Battery fault diagnosis device and method for determining FDC (Fault Detection Counter) value by applying weighting

Abstract

The present invention relates to a battery fault diagnosis device and a method for determining a FDC (Fault Detection Counter) value by applying weighting. The battery fault diagnosis device of the present invention includes: a measurement unit that generates measurement data of each cell voltage of a plurality of battery cells included in a battery pack; an FDC determination unit that increases an FDC value with an increasing slope or decreases the FDC value with a decreasing slope based on a result of comparing the measurement data with a predetermined threshold voltage; a weighting determination unit that determines a target weighting to be applied to the increasing slope or the decreasing slope based on the FDC value at a time when the increasing slope or the decreasing slope is applied and a magnitude of a voltage deviation obtained by subtracting the threshold voltage 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.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0011465, filed January 25, 2024, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present disclosure relates to a battery fault diagnosis device and a method for determining a FDC (Fault Detection Counter) value. [Background technology]

[0003] According to the ISO-14229 standard protocol definition, when reading the FDC (Fault Detection Counter) to determine the DTC (Diagnostic Trouble Code), the FDC tends to increase or decrease regularly in accordance with the test period with a predefined step-up or step-down size in the range of 0x80 to 0x7F when a diagnosis is initiated or terminated according to the specified diagnosis.

[0004] However, in order for the diagnostic target to reach 0x7F from FDC=0, which is the normal state, using only the specified step-up or step-down size, and thus satisfy the condition, a large number of step-ups must be repeated. Conversely, in order for the diagnostic target to reach 0x80 from the normal state using only the specified step-up or step-down size, and thus satisfy the condition for canceling the diagnosis, a large number of step-downs must be repeated. This results in a problem of a long wait time until the diagnostic condition or the diagnostic cancel condition is satisfied.

[0005] In recent years, there has been a need for rapid response to battery failures in order to diagnose thermal events and isolation events in batteries. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a battery fault diagnosis device and a method for determining an FDC (Fault Detection Counter) value by applying weighting to determine the FDC value. [Means for solving the problem]

[0007] According to one aspect of the present invention, a battery fault diagnosis device generates Fault Detection Counter (FDC) information from a lower threshold to an upper threshold for a battery to diagnose a battery fault, and includes: a measurement unit connected to a battery pack and generating measurement data indicating each cell voltage of a plurality of battery cells included in the battery pack; an FDC determination unit that increases an FDC value with an increasing slope or decreases an FDC value with a decreasing slope based on a result of comparing the measurement data with a predetermined threshold voltage; a weighting determination unit that determines a target weight to be applied to the increasing slope or the decreasing slope based on the FDC value at a time when the increasing slope or the decreasing slope is applied and a magnitude of a voltage deviation obtained by subtracting the threshold voltage 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.

[0008] When the voltage deviation exceeds 0, the FDC determination unit selects the increasing slope from the increasing slope and the decreasing slope, and determines a value obtained by applying a first object weight determined by the weight determination unit to a predetermined reference increasing slope that has been previously stored as the increasing slope; when the voltage deviation is less than 0, the FDC determination unit selects the decreasing slope from the increasing slope and the decreasing slope, and determines a value obtained by applying a second object weight determined by the weight determination unit to a predetermined reference decreasing slope that has been previously stored as the decreasing slope.

[0009] If the FDC value at the time of application is less than or equal to the lower limit value of a predetermined weight application range between the upper threshold and the lower threshold or greater than or equal to the upper limit value of the weight application range, the weight determination unit can determine the target weight to be 1.

[0010] If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the weight determination unit determines one of a plurality of reference weights as the target weight depending on the magnitude of the voltage deviation, and the plurality of reference weights have a larger value as the ratio of the voltage deviation to the threshold voltage value increases.

[0011] If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the increased deviation, the FDC determination unit can determine the FDC value as the upper limit value of the weight application range.

[0012] If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the reduction deviation, the FDC determination unit can determine the FDC value as the lower limit of the weight application range.

[0013] According to another aspect of the present invention, a method for determining an FDC value by applying weighting includes generating Fault Detection Counter (FDC) information for a battery from a lower threshold to an upper threshold, and determining an FDC value by applying weighting in a device for diagnosing battery faults. The method may include generating measurement data indicating the cell voltages of each of a plurality of battery cells included in a battery pack; determining a target weighting to be applied to the FDC value based on the FDC value at the time when the FDC value is applied and the magnitude of a voltage deviation obtained by subtracting the threshold voltage 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; 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, 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.

[0014] The method may further include the steps of selecting one of the increasing slope and the decreasing slope based on whether the voltage deviation is greater than 0 or less than 0; determining the increasing slope by applying a first object weight determined by the weight determination unit to a predetermined reference increasing slope that has been previously stored; and determining the decreasing slope by applying a second object weight determined by the weight determination unit to a predetermined reference decreasing slope that has been previously stored.

[0015] The method may further include a step of setting the target weight to 1 if the FDC value at the time of application is equal to or less than the lower limit value of a predetermined weight application range between the upper threshold and the lower threshold, or equal to or greater than the upper limit value of the weight application range.

[0016] If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the method further includes a step of determining one of a plurality of reference weights as the target weight depending on the magnitude of the voltage deviation, and the plurality of reference weights have larger values ​​as the ratio of the voltage deviation to the threshold voltage value increases.

[0017] The method may further include a step of determining the FDC value as the upper limit value of the weight application range if the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation exceeds 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the increased deviation.

[0018] The method may further include determining the FDC value as the lower limit value of the weight application range if the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the reduced deviation. [Effects of the Invention]

[0019] According to an embodiment of the present invention, weighting for specific diagnoses using battery measurement data can be defined, and the strength of areas that affect the DTC diagnosis conditions or diagnosis cancellation conditions and areas that do not can be adjusted, thereby enabling the diagnosis to be cancelled quickly.

[0020] According to the present invention, the counter step size is changed according to the magnitude of the deviation between the measurement data and the threshold value, so that the more serious the problem occurring in the battery, the more quickly the diagnostic condition can be reached.

[0021] According to the embodiment of the present invention, it is possible to prevent excessive time from being required to cancel the diagnosis after a diagnostic condition occurs, thereby improving the convenience of using a vehicle or the like. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram schematically illustrating a battery system including a battery fault diagnosis device according to an embodiment. [Figure 2] 10 is a graph illustrating the increase slope when no weighting is applied. [Figure 3] 10 is a graph illustrating the decrease slope when no weighting is applied. [Figure 4] 3 is a diagram for explaining a weight application range in the graph shown in FIG. 2; [Figure 5] FIG. 10 is a diagram illustrating an example of a weighting coefficient map according to an embodiment. [Figure 6] 10 is a graph illustrating an exemplary operation of determining an FDC value as a weighted slope, according to one embodiment. [Figure 7] 1 is a flowchart of a method for determining a weighted FDC value according to an embodiment. [Figure 8] 8 is a detailed flowchart of step S200 shown in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. Identical or similar components will be designated by identical or similar drawing numbers, and redundant descriptions will be omitted. The suffixes "module" and / or "section" used in the following description for components are added or used interchangeably solely for ease of description and do not have any meaning or function to distinguish them from one another. Furthermore, when describing the embodiments disclosed herein, if a detailed description of related publicly known technology is deemed to obscure the gist of the embodiments disclosed herein, such a detailed description will be omitted. Furthermore, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, and should not be construed as limiting the technical concepts disclosed herein, but should be understood to include all modifications, equivalents, or alternatives within the concept and technical scope of the present invention.

[0024] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

[0025] When a component is said to be "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. On the other hand, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there is no other component in between.

[0026] In this application, the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are to be understood as not precluding the possible presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] FIG. 1 is a diagram illustrating a battery system including a battery fault diagnosis device according to an embodiment.

[0028] Referring to FIG. 1, a battery system 1 may include a battery pack 10, a battery fault diagnosis device 20, and relays 30, 31.

[0029] One end of the relays 30, 31 is connected to the battery pack 10, and the other end of the relays 30, 31 is connected to at least one component of the external device 2. The on / off of the relays 30, 31 can be controlled by relay control signals (RCS1, RCS2) supplied from the battery fault diagnosis device 20.

[0030] The battery system 1 is connected to an external device 2. The external device 2 may include a load and a charging device, such as an inverter or a converter. When the external device 2 is a charger, both ends (P+, P-) of the battery system 1 are connected to the charger, and the battery system 1 can be charged by receiving power from the charger. When the external device 2 is a load, both ends (P+, P-) of the battery system 1 are connected to the load, and power supplied by the battery pack 10 can be discharged through the load.

[0031] The battery pack 10 may be implemented with two or more battery cells connected in series, a plurality of battery cells each having two or more battery cells connected in parallel, or two or more battery cells connected in parallel.

[0032] The battery fault diagnosis device 20 can diagnose a battery fault by generating fault detection counter (FDC) information ranging from a lower threshold to an upper threshold for the battery. The battery fault diagnosis device 20 can set a diagnostic trouble code (DTC) value corresponding to the FDC value. The battery fault diagnosis device 20 can be provided in a battery management system (BMS) of the 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 to obtain 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 the DTC value set by the battery system 1.

[0033] The battery fault diagnosis device 20 may include a storage unit 210, a measurement unit 220, an FDC determination unit 230, a weighting determination unit 240, and a DTC setting unit 250. The storage unit 210 is a component corresponding to the memory of the battery fault diagnosis device 20, and the FDC determination unit 230, the weighting determination unit 240, and the DTC setting unit 250 are included in a component corresponding to the processor of the battery fault diagnosis device 20.

[0034] The measurement unit 220 is connected to the battery pack 10 and can generate measurement data indicating the status of the battery pack 10. The measurement unit 220 is electrically connected to the battery pack 10. The status of the battery pack 10 can include at least one of the voltage, current, and temperature of the battery pack 10. The measurement unit 220 can include at least one of a voltage sensor, a current sensor, and a temperature sensor. The voltage sensor can measure the positive terminal voltage and / or negative terminal voltage of the battery pack 10, the cell voltage of each of the battery cells included in the battery pack 10, etc. The current sensor can measure the current flowing through the battery pack 10 while the battery pack 10 is charging or discharging. The temperature sensor can be provided adjacent to the battery pack 10 and can measure the temperature of the battery pack 10. The measurement data can include at least one of the voltage measured by the voltage sensor, the current measured by the current sensor, and the temperature measured by the temperature sensor.

[0035] For convenience of explanation, the following description will be given assuming that the measurement data is the cell voltage of each of the plurality of battery cells included in the battery pack 10.

[0036] The FDC determination unit 230 may increase the FDC value at an increasing rate or decrease the FDC value at a decreasing rate based on a 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 when the cell voltage, which is the measurement data, is in a normal state.

[0037] If the measurement data indicates a fail condition, the FDC determination unit 230 may increase the FDC value at an increasing rate. For example, if a voltage deviation (hereinafter referred to as "voltage deviation") obtained by subtracting a predetermined threshold voltage value from the measurement data exceeds 0, the FDC determination unit 230 may indicate a fail condition. For convenience of explanation, it is assumed that the FDC determination unit 230 increases the FDC value at an increasing rate when the voltage deviation exceeds 0.

[0038] If the measurement data is in a pass condition, the FDC determination unit 230 can decrease the FDC value at a decreasing slope. For example, if the voltage deviation is less than 0, the measurement data is in a pass condition. For convenience of explanation, it is assumed below that the FDC determination unit 230 decreases the FDC value at a decreasing slope when the voltage deviation is less than 0.

[0039] When the FDC value determined by the FDC determination unit 230 reaches a predetermined upper threshold, the DTC setting unit 250 sets the DTC value corresponding to the determined FDC to a first value indicating that the battery pack 10 is abnormal, and when the determined FDC value reaches a predetermined lower threshold, the DTC setting unit 250 sets the DTC value corresponding to the determined FDC to a second value indicating that the battery pack 10 is normal. The first value may indicate that a diagnostic condition (Test Fail) has been reached and that a diagnosis of the battery pack 10 is required. The second value may indicate that a diagnostic cancellation condition (Test Pass) has been reached and that a diagnosis that has already occurred in the battery pack 10 can be canceled.

[0040] A predetermined upper threshold and a predetermined lower threshold to be compared with the FDC value are stored in the storage unit 210. For example, the upper threshold is 0x7F=127, and the lower threshold is 0x80=-128.

[0041] When the FDC value determined by the FDC determination unit 230 reaches a predetermined upper threshold, the DTC setting unit 250 can determine that the battery pack 10 is abnormal, based on the failure test results for the measurement data. When the FDC value determined by the FDC determination unit 230 reaches a predetermined lower threshold, 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 state in which the battery pack 10 is abnormal means that the diagnostic condition has been met, and the state in which the battery pack 10 is normal means that the diagnostic release condition has been met.

[0042] The increasing slope is the number of steps by which the FDC counter value is increased (increased) corresponding to a predetermined test period, and the decreasing slope is the number of steps by which the FDC counter value is decreased (decreased) corresponding to the predetermined test period. For example, the increasing slope and decreasing slope are the number of steps by which the FDC counter value is increased or decreased for a test period of 100 ms. Therefore, if the test period is 100 ms, the decreasing slope is X Steps / 100 ms, and the voltage deviation value is less than 0 for a period from a first time point to a second time point 300 ms after the first time point, the FDC determiner 230 may determine the FDC value at the second time point by decreasing the FDC value at the first time point by 3X in accordance with the ratio of X Steps / 100 ms for 300 ms.

[0043] The weight determiner 240 may determine a weight to be applied to the increasing slope and / or decreasing slope used by the FDC determiner 230 based on the FDC value at the time when the FDC determiner 230 applies the increasing slope or decreasing slope and the magnitude of the voltage deviation. Hereinafter, for convenience of explanation, a voltage deviation greater than 0 may indicate a state in which the weight determiner 240 determines a weight to be applied to the increasing slope and / or the FDC determiner 230 can increase the FDC value at an increasing slope. Also, for convenience of explanation, a voltage deviation less than 0 may indicate a state in which the weight determiner 240 determines a weight to be applied to the decreasing slope and / or the FDC determiner 230 can decrease the FDC value at a decreasing slope.

[0044] When the voltage deviation exceeds 0, the FDC determination unit 230 selects an increasing slope from the increasing slope and the decreasing slope, and determines the increasing slope as a value obtained by applying the first target weight determined by the weight determination unit 240 to a predetermined increasing reference slope that has been previously stored.

[0045] If the voltage deviation is less than 0, the FDC determination unit 230 selects a decreasing slope from the increasing slope and the decreasing slope, and determines the decreasing slope as a value obtained by applying the second target weight determined by the weight determination unit 240 to a predetermined decreasing reference slope that has already been stored.

[0046] For example, the increasing slope is a value obtained by multiplying the reference increasing slope by the object weighting, and the decreasing slope is a value obtained by multiplying a previously stored predetermined reference decreasing slope by the object weighting.

[0047] The storage unit 210 stores a predetermined threshold voltage value, a predetermined reference increase slope, and a predetermined reference decrease slope to be compared with the measurement data. The predetermined threshold voltage value is, for example, 4.0 V. The predetermined reference increase slope and the predetermined reference decrease slope vary depending on the type of measurement data (e.g., voltage, current, temperature, etc.). For example, the reference increase slope corresponding to cell voltage is 9 steps / 100 ms, and the reference decrease slope corresponding to cell voltage is 13 steps / 100 ms. Hereinafter, the reference increase slope and the reference decrease slope corresponding to cell voltage will be described as following the above example, but this is for convenience of explanation and is not intended to limit the invention. In one embodiment, the reference increase slope and the reference decrease slope are values ​​that vary depending on the diagnosis target, project, etc. Here, the diagnosis target is the target indicated by the DTC corresponding to the determined FDC value, and the project is the target for managing the vehicle using the diagnosis target.

[0048] When the target weighting is 1, the increasing slope is the previously stored reference increasing slope, and the decreasing slope is the previously stored reference decreasing slope. Hereinafter, for convenience of explanation, each of the increasing slope and decreasing slope (e.g., increasing slope) used by the FDC determination unit 230 is a value obtained by applying the target weighting to a corresponding reference slope (e.g., increasing slope) among the previously stored predetermined reference increasing slopes and predetermined reference decreasing slopes. Therefore, hereinafter, when the weighting determination unit 240 determines the target weighting to 1, it may indicate that no weighting is applied to the increasing slope or decreasing slope.

[0049] FIG. 2 is a graph illustrating the increase slope when no weighting is applied.

[0050] 2, the reference increase slope corresponding to the cell voltage is 9 steps / 100 ms, and if no weighting is applied to the increase slope, the FDC value can increase by 9 every 100 ms. In FIG. 2, it is explained that the lower limit threshold of FDC is 0x80 and the upper limit threshold of FDC is 0x7F.

[0051] During the failure test period, if the voltage deviation exceeds 0, the FDC determination unit 230 may increase the FDC value from the FDC lower threshold (0x80) at an increasing slope. If the FDC value reaches the FDC upper threshold (0x7F), the DTC setting unit 250 may set the DTC value to a first value at the time (t1) when the FDC value reaches the FDC upper threshold (0x7F).

[0052] FIG. 3 is a graph illustrating the decrease slope when no weighting is applied.

[0053] 3, if the reference decrease slope corresponding to the cell voltage is 13 steps / 100 ms and no weighting is applied to the decrease slope, the FDC value can decrease by 13 every 100 ms. In FIG. 3, it is explained that the lower limit threshold of FDC is 0x80 and the upper limit threshold of FDC is 0x7F.

[0054] During the failure test period, if the voltage deviation is less than 0, the FDC determination unit 230 may decrease the FDC value from the upper threshold (0x7F) at a decreasing slope (13 steps / 100 ms). When the FDC value reaches the lower threshold (0x80), the DTC setting unit 250 may set the DTC value to a second value at the time (t2) when the FDC value reaches the lower threshold (0x80).

[0055] Hereinafter, in one embodiment, the operation of the FDC determination unit 230 to determine an FDC value with an increasing or decreasing slope to which the weight determined by the weight determination unit 240 is applied will be described.

[0056] The weight determination unit 240 determines a target weight of 1 or more when the FDC value at the time when the increasing slope or decreasing slope is applied is within a predetermined weight application range (hereinafter referred to as "weight application range") between an upper FDC threshold and a lower FDC threshold, and can determine the target weight to 1 when the FDC value exceeds the weight application range. Here, the weight application range is a range between the upper FDC threshold and the lower FDC threshold that indicates a normal condition. The lower limit value of the weight application range is a value greater than the above-mentioned lower FDC threshold, and the upper limit value of the weight application range is a value less than the above-mentioned upper FDC threshold. For example, the lower limit value of the weight application range is 0x9B, and the upper limit value of the weight application range is 0x64.

[0057] Specifically, if the FDC value at the time when the increasing slope or decreasing slope is applied is equal to or less than the lower limit of the weight application range or equal to or greater than the upper limit of the weight application range, the weight determination unit 240 can determine the target weight to be 1.

[0058] However, this is for convenience of explanation, and the invention is not limited thereto. In an embodiment, when the voltage deviation is less than 0 and the FDC value at the time when the decreasing slope is applied is equal to or less than the lower limit of the weight application range, or when the voltage deviation is greater than 0 and the FDC value at the time when the increasing slope is applied is equal to or greater than the upper limit of the weight application range, the weight determination unit 240 may determine the target weight to be 1. In other words, when the FDC value at the time when the increasing slope or the decreasing slope is applied is equal to or less than the lower limit of the weight application range but the FDC value is increased, or when the FDC value at the time when the increasing slope or the decreasing slope is applied is equal to or greater than the upper limit of the weight application range but the FDC value is decreased, the weight determination unit 240 may determine that the target weight is within the weight application range.

[0059] Hereinafter, the operation of the weight determination unit 240 to compare the FDC value at the time when the increasing gradient or decreasing gradient is applied with the weight application range and determine the target weight will be referred to as a "first weight determination operation."

[0060] FIG. 4 is a diagram for explaining the weight application range in the graph shown in FIG.

[0061] Referring to FIG. 4, the weight application range can be between 0x9B and 0x64 between the FDC lower threshold (0x80) and the FDC upper threshold (0x7F).

[0062] For example, if the FDC value at a first time point is a value between the FDC lower limit threshold (0x80) and the lower limit value (0x9B) of the weight application range, the weight determination unit 240 can determine the target weight from the first time point to a second time point after the first time point to be 1. Therefore, if the voltage deviation corresponding to the period from the first time point to the second time point is less than 0, the FDC determination unit 230 can determine the decrease slope from the first time point to the second time point as the decrease reference slope.

[0063] Furthermore, if the FDC value at the third time point is a value between the FDC upper threshold (0x7F) and the upper limit value of the weight application range (0x64), the weight determination unit 240 can determine the target weight from the third time point to the fourth time point after the third time point to be 1. Therefore, if the voltage deviation corresponding to the period from the third time point to the fourth time point after the third time point exceeds 0, the FDC determination unit 230 can determine the increase slope from the third time point to the fourth time point as the reference increase slope.

[0064] If the FDC value at the time when the increasing slope or decreasing slope is applied is within the weight application range, the weight determination unit 240 may determine the value of the target weight according to the magnitude of the voltage deviation.

[0065] Hereinafter, the operation of the weight determination unit 240 to determine the value of the target weight according to the magnitude of the voltage deviation will be referred to as a “second weight determination operation.” Hereinafter, a process of the weight determination unit 240 determining the value of the target weight according to the magnitude of the voltage deviation will be described.

[0066] The storage unit 210 stores a weight factor map including multiple reference weights corresponding to multiple threshold deviation intervals. The weight factor map may include multiple increasing reference weights corresponding to multiple increasing threshold deviation intervals and multiple decreasing reference slopes corresponding to multiple decreasing threshold deviation intervals. When the FDC determiner 230 selects to apply an increasing weight from the increasing slopes and the decreasing slopes, the weight determiner 240 may determine one of the multiple increasing reference weights corresponding to the multiple increasing threshold deviation intervals as the target weight. Alternatively, when the FDC determiner 230 selects to apply a decreasing weight from the increasing slopes and the decreasing slopes, the weight determiner 240 may determine one of the multiple decreasing reference slopes corresponding to the multiple decreasing threshold deviation intervals as the target weight. Hereinafter, the multiple threshold deviation intervals may refer to multiple corresponding threshold deviation intervals from the multiple increasing threshold deviation intervals and the multiple decreasing threshold deviation intervals, and the multiple reference weights may refer to multiple corresponding reference weights from the multiple increasing reference weights and the multiple decreasing reference slopes.

[0067] The weighting determination unit 240 can determine, as the target weighting, a reference weighting corresponding to a threshold deviation section to which the ratio of the voltage deviation to the threshold voltage value belongs among the multiple threshold deviation sections. Here, the larger the threshold deviation indicated by each of the multiple threshold deviation sections, the larger the multiple reference weightings become. The ratio of the voltage deviation to the threshold voltage value is the value obtained by dividing the absolute value of the voltage deviation by the threshold voltage value.

[0068] FIG. 5 is a diagram illustrating an example of a weighting coefficient map according to an embodiment.

[0069] 5, the multiple increase threshold deviation ranges corresponding to the Fail Condition may include ranges 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 criteria weightings, the increase criteria weighting corresponding to the increase threshold deviation range of 1% or more and less than 2% is 1.5, the increase criteria weighting corresponding to the increase threshold deviation range of 2% or more and less than 3% is 3, and the increase criteria weighting corresponding to the increase threshold deviation range of 3% or more and less than 3.5% is 4.5. The target weighting corresponding to less than 1% that does not belong to the multiple increase threshold deviation ranges is 1.

[0070] 5, the plurality of reduction threshold deviation sections corresponding to the 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 weightings, the reduction criteria weighting corresponding to the reduction threshold deviation section of 1% or more and less than 4% is 1.5, the reduction criteria weighting corresponding to the reduction threshold deviation section of 4% or more and less than 7% is 3, and the reduction criteria weighting corresponding to the reduction threshold deviation section of 7% or more and less than 10% is 4.5. The target weighting corresponding to less than 1% that does not belong to the plurality of reduction threshold deviation sections is 1.

[0071] Hereinafter, the plurality of increasing threshold deviation sections and the corresponding plurality of increasing criterion weightings, and the plurality of decreasing threshold deviation sections and the corresponding plurality of decreasing threshold deviation sections will be described as following the example of Fig. 5, but this is for convenience of explanation and the invention is not limited to this. In one embodiment, the number of the plurality of increasing threshold deviation sections, the number of the plurality of decreasing threshold deviation sections, the threshold deviation values ​​indicated by the plurality of increasing threshold deviation sections and the plurality of decreasing threshold deviation sections, and the respective values ​​of the plurality of increasing criterion weightings and the plurality of decreasing criterion weightings are values ​​that vary depending on the diagnosis target, project, etc.

[0072] This is to enable the application of a larger target weight within a predetermined weight application range as the voltage deviation value becomes larger, in order to reach a diagnosis condition or a diagnosis cancellation condition faster than by increasing or decreasing the FDC value at a constant increase or decrease slope.

[0073] However, if the voltage deviation value is very large, the diagnostic condition or diagnostic release condition can be immediately reached without additional FDC counting operations, or an FDC value close to the diagnostic condition or diagnostic release condition can be reached, thereby making it possible to respond to large voltage deviations in the battery pack 10.

[0074] If the voltage deviation exceeds 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of increased deviation, the FDC determiner 230 may determine the FDC value as the upper limit threshold of the FDC. For example, if the voltage deviation exceeds 0 and exceeds 3.5% of the threshold voltage value, the FDC determiner 230 may immediately increase the FDC value to the upper limit threshold (0x7F). In this case, because the FDC value has reached the upper limit threshold, the DTC setter 250 may set the DTC value corresponding to the FDC to a first value indicating that the battery pack 10 is abnormal.

[0075] If the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the reduced deviation, the FDC determiner 230 may determine the FDC value as the lower threshold of the FDC. For example, if the voltage deviation is less than 0 and exceeds 10% of the threshold voltage value, the FDC determiner 230 may immediately reduce the FDC value to the lower threshold (0x80). In this case, since the FDC value has reached the lower threshold, the DTC setter 250 may set the DTC value corresponding to the FDC to a second value indicating that the battery pack 10 is normal.

[0076] In the following, the deviation upper limit may refer to the corresponding deviation upper limit among the increasing deviation upper limit and the decreasing deviation upper limit.

[0077] However, the above embodiment is merely an example of a case where the voltage deviation value is very large and exceeds the upper deviation limit, and the invention is not limited thereto. In some embodiments, when the voltage deviation exceeds the upper deviation limit, the FDC determiner 230 may determine the FDC value as the upper or lower limit of the weight 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 upper deviation limit, the FDC determiner 230 may determine the FDC value as the upper limit of the weight application range. Alternatively, when the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper deviation limit, the FDC determiner 230 may determine the FDC value as the lower limit of the weight application range.

[0078] Hereinafter, the operation of the FDC determination unit 230 to determine the FDC value depending on whether the voltage deviation exceeds the deviation upper limit will be referred to as the "third weighting determination operation."

[0079] The above-described first to third weight determination operations can be performed sequentially. For example, if the FDC value at the time when the increasing slope or decreasing slope is applied is outside the weight application range, the weight determination unit 240 can determine the target weight value to be 1 even if the voltage deviation ratio exceeds a predetermined increasing slope upper limit or a predetermined decreasing slope upper limit. However, the embodiment is not limited thereto. In an embodiment, if the voltage deviation ratio exceeds a predetermined increasing slope upper limit or a predetermined decreasing slope upper limit (e.g., the increasing slope), the FDC determination unit 230 can determine the FDC value as the corresponding value (e.g., the upper limit) of the upper limit or lower limit of the weight application range, even if the FDC value at the time when the increasing slope or decreasing slope (e.g., the increasing slope) is applied is within the weight application range.

[0080] FIG. 6 is a graph for illustratively explaining the operation of determining an FDC value using a weighted gradient according to one embodiment.

[0081] For convenience of explanation, the FDC value is shown in decimal notation in Fig. 6. The FDC value at the start of the fault test (t101) is assumed to be 0, which indicates a normal condition. In Fig. 6, the upper threshold of the FDC is 127, the lower threshold of the FDC is -128, the weight application range is from -101 to 100, and the threshold voltage value is 4V.

[0082] The example of FIG. 6 will be described below based on the following assumptions. The increasing reference slope corresponding to the cell voltage is 9 steps / 100 ms, and the decreasing reference slope corresponding to the cell voltage is 13 steps / 100 ms. The increasing reference weights corresponding to the increasing threshold deviation ranges and the decreasing reference weights corresponding to the decreasing threshold deviation ranges follow the example of FIG. 5. The target weight corresponding to less than 1% and not belonging to the increasing threshold deviation ranges 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 determiner 230 determines the FDC value as the upper limit of the weight application range. If the voltage deviation is less than 0 and the ratio of the voltage deviation to the threshold voltage value exceeds 10%, the FDC determiner 230 determines the FDC value as the lower limit of the weight application range.

[0083] 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%. Because the threshold deviation exceeds 0, the FDC value at time t101 is less than the upper limit of the weight application range, and the ratio of the voltage deviation to the threshold voltage value is less than 1%, the corresponding object weight is 1. The weight determination unit 240 determines the object weight from time t101 to time t102 to be 1, and the FDC determination unit 230 can apply an increase slope from time t101 to time t102 obtained by multiplying the increase reference slope by the object weight. Therefore, the FDC value at time t102 is 0+9(Steps / 100ms)×1×200(ms)=18.

[0084] 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%. Because the threshold deviation is less than 0, the FDC value at time t102 exceeds the lower limit of the weight application range, and the ratio of the voltage deviation to the threshold voltage value is less than 1%, the corresponding target weight is 1. The weight determination unit 240 determines the target weight from time t102 to time t103 to be 1, and the FDC determination unit 230 can apply a decrease slope from time t102 to time t103 obtained by multiplying the decrease reference slope by the target weight. Therefore, the FDC value at time t103 is 18-13 (Steps / 100 ms) x 1 x 200 (ms) = -8.

[0085] 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%. Because the FDC value at time t103 is less than the upper limit of the weight application range, the threshold deviation is greater than 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 to be 3, and the FDC determination unit 230 can apply an increase slope from time t103 to time t104 that is obtained by multiplying the increase reference slope by the target weight. Therefore, the FDC value at time t104 is −8+9(Steps / 100 ms)×3×400(ms)=100.

[0086] 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 is |0.1| / 4 = 2.5%. Because the FDC value at time t104 is equal to or greater than the upper limit of the weight application range, the corresponding target weight is 1. The weight determination unit 240 determines the target weight from time t104 to time t105 to be 1, and the FDC determination unit 230 can apply an increase slope from time t104 to time t105 that is the increase reference slope multiplied by the target weight. Therefore, the FDC value at time t105 is 100 + 9 (Steps / 100 ms) × 1 × 200 (ms) = 118.

[0087] 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 3.4V. 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 is |-0.6| / 4=15%. Because the FDC value at time t105 is equal to or greater than the upper limit of the weight application range, the corresponding target weight is 1. The weight determination unit 240 determines the target weight from time t105 to time t106 to be 1, and the FDC determination unit 230 can apply a decrease slope from time t105 to time t106 that is the decrease reference slope multiplied by the target weight. Therefore, the FDC value at time t106 is 118-13 (Steps / 100 ms) × 1 × 200 (ms) = 92.

[0088] 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%. Because the FDC value at time t106 is less than the upper limit of the weight application range, the threshold deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds 10%, FDC determiner 230 can determine the FDC value at time t107 to be −101.

[0089] 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 3.4V. 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 is |-0.6| / 4=15%. Because the FDC value at time t107 is equal to or less than the lower limit of the weight application range, the corresponding target weight is 1. The weight determination unit 240 determines the target weight from time t107 to time t108 to be 1, and the FDC determination unit 230 can apply a decrease slope from time t107 to time t108 that is the decrease reference slope multiplied by the target weight. Therefore, the FDC value at time t108 is -101-13(Steps / 100 ms)×1×200(ms)=-127.

[0090] 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 3.4V. 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 is |-0.6| / 4=15%. Because the FDC value at time t108 is equal to or less than the lower limit of the weight application range, the corresponding target weight is 1. The weight determination unit 240 determines the target weight from time t108 to time t109 to be 1, and the FDC determination unit 230 can apply a decrease slope from time t108 to time t109 obtained by multiplying the decrease reference slope by the target weight. Therefore, the FDC value at time t108 is -127-13(Steps / 100 ms)×1×100(ms)=-140. However, since the lower limit threshold for FDC is −128, the FDC value reaches the lower limit threshold between time t107 and time t108, and the FDC determination section 230 can determine the FDC value at time t108 to be −128.

[0091] Referring to FIG. 6, since the FDC value reaches the lower threshold value between time t107 and time t108, the DTC setting unit 250 can set the DTC value of the cell voltage corresponding to the FDC at the time when the lower threshold value is reached to a second value indicating that the battery pack 10 is normal.

[0092] FIG. 7 is a flowchart of a method for determining a weighted FDC value according to one embodiment.

[0093] In the following description of each component of the battery system 1, the description of parts that overlap with the contents already described may be omitted.

[0094] Referring to FIG. 7, the battery failure diagnosis device 20 may generate measurement data indicating the cell voltages of each of the plurality of battery cells included in the battery pack 10 (S100).

[0095] The battery failure diagnosis device 20 may determine a weight to be applied to the increasing or decreasing slope of the FDC value based on the magnitude of the voltage deviation and the FDC value at the time when the increasing or decreasing slope is applied (S200).

[0096] FIG. 8 is a detailed flowchart of step S200 shown in FIG.

[0097] Referring to FIG. 8, the battery failure diagnosis device 20 may determine whether the FDC value at the time when the FDC determiner 230 applies the increasing slope or decreasing slope is within the weight application interval (S210).

[0098] In step S210, if the FDC value at the time when the increasing slope or decreasing slope is applied falls outside the weight application interval ('No' in S210), the battery fault diagnosis device 20 can determine the target weight to be 1 (S220).

[0099] In step S210, if the FDC value at the time when the increasing slope or decreasing slope is applied is within the weight application interval ('Yes' in S210), the battery fault diagnosis device 20 can determine whether the voltage deviation exceeds the deviation upper limit (S230).

[0100] In step S230, if the voltage deviation exceeds the upper deviation limit ("Yes" in S230), the battery fault diagnosis device 20 may determine the FDC value as the upper or lower limit of the weight application range (S240). If the voltage deviation exceeding 0 exceeds the upper increasing deviation limit, the battery fault diagnosis device 20 may determine the FDC value as the upper limit of the weight application range. Alternatively, in this case, the battery fault diagnosis device 20 may determine the FDC value as the upper FDC threshold. If the voltage deviation less than 0 exceeds the upper decreasing deviation limit, the battery fault diagnosis device 20 may determine the FDC value as the lower FDC threshold.

[0101] In step S230, if the voltage deviation does not exceed the deviation upper limit ("No" in S230), the battery fault diagnosis device 20 can determine a target weighting according to the magnitude of the voltage deviation (S250). Specifically, the battery fault diagnosis device 20 can determine, as the target weighting, a reference weighting corresponding to the ratio of the voltage deviation to the threshold voltage value from among a plurality of reference weightings included in the weighting coefficient map.

[0102] Referring again to FIG. 7, the battery failure diagnosis device 20 may determine the FDC value by increasing or decreasing the FDC value with a gradient to which the object weighting is applied (S300).

[0103] 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 going through step S300 of Fig. 7. Step S240 of Fig. 8 is performed to determine the value of the FDC regardless of the value of the target weight.

[0104] Referring to FIG. 7, the battery failure diagnosis device 20 may determine whether the FDC value reaches an upper or lower threshold (S400).

[0105] In step S400, when the FDC value reaches the upper limit threshold (upper limit threshold reached in S400), the battery fault diagnosis device 20 can set the DTC value related to the cell voltage corresponding to the FDC to a first value indicating that the battery pack 10 is abnormal (S500).

[0106] In step S400, when the FDC value reaches the lower limit threshold (reach lower limit threshold in S400), the battery fault diagnosis device 20 can set the DTC value related to the cell voltage corresponding to the FDC to a second value indicating that the battery pack 10 is normal (S600).

[0107] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to these examples, and various modifications and improvements made by those skilled in the art to which the present invention pertains also fall within the scope of the present invention.

Claims

1. 1. An apparatus for generating fault detection count (FDC) information from a lower threshold to an upper threshold for a battery and diagnosing a battery fault, comprising: a measurement unit connected to the battery pack and configured to generate measurement data indicating cell voltages of each of a plurality of battery cells included in the battery pack; an FDC determination unit that increases the FDC value at an increasing slope or decreases the FDC value at a decreasing slope based on a result of comparing the measurement data with a predetermined threshold voltage value; a weighting determination unit that determines a target weighting to be applied to the increasing slope or the decreasing slope based on an FDC value at a time point when 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 that sets 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, and sets the DTC value corresponding to the FDC value to a second value indicating that the battery pack is normal when the FDC value reaches a predetermined lower threshold. A battery fault diagnosis device including:

2. The FDC determination unit 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 determining unit to a predetermined reference increasing slope that has been previously stored 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 object weight determined by the weight determining unit to a predetermined decreasing reference slope that has been previously stored is determined as the decreasing slope. The battery fault diagnosis device according to claim 1 .

3. If the FDC value at the time of application is equal to or less than the lower limit of a predetermined weight application range between the upper threshold and the lower threshold, or equal to or greater than the upper limit of the weight application range, The weight determination unit determining the subject weight to be 1; 3. The battery failure diagnosis device according to claim 1 or 2.

4. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, The weight determination unit determining one of a plurality of reference weights as the target weight according to the magnitude of the voltage deviation; The plurality of reference weights have values ​​that are larger as the ratio of the voltage deviation to the threshold voltage value is larger.

3. The battery failure diagnosis device according to claim 1 or 2.

5. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation is greater than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the incremental deviation, The FDC determination unit determining the FDC value as the upper limit of the weight application range; 3. The battery failure diagnosis device according to claim 1 or 2.

6. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation is less than 0, and the ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the reduced deviation, The FDC determination unit determining the FDC value as the lower limit of the weight application range; 3. The battery failure diagnosis device according to claim 1 or 2.

7. 1. A method for diagnosing a battery fault by generating fault detection count (FDC) information from a lower threshold to an upper threshold for a battery, the method comprising: generating measurement data indicative of cell voltages of each of a plurality of battery cells included in the battery pack; determining a target weight to be applied to the increasing slope or decreasing slope of the FDC value based on the FDC value at the time when the increasing slope or decreasing slope of the FDC value is applied and the magnitude of a voltage deviation obtained by subtracting a predetermined threshold voltage value from the measurement data; increasing the FDC value at the increasing slope or decreasing the FDC value at the decreasing slope based on a result of comparing the measurement data with the threshold voltage value; and When the FDC value reaches a predetermined upper threshold, setting the DTC value corresponding to the FDC value to a first value indicating that the battery pack is abnormal, and when the FDC value reaches a predetermined lower threshold, setting the DTC value to a second value indicating that the battery pack is normal. method.

8. selecting one of the increasing slope and the decreasing slope based on whether the voltage deviation is greater than 0 or whether the voltage deviation is less than 0; determining the increase slope by applying a first object weighting to a previously stored predetermined increase reference slope; and The method further includes applying a second object weighting to a previously stored predetermined reference slope of decrease to determine the slope of decrease. The method of claim 7.

9. The method further includes determining the target weight as 1 when the FDC value at the time of application is equal to or less than a lower limit value of a predetermined weight application range between the upper threshold and the lower threshold, or equal to or greater than an upper limit value of the weight application range.

9. The method according to claim 7 or 8.

10. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, determining one of a plurality of reference weights as the target weight according to the magnitude of the voltage deviation, The plurality of reference weights have values ​​that are larger as the ratio of the voltage deviation to the threshold voltage value is larger.

9. The method according to claim 7 or 8.

11. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation exceeds 0, and a ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the incremental deviation, the FDC value is determined to be the upper limit of the weight application range.

9. The method according to claim 7 or 8.

12. If the FDC value at the time of application is within a predetermined weight application range between the upper threshold and the lower threshold, the voltage deviation is less than 0, and a ratio of the voltage deviation to the threshold voltage value exceeds a predetermined upper limit of the reduced deviation, the FDC value is determined as the lower limit of the weight application range.

9. The method according to claim 7 or 8.

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