination unit (230) can determine the FDC value as a corresponding value among the upper limit value and the lower limit value of the weighted application range (e.g., the upper limit value) even if the FDC value at the time of applying the increasing slope or decreasing slope (e.g., the increasing slope) is within the weighted application range.

[0088] FIG. 6 is a graph illustrating an operation of determining an FDC value with a weighted slope according to one embodiment.

[0089] For convenience of explanation, the FDC value is shown in decimal in Fig. 6. The FDC value at the start point of the fault test (t101) is assumed to be 0 in the normal condition. In Fig. 6, the upper limit threshold value of FDC is 127, the lower limit threshold value of FDC is -128, the weighted application range is from -101 to 100, and the threshold voltage value is 4 V.

[0090] Hereinafter, the example of Fig. 6 will be described according to the assumptions described below. The increase reference slope corresponding to the cell voltage is 9 Steps / 100ms, and the decrease reference slope corresponding to the cell voltage is 13 Steps / 100ms. The multiple increase reference weights corresponding to the multiple increase threshold deviation sections, and the multiple decrease reference weights corresponding to the multiple decrease threshold deviation sections, follow the example of Fig. 5. The target weight corresponding to less than 1% that does not fall into the multiple increase threshold deviation sections is 1. If the voltage deviation exceeds 0 and the ratio of the voltage deviation to the threshold voltage value exceeds 3.5%, the FDC determination unit (230) determines the FDC value as the upper limit value of the weighted application range. The target weight corresponding to less than 1% that does not fall into the multiple decrease threshold deviation sections is 1. If the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds 10%, the FDC determination unit (230) determines the FDC value as the lower limit value of the weighted application range.

[0091] The time from time t101 to time t102 is 200 ms, and the cell voltage, which is the measurement data from time t101 to time t102, is 4.005 V. The voltage deviation from time t101 to time t102 is 4.005-4=0.005, and the ratio of the voltage deviation to the threshold voltage value is 0.005 / 4=0.125%. The threshold deviation exceeds 0, the FDC value at time t101 is less than the upper limit of the weighted application range, and the ratio of the voltage deviation to the threshold voltage value is less than 1%, so the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t101 to time t102 as 1, and the FDC determination unit (230) can apply an increase slope obtained by multiplying the target weight by the increase reference slope from time t101 to time t102. Therefore, the FDC value at time t102 can be 0+9(Steps / 100ms)*1*200(ms)=18.

[0092] The time from time t102 to time t103 is 200 ms, and the cell voltage, which is the measurement data from time t102 to time t103, is 3.995 V. The voltage deviation from time t102 to time t103 is 3.995-4=-0.005, and the ratio of the voltage deviation to the threshold voltage value is |-0.005| / 4=0.125%. The threshold deviation is less than 0, the FDC value at time t102 exceeds the lower limit of the weighted application range, and the ratio of the voltage deviation to the threshold voltage value is less than 1%, so the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t102 to time t103 as 1, and the FDC determination unit (230) can apply a reduction slope obtained by multiplying the target weight by the reduction reference slope from time t102 to time t103. Therefore, the FDC value at time t103 can be 18-13(Steps / 100ms)*1*200(ms)=-8.

[0093] The time from time t103 to time t104 is 400 ms, and the cell voltage, which is the measurement data from time t103 to time t104, is 4.1 V. The voltage deviation from time t103 to time t104 is 4.1-4=0.1, and the ratio of the voltage deviation to the threshold voltage value is |0.1| / 4=2.5%. Since the FDC value at time t103 is less than the upper limit of the weighted application range, the threshold deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value is 2% or more and less than 3%, the corresponding target weight is 3. The weight determination unit (240) determines the target weight from time t103 to time t104 as 3, and the FDC determination unit (230) can apply an increase slope obtained by multiplying the target weight by the increase reference slope from time t103 to time t104. Therefore, the FDC value at time t104 can be -8+9(Steps / 100ms)*3*400(ms)=100.

[0094] The time from time t104 to time t105 is 200 ms, and the cell voltage, which is the measurement data from time t104 to time t105, is 4.1 V. The voltage deviation from time t104 to time t105 is 4.1-4=0.1, and the ratio of the voltage deviation to the threshold voltage value is |0.1| / 4=2.5%. Since the FDC value at time t104 is greater than or equal to the upper limit of the weighted application range, the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t104 to time t105 as 1, and the FDC determination unit (230) can apply an increasing slope obtained by multiplying the target weight by the increasing reference slope from time t104 to time t105. Therefore, the FDC value at time t105 can be 100+9(Steps / 100ms)*1*200(ms)=118.

[0095] The time from time t105 to time t106 is 200 ms, and the cell voltage, which is the measurement data from time t105 to time t106, is 3.4 V. The voltage deviation from time t105 to time t106 is 3.4-4=-0.6, and the ratio of the voltage deviation to the threshold voltage value is |-0.6| / 4=15%. Since the FDC value at time t105 is greater than or equal to the upper limit of the weighted application range, the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t105 to time t106 as 1, and the FDC determination unit (230) can apply a reduction slope obtained by multiplying the target weight by the reduction reference slope from time t105 to time t106. Therefore, the FDC value at time t106 can be 118-13(Steps / 100ms)*1*200(ms)=92.

[0096] The time from time t106 to time t107 is 100 ms, and the cell voltage, which is the measurement data from time t106 to time t107, is 3.4 V. The voltage deviation from time t106 to time t107 is 3.4-4=-0.6, and the ratio of the voltage deviation to the threshold voltage value is |-0.6| / 4=15%. Since the FDC value at time t106 is less than the upper limit of the weighted application range, the threshold deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds 10%, the FDC determination unit (230) can determine the FDC value at time t107 as -101.

[0097] The time from time t107 to time t108 is 200 ms, and the cell voltage, which is the measurement data from time t107 to time t108, is 3.4 V. The voltage deviation from time t107 to time t108 is 3.4-4=-0.6, and the ratio of the voltage deviation to the threshold voltage value is |-0.6| / 4=15%. Since the FDC value at time t107 is less than or equal to the lower limit of the weighted application range, the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t107 to time t108 as 1, and the FDC determination unit (230) can apply a reduction slope obtained by multiplying the target weight by the reduction reference slope from time t107 to time t108. Therefore, the FDC value at time t108 can be -101-13(Steps / 100ms)*1*200(ms)=-127.

[0098] The time from time t108 to time t109 is 100 ms, and the cell voltage, which is the measurement data from time t108 to time t109, is 3.4 V. The voltage deviation from time t108 to time t109 is 3.4-4=-0.6, and the ratio of the voltage deviation to the threshold voltage value is |-0.6| / 4=15%. Since the FDC value at time t108 is less than or equal to the lower limit of the weighted application range, the corresponding target weight is 1. The weight determination unit (240) determines the target weight from time t108 to time t109 as 1, and the FDC determination unit (230) can apply a reduction slope obtained by multiplying the target weight by the reduction reference slope from time t108 to time t109. Therefore, the FDC value at time t108 may be -127-13(Steps / 100ms)*1*100(ms)=-140. However, since the lower limit threshold value of FDC is -128, the FDC value reaches the lower limit threshold value between time t107 and time t108, and the FDC determination unit (230) may determine the FDC value at time t108 as -128.

[0099] Referring to FIG. 6, since the FDC value reaches the lower threshold value between the time points t107 and t108, the DTC setting unit (250) can set the DTC value of the cell voltage corresponding to the FDC to a second value indicating that the battery pack (10) is normal in response to the time point at which the lower threshold value is reached.

[0100] Figure 7 is a flowchart of a method for determining a weighted FDC value according to one embodiment.

[0101] Below, in the description of each component of the battery system (1), descriptions of parts that overlap with the previous descriptions may be omitted.

[0102] Referring to FIG. 7, the battery failure diagnosis device (20) can generate measurement data indicating the cell voltage of each of the plurality of battery cells included in the battery pack (10) (S100).

[0103] The battery failure diagnosis device (20) can determine a weight applied to the increasing slope or decreasing slope of the FDC value based on the size of the voltage deviation and the FDC value at the time of applying the increasing slope or decreasing slope (S200).

[0104] Figure 8 is a detailed flowchart of step S200 illustrated in Figure 7.

[0105] Referring to FIG. 8, the battery failure diagnosis device (20) can determine whether the FDC value at the time when the FDC determination unit (230) applies an increasing slope or a decreasing slope is within the weighted application range (S210).

[0106] If the FDC value at the time of applying the increasing slope or decreasing slope at step S210 is outside the weighted application range (NO at S210), the battery failure diagnosis device (20) can determine the target weight as 1 (S220).

[0107] If the FDC value at the time of applying the increasing slope or decreasing slope at step S210 is within the weighted application range (e.g., in S210), the battery failure diagnosis device (20) can determine whether the voltage deviation exceeds the deviation upper limit (S230).

[0108] If the voltage deviation exceeds the deviation upper limit at step S230 (yes in S230), the battery failure diagnosis device (20) may determine the FDC value as the upper limit or lower limit of the weighted application range (S240). If the voltage deviation exceeding 0 exceeds the increasing deviation upper limit, the battery failure diagnosis device (20) may determine the FDC value as the upper limit of the weighted application range. Alternatively, in this case, the battery failure diagnosis device (20) may determine the FDC value as the upper limit threshold value of the FDC. If the voltage deviation less than 0 exceeds the decreasing deviation upper limit, the battery failure diagnosis device (20) may determine the FDC value as the lower limit of the weighted application range. Alternatively, in this case, the battery failure diagnosis device (20) may determine the FDC value as the lower limit threshold value of the FDC.

[0109] If the voltage deviation does not exceed the deviation upper limit at step S230 (NO at S230), the battery failure diagnosis device (20) may determine a target weight based on the magnitude of the voltage deviation (S250). Specifically, the battery failure diagnosis device (20) may determine a reference weight corresponding to the ratio of the voltage deviation to the threshold voltage value among the multiple reference weights included in the weighting coefficient map as the target weight.

[0110] Referring again to FIG. 7, the battery failure diagnosis device (20) can determine the FDC value by increasing or decreasing the FDC value with a slope to which the target weight is applied (S300).

[0111] In step S200 of FIG. 7, if step S240 of FIG. 8 is performed among steps S210 to S240 shown in FIG. 8, step S400 of FIG. 7 can be performed without having to go through step S300 of FIG. 7. This is because step S240 of FIG. 8 determines the value of FDC regardless of the value of the target weight.

[0112] Referring to Fig. 7, the battery failure diagnosis device (20) can determine whether the FDC value has reached the upper threshold value or the lower threshold value (S400).

[0113] When the FDC value reaches the upper threshold value at step S400 (at S400, reaching the upper threshold value), the battery failure diagnosis device (20) can set the DTC value for the cell voltage corresponding to the FDC to a first value indicating that the battery pack (10) is abnormal (S500).

[0114] When the FDC value reaches the lower limit threshold at step S400 (at S400, the lower limit threshold is reached), the battery failure diagnosis device (20) can set the DTC value for the cell voltage corresponding to the FDC to a second value indicating that the battery pack (10) is normal (S600).

[0115] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by a person having ordinary skill in the art to which the present invention pertains also fall within the scope of the present invention.

Claims

1. In a device that diagnoses a battery fault by generating fault detection counter (FDC) information from a lower threshold value to an upper threshold value for the battery, A measuring unit connected to a battery pack and generating cell voltage measurement data for each of a plurality of battery cells included in the battery pack; An FDC determination unit that increases the FDC value with an increasing slope or decreases the FDC value with a decreasing slope based on the result of comparing the above measurement data with a predetermined threshold voltage value; A weight determination unit that determines a target weight to be applied to the increasing slope or the decreasing slope based on the FDC value at the time of applying the increasing slope or the decreasing slope and the magnitude of the voltage deviation obtained by subtracting the threshold voltage value from the measurement data; and A DTC setting unit that sets a DTC value corresponding to the FDC to a first value indicating that the battery pack is abnormal when the FDC value reaches a predetermined upper threshold, and sets the DTC value to a second value indicating that the battery pack is normal when the FDC value reaches a predetermined lower threshold. A battery failure diagnostic device including:

2. In paragraph 1, The above FDC decision unit is, If the voltage deviation exceeds 0, the increasing slope is selected from the increasing slope and the decreasing slope, and a value obtained by applying the first target weight determined by the weight determination unit to a predetermined increase reference slope stored in advance is determined as the increasing slope. If the voltage deviation is less than 0, the decreasing slope is selected from the increasing slope and the decreasing slope, and a value obtained by applying the second target weight determined by the weight determination unit to a predetermined decreasing reference slope stored in advance is determined as the decreasing slope. Battery failure diagnostic device.

3. In paragraph 1, If the FDC value at the time of application is less than or equal to the lower limit of a predetermined weighted application range between the upper limit threshold and the lower limit threshold, or greater than or equal to the upper limit of the weighted application range, The above weight determination unit, Determine the above target weight as 1, Battery failure diagnostic device.

4. In paragraph 1, If the FDC value at the time of application is within a predetermined weighted application range between the upper and lower threshold values, The above weight determination unit, Depending on the size of the voltage deviation, one of the plurality of reference weights is determined as the target weight, The above plurality of reference weights have a larger value as the ratio of the voltage deviation to the threshold voltage value increases. Battery failure diagnostic device.

5. In paragraph 1, If the FDC value at the time of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit, The above FDC decision unit is, determining the above FDC value as the upper limit of the weighted application range; Battery failure diagnostic device.

6. In paragraph 1, If the FDC value at the time of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined reduction deviation upper limit, The above FDC decision unit is, determining the above FDC value as the lower limit of the weighted application range; Battery failure diagnostic device.

7. In a method for determining a FDC value by applying a weight to a device that diagnoses a battery fault by generating FDC information from a lower threshold value to an upper threshold value for the battery, A step of generating measurement data representing the cell voltage of each of a plurality of battery cells included in a battery pack; A step of determining a target weight applied to the increasing slope or the decreasing slope based on the FDC value at the time of applying the increasing slope or decreasing slope of the FDC value and the magnitude of the voltage deviation obtained by subtracting the threshold voltage value from the measurement data; A step of increasing the FDC value with the increasing slope or decreasing the FDC value with the decreasing slope based on the result of comparing the above measurement data with a predetermined threshold voltage value; and When the FDC value reaches a predetermined upper threshold, a step of setting the DTC value corresponding to the FDC to a first value indicating that the battery pack is abnormal, and when the FDC value reaches a predetermined lower threshold, a step of setting the DTC value to a second value indicating that the battery pack is normal, method.

8. In paragraph 7, A step of selecting one of the increasing slope and the decreasing slope based on whether the voltage deviation exceeds 0 or whether the voltage deviation is less than 0; A step of determining the increase slope by applying the first target weight determined by the weight determination unit to a predetermined increase reference slope stored in advance; and Further comprising a step of determining the reduction slope by applying the second target weight determined by the weight determination unit to a predetermined reduction reference slope stored in advance. method.

9. In paragraph 7, If the FDC value at the time of application is less than or equal to the lower limit of a predetermined weighted application range between the upper limit threshold value and the lower limit threshold value or greater than or equal to the upper limit of the weighted application range, the step of determining the target weight as 1 is further included. method.

10. In paragraph 7, If the FDC value at the time of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the step of determining one of a plurality of reference weights as the target weight based on the size of the voltage deviation is further included. The above plurality of reference weights have a larger value as the ratio of the voltage deviation to the threshold voltage value increases. method.

11. In paragraph 7, If the FDC value at the time of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined increase deviation upper limit, the step of determining the FDC value as the upper limit value of the weighted application range is further included. method.

12. In paragraph 7, If the FDC value at the time of application is within a predetermined weighted application range between the upper threshold value and the lower threshold value, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined reduced deviation upper limit, the step of determining the FDC value as the lower limit value of the weighted application range is further included. method.

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