Battery management devices

Abstract

A battery management device according to an embodiment disclosed in this document includes: a shunt resistor connected to a battery; and a voltage generation unit for generating a first output value and a second output value, the difference between the first output value and the second output value corresponding to the magnitude of a voltage applied to the shunt resistor, wherein the difference between the first output value and the second output value may correspond to the magnitude of a voltage applied to the shunt resistor when a charging overcurrent or a discharging overcurrent flows in the shunt resistor.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0023639, filed on February 22, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This disclosure relates to a battery management device. Background Technology

[0005] Recently, research and development of rechargeable batteries have been actively pursued. Here, rechargeable batteries, as rechargeable / dischargeable batteries, can include all conventional nickel (Ni) / cadmium (Cd) batteries, Ni / metal hydride (MH) batteries, and more recently, lithium-ion batteries. Among rechargeable batteries, lithium-ion batteries have a much higher energy density than traditional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured to be small and lightweight, making them suitable for use as power sources in mobile devices. Recently, their applications have expanded to power electric vehicles, attracting attention as a next-generation energy storage medium.

[0006] Furthermore, when an overcurrent flows during the charging or discharging of a lithium-ion battery, the internal temperature of the battery rises, potentially causing a fire in a vehicle equipped with the battery. To prevent this, an overcurrent detection function is needed to continuously determine whether an overcurrent is flowing through the battery, and the operational integrity of the overcurrent detection function must also be ensured. Summary of the Invention

[0007] Technical issues

[0008] The embodiments disclosed herein are intended to provide a battery management device capable of diagnosing the operation of the battery's overcurrent detection function.

[0009] The technical problems of the embodiments disclosed herein are not limited to those described above, and other unmentioned technical problems will be clearly understood by those skilled in the art based on the following description.

[0010] Technical solution

[0011] A battery management device according to an embodiment disclosed herein includes: a shunt resistor connected to a battery; and a voltage generation unit configured to generate a first output value and a second output value, the difference between the first output value and the second output value corresponding to the magnitude of a voltage applied to the shunt resistor, wherein the difference between the first output value and the second output value corresponds to the magnitude of a voltage applied to the shunt resistor when a charging overcurrent or a discharging overcurrent flows in the shunt resistor.

[0012] In one embodiment, the voltage generation unit may be configured to generate the first output value and the second output value when the charging overcurrent or the discharging overcurrent does not flow in the shunt resistor.

[0013] In one embodiment, the voltage generation unit may be configured to generate the first output value, which is the difference between the magnitude of the voltage applied to the shunt resistor when the charging overcurrent flows in the shunt resistor and the voltage of the battery, and the voltage generation unit may be configured to generate a second output value equal to the voltage of the battery.

[0014] In one embodiment, the voltage generation unit may be configured to generate a first output value equal to the voltage of the battery, and to generate a second output value, the second output value being the difference between the voltage applied to the shunt resistor and the voltage of the battery when the discharge overcurrent flows in the shunt resistor.

[0015] In one embodiment, the battery management device may further include a determining unit configured to receive the first output value and the second output value, and determine whether the charging overcurrent or the discharging overcurrent flows in the shunt resistor.

[0016] In one embodiment, the determining unit may include: an amplifier configured to receive and amplify the first output value and the second output value; a comparator configured to compare the output of the amplifier with a reference value; and a controller configured to determine whether the charging overcurrent or the discharging overcurrent flows in the shunt resistor based on the output of the amplifier or the comparator.

[0017] In one embodiment, the voltage generation unit may include a plurality of resistors and a plurality of switches, wherein the plurality of switches include any one of negative-positive-negative NPN bipolar junction transistors (BJTs), positive-negative-positive PNP BJTs, and metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0018] A battery management device according to an embodiment disclosed herein includes: a shunt resistor connected to a battery; a first resistor connected to the shunt resistor at a first node; a second resistor connected to the first resistor at a second node; a third resistor connected to the shunt resistor at a third node; a fourth resistor connected to the third resistor at a fourth node; a first switch connected to the second resistor; a second switch connected to the fourth resistor; and a determining unit configured to receive a voltage at the second node and a voltage at the fourth node, and to determine whether an overcurrent flows in the shunt resistor.

[0019] In one embodiment, the determining unit may include: an amplifier configured to receive the voltage of the second node and the voltage of the fourth node and amplify the difference between them; a comparator configured to compare the output of the amplifier with a reference value; and a controller configured to determine whether the charging overcurrent or the discharging overcurrent flows in the shunt resistor based on the output of the amplifier or the comparator.

[0020] In one embodiment, the controller may be configured to control the first switch and the second switch to short-circuit the first switch and open the second switch to detect the charging overcurrent, and to short-circuit the second switch and open the first switch to detect the discharging overcurrent.

[0021] In one embodiment, the controller may also be configured to disconnect both the first switch and the second switch when the battery is being charged or discharged.

[0022] In one embodiment, the battery management device may further include a relay connected to the shunt resistor, wherein the relay is controlled by a control signal from the controller, and the controller is further configured to disconnect the relay when the first switch or the second switch is short-circuited.

[0023] In one embodiment, the first switch and the second switch may include any one of PNP type BJT, NPN type BJT and MOSFET.

[0024] In one embodiment, the sizes of the first resistor and the second resistor can be configured such that the difference between the voltage of the second node and the voltage of the battery corresponds to the voltage applied to the shunt resistor when the overcurrent flows during battery charging, and the sizes of the third resistor and the fourth resistor can be configured such that the difference between the voltage of the fourth node and the voltage of the battery corresponds to the voltage applied to the shunt resistor when the overcurrent flows during battery discharging.

[0025] Beneficial effects

[0026] The battery management device according to the embodiments disclosed herein can diagnose the operation of the battery's overcurrent detection function. Attached Figure Description

[0027] Figure 1 A battery pack according to an embodiment disclosed herein is shown.

[0028] Figure 2 and Figure 3 A battery management system according to an embodiment disclosed herein is shown.

[0029] Figure 4 This is a diagram used to describe in detail the voltage generation unit in a battery management system according to the embodiments disclosed herein.

[0030] Figure 5 This is a diagram used to describe a defined unit in a battery management device according to an embodiment disclosed herein. Detailed Implementation

[0031] In the following, the embodiments disclosed in this document will be described in detail with reference to the exemplary accompanying drawings. When adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals, even if they are shown in different drawings. Furthermore, in describing the embodiments disclosed in this document, a detailed description will be omitted if it is determined that a detailed description of a related known configuration or function would hinder understanding of the embodiments disclosed in this document.

[0032] In describing the components of the embodiments disclosed herein, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are used only to distinguish one component from another and do not limit the component to its nature, order, sequence, etc. The terms used herein, including technical and scientific terms, have the same meaning as those commonly understood by those skilled in the art, provided that these terms are not defined differently. Generally, terms defined in commonly used dictionaries should be interpreted as having the same meaning as in the context of the related art and should not be interpreted as having an ideal or exaggerated meaning unless they are clearly defined in this application.

[0033] Figure 1 A battery pack according to an embodiment disclosed herein is shown.

[0034] refer to Figure 1 The battery pack 10 according to the embodiments disclosed herein may include a battery module 100, a battery management device 200, and a relay 300.

[0035] Battery module 100 may include multiple battery cells 110, 120, 130, and 140. Although multiple battery cells... Figure 1 The diagram shows four cells, but this disclosure is not limited to this, and the battery module 100 may include n battery cells (n is a natural number greater than or equal to 2). The battery module 100 can supply power to a target device (not shown). For this purpose, the battery module 100 may be electrically connected to the target device. Here, the target device may include an electrical, electronic, or mechanical device that operates by receiving power from the battery pack 10, which includes a plurality of battery cells 110, 120, 130, and 140, and the target device may be, for example, an electric vehicle (EV), but is not limited thereto.

[0036] The multiple battery cells 110, 120, 130, and 140 can be lithium-ion (Li-ion) batteries, lithium-ion polymer batteries, nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, etc., and are not limited to these. Furthermore, although in Figure 1 The diagram shows one battery module 100, but according to the embodiment, the battery module 100 can be configured as multiple.

[0037] The battery management device 200 can manage and / or control the state and / or operation of the battery module 100. For example, the battery management device 200 can manage and / or control the state and / or operation of multiple battery cells 110, 120, 130, and 140 included in the battery module 100. The battery management device 200 can manage the charging and / or discharging of the battery module 100.

[0038] Furthermore, the battery management device 200 can monitor the voltage, current, temperature, insulation resistance, etc. of the battery pack 10, battery module 100, and / or each of the multiple battery cells 110, 120, 130, and 140 included in the battery module 100. Sensors or various measurement modules, not shown, for monitoring performed by the battery management device 200, can be additionally installed in the charging / discharging path of the battery module 100, etc., at any location. The battery management device 200 can calculate parameters indicating the state of the battery module 100, such as state of charge (SOC), state of health (SOH), etc., based on the monitored measurements such as voltage, current, and temperature.

[0039] The battery management device 200 can control the operation of the relay 300. For example, the battery management device 200 can short-circuit the relay 300 to supply power to the target device. When the charging device is connected to the battery pack 10, the battery management device 200 can short-circuit the relay 300.

[0040] The battery management device 200 can diagnose whether the overcurrent detection function is working properly. To this end, when the battery module 100 is charging or discharging, the battery management device 200 can detect whether overcurrent is flowing in the battery module 100. When overcurrent is detected in the battery module 100, the battery management device 200 can disconnect the relay 300. Therefore, the battery management device 200 can determine whether the overcurrent detection function is working properly and can improve the ISO 26262 and Automotive Safety Integrity Level (ASIL) safety levels.

[0041] In the following text, reference will be made to Figure 2 and Figure 3 Describes the detailed operation of the battery management device 200.

[0042] Figure 2 and Figure 3 A battery management system according to an embodiment disclosed herein is shown.

[0043] refer to Figure 2 The battery management device 200 according to the embodiments disclosed herein may include a shunt resistor 210 and a voltage generation unit 220.

[0044] Shunt resistor 210 can sense the current flowing in a circuit. For example, the magnitude of the current flowing in the circuit can be sensed by measuring the voltage applied to shunt resistor 210 relative to the current flowing in the circuit. Shunt resistor 210 can be connected to battery module 100.

[0045] The voltage generation unit 220 can generate a first output value and a second output value. The voltage generation unit 220 can be connected to the two terminals of the shunt resistor 210. When a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210, the voltage generation unit 220 can generate a first output value and a second output value, the difference between which corresponds to the magnitude of the voltage applied to the shunt resistor 210. In other words, when a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210, the difference between the first output value and the second output value corresponds to the magnitude of the voltage applied to the shunt resistor 210.

[0046] According to the implementation, when the charging overcurrent or discharging overcurrent does not flow in the shunt resistor 210, the voltage generation unit 220 can generate a first output value and a second output value. For example, the battery management device 200 can diagnose the charging overcurrent detection function or the discharging overcurrent detection function based on the first output value and the second output value generated when the charging overcurrent or discharging overcurrent does not flow in the shunt resistor 210.

[0047] Here, charging overcurrent can be defined as the overcurrent flowing in the battery module 100, the circuit connected to the battery module 100, and / or the device connected to the battery module 100 during charging. Similarly, discharging overcurrent can be defined as the overcurrent flowing in the battery module 100, the circuit connected to the battery module 100, and / or the device connected to the battery module 100 during discharging. For example, in the battery management device 200, the levels of charging and discharging overcurrents can be preset values.

[0048] According to the embodiment, the voltage generation unit 220 can generate a first output value, which is the difference between the magnitude of the voltage applied to the shunt resistor 210 when a charging overcurrent flows in the shunt resistor 210 and the magnitude of the battery voltage. For example, when a charging overcurrent flows in the shunt resistor 210, the voltage generation unit 220 can generate a first output value that is smaller than the magnitude of the voltage of the battery module 100 than the magnitude of the voltage applied to the shunt resistor 210. That is, when a charging overcurrent flows in the shunt resistor 210, the first output value can be obtained by subtracting the magnitude of the voltage applied to the shunt resistor 210 from the voltage of the battery module 100. Furthermore, the voltage generation unit 220 can generate a second output value equal to the battery voltage. For example, the voltage generation unit 220 can generate a second output value with a magnitude corresponding to the magnitude of the voltage of the battery module 100.

[0049] The battery management device 200 can detect charging overcurrent based on a first output value and a second output value generated in the voltage generation unit 220.

[0050] According to the embodiment, the voltage generation unit 220 can generate a second output value equal to the battery voltage. For example, the voltage generation unit 220 can generate a first output value whose magnitude corresponds to the voltage of the battery module 100. Furthermore, when a discharge overcurrent flows in the shunt resistor 210, the voltage generation unit 220 can generate a second output value, which is the difference between the voltage applied to the shunt resistor 210 and the battery voltage. For example, when a discharge overcurrent flows in the shunt resistor 210, the voltage generation unit 220 can generate a second output value whose magnitude is smaller than the voltage of the battery module 100 than the voltage applied to the shunt resistor 210. In other words, when a discharge overcurrent flows in the shunt resistor 210, the second output value can be obtained by subtracting the voltage applied to the shunt resistor 210 from the voltage of the battery module 100.

[0051] The battery management device 200 can detect discharge overcurrent based on a first output value and a second output value generated in the voltage generation unit 220.

[0052] Alternatively, according to the implementation, the voltage generation unit 220 can be implemented using multiple resistors and multiple switches. For example, the multiple switches can be any of a negative-positive-negative (NPN) bipolar junction transistor (BJT), a positive-negative-positive (PNP) BJT, and a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0053] refer to Figure 3 In addition to the shunt resistor 210 and the voltage generation unit 220, the battery management device according to the embodiments disclosed herein may also include a determination unit 230.

[0054] The determining unit 230 can determine whether an overcurrent flows in the shunt resistor 210 based on the first and second output values ​​generated in the voltage generating unit 220. That is, when the charging overcurrent or discharging overcurrent does not flow directly in the shunt resistor 210, the voltage generating unit 220 can generate the applied voltage when the charging overcurrent or discharging overcurrent flows in the shunt resistor 210, and the determining unit 230 can receive the generated first and second output values ​​and determine whether an overcurrent flows in the shunt resistor 210.

[0055] Therefore, it is possible to diagnose whether the determination unit 230 is performing the overcurrent detection function correctly. For example, if the determination unit 230 fails to determine that an overcurrent is flowing in the shunt resistor 210 even though it receives the first output value and the second output value from the voltage generation unit 220, it can be diagnosed that the determination unit 230 is not performing the overcurrent detection function correctly.

[0056] Now refer to Figure 4 The voltage generation unit 220 in the battery management device 200 is described in detail.

[0057] Figure 4 This is a diagram used to describe in detail the voltage generation unit in a battery management system according to the embodiments disclosed herein.

[0058] refer to Figure 4 The voltage generation unit 220 according to the embodiments disclosed herein may include a plurality of resistors 221 and a plurality of switches 222.

[0059] Multiple resistors 221 (R1, R2, R3, and R4) can be connected to the two terminals of the shunt resistor 210. More specifically, the first resistor R1 can be connected to the shunt resistor 210 at the first node N1. The second resistor R2 can be connected to the first resistor R1 at the second node N2. The third resistor R3 can be connected to the shunt resistor 210 at the third node N3. The fourth resistor R4 can be connected to the third resistor R3 at the fourth node N4.

[0060] The values ​​of multiple resistors 221 can be set to distribute the voltage of the battery module 100 based on the levels of charging overcurrent and discharging overcurrent.

[0061] For example, the values ​​of the first resistor R1 and the second resistor R2 can be set such that when a charging overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the second node N2 and the voltage of the battery module 100 corresponds to the voltage applied to the shunt resistor 210. Furthermore, the values ​​of the third resistor R3 and the fourth resistor R4 can be set such that when a discharging overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the fourth node N4 and the voltage of the battery module 100 corresponds to the voltage applied to the shunt resistor 210.

[0062] In addition, such as Figure 4 As shown, the plurality of resistors 221 includes a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4, but the invention is not limited thereto. For example, at least one of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 may include a plurality of resistors.

[0063] Multiple switches 222 (SW1 and SW2) can be connected to multiple resistors 221 respectively. More specifically, the first switch SW1 can be connected to the second resistor R2, and the second switch SW2 can be connected to the fourth resistor R4.

[0064] In addition, the multiple switches 222 can be any of PNP type BJT, NPN type BJT, and MOSFET. For example, the multiple switches 222 can be PNP type BJT.

[0065] Multiple switches 222 can be controlled by the control signal S cmd1 and S cmd2 Control. For example, the first switch SW1 can be controlled by the first control signal S. cmd1 The second switch SW2 can be controlled by the second control signal S. cmd2 Control. Control signal S cmd1 and S cmd2 It can be generated in controller 233 (see Figure 5 However, this disclosure is not limited thereto; a first controller and a second controller may exist to generate the first control signal S, respectively. cmd1 Second control signal S cmd2 This controls the first switch SW1 and the second switch SW2.

[0066] The controller 233 can short-circuit the first switch SW1 and open the second switch SW2 to detect charging overcurrent. Additionally, the controller 233 can short-circuit the second switch SW2 and open the first switch SW1 to detect discharging overcurrent.

[0067] When the battery module 100 is charged or discharged, the first switch SW1 and the second switch SW2 can be controlled by the control signal S. cmd1 and S cmd2 Disconnect. When the first switch SW1 and the second switch SW2 are disconnected, the voltage of the first node N1 can be applied to the second node N2, and the voltage of the third node N3 can be applied to the fourth node N4, so that the determining unit 230 can receive the magnitude of the voltage applied to the two terminals of the shunt resistor 210. That is, when the battery module 100 is charged or discharged, the determining unit 230 can determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210.

[0068] The determining unit 230 can receive the voltages applied to the second node N2 and the fourth node N4, and determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210 based on the received voltages. That is, if the charging overcurrent or discharging overcurrent does not flow directly in the shunt resistor 210, the battery management device 200 can determine whether the determining unit 230 is operating normally based on the voltages allocated to the second node N2 and the fourth node N4.

[0069] Now refer to Figure 5 Detailed description of unit 230.

[0070] Figure 5This is a diagram used to describe a defined unit in a battery management device according to an embodiment disclosed herein.

[0071] Reference Figure 5 In the battery management device 200 according to the embodiments disclosed herein, the determining unit 230 may include an amplifier 231, a comparator 232, and a controller 233.

[0072] Amplifier 231 can amplify the difference between a first output value and a second output value transmitted from voltage generation unit 220. For example, amplifier 231 can amplify the value obtained by subtracting the second output value from the first output value. Amplifier 231 may include an operational amplifier (OP-AMP).

[0073] For example, amplifier 231 can receive voltages applied to the second node N2 and the fourth node N4. In this case, the magnitude of the voltage at the second node N2 can correspond to a first output value, and the magnitude of the voltage at the fourth node N4 can correspond to a second output value.

[0074] Comparator 232 can receive the output of amplifier 231, compare the received output with a reference value, and output the comparison result. For example, when the output of amplifier 231 is greater than the reference value, comparator 232 can output a first value, and when the output of amplifier 231 is less than the reference value, comparator 232 can output a second value. Here, the reference value can be set equally or differently depending on when a charging overcurrent is detected and when a discharging overcurrent is detected.

[0075] The controller 233 can receive the output of the amplifier 231 and convert the received output into a digital signal, and compare the digital signal with a preset value to determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210. When both the first switch SW1 and the second switch SW2 are open, the controller 233 can determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210 based on the output of the amplifier 231. For example, the controller 233 can be implemented using a microcontroller or an analog-to-digital converter (ADC) that receives the output of the amplifier 231.

[0076] Furthermore, the controller 233 can determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210 based on the comparison result output from the comparator 232. For example, when the comparison result has a first value, the controller 233 can determine that a charging overcurrent flows in the shunt resistor 210. That is, when the first switch SW1 or the second switch SW2 is short-circuited, the controller 233 can determine whether a charging overcurrent or a discharging overcurrent flows in the shunt resistor 210 based on the comparison result of the comparator 232.

[0077] Additionally, the controller 233 can generate control signals for controlling multiple switches 222. For example, the controller 233 can generate a first control signal S. cmd1 To control the first switch SW1, and can generate a second control signal S cmd2 To control the second switch SW2.

[0078] As a result, when the overcurrent does not flow in the shunt resistor 210, the controller 233 can determine whether the amplifier 231 and comparator 232 are functioning correctly based on the first and second output values ​​input from the voltage generation unit 220. That is, the battery management device 200 can guide the user when the charging overcurrent detection function or the discharging overcurrent detection function is malfunctioning. In this way, it is possible to diagnose whether the determination unit 230 is performing the overcurrent detection function correctly.

[0079] Furthermore, when the battery module 100 is not being charged or discharged, the controller 233 can disconnect the relay 300. For example, the controller 233 can generate a control signal to disconnect the relay 300.

[0080] Controller 233 can generate control signal S when relay 300 is off. cmd1 and S cmd2 The first switch SW1 and the second switch SW2 are alternately short-circuited to diagnose whether the charging overcurrent detection function or the discharging overcurrent detection function is working.

[0081] In the following text, the diagnosis of the overcurrent detection function during the operation of the circuit will be described based on the structure of the battery management device 200.

[0082] As described above, the battery management device 200 according to the embodiments disclosed herein can diagnose overcurrent detection functions. When the battery module 100 is not being charged or discharged, the battery management device 200 can disconnect the relay 300 and perform diagnostic functions for charging overcurrent detection or discharging overcurrent detection.

[0083] The battery management device 200 can diagnose the charging overcurrent detection function. To diagnose the charging overcurrent detection function, the controller 233 can generate multiple control signals S. cmd1 and S cmd2 This causes the first switch SW1 to short-circuit and the second switch SW2 to open. When the first switch SW1 is short-circuited, the voltage of the battery module 100 can be distributed by the shunt resistor 210, the first resistor R1, and the second resistor R2, and the distributed voltage can be applied to the second node N2. However, the voltage applied to the shunt resistor 210 can be much smaller than the voltage applied to the first resistor R1 and the second resistor R2. When the second switch SW2 is open, the voltage of the battery module 100 can be applied to the fourth node N4.

[0084] As described above, the values ​​of the first resistor R1 and the second resistor R2 can be set such that when a charging overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the second node N2 and the voltage of the battery module 100 corresponds to the magnitude of the voltage applied to the shunt resistor 210. The voltage applied to the second node N2 and the voltage applied to the fourth node N4 can be input to the amplifier 231, and the amplifier 231 can amplify the difference between the voltage applied to the second node N2 and the voltage applied to the fourth node N4. The amplified voltage can be input to the comparator 232. The comparator 232 can compare the magnitude of the amplified voltage with a first reference value. The output of the comparator 232 can be input to the controller 233, and the controller 233 can determine whether a charging overcurrent flows in the shunt resistor 210 based on the output of the comparator 232.

[0085] In other words, when the charging overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the second node N2 and the voltage applied to the fourth node N4 corresponds to the magnitude of the voltage applied to the shunt resistor 210, so that the battery management device 200 can diagnose the operation of the charging overcurrent detection function when the charging overcurrent does not flow directly in the shunt resistor 210.

[0086] The battery management device 200 can diagnose the discharge overcurrent detection function. To diagnose the discharge overcurrent detection function, the controller 233 can generate multiple control signals S. cmd1 and S cmd2 The first switch SW1 is disconnected and the second switch SW2 is short-circuited. When the second switch SW2 is short-circuited, the voltage of the battery module 100 can be distributed by the third resistor R3 and the fourth resistor R4, and the distributed voltage can be applied to the fourth node N4. When the first switch SW1 is open, the voltage of the battery module 100 can be applied to the second node N2.

[0087] As described above, the values ​​of the third resistor R3 and the fourth resistor R4 can be set such that when a discharge overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the fourth node N4 and the voltage of the battery module 100 corresponds to the magnitude of the voltage applied to the shunt resistor 210. The voltages applied to the second node N2 and the fourth node N4 can be input to the amplifier 231, which amplifies the difference between them. The amplified voltage can then be input to the comparator 232 for comparison with a second reference value. The output of the comparator 232 can be input to the controller 233, which determines whether a discharge overcurrent flows in the shunt resistor 210 based on the output of the comparator 232.

[0088] In other words, when the discharge overcurrent flows in the shunt resistor 210, the difference between the voltage applied to the second node N2 and the voltage applied to the fourth node N4 corresponds to the magnitude of the voltage applied to the shunt resistor 210, so that the battery management device 200 can diagnose the operation of the discharge overcurrent detection function when the discharge overcurrent does not flow directly in the shunt resistor 210.

[0089] As described above, when the charging overcurrent or discharging overcurrent does not flow directly in the shunt resistor 210, the battery management device 200 can diagnose the operation of the charging overcurrent detection function or the discharging overcurrent detection function. Therefore, the battery management device 200 can identify the integrity of the overcurrent detection function.

[0090] The above description is merely an illustration of the technical concept of this disclosure, and various modifications and changes can be made by those skilled in the art without departing from the essential features of the embodiments disclosed herein.

[0091] Therefore, the embodiments disclosed herein are intended to describe, and not limit, the technical spirit of the embodiments disclosed herein, and the scope of the technical spirit of this disclosure is not limited to these embodiments. The scope of protection of the technical spirit disclosed herein should be interpreted by the appended claims, and all technical spirit within the same scope should be understood to be included within the scope of this disclosure.

Claims

1. A battery management device, the battery management device comprising: A shunt resistor, which is connected to the battery; A voltage generation unit is configured to generate a first output value and a second output value, the difference between the first output value and the second output value corresponding to the magnitude of the voltage applied to the shunt resistor. The voltage generation unit is further configured to generate the first output value and the second output value when the charging overcurrent or discharging overcurrent does not flow in the shunt resistor. Wherein, when the charging overcurrent or the discharging overcurrent flows in the shunt resistor, the difference between the first output value and the second output value corresponds to the magnitude of the voltage applied to the shunt resistor; and A determining unit is configured to receive the first output value and the second output value, and determine whether the charging overcurrent or the discharging overcurrent flows in the shunt resistor. Specifically, if the determining unit fails to determine that the overcurrent is flowing in the shunt resistor even though it receives the first output value and the second output value from the voltage generation unit, it is diagnosed that the determining unit has failed to perform the overcurrent detection function normally.

2. The battery management device according to claim 1, wherein, The voltage generation unit is configured to generate a first output value, which is the difference between the magnitude of the voltage applied to the shunt resistor when the charging overcurrent flows in the shunt resistor and the voltage of the battery, and the voltage generation unit is configured to generate a second output value, which is equal to the voltage of the battery.

3. The battery management device according to claim 1, wherein, The voltage generation unit is configured to generate a first output value equal to the voltage of the battery, and the voltage generation unit is configured to generate a second output value, which is the difference between the voltage applied to the shunt resistor and the voltage of the battery when the discharge overcurrent flows in the shunt resistor.

4. The battery management device according to claim 1, wherein, The determining unit includes: An amplifier configured to receive and amplify the first output value and the second output value; A comparator configured to compare the output of the amplifier with a reference value; and A controller configured to determine whether the charging overcurrent or the discharging overcurrent flows in the shunt resistor based on the output of the amplifier or the comparator.

5. The battery management device according to claim 1, wherein, The voltage generation unit includes multiple resistors and multiple switches, and the multiple switches include any one of negative-positive-negative NPN bipolar junction transistors (BJTs), positive-negative-positive PNP BJTs, and metal-oxide-semiconductor field-effect transistors (MOSFETs).

6. A battery management device, the battery management device comprising: A shunt resistor, which is connected to the battery; A first resistor is connected to the shunt resistor at a first node; The second resistor is connected to the first resistor at the second node; A third resistor is connected to the shunt resistor at a third node; A fourth resistor is connected to the third resistor at a fourth node; A first switch, which is connected to the second resistor; A second switch, which is connected to the fourth resistor; as well as A determining unit is configured to receive the voltage of the second node and the voltage of the fourth node, and to determine whether an overcurrent is flowing in the shunt resistor.

7. The battery management device according to claim 6, wherein, The determining unit includes: An amplifier configured to receive the voltage of the second node and the voltage of the fourth node and amplify the difference between them; A comparator configured to compare the output of the amplifier with a reference value; and A controller configured to determine whether a charging overcurrent or a discharging overcurrent is flowing in the shunt resistor based on the output of the amplifier or the comparator.

8. The battery management device according to claim 7, wherein, The controller is configured to control the first switch and the second switch to short-circuit the first switch and disconnect the second switch to detect the charging overcurrent, and to short-circuit the second switch and disconnect the first switch to detect the discharging overcurrent.

9. The battery management device according to claim 8, wherein, The controller is configured to disconnect both the first switch and the second switch when the battery is being charged or discharged.

10. The battery management device of claim 8, further comprising a relay connected to the shunt resistor. in, The relay is controlled by a control signal from the controller, and the controller is configured to disconnect the relay when the first switch or the second switch is short-circuited.

11. The battery management device according to claim 6, wherein, The first switch and the second switch include any one of the following: positive-negative-positive PNP bipolar junction transistor (BJT), negative-positive-negative NPN BJT, and metal-oxide-semiconductor field-effect transistor (MOSFET).

12. The battery management device according to claim 6, wherein, The first resistor and the second resistor are sized such that the difference between the voltage of the second node and the voltage of the battery corresponds to the voltage applied to the shunt resistor when the overcurrent flows during the charging of the battery, and the third resistor and the fourth resistor are sized such that the difference between the voltage of the fourth node and the voltage of the battery corresponds to the voltage applied to the shunt resistor when the overcurrent flows during the discharging of the battery.

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