Battery management system capable of diagnosing fault of shutter resistor and method for diagnosing

Abstract

The present disclosure relates to a battery management system capable of diagnosing a fault of a shunt resistor and a method of diagnosing a fault of a shunt resistor using the same. The battery management system includes: an auxiliary current detector that detects an auxiliary current flowing through an auxiliary shunt resistor based on a voltage generated across the auxiliary shunt resistor; an auxiliary battery voltage measurer connected to a positive terminal and a negative terminal of the auxiliary battery and measuring a voltage of the auxiliary battery; a main battery voltage measurer connected to a positive terminal and a negative terminal of the main battery and measuring a voltage of the main battery; a current predictor that receives the voltage of the auxiliary battery from the auxiliary battery voltage measurer, predicts a first current by dividing the voltage of the auxiliary battery by an internal resistance of the auxiliary battery, receives the voltage of the main battery from the main battery voltage measurer, and predicts a second current by dividing the voltage of the main battery by an internal resistance of the main battery; and a state diagnosis section that calculates an average value of the first current and the second current, calculates a first error rate based on the average value and the auxiliary current, and diagnoses a state of the auxiliary shunt resistor based on the calculated first error rate.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0052988, filed with the Korean Intellectual Property Office on April 19, 2024, the entire contents of which are incorporated herein by reference.

[0003] This disclosure relates to a battery management system capable of diagnosing shunt resistor failures and a method for diagnosing shunt resistor failures using the battery management system. Background Technology

[0004] Commercially available batteries include nickel-cadmium (NiCd), nickel-metal hydride (NiMH), nickel-zinc (NiZn), and lithium-ion (LiN) batteries. The power supply systems for these batteries typically incorporate current sensors for measuring current. These current sensors measure the current flowing through the battery's charging / discharging path to monitor the battery's state and detect overcurrent. Furthermore, the current measured by the current sensor can be used to calculate the State of Charge (SOC) or as a basis for determining whether the charging / discharging process is functioning correctly.

[0005] A shunt resistor is used to measure the current flowing through a battery, and the current can be measured by measuring the voltage across the shunt resistor. However, if the shunt resistor is not functioning properly, the current flowing through the battery cannot be measured correctly. Therefore, even in abnormal situations such as overcurrent, it may not be able to prevent current from flowing properly, leading to serious problems such as battery failure or explosion.

[0006] Conventionally, the condition of a shunt resistor can be diagnosed by comparing the current flowing through it with a predicted current value based on the voltage value obtained from a unit voltage meter. However, when multiple charging / discharging conditions may exist, such as charging, discharging, and simultaneous charging / discharging modes—that is, when using two shunt resistors (e.g., when a main shunt resistor and an auxiliary shunt resistor are used together)—the conventional method for diagnosing the condition of the auxiliary shunt resistor can only diagnose its condition when it is charging through the charging path but not discharging through the discharging path. Therefore, a method is needed that can diagnose the condition of the auxiliary shunt resistor regardless of the charging / discharging mode. Summary of the Invention

[0007] [Technical Issues]

[0008] This disclosure seeks to provide a battery management system capable of diagnosing shunt resistor failures in a battery system capable of charging, discharging, and charge / discharging modes and including a main shunt resistor and an auxiliary shunt resistor, as well as a method for diagnosing shunt resistor failures using the battery management system.

[0009] [Technical Solution]

[0010] According to embodiments of this disclosure, a battery management system capable of diagnosing shunt resistor faults includes: an auxiliary current detector that detects an auxiliary current flowing through the auxiliary shunt resistor based on a voltage generated across the two ends of the auxiliary shunt resistor; an auxiliary battery voltage meter connected to the positive and negative terminals of an auxiliary battery and measuring the voltage of the auxiliary battery; a main battery voltage meter connected to the positive and negative terminals of a main battery and measuring the voltage of the main battery; a current predictor that predicts a first current by dividing the voltage of the auxiliary battery measured by the auxiliary battery voltage meter by the internal resistance of the auxiliary battery, and predicts a second current by dividing the voltage of the main battery measured by the main battery voltage meter by the internal resistance of the main battery; and a state diagnostic unit that calculates an average of the first current and the second current, calculates a first error rate based on the average and the auxiliary current, and diagnoses the state of the auxiliary shunt resistor based on the calculated first error rate.

[0011] The current predictor can receive the auxiliary current from the auxiliary current detector and calculate the internal resistance of the auxiliary battery by dividing the voltage of the auxiliary battery by the auxiliary current.

[0012] The battery management system may include a main current detector that detects the main current flowing through the main shunt resistor based on the voltage generated across the main shunt resistor.

[0013] The current predictor can receive the main current from the main current detector and calculate the internal resistance of the main battery by dividing the voltage of the main battery by the main current.

[0014] The status diagnostic unit can determine whether the auxiliary current is greater than or equal to the reference value, and can determine that the auxiliary shunt resistor is in the open state when the auxiliary current is greater than or equal to the reference value.

[0015] The status diagnostic unit can determine that the auxiliary shunt resistor is in a short-circuit state when the first error rate is greater than or equal to a predetermined threshold, and determine that the auxiliary shunt resistor is in a drift state when the first error rate is within a predetermined range less than the threshold.

[0016] The status diagnostic unit can calculate the second error rate based on the second current and the main current, and diagnose the status of the main shunt resistor based on the calculated second error rate.

[0017] The status diagnostics unit can determine whether the main current is greater than or equal to the reference value, and when the main current is greater than or equal to the reference value, it can determine that the main shunt resistor is in the open state.

[0018] The status diagnostic unit can determine that the main shunt resistor is in a short-circuit state when the second error rate is greater than or equal to a predetermined threshold, and determine that the main shunt resistor is in a drift state when the second error rate is within a predetermined range less than the threshold.

[0019] In a battery system including an auxiliary shunt resistor and a main shunt resistor according to an embodiment of the present disclosure, a method for diagnosing faults in the auxiliary shunt resistor and the main shunt resistor includes: an auxiliary current detector detecting an auxiliary current flowing through the auxiliary shunt resistor based on a voltage generated across the auxiliary shunt resistor; a current predictor predicting a first current by dividing the voltage of the auxiliary battery measured by an auxiliary battery voltage meter by the internal resistance of the auxiliary battery, and predicting a second current by dividing the voltage of the main battery measured by a main battery voltage meter by the internal resistance of the main battery; a status diagnostic unit calculating an average of the first current and the second current when the auxiliary current is less than a reference value, and calculating a first error rate using the auxiliary current and the average value; and the status diagnostic unit determining the status of the auxiliary shunt resistor based on the first error rate.

[0020] Predicting the second current may include: a current predictor receiving an auxiliary current detected by an auxiliary current detector, and calculating the internal resistance of the auxiliary battery by dividing the voltage of the auxiliary battery by the auxiliary current; and a current predictor receiving a main current detected by a main current detector based on the voltage generated across the main shunt resistor, and calculating the internal resistance of the main battery by dividing the voltage of the main battery by the main current.

[0021] Calculating the first error rate may include: the status diagnostic unit determining whether the auxiliary current is greater than or equal to a predetermined reference value, and determining that the auxiliary shunt resistor is in the off state when the auxiliary current is greater than or equal to the predetermined reference value.

[0022] Calculating the first error rate may include: calculating the ratio of the difference between the auxiliary current and the average of the first current and the second current to the average of the first current and the second current as the first error rate.

[0023] Determining the state of the auxiliary shunt resistor may include: determining whether a first error rate is greater than or equal to a predetermined threshold, and determining that the auxiliary shunt resistor is in a short-circuit state when the first error rate is greater than or equal to the threshold.

[0024] Determining the state of the auxiliary shunt resistor may include: determining whether a first error rate is within a predetermined range less than a threshold, and determining that the auxiliary shunt resistor is in a drift state when the first error rate is within a predetermined range less than the threshold.

[0025] According to an embodiment, the method may further include: a main current detector detecting the main current flowing through the main shunt resistor based on the voltage generated across the main shunt resistor; a current predictor predicting a second current by dividing the voltage of the main battery by the internal resistance of the main battery; a state diagnostic unit calculating a second error rate using the main current and the second current; and the state diagnostic unit determining the state of the main shunt resistor based on the second error rate.

[0026] [Beneficial Effects]

[0027] According to embodiments of this disclosure, in a battery system that includes both a main shunt resistor and an auxiliary shunt resistor capable of simultaneous charging / discharging, the state of the auxiliary shunt resistor can be accurately diagnosed.

[0028] The effects that can be obtained from this disclosure are not limited to those mentioned above, and other effects not described herein will be apparent to those skilled in the art as described below. Attached Figure Description

[0029] Figure 1 A battery system according to an embodiment of the present disclosure is shown.

[0030] Figure 2 This is a block diagram of a battery management system according to an embodiment of the present disclosure.

[0031] Figure 3 This is a flowchart of a method for diagnosing auxiliary shunt resistor faults according to an embodiment of this disclosure.

[0032] Figure 4 This is a flowchart of a method for diagnosing a fault in a main shunt resistor according to an embodiment of this disclosure. Detailed Implementation

[0033] In describing the embodiments disclosed in this disclosure, detailed descriptions of relevant known technologies are omitted if they are determined to obscure the essential points of the embodiments disclosed herein. The accompanying drawings are intended only to facilitate understanding of the exemplary embodiments disclosed herein, and it should be understood that the technical ideas disclosed herein are not limited to the drawings and include all modifications, equivalents, or alternatives within the scope of the ideas and techniques of this disclosure.

[0034] Although terms such as "first" and "second" are used to explain various components, components are not limited to these terms. These terms are only used to distinguish one component from another.

[0035] It should be understood that when a component is referred to as "connected" or "coupled" to another component, it can be directly connected or coupled to the other component, or there may be other intermediate components. On the other hand, it should be understood that when a component is referred to as "directly connected or coupled" to another component, there are no other intermediate components.

[0036] Throughout this specification, the terms “comprising” and “having” are intended to specify the presence of the stated features, integers, steps, operations, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, or combinations thereof.

[0037] The contents of this disclosure will be described in detail below with reference to the accompanying drawings.

[0038] Figure 1 A battery system 1 according to an embodiment of the present disclosure is shown.

[0039] Reference Figure 1 According to embodiments of the present disclosure, the battery system 1 may include a main battery 10, an auxiliary battery 2, contactors C1 to C3, a main shunt resistor R2, an auxiliary shunt resistor R1, and a battery management system 20.

[0040] exist Figure 1 In this configuration, the main battery 10 is connected between node N, which connects the first power terminal P+_DSG and the second power terminal P+_CHG of the battery system 1, and the third power terminal P-. A first contactor C1 can be connected between the positive terminal of the main battery 10 and node N, a second contactor C2 can be connected between node N and the first power terminal P+_DSG, and an auxiliary shunt resistor R1 and a third contactor C3 can be connected between node N and the second power terminal P+_CHG. A main shunt resistor R2 is connected between the negative terminal of the main battery 10 and the third power terminal P-, and can provide grounding. In this disclosure, the potential of the positive terminal is higher than the potential of the negative terminal.

[0041] The main battery 10 is a secondary battery capable of being charged, discharged, and charged / discharged. According to an embodiment, the main battery 10 may include multiple battery cells connected in series and parallel.

[0042] The auxiliary battery 2 is a charger that supplies power to the main battery 10 to charge it. According to an embodiment, the auxiliary battery 2 may include multiple battery cells connected in series and parallel, and may be a rechargeable and dischargeable secondary battery. The electrical connection between the auxiliary battery 2 and the main battery 10 is controlled by the ON / OFF operation of the first contactor C1 and the third contactor C3.

[0043] Contactors C1 to C3 act as switches controlling the connection between the main battery 10 and the auxiliary battery 2, as well as the connection between the main battery 10 and the external device 3. For example, in Figure 1 In this configuration, when the first contactor C1 and the third contactor C3 are connected, the main battery 10 and the auxiliary battery 2 are electrically connected, and the main battery 10 is charged. When the first contactor C1 and the second contactor C2 are connected, the main battery 10 is connected to the external device 3, and the main battery 10 is discharged. In this case, the external device 3 may be a load such as a vehicle. According to an embodiment, the contactors may include the first contactor C1 to the third contactor C3, and the first contactor C1 to the third contactor C3 may be a relay or a MOSFET.

[0044] The main shunt resistor R2 is a shunt resistor element used to detect the current flowing through a specific point in the battery system 1 when the main battery 10 is being charged and / or discharged. According to an embodiment, the main shunt resistor R2 can detect the current flowing between the negative terminal of the main battery 10 and the third power terminal P- when the main battery 10 is discharged by the external device 3 according to the closing operation of the first contactor C1 and the second contactor C2—that is, when a discharge cycle is in progress. Additionally, the main shunt resistor R2 can detect the current flowing between the negative terminal of the main battery 10 and the third power terminal P- when the main battery 10 is charged by the auxiliary battery 2 according to the closing operation of the first contactor C1 and the third contactor C3—that is, when a charging cycle is in progress. Figure 1 In the diagram, the main shunt resistor R2 is shown connected between the negative terminal of the main battery 10 and the third power terminal P-. However, the location of the main shunt resistor R2 is not limited to this and can be freely changed, as long as the current flowing in the main battery 10 during charging and / or discharging can be measured.

[0045] The auxiliary shunt resistor R1 is a shunt resistor element used to detect the current flowing through a specific point in the battery system 1 when the main battery 10 is being charged. According to an embodiment, the auxiliary shunt resistor R1 can detect the current flowing between node N and the third contactor C3 when the main battery 10 is charged by the auxiliary battery 2 according to the closing operation of the first contactor C1 and the third contactor C3—that is, when a charging cycle is in progress. Figure 1 In the diagram, the auxiliary shunt resistor R1 is shown connected between node N and the third contactor C3. However, the location of the auxiliary shunt resistor R1 is not limited to this and can be freely changed, as long as the current flowing through the auxiliary battery 2 during the charging of the main battery 10 can be measured.

[0046] The battery management system 20 (BMS) may include an auxiliary current detector 21, a controller 22, an auxiliary battery voltage meter 26, and a main battery voltage meter 27. Here, the controller 22 may include a current predictor 23 and a condition diagnostic unit 24. According to an embodiment, the battery management system 20 may also include a main current detector 25.

[0047] The auxiliary current detector 21, main current detector 25, auxiliary battery voltage meter 26, and main battery voltage meter 27 can send and receive signals to the controller 22 via wired or wireless communication methods. For example, the controller 22 can generate control signals and send them to each of the auxiliary current detector 21, main current detector 25, auxiliary battery voltage meter 26, and main battery voltage meter 27. These detectors can detect or measure the auxiliary current, main current, voltage of the auxiliary battery 2, and voltage of the main battery 10, respectively, based on the control signals. Furthermore, the auxiliary current detector 21 can detect the auxiliary current and send it to the controller 22, and the main current detector 25 can detect the main current and send it to the controller 22. Similarly, the auxiliary battery voltage meter 26 can measure the voltage of the auxiliary battery 2 and send it to the controller 22, and the main battery voltage meter 27 can measure the voltage of the main battery 10 and send it to the controller 22.

[0048] In other words, the battery management system 20 can measure the voltage, current, and temperature of the main battery 10, and can also measure the voltage, current, and temperature of the auxiliary battery 2. Furthermore, the battery management system 20 can use the voltage, current, and temperature of the main battery 10 and the auxiliary battery 2 to diagnose the state of the main shunt resistor R2 and the auxiliary shunt resistor R1, respectively.

[0049] The following will refer to Figure 2 A detailed description of a battery management system 20 according to embodiments of this disclosure is provided.

[0050] Figure 2 This is a block diagram of a battery management system 20 according to an embodiment of the present disclosure.

[0051] Reference Figure 1 and Figure 2The auxiliary current detector 21 detects the auxiliary current flowing through the auxiliary shunt resistor R1 based on the voltage generated across the auxiliary shunt resistor R1. For example, the auxiliary current detector 21 can measure the voltage generated across the auxiliary shunt resistor and divide the measured voltage value by the resistance value of the auxiliary shunt resistor R1 to detect the auxiliary current flowing through the auxiliary shunt resistor R1. In this case, the resistance value of the auxiliary shunt resistor R1 can be stored as a pre-known value in the memory 28 or in the auxiliary current detector 21.

[0052] The main current detector 25 detects the main current flowing through the main shunt resistor R2 based on the voltage generated across the main shunt resistor R2. For example, the main current detector 25 can measure the voltage generated across the main shunt resistor and divide the measured voltage value by the resistance value of the main shunt resistor R2 to detect the main current flowing through the main shunt resistor R2. In this case, the resistance value of the main shunt resistor R2 can be stored as a pre-known value in the memory 28 or the main current detector 25.

[0053] The auxiliary battery voltage meter 26 is connected to the positive and negative terminals of the auxiliary battery 2 and measures the voltage of the auxiliary battery 2. Here, the voltage of the auxiliary battery 2 refers to the voltage difference between the positive and negative terminals of the auxiliary battery 2.

[0054] The main battery voltage meter 27 is connected to the positive and negative terminals of the main battery 10 and measures the voltage of the main battery 10. Here, the voltage of the main battery 10 refers to the voltage difference between the positive and negative terminals of the main battery 10.

[0055] The current predictor 23 can predict a first current using the voltage and internal resistance of the auxiliary battery 2, and can predict a second current using the voltage and internal resistance of the main battery 10. For example, the current predictor 23 can predict the first current by dividing the voltage of the auxiliary battery 2, measured by the auxiliary battery voltage meter 26, by the internal resistance of the auxiliary battery 2. The current predictor 23 can predict the second current by dividing the voltage of the main battery 10, measured by the main battery voltage meter 27, by the internal resistance of the main battery 10.

[0056] At this time, the voltage of the auxiliary battery 2 is received from the auxiliary battery voltage measuring device 26, and the voltage of the main battery 10 is received from the main battery voltage measuring device 27. According to the embodiment, the internal resistance of the auxiliary battery 2 and the internal resistance of the main battery 10 can be data recorded in the memory 28 or values ​​calculated by the current predictor 23.

[0057] For example, the current predictor 23 can receive the auxiliary current from the auxiliary current detector 21 and the voltage of the auxiliary battery 2 from the auxiliary battery voltage meter 26, and then divide the voltage of the auxiliary battery 2 by the auxiliary current to calculate the internal resistance of the auxiliary battery 2. Alternatively, the current predictor 23 can receive the temperature measurement value of the auxiliary battery 2 measured by the sensing unit 29, detect the internal resistance of the auxiliary battery 2 from a table stored in the memory 28 based on the temperature measurement value, and determine that internal resistance as the internal resistance of the auxiliary battery 2. In this case, a table listing the internal resistance values ​​based on the temperature value of the auxiliary battery 2 can be stored in the memory 28.

[0058] For example, the current predictor 23 can receive the main current from the main current detector 25 and the voltage of the main battery 10 from the main battery voltage meter 27, and then divide the voltage of the main battery 10 by the main current to calculate the internal resistance of the main battery 10. Alternatively, the current predictor 23 can receive the temperature measurement value of the main battery 10 measured by the sensing unit 29, detect the internal resistance of the main battery 10 from a table stored in the memory 28 based on the temperature measurement value, and determine the internal resistance of the main battery 10. In this case, a table listing the internal resistance values ​​based on the temperature value of the main battery 10 can be stored in the memory 28.

[0059] The status diagnostic unit 24 can calculate the average value of the first current and the second current, and use the average value to calculate the first error rate.

[0060] Here, the first error rate corresponds to a reference used for diagnosing the state of the auxiliary shunt resistor R1, and the state diagnosis unit 24 can derive the first error rate using the auxiliary current and the average of the first current and the second current. For example, the state diagnosis unit 24 can calculate the ratio of the difference between the auxiliary current and the average of the first current and the second current to the average of the first current and the second current as the first error rate, as shown in Equation 1.

[0061] (Equation 1)

[0062]

[0063] The status diagnostic unit 24 can determine the status of the auxiliary shunt resistor R1 based on a first error rate. For example, the status diagnostic unit 24 can determine whether the auxiliary current is greater than or equal to a reference value, and if the auxiliary current is greater than or equal to the reference value, it determines that the auxiliary shunt resistor R1 is in the off state. The reference value can be determined based on the current range that the auxiliary current can have and the value of the auxiliary shunt resistor in the off state.

[0064] Furthermore, the status diagnostic unit 24 can determine whether the first error rate is greater than or equal to a predetermined threshold, and can determine that the auxiliary shunt resistor R1 is in a short-circuit state when the first error rate is greater than or equal to the threshold. The threshold can be set to any value within the range from 100% to a ratio based on 100% minus a specified margin. Additionally, the status diagnostic unit 24 can determine whether the first error rate is within a predetermined range less than the threshold, and can determine that the auxiliary shunt resistor R1 is in a drift state when the first error rate is within the predetermined range. The predetermined range can be determined based on the range of each of the first current, the second current, and the auxiliary current in the drift state of the auxiliary shunt resistor R1.

[0065] According to the implementation, the status diagnosis unit 24 can calculate the second error rate based on the second current and the main current.

[0066] Here, the second error rate corresponds to a reference used for diagnosing the state of the main shunt resistor R2, and the state diagnosis unit 24 can use the main current and the second current to derive the second error rate. For example, the state diagnosis unit 24 can calculate the ratio of the difference between the main current and the second current to the second current as the second error rate, as shown in Equation 2.

[0067] (Equation 2)

[0068]

[0069] According to the embodiment, the status diagnosis unit 24 can diagnose the status of the main shunt resistor R2 based on the second error rate. For example, the status diagnosis unit 24 can determine whether the main current is greater than or equal to a reference value, and can determine that the main shunt resistor R2 is in an open state when the main current is greater than or equal to the reference value. The reference value can be determined based on the current range that the main current can have and the value of the main shunt resistor R2 in the open state.

[0070] Furthermore, the status diagnostic unit 24 can determine whether the second error rate is greater than or equal to a predetermined threshold, and can determine that the main shunt resistor R2 is in a short-circuit state when the second error rate is greater than or equal to the threshold. The threshold can be set to any value within the range from 100% to a ratio based on 100% minus a specified margin. Additionally, the status diagnostic unit 24 can determine whether the second error rate is within a predetermined range below the threshold, and can determine that the main shunt resistor R2 is in a drift state when the second error rate is within the predetermined range. The predetermined range can be determined based on the range of each of the main current and the second current in the drift state of the main shunt resistor R2.

[0071] Figure 3 This is a flowchart illustrating a method for diagnosing a fault in the auxiliary shunt resistor R1 according to an embodiment of this disclosure; and Figure 4This is a flowchart of a method for diagnosing a fault in the main shunt resistor R2 according to an embodiment of the present disclosure.

[0072] Reference Figure 3 and Figure 4 The method for diagnosing shunt resistor faults according to embodiments of this disclosure may include a method for diagnosing faults in the auxiliary shunt resistor R1 and / or a method for diagnosing faults in the main shunt resistor R2. In other words, the method according to embodiments of this disclosure can diagnose the condition of the auxiliary shunt resistor R1 and / or the main shunt resistor R2 in a battery system 1 that includes the auxiliary shunt resistor R1 and the main shunt resistor R2.

[0073] Reference Figure 3 The method for diagnosing a fault in the auxiliary shunt resistor R1 according to the embodiments of the present disclosure may include an auxiliary current detection step (S110), a current prediction step (S120), an error rate calculation step (S130), and a condition diagnosis step (S140).

[0074] In the auxiliary current detection step (S110), the auxiliary current detector 21 detects the auxiliary current flowing through the auxiliary shunt resistor R1 based on the voltage generated across the auxiliary shunt resistor R1. In this case, the detected auxiliary current can be sent to the controller 22.

[0075] In the current prediction step (S120), the current predictor 23 uses the voltage and internal resistance of the auxiliary battery 2 and the voltage and internal resistance of the main battery 10 to predict the first current and the second current, respectively. For example, the current predictor 23 can predict the first current by dividing the voltage of the auxiliary battery 2 measured by the auxiliary battery voltage measuring device 26 by the internal resistance of the auxiliary battery 2 (S121). The current predictor 23 can predict the second current by dividing the voltage of the main battery 10 measured by the main battery voltage measuring device 27 by the internal resistance of the main battery 10 (S122).

[0076] According to the implementation, the internal resistance of the auxiliary battery 2 can be determined using either the auxiliary current or the temperature measurement value of the auxiliary battery 2. For example, the current predictor 23 can receive the auxiliary current from the auxiliary current detector 21 and the voltage of the auxiliary battery 2 from the auxiliary battery voltage meter 26, and then divide the voltage of the auxiliary battery 2 by the auxiliary current to calculate the internal resistance of the auxiliary battery 2. Alternatively, the current predictor 23 can receive the temperature measurement value of the auxiliary battery 2 measured by the sensing unit 29, detect the internal resistance of the auxiliary battery 2 from a table stored in the memory 28 based on the temperature measurement value, and determine that internal resistance as the internal resistance of the auxiliary battery 2. In this case, a table listing the internal resistance values ​​based on the temperature value of the auxiliary battery 2 can be stored in the memory 28.

[0077] According to the implementation, the internal resistance of the main battery 10 can be determined using either the main current or the temperature measurement value of the main battery 10. For example, the current predictor 23 can receive the main current from the main current detector 25 and the voltage of the main battery 10 from the main battery voltage meter 27, and then divide the voltage of the main battery 10 by the main current to calculate the internal resistance of the main battery 10. Here, the main current can be detected by the main current detector 25 based on the voltage generated across the main shunt resistor R2. Alternatively, the current predictor 23 can receive the temperature measurement value of the main battery 10 measured by the sensing unit 29, detect the internal resistance of the main battery 10 from a table stored in the memory 28 based on the temperature measurement value, and determine the internal resistance of the main battery 10. In this case, a table listing the internal resistance values ​​based on the temperature value of the main battery 10 can be stored in the memory 28.

[0078] In the error rate calculation step (S130), the status diagnostic unit 24 can calculate the average value of the first current and the second current (S133), and the status diagnostic unit 24 can use the auxiliary current and the average value of the first current and the second current to calculate the first error rate (S134). In this case, the status diagnostic unit 24 can receive the first current and the second current from the current predictor 23, and receive the auxiliary current from the auxiliary current detector 21.

[0079] Here, the first error rate corresponds to a reference used for diagnosing the state of the auxiliary shunt resistor R1, and the state diagnosis unit 24 can derive the first error rate using the auxiliary current and the average of the first current and the second current. For example, the state diagnosis unit 24 can calculate the ratio of the difference between the auxiliary current and the average of the first current and the second current to the average of the first current and the second current as the first error rate.

[0080] According to the embodiment, in the error rate calculation step (S130), the status diagnosis unit 24 can determine whether the auxiliary current is greater than or equal to a reference value (S131). In this case, when the auxiliary current is greater than or equal to a predetermined reference value, the status diagnosis unit 24 can determine that the auxiliary shunt resistor R1 is in an open state (S132). In other words, when the auxiliary current is greater than or equal to a predetermined reference value, the status diagnosis unit 24 can diagnose the state of the auxiliary shunt resistor R1 without calculating the first error rate.

[0081] In the status diagnosis step (S140), the status diagnosis unit 24 can determine the status of the auxiliary shunt resistor R1 based on the first error rate.

[0082] According to the embodiment, the state diagnosis step (S140) may include a short-circuit determination step (S141 and S142) and a drift determination step (S143 and S144). For example, in the state diagnosis step (S140), the state diagnosis unit 24 can determine whether the auxiliary shunt resistor R1 is in a short-circuit state by determining whether the first error rate is greater than or equal to a predetermined threshold (S141) and by determining that the auxiliary shunt resistor R1 is in a short-circuit state when the first error rate is greater than or equal to the predetermined threshold (S142). Alternatively, in the state diagnosis step (S140), the state diagnosis unit 24 can determine whether the auxiliary shunt resistor R1 is in a drift state by determining whether the first error rate is within a predetermined range less than a threshold (S143) and by determining that the auxiliary shunt resistor R1 is in a drift state when the first error rate is within a predetermined range less than a threshold (S144).

[0083] Figure 4 This is a flowchart of a method for diagnosing a fault in the main shunt resistor R2 according to an embodiment of the present disclosure.

[0084] Reference Figure 4 The method for diagnosing a fault in the main shunt resistor R2 according to the embodiments of the present disclosure may include a main current detection step (S210), a current prediction step (S220), an error rate calculation step (S230), and a condition diagnosis step (S240).

[0085] In the main current detection step (S210), the main current detector 25 detects the main current flowing through the main shunt resistor R2 based on the voltage generated across the main shunt resistor R2. In this case, the detected main current can be sent to the controller 22.

[0086] In the current prediction step (S220), the current predictor 23 uses the voltage and internal resistance of the main battery 10 to predict the second current. For example, the current predictor 23 can predict the second current by dividing the voltage of the main battery 10 measured by the main battery voltage measuring device 27 by the internal resistance of the main battery 10 (S220).

[0087] According to the implementation, the internal resistance of the main battery 10 can be determined using either the main current or the temperature measurement value of the main battery 10. For example, the current predictor 23 can receive the main current from the main current detector 25 and the voltage of the main battery 10 from the main battery voltage meter 27, and then divide the voltage of the main battery 10 by the main current to calculate the internal resistance of the main battery 10. Alternatively, the current predictor 23 can receive the temperature measurement value of the main battery 10 measured by the sensing unit 29, detect the internal resistance of the main battery 10 from a table stored in the memory 28 based on the temperature measurement value, and determine the internal resistance of the main battery 10. In this case, a table listing the internal resistance values ​​based on the temperature value of the main battery 10 can be stored in the memory 28.

[0088] In the error rate calculation step (S230), the status diagnostic unit 24 can calculate the second error rate using the second current and the main current (S233). In this case, the status diagnostic unit 24 can receive the second current from the current predictor 23 and the main current from the main current detector 25.

[0089] Here, the second error rate corresponds to a reference used for diagnosing the state of the main shunt resistor R2, and the state diagnosis unit 24 can use the main current and the second current to derive the second error rate. For example, the state diagnosis unit 24 can calculate the ratio of the difference between the main current and the second current to the second current as the second error rate.

[0090] According to the embodiment, in the error rate calculation step (S230), the status diagnosis unit 24 can determine whether the main current is greater than or equal to a reference value (S231). In this case, when the main current is greater than or equal to a predetermined reference value, the status diagnosis unit 24 can determine that the main shunt resistor R2 is in an open state (S232). In other words, when the main current is greater than or equal to a predetermined reference value, the status diagnosis unit 24 can diagnose the state of the main shunt resistor R2 without calculating the second error rate.

[0091] In the status diagnosis step (S240), the status diagnosis unit 24 can determine the status of the main shunt resistor R2 based on the second error rate.

[0092] According to the embodiment, the state diagnosis step (S240) may include a short-circuit determination step (S241 and S242) and a drift determination step (S243 and S244). For example, in the state diagnosis step (S240), the state diagnosis unit 24 may determine whether the main shunt resistor R2 is in a short-circuit state by determining whether the second error rate is greater than or equal to a predetermined threshold (S241) and by determining that the main shunt resistor R2 is in a short-circuit state when the first error rate is greater than or equal to the predetermined threshold (S242). Alternatively, in the state diagnosis step (S240), the state diagnosis unit 24 may determine whether the main shunt resistor R2 is in a drift state by determining whether the second error rate is within a predetermined range less than a threshold (S243) and by determining that the main shunt resistor R2 is in a drift state when the second error rate is within a predetermined range less than a threshold (S244).

[0093] On the other hand, the above methods can be written as programs that can be executed on a computer and implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium. Computer-readable recording media can include storage media such as magnetic storage media, such as ROM, RAM, USB, floppy disks, or hard disks, or optically readable media such as CD-ROMs or DVDs.

[0094] The scope of this disclosure is defined by the appended claims, and not by the detailed description of the embodiments, and it should be understood that all modifications and embodiments of the claims and their equivalents are included within the scope of this disclosure.

Claims

1. A battery management system, comprising: An auxiliary current detector that detects the auxiliary current flowing through the auxiliary shunt resistor based on the voltage generated across the auxiliary shunt resistor; An auxiliary battery voltage measuring device is connected to the positive and negative terminals of an auxiliary battery and measures the voltage of the auxiliary battery. A main battery voltage measuring device is connected to the positive and negative terminals of the main battery and measures the voltage of the main battery. A current predictor that predicts a first current by dividing the voltage of the auxiliary battery, measured by the auxiliary battery voltage meter, by the internal resistance of the auxiliary battery, and predicts a second current by dividing the voltage of the main battery, measured by the main battery voltage meter, by the internal resistance of the main battery. as well as The status diagnostic unit calculates the average value of the first current and the second current, calculates a first error rate based on the average value and the auxiliary current, and diagnoses the status of the auxiliary shunt resistor based on the calculated first error rate.

2. The battery management system according to claim 1, wherein, The current predictor The auxiliary current is received from the auxiliary current detector, and the internal resistance of the auxiliary battery is calculated by dividing the voltage of the auxiliary battery by the auxiliary current.

3. The battery management system according to claim 1, comprising: A main current detector that detects the main current flowing through the main shunt resistor based on the voltage generated across the main shunt resistor.

4. The battery management system according to claim 3, wherein, The current predictor The main current is received from the main current detector, and the internal resistance of the main battery is calculated by dividing the voltage of the main battery by the main current.

5. The battery management system according to claim 1, wherein, The status diagnostic unit Determine whether the auxiliary current is greater than or equal to a reference value, and determine that the auxiliary shunt resistor is in an open state when the auxiliary current is greater than or equal to the reference value.

6. The battery management system according to claim 1, wherein, The status diagnostic unit The auxiliary shunt resistor is determined to be in a short-circuit state when the first error rate is greater than or equal to a predetermined threshold, and the auxiliary shunt resistor is determined to be in a drift state when the first error rate is within a predetermined range less than the threshold.

7. The battery management system according to claim 3, wherein, The status diagnostic unit A second error rate is calculated based on the second current and the main current, and the state of the main shunt resistor is diagnosed based on the calculated second error rate.

8. The battery management system according to claim 7, wherein, The status diagnostic unit Determine whether the main current is greater than or equal to a reference value, and determine that the main shunt resistor is in an open state when the main current is greater than or equal to the reference value.

9. The battery management system according to claim 7, wherein, The status diagnostic unit The main shunt resistor is determined to be in a short-circuit state when the second error rate is greater than or equal to a predetermined threshold, and the main shunt resistor is determined to be in a drift state when the second error rate is within a predetermined range less than the threshold.

10. A method for diagnosing an auxiliary shunt resistor fault and a main shunt resistor fault in a battery system including an auxiliary shunt resistor and a main shunt resistor, the method comprising: The auxiliary current detector detects the auxiliary current flowing through the auxiliary shunt resistor based on the voltage generated across the auxiliary shunt resistor; The current predictor predicts a first current by dividing the voltage of the auxiliary battery, measured by the auxiliary battery voltage meter, by the internal resistance of the auxiliary battery, and predicts a second current by dividing the voltage of the main battery, measured by the main battery voltage meter, by the internal resistance of the main battery. When the auxiliary current is less than the reference value, the status diagnostic unit calculates the average value of the first current and the second current, and calculates the first error rate using the auxiliary current and the average value; as well as The status diagnostic unit determines the status of the auxiliary shunt resistor based on the first error rate.

11. The method for diagnosing shunt resistor faults according to claim 10, wherein, Predicting the second current includes: The current predictor receives the auxiliary current detected by the auxiliary current detector, and calculates the internal resistance of the auxiliary battery by dividing the voltage of the auxiliary battery by the auxiliary current; and The current predictor receives the main current detected by the main current detector based on the voltage generated across the main shunt resistor, and calculates the internal resistance of the main battery by dividing the voltage of the main battery by the main current.

12. The method for diagnosing shunt resistor faults according to claim 10, wherein, Calculating the first error rate includes: The status diagnostic unit determines whether the auxiliary current is greater than or equal to a predetermined reference value; and When the auxiliary current is greater than or equal to a predetermined reference value, the auxiliary shunt resistor is determined to be in an open state.

13. The method for diagnosing shunt resistor faults according to claim 10, wherein, Calculating the first error rate includes: The first error rate is calculated as the ratio of the difference between the auxiliary current and the average of the first current and the second current to the average of the first current and the second current.

14. The method for diagnosing shunt resistor faults according to claim 10, wherein, Determining the state of the auxiliary shunt resistor includes: Determine whether the first error rate is greater than or equal to a predetermined threshold; and When the first error rate is greater than or equal to the threshold, it is determined that the auxiliary shunt resistor is in a short-circuit state.

15. The method for diagnosing shunt resistor faults according to claim 10, wherein, Determining the state of the auxiliary shunt resistor includes: Determine whether the first error rate is within a predetermined range less than a threshold; and When the first error rate is within a predetermined range less than the threshold, the auxiliary shunt resistor is determined to be in a drift state.

16. The method for diagnosing a shunt resistor fault according to claim 10, further comprising: The main current detector detects the main current flowing through the main shunt resistor based on the voltage generated across the main shunt resistor; The current predictor predicts the second current by dividing the voltage of the main battery by the internal resistance of the main battery. The status diagnostic unit uses the main current and the second current to calculate the second error rate; and The status diagnostic unit determines the status of the main shunt resistor based on the second error rate.

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