Battery management device having switching fault diagnosis function, and system and method

Abstract

The invention discloses a battery management device with a switch fault diagnosis function, and a system and a method including the same. The battery management apparatus includes: a main switch mounted on a first line connected to one terminal of a battery; a pre-charge circuit including a first pre-charge resistor, a pre-charge switch, and a second pre-charge resistor sequentially connected in series with each other, and connected in parallel with both ends of the main switch; a current measuring unit that measures a current flowing through a second line connected to the other terminal of the battery; a diagnostic switch mounted on a branch line connecting one end of the pre-charge switch and the second line to each other; and a control unit operably coupled with the main switch, the pre-charge switch, the diagnostic switch, and the current measurement unit. The control unit may be configured to receive a diagnostic current value from the current measuring unit when the diagnostic switch is turned on or off, and diagnose whether at least one of the main switch and the pre-charge switch has a weld fault based on a magnitude of the diagnostic current value.

Description

Technical Field

[0001] The present disclosure relates to a battery management device with a switch fault diagnosis function and a system and method including the battery management device, and more specifically, to a battery management device capable of reliably diagnosing welding faults of a main switch and a pre-charging switch installed on a line connecting a battery and a load and a system and method including the battery management device.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0019003 filed in Korea on February 13, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0003] Recently, the demand for portable electronic products such as notebook computers, video cameras, and portable phones has increased dramatically, and electric vehicles, energy storage batteries, robots, satellites, etc. have been vigorously developed. Therefore, high-performance batteries that allow repeated charging and discharging are being actively studied.

[0004] Currently commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries have advantages in that they have almost no memory effect compared to nickel-based batteries and also have very low self-discharge rate and high energy density.

[0005] The battery includes a plurality of cells. The plurality of cells may be connected in series and / or in parallel according to the operating voltage of the load. The load may be a power consuming device including a power converter (such as an inverter) or a charging device that provides a charging current to the battery.

[0006] The power line connecting the battery and the load includes a pre-charging circuit, which is connected in parallel with the main switch of the power line and includes a pre-charging resistor and a pre-charging switch.

[0007] When the battery and the load are connected, the pre-charge switch is first turned on before the main switch is turned on. Then, as the current flows from the battery through the pre-charge resistor to the capacitor included in the input terminal of the load, the capacitor is charged. The magnitude of the charging current of the capacitor gradually increases. The charging time of the capacitor depends on the time constant determined by the resistance of the pre-charge resistor and the capacitance of the capacitor. When the capacitor is fully or sufficiently charged, the pre-charge switch is turned off and the main switch is turned on. If the main switch is turned on after the capacitor is charged, the phenomenon that the surge current flows from the high-voltage battery to the load can be prevented. For reference, the surge current may damage the circuit components included in the load or cause electric shock.

[0008] Meanwhile, if a welding failure occurs in the main switch, there is a problem that a surge current flows to the load through the main switch even if the main switch is controlled to be disconnected when the battery and the load are connected. In addition, if a welding failure occurs in the pre-charge switch, there is a problem that the battery discharge continues through the pre-charge resistor even if both the main switch and the pre-charge switch are controlled to be disconnected.

[0009] Therefore, in the related art, there is a need for a technology that can reliably diagnose welding faults of a main switch and a pre-charge switch.

[0010] As an example of related art, there is a technique that measures the voltage difference between the front end and the rear end of the main switch before turning on the pre-charge switch, and diagnoses that a welding fault has occurred in the main switch if the voltage difference is 0. However, this technique has a limitation that a welding fault of the pre-charge switch cannot be diagnosed.

[0011] As another example of the related art, there is a technology that measures the magnitude of the current flowing through the power line after both the main switch and the pre-charge switch are controlled to be disconnected, and if the magnitude of the current exceeds a threshold value, diagnoses that a welding fault has occurred in the main switch. However, even if the main switch is normal and a welding fault occurs in the pre-charge switch, current flows through the power line, so the diagnosis of the main switch fault is not accurate. Summary of the invention

[0012] Technical issues

[0013] The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure aims to provide a battery management device and a system and method including the battery management device, which can reliably diagnose the welding fault of a main switch installed on a power line connecting a battery and a load and a pre-charging switch included in a pre-charging circuit.

[0014] These and other purposes and advantages of the present disclosure can be understood from the following detailed description, and will become more fully apparent from the exemplary embodiments of the present disclosure. In addition, it will be easily understood that the purposes and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0015] Technical Solution

[0016] In one aspect of the present disclosure, a battery management device with a switch fault diagnosis function is provided, which includes: a main switch installed on a first line connected to one terminal of a battery; a pre-charging circuit including a first pre-charging resistor, a pre-charging switch and a second pre-charging resistor connected in series in sequence, the pre-charging circuit being connected in parallel with both ends of the main switch; a current measuring unit configured to measure a current flowing through a second line connected to another terminal of the battery; a diagnostic switch installed on a branch line connecting one end of the pre-charging switch and the second line; and a control unit operably coupled to the main switch, the pre-charging switch, the diagnostic switch and the current measuring unit.

[0017] The control unit may be configured to receive a diagnostic current value from the current measuring unit in a state where the diagnostic switch is turned on or off, and diagnose whether at least one of the main switch and the pre-charge switch has a welding fault according to a magnitude of the diagnostic current value.

[0018] The battery management device may further include: a first voltage measuring unit configured to measure a battery voltage between a first terminal and a second terminal of the battery; and a second voltage measuring unit configured to measure a voltage of a load between a first connection terminal and a second connection terminal of the load.

[0019] The control unit can be configured to receive the battery voltage and the voltage of the load from the first voltage measuring unit and the second voltage measuring unit, respectively, and receive a diagnostic current value from the current measuring unit when the main switch and the pre-charging switch are disconnected, and diagnose that there is no welding fault in the main switch and the pre-charging switch when the condition that the difference between the battery voltage and the voltage of the load is greater than a preset threshold voltage value and the diagnostic current value is substantially 0 is met.

[0020] The control unit may optionally be configured to, when the conditions that the difference between the battery voltage and the voltage of the load is substantially 0 and the diagnostic current value is substantially 0 are satisfied, turn on the diagnostic switch and then receive the diagnostic current value from the current measuring unit, and when the condition that the diagnostic current value is greater than a preset first threshold current value is satisfied, diagnose that a welding fault has occurred in either the main switch or the pre-charging switch.

[0021] The control unit may optionally be configured to diagnose that there is a welding fault in the main switch and the pre-charging switch when a condition that the diagnosis current value is greater than a preset second threshold current value (greater than the first threshold current value) is satisfied.

[0022] In one aspect, the first pre-charge resistor and the second pre-charge resistor may have a first resistance value and a second resistance value, respectively, wherein the first resistance value is greater than the second resistance value. In addition, the first threshold current value is split into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnostic resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (greater than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnostic resistance of the main switch and the battery voltage. The control unit may be optionally configured to: when the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second sub-threshold current value, diagnose that a welding fault has occurred in the pre-charge switch, when the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the second threshold current value, diagnose that a welding fault has occurred in the main switch, and when the diagnostic current value is greater than the second threshold current value, diagnose that a welding fault has occurred in both the main switch and the pre-charge switch.

[0023] In another aspect, the first pre-charge resistor and the second pre-charge resistor may have a first resistance value and a second resistance value, respectively, wherein the second resistance value is greater than the first resistance value. In addition, the first threshold current value may be split into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnostic resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (less than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnostic resistance of the main switch and the battery voltage. In this case, the control unit may be optionally configured to: when the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the first sub-threshold current value, diagnose that a welding fault has occurred in the main switch, when the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second threshold current value, diagnose that a welding fault has occurred in the pre-charge switch, and when the diagnostic current value is greater than the second threshold current value, diagnose that a welding fault has occurred in both the main switch and the pre-charge switch.

[0024] The battery management device may further include a storage medium operably coupled to the control unit, and the control unit may be configured to record the fault diagnosis results of the main switch and the pre-charge switch on the storage medium.

[0025] The battery management apparatus may further include an output device operably coupled to the control unit, and the control unit may be configured to read the fault diagnosis result from the storage medium and visually output the fault diagnosis result through the output device.

[0026] The battery management device may further include a communication interface operably coupled to the control unit, and the control unit may be configured to read the fault diagnosis result from the storage medium and transmit the fault diagnosis result to the outside through the communication interface.

[0027] In another aspect of the present disclosure, a system is also provided, which includes a battery management device having at least one of the above features, and a vehicle including the system.

[0028] In another aspect of the present disclosure, a battery management method with a switch fault diagnosis function is also provided, which uses: a main switch installed on a first line connected to one terminal of a battery; a pre-charging circuit, which includes a first pre-charging resistor, a pre-charging switch and a second pre-charging resistor connected in series in sequence, and the pre-charging circuit is connected in parallel with both ends of the main switch; a current measuring unit, which is configured to measure the current flowing through a second line connected to another terminal of the battery; and a diagnostic switch installed on a branch line connecting one end of the pre-charging switch and the second line. The battery management method includes: (a) receiving a diagnostic current value from the current measuring unit when the diagnostic switch is turned on or off; and (b) diagnosing whether at least one of the main switch and the pre-charging switch has a welding fault according to the size of the diagnostic current value.

[0029] The battery management method may further include measuring a battery voltage between first and second terminals of the battery and a voltage of a load between first and second connection terminals of the load in a state where the main switch and the pre-charge switch are turned off.

[0030] In step (b) of the battery management method, optionally, when the difference between the battery voltage and the voltage of the load is greater than a preset threshold voltage value and the diagnostic current value is substantially 0, it can be diagnosed that there is no welding fault in the main switch and the pre-charge switch.

[0031] In step (a) of the battery management method, when the difference between the battery voltage and the voltage of the load is substantially 0 and the diagnostic current value is substantially 0 is satisfied, the diagnostic switch may be turned on and then the diagnostic current value may be received from the current measuring unit.

[0032] In step (b), when a condition that the diagnosis current value is greater than a preset first threshold current value is satisfied, it can be diagnosed that a welding fault has occurred in any one of the main switch and the pre-charge switch.

[0033] In step (b) of the battery management method, when the condition that the diagnostic current value is greater than a preset second threshold current value (greater than the first threshold current value) is satisfied, it can be diagnosed that both the main switch and the pre-charge switch have welding faults.

[0034] In one aspect, the first pre-charge resistor and the second pre-charge resistor may have a first resistance value and a second resistance value, respectively, wherein the first resistance value is greater than the second resistance value. In addition, the first threshold current value is split into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnostic resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (greater than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnostic resistance of the main switch and the battery voltage. In step (b) of the battery management method, when the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second sub-threshold current value, it can be diagnosed that a welding fault has occurred in the pre-charge switch, when the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the second threshold current value, it can be diagnosed that a welding fault has occurred in the main switch, and when the diagnostic current value is greater than the second threshold current value, it can be diagnosed that a welding fault has occurred in both the main switch and the pre-charge switch.

[0035] In another aspect, the first pre-charge resistor and the second pre-charge resistor may have a first resistance value and a second resistance value, respectively, wherein the second resistance value is greater than the first resistance value. In addition, the first threshold current value may be split into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnostic resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (less than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnostic resistance of the main switch and the battery voltage. In step (b) of the battery management method, when the diagnostic current value is greater than the second sub-threshold current value and is equal to or less than the first sub-threshold current value, it can be diagnosed that a welding fault has occurred in the main switch, when the diagnostic current value is greater than the first sub-threshold current value and is equal to or less than the second threshold current value, it can be diagnosed that a welding fault has occurred in the pre-charge switch, and when the diagnostic current value is greater than the second threshold current value, it can be diagnosed that a welding fault has occurred in both the main switch and the pre-charge switch.

[0036] The battery management method may further include recording the fault diagnosis results of the main switch and the pre-charge switch on a storage medium.

[0037] The battery management method may further include reading the fault diagnosis result from the storage medium and visually outputting the fault diagnosis result through an output device.

[0038] The battery management method may further include: reading the fault diagnosis result from the storage medium and transmitting the fault diagnosis result to the outside through the communication interface.

[0039] Beneficial Effects

[0040] According to the present disclosure, by installing a pre-charging circuit in which a first pre-charging resistor, a pre-charging switch, and a second pre-charging resistor are sequentially connected in series, and a diagnostic switch on a branch line connecting one end of the pre-charging switch and a low-potential line of the battery, and analyzing the magnitude of the diagnostic current value measured immediately after the diagnostic switch is turned on, it is possible to reliably diagnose a welding fault of a main switch and / or a pre-charging switch installed on a high-potential line of the battery.

[0041] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0043] Figure 1 is a block diagram schematically illustrating a configuration of a battery management device with a switch fault diagnosis function according to an embodiment of the present disclosure.

[0044] Figure 2 FIG. 2 is a schematic diagram showing a first main switch SW1 installed on a high potential line of a battery and / or a pre-charge switch (SW 1 ) included in a pre-charge circuit according to an embodiment of the present disclosure. FC ) shows the current flow in the branch line (L3) when a welding fault occurs in ).

[0045] Figure 3 is a flowchart for illustrating a battery management method with a switch fault diagnosis function according to an embodiment of the present disclosure.

[0046] Figure 4 is a flowchart for illustrating a battery management method with a switch fault diagnosis function according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in this specification and the appended claims should not be understood as limited to the general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the principle of allowing the inventor to appropriately define the terms for the best interpretation.

[0048] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0049] Terms including ordinal numbers such as “first,” “second,” etc. are used to distinguish one element from another element among various elements, and are not intended to limit the elements by the terms.

[0050] Throughout the specification, when a part is referred to as "including" or "comprising" any element, unless otherwise explicitly stated, it means that the part may also include other elements without excluding other elements. In addition, terms such as <control unit> described in the specification refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

[0051] Furthermore, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0052] Figure 1 is a block diagram schematically showing a configuration of a battery management device 100 having a switch fault diagnosis function according to an embodiment of the present disclosure.

[0053] See also Figure 1 , the battery management device 100 is connected between the battery B and the load L. The load L may be a device that consumes energy from the battery B. The load L may include a capacitor C at an input terminal. In addition, the load L may include a power converter such as an inverter (INV) that converts direct current supplied from the battery B into alternating current. In a modification, the load L may be a charging device (not shown) that supplies a charging current to the battery B.

[0054] The battery management device 100 can control the electrical connection between the battery B and the load L and diagnose the welding fault of the switch. The battery management device 100 can also perform the following operations: control the charging and discharging of the battery B, measure the voltage, temperature and current of the battery B, use the voltage, temperature and current of the battery B to determine the SOC (state of charge) and SOH (state of health) of the battery B, or protect the battery B from dangerous conditions such as overcharge / overdischarge / overcurrent / short circuit.

[0055] The battery management device 100 may include a first line L1 and a second line L2 connecting the battery B and the load L. The first line L1 and the second line L2 are power lines through which a charging current or a discharging current flows. The first line L1 is a high voltage line, and the second line L2 is a low voltage line.

[0056] The battery management device 100 may further include a first main switch SW1 and a second main switch SW2 mounted on the first line L1 and the second line L2, respectively. In a modification, the second main switch SW2 may be omitted.

[0057] The battery management device 100 may further include a first pre-charging resistor 11, a pre-charging switch SW FC and a precharge circuit 10 including a second precharge resistor 12 , and the precharge circuit 10 may be connected in parallel to both ends of the first main switch SW1 .

[0058] The first pre-charge resistor 11 is installed adjacent to the battery B, and the second pre-charge resistor 12 is installed adjacent to the load L.

[0059] The first pre-charge resistor 11 may have a first resistance value, and the second pre-charge resistor 12 may have a second resistance value. The first resistance value and the second resistance value may be the same or different.

[0060] The battery management device 100 may include a current measuring unit 20 for measuring the current flowing through the second line L2. The current measuring unit 20 may be a known current sensor capable of measuring the magnitude of the current. In an embodiment, the current measuring unit 20 may output an output indicating the current flowing through the sensing resistor R installed on the second line L2. S The voltage value of the magnitude of the current. The voltage value can be converted into a current value by Ohm's law. The current measuring unit 20 may be replaced with a Hall sensor that measures the magnitude of the current using the strength of the magnetic field formed around the second line L2.

[0061] The battery management device 100 may further include a pre-charge switch SW FC The diagnostic switch SW on one end of the second line L2 and the branch line L3 diag The branch line L3 corresponds to a line connected to the battery B and the load L in parallel.

[0062] The battery management device 100 may include a first main switch SW1, a second main switch SW2, a pre-charge switch SW FC , Diagnostic switch SW diag A control unit 30 is operatively coupled to the current measuring unit 20 .

[0063] In the figure, symbol S1 is a voltage signal for controlling the first main switch SW1 to be turned on or off, symbol S2 is a voltage signal for controlling the second main switch SW2 to be turned on or off, and symbol S FC It controls the pre-charge switch SW FC The voltage signal is switched on or off, and the symbol S diag It is the control diagnostic switch SW diag A voltage signal that switches on or off.

[0064] The control unit 30 may be configured to diagThe diagnostic current value I is received from the current measuring unit 20 in the state of being turned on or off. diag , and based on the diagnostic current value I diag The size of the first main switch SW1 and the pre-charge switch SW FC At least one of the welding failures.

[0065] In the embodiment, the first main switch SW1, the second main switch SW2 and the pre-charge switch SW FC Can be a relay switch, and the diagnostic switch SW diag It may be a semiconductor switch, such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0066] Composition switch SW1, SW2, SW FC , SW diag The components may be replaced by other mechanical switches or other semiconductor switches known in the art.

[0067] A welding fault of a switch refers to a fault in which the switch is maintained in the on state even if an off control signal is applied to the switch in the on state. In one example, a welding fault occurs when contacts included in a relay switch become adhered to each other and remain in contact. Adhesion of the contacts may occur when the contacts are partially melted due to an excessive current flowing through the switch or an arc generated during the switch operation.

[0068] The battery management device 100 may further include a battery voltage V between the first terminal T1 and the second terminal T2 of the battery B. BAT The first voltage measuring unit 40 measures the voltage V of the load between the first connection terminal P1 and the second connection terminal P2 of the load L. Load The second voltage measuring unit 50′.

[0069] According to one aspect, the control unit 30 may receive the battery voltage V from the first voltage measuring unit 40 and the second voltage measuring unit 50, respectively. BAT and the load voltage V Load , and in the first main switch SW1, the optional second main switch SW2 and the pre-charge switch SW diag The diagnostic current value I is received from the current measuring unit 20 in the disconnected state. diag .

[0070] If the battery voltage V BAT The load voltage V Load The difference between them is greater than the preset threshold voltage V th And the diagnostic current value I diag If the threshold voltage value V is substantially 0, the control unit 30 can also diagnose that there is no welding failure in the first switch SW1.th Can be preset. In one example, the threshold voltage value V th Can be set to a value equal to or greater than 1 volt.

[0071] According to another aspect, the control unit 30 may receive the battery voltage V from the first voltage measuring unit 40 and the second voltage measuring unit 50, respectively. BAT and the load voltage V Load , and in the first main switch SW1, the optional second main switch SW2 and the pre-charge switch SW FC The diagnostic current value I is received from the current measuring unit 20 in the disconnected state. diag .

[0072] If the battery voltage V BAT The load voltage V Load The difference between them is substantially 0 and the diagnostic current value I diag The control unit 30 can also turn on the diagnostic switch SW diag And then receives the diagnostic current value I from the current measuring unit 20 diag .

[0073] For reference, if the load L is not operating or the battery B is electrically separated from the load L, even if the battery voltage V BAT The load voltage V Load The difference between them is basically 0, and the diagnostic current value I diag May also be 0.

[0074] If the diagnostic current value I diag Greater than the preset first threshold current value I th1 If the condition is met, the control unit 30 can also diagnose the condition between the first main switch SW1 and the pre-charge switch SW FC A welding failure has occurred in any of the .

[0075] Figure 2 is a diagram showing an embodiment of the present disclosure when the first main switch SW1 and / or the pre-charge switch SW FC FIG. 4 is a diagram showing the current flowing in the branch line L3 when a welding fault occurs.

[0076] Current I1 represents the current when the pre-charge switch SW FC When a welding failure occurs in the circuit, the first pre-charge resistor 11 and the pre-charge switch SW FC The current I2 represents the current flowing on the branch line L3 through the first main switch SW1 and the second pre-charge resistor 12 when a welding fault occurs in the first main switch SW1. The current I3 represents the current flowing on the branch line L3 when the voltage V LoadThe current flowing through the second pre-charge resistor 12 when it is greater than 0.

[0077] The magnitudes of the currents I1 , I2 , and I3 can be determined by the following formula 1 according to Ohm's law.

[0078] <Formula 1>

[0079]

[0080]

[0081]

[0082] In Formula 1, R1 and R2 are the first resistance value of the first pre-charge resistor 11 and the second resistance value of the second pre-charge resistor 12, respectively. SW_FC When the precharge switch SW FC When a welding failure occurs in the pre-charge switch SW FC The resistance value of the weld measured at both ends. SW1 is the value of the welding resistance measured at both ends of the first main switch SW1 when a welding failure occurs in the first main switch SW1. R1 and R2 can be known in advance according to the specifications of the components, and R SW_FC and R SW1 This is a value that can be known in advance through experiments in which the switch components are intentionally welded.

[0083] Diagnostic current value I diag It may be approximately equal to the sum of the magnitudes of currents I1, I2, and I3.

[0084] If the first precharge resistor 11 and the second precharge resistor 12 are made of the same resistor element, and the first main switch SW1 and the precharge switch SW FC are the same switching elements, the first threshold current value I can be determined by the following formula 2 th1 .

[0085] <Formula 2>

[0086]

[0087] The first threshold current value I th1 can be less than when the precharge switch SW FC The magnitude of the current I1 that flows when a welding fault actually occurs in the first main switch SW1 is smaller than the magnitude of the current I2 that flows when a welding fault actually occurs in the first main switch SW1.

[0088] In Formula 2, R1 and R2 may be substantially the same, and R SW_FC@max and R SW1@max Can be substantially the same.

[0089] In Formula 2, R SW_FC@max corresponding to the pre-charge switch SW FC Precharge switch SW with welding fault FC The maximum resistance value of the precharge switch SW FC When there is no welding fault, the precharge switch SW FC The resistance value R SW_FC is very large, ranging from tens to hundreds of megohms, so the magnitude of I1 is actually 0. FC The welding between the contacts is slow. If the precharge switch SW FC The resistance value R SW_FC is reduced to the fusing diagnostic resistor R SW_FC@max Below this, the magnitude of I1 increases to several mA and may gradually increase as the welding proceeds.

[0090] In Formula 2, R SW1@max corresponds to a value that can be known in advance as the maximum welding resistance value of the first main switch SW1 that can be diagnosed as having a welding fault in the first main switch SW1 (hereinafter, referred to as welding diagnosis resistance). When there is no welding fault in the first main switch SW1, the resistance value R of the first main switch SW1 SW1 is very large, at a level of tens to hundreds of megohms, so the magnitude of I2 is actually 0. As the welding between the contact parts of the first main switch SW1 slowly proceeds, if the resistance value R of the first main switch SW1 SW1 is reduced to the fusing diagnostic resistor R SW1@max Below this, the magnitude of I2 increases to several mA and may gradually increase as the welding proceeds.

[0091] is a current value set as a diagnosis margin, and may be set to an appropriate value in consideration of a measurement error of the current measuring unit 20 , the magnitude of the current I3 , and the sensitivity of the fault diagnosis.

[0092] may have a fixed value greater than or equal to 0, or may vary depending on the load voltage V Load The value changes.

[0093] In an embodiment, Can be set in the range of 0 to several hundred mA.

[0094] According to another aspect, if the diagnostic current value I diag Greater than the preset second threshold current value I th2(greater than the first threshold current value I th1 ), the control unit 30 can diagnose the first main switch SW1 and the pre-charge switch SW FC Both have fusion failures.

[0095] The second threshold current value I can be preset by the following formula 3: th2 .

[0096] <Formula 3>

[0097]

[0098] If the first precharge resistor 11 and the second precharge resistor 12 are the same resistor element and the first main switch SW1 and the precharge switch SW FC are the same switching elements, the second threshold current value I can be preset by the following formula 4 th2 .

[0099] <Formula 4>

[0100]

[0101]

[0102] The second threshold current value I th2 can be smaller than the current that is generated when the precharge switch SW FC The sum of the current I1 that flows when a welding fault actually occurs in the first main switch SW1 and the current I2 that flows when a welding fault actually occurs in the first main switch SW1.

[0103] In Formula 4, R1 and R2 may be substantially the same, and R SW_FC@max and R SW1@max Can be substantially the same.

[0104] is a current value set as a diagnosis margin, and may be set to an appropriate value in consideration of a measurement error of the current measuring unit 20 , the magnitude of the current I3 , and the sensitivity of the fault diagnosis.

[0105] may have a fixed value greater than or equal to 0, or may vary depending on the load voltage V Load The value changes.

[0106] In an embodiment, Can be set in the range of 0 to several hundred mA.

[0107] According to another modification, in order to improve the accuracy of welding fault diagnosis, the first resistance value R1 of the first pre-charge resistor 11 and the second resistance value R2 of the second pre-charge resistor 12 may be different. In one example, the first resistance value R1 may be 1.5 to 2 times the second resistance value R2. Conversely, the second resistance value R2 may be 1.5 to 2 times the first resistance value R2.

[0108] In this modification, the first threshold current value I th1 Can be set to be split into two different values, namely the first sub-threshold current value I th1-1 and the second sub-threshold current value I th1-2 , as shown in Equation 5 below.

[0109] <Formula 5>

[0110]

[0111]

[0112] In an embodiment, the first sub-threshold current value I th1-1 can be less than the second sub-threshold current value I th1-2 However, it is obvious to a person skilled in the art that the opposite is also possible.

[0113] In Formula 5, when the precharge switch SW FC When the pre-charge switch SW is the same switch element as the first main switch SW1, FC The welding diagnosis resistor R SW_FC@max and the fused diagnostic resistor R of the first main switch SW1 SW1@max Can be substantially the same.

[0114] is a current value set as a diagnosis margin, and may be set to an appropriate value in consideration of a measurement error of the current measuring unit 20 , the magnitude of the current I3 , and the sensitivity of the fault diagnosis.

[0115] may have a fixed value greater than or equal to 0, or may vary depending on the load voltage V Load The value changes.

[0116] In an embodiment, Can be set in the range of 0 to several hundred mA.

[0117] According to the modification, the first resistance value R1 may be greater than the second resistance value R2, and the first sub-threshold current value I th1-1 can be less than the second sub-threshold current value I th1-2 In this case, if the diagnostic switch SW diagThe diagnostic current value I measured when it is turned on diag Greater than the first sub-threshold current value I th1-1 and is equal to or less than the second sub-threshold current value I th1-2 , the control unit 30 can diagnose that the pre-charge switch SW FC In addition, if the diagnostic current value I diag The magnitude is greater than the second sub-threshold current value I th1-2 and is equal to or less than the second threshold current value I th2 , the control unit 30 can diagnose that a welding fault has occurred in the first main switch SW1. In addition, if the diagnostic current value I diag Greater than the second threshold current value I th2 , the control unit 30 can diagnose that the first main switch SW1 and the pre-charge switch SW FC In both cases, a fusion failure has occurred.

[0118] According to another modification, the second resistance value R2 may be greater than the first resistance value R1, and the second sub-threshold current value I th1-2 can be less than the first sub-threshold current value I th1-1 In this case, if the diagnostic switch SW diag The diagnostic current value I measured when it is turned on diag The magnitude is greater than the second sub-threshold current value I th1-2 and is equal to or less than the first sub-threshold current value I th1-1 , the control unit 30 can diagnose that a welding fault has occurred in the first main switch SW1. In addition, if the diagnostic current value I diag The magnitude is greater than the first sub-threshold current value I th1-1 and is equal to or less than the second threshold current value I th2 , the control unit 30 can diagnose that the pre-charge switch SW FC In addition, if the diagnostic current value I diag The magnitude is greater than the second threshold current value I th2 , the control unit 30 can diagnose that the first main switch SW1 and the pre-charge switch SW FC In both cases, a fusion failure has occurred.

[0119] In another aspect, the battery management device 100 may further include a storage medium 60. The control unit 30 may be operably coupled to the storage medium 60. The storage medium 60 is not limited to being included inside the control unit 30. The storage medium 60 may store data and programs required for the calculation operation performed by the control unit 30. The control unit 60 may cumulatively store data representing the result of the calculation operation, such as the fault diagnosis result of the switch, in the storage medium 60 together with a time stamp. The fault diagnosis result of the switch may include the first main switch SW1 and the pre-charge switch SW2. FC The identification information of the switch in which the welding failure has occurred.

[0120] The control unit 30 is a control circuit and may be implemented in hardware using at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a microprocessor, or an electrical unit for performing other functions.

[0121] The storage medium 60 may be, for example, at least one type of storage medium among a flash memory type, a hard disk type, a solid state disk (SSD) type, a silicon disk drive (SDD) type, a multimedia card micro type, a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), or a programmable read-only memory (PROM).

[0122] According to another aspect, the battery management apparatus 100 may further include an output device 70. The control unit 30 may be operably coupled to the output device 70. The output device 70 may be a display that visually displays information. The control unit 30 may read the fault diagnosis result of the switch from the storage medium 60 and visually output the fault diagnosis result through the output device 70. The output device 70 may be provided in a load L that receives power from the battery B. For example, when the load L is an electric vehicle, the output device 70 may be an integrated information display of the electric vehicle.

[0123] According to another aspect, the battery management device 100 may further include a communication interface 80. The control unit 30 may be operably coupled to the communication interface 80. The control unit 30 may read the fault diagnosis result of the switch from the storage medium 60 and transmit the fault diagnosis result to the outside through the communication interface 80.

[0124] The communication interface 80 may include a communication circuit configured to support wired communication and / or wireless communication between the control unit 30 and the external device. The wired communication may be, for example, CAN (Controller Area Network) communication, and the wireless communication may be mobile communication such as 4G or 5G, or short-range communication such as Wi-Fi, ZigBee, or Bluetooth. Any type of communication protocol may be used as long as it supports wired or wireless communication between the control unit 30 and the external device.

[0125] In one example, the external device may be provided in the load L. When the load L is an electric vehicle, the external device may be an integrated control system of the electric vehicle. When the fault diagnosis result of the switch transmitted from the control unit 30 indicates that a welding fault has occurred in the first main switch and / or the pre-charging switch, the integrated control system may output a warning message through an integrated information display of the electric vehicle.

[0126] In another example, the external device may be a remote server computer. If the fault diagnosis result of the switch transmitted from the control unit 30 indicates that a welding fault has occurred in the first main switch and / or the pre-charge switch, the remote server computer may use a program installed on the driver's mobile phone terminal to send a warning message indicating that the battery B needs to be checked.

[0127] In another example, the external device may be an on-board diagnostic device connected through the communication interface 80. The on-board diagnostic device is a device that checks the status of various components included in the electric vehicle. When the on-board diagnostic device is connected through the communication interface 80, the control unit 30 may read the fault diagnosis result of the switch stored in the storage medium 60 and transmit the fault diagnosis result to the on-board diagnostic device through the communication interface 80. Then, the operator may recognize the fault diagnosis result of the switch output through the display of the on-board diagnostic device, and perform an operation on the first main switch SW1 and / or the pre-charge switch SW2 of the battery B. FC Perform a detailed inspection.

[0128] In the present disclosure, the control unit 30 may optionally include a processor, an application specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc. known in the art to execute the above-mentioned various control logics.

[0129] In addition, when the control logic is implemented as software, the control unit 25 can be a processor that executes a set of program modules. In this case, the program modules can be stored in a memory and executed by the processor. The memory can be set inside or outside the processor and can be connected to the processor through various well-known computer components. In addition, the memory can be included in the storage medium 26. In addition, the memory generally refers to a device that stores information, regardless of the type of device, and does not refer to a specific memory device.

[0130] In addition, one or more of the various control logics of the control unit 30 can be combined, and the combined control logic can be written into a computer-readable code system and recorded on a computer-readable storage medium. The type of storage medium is not particularly limited as long as it can be accessed by a processor included in the computer. As an example, the storage medium includes at least one selected from the group including ROM, RAM, registers, CD-ROM, magnetic tape, hard disk, floppy disk and optical data recording device. In addition, the code system can be distributed and stored in a computer connected via a network and executed therein. In addition, the functional program, code and code segment for implementing the combined control logic can be easily inferred by a programmer in the field to which the present disclosure belongs.

[0131] The battery management device 100 according to an embodiment of the present disclosure may be included in a battery management system, which is referred to as a BMS in the art. In addition, the battery management device 100 may be included in a battery diagnostic system. In addition, the battery management device 100 may be included in various systems in which a battery B is installed. In addition, a system including the battery management device 100 may be included in a vehicle. The vehicle may be a two-wheeled, three-wheeled, or four-wheeled vehicle. The vehicle may include a motor mechanism driven by power supplied by the battery B.

[0132] Hereinafter, the battery management method with a switch fault diagnosis function according to the above-mentioned embodiment of the present disclosure will be described in detail.

[0133] Figure 3 is a flowchart for illustrating a battery management method with a switch fault diagnosis function according to an embodiment of the present disclosure. Figure 3 The steps in may be performed by the control unit 30 before charging or discharging of the battery B starts.

[0134] See also Figure 3 First, in step S10, the control unit 30 determines whether a fault diagnosis cycle of the switch has been reached. Preferably, the fault of the switch can be diagnosed before charging or discharging of the battery B starts.

[0135] If the determination in step S10 is NO, the processing progress is maintained.

[0136] If the determination in step S10 is yes, then in step S20, the control unit 30 turns off the first main switch SW1 and the pre-charge switch SW FC Optionally, the control unit 30 may also disconnect the second main switch SW2 together with the first main switch SW1 in step S20. Step S30 is performed after step S20.

[0137] In step S30, the control unit 30 receives the battery voltage V from the first voltage measuring unit 40. BAT , receiving the load voltage V from the second voltage measurement unit 40 Load , and receives the current flowing through the sensing resistor R from the current measuring unit 20 S The diagnostic current value I diag In addition, the control unit 30 determines the battery voltage V BAT The load voltage V Load Is the difference between the two greater than the threshold voltage V th And the diagnostic current value I diag Is it basically 0?

[0138] If the determination in step S30 is yes, the control unit 30 diagnoses the first main switch SW1 and the pre-charge switch SW in step S40. FC Here, the normal state means a state without welding failure. In addition, in order to start charging or discharging the battery B, the control unit 30 turns on the second main switch SW2 in step S50 and turns on the pre-charge switch SW in step S60. FC , the first main switch SW1 is turned on in step S70, and the pre-charge switch SW is turned off in step S80. FC The pre-charge switch SW FC Between the turn-on point of the first main switch SW1 and the turn-on point of the first main switch SW2, a time interval is set so that the capacitor on the load L connected in parallel with the battery B can be fully charged. After step S80, the diagnosis of the switch is completed, and the battery B can be charged or discharged.

[0139] If the determination in step S30 is NO, the diagnosis of the first main switch SW1 and the pre-charge switch SW FC The process of welding failure.

[0140] Specifically, in step S90, the control unit 30 turns on the diagnosis switch SW of the branch line L3. diag Then, in step S100, the control unit 30 receives the current flowing through the sensing resistor R through the current measuring unit 20. S The diagnostic current value I diag , and determine the diagnostic current value I diag Is the magnitude greater than the preset first threshold current value Ith1 .

[0141] In an embodiment, if the first pre-charge resistor 11 and the second pre-charge resistor 12 are composed of the same resistor element, and the first main switch SW1 and the pre-charge switch SW FC The type is the same, then the first threshold current value I th1 It may be preset to a current value determined by Formula 2 and recorded in advance on the storage medium 60 .

[0142] If the determination in step S100 is NO, the control unit 30 performs steps S40 to S80 .

[0143] Meanwhile, if the determination in step S100 is yes, then in step S110, the control unit 30 determines the diagnosis current value I diag Is the magnitude greater than the preset second threshold current value I th2 .

[0144] In an embodiment, if the first pre-charge resistor 11 and the second pre-charge resistor 12 are the same resistor element, and the first main switch SW1 and the pre-charge switch SW FC are the same switching elements, then the second threshold current value I th2 It may be preset to a current value determined by Formula 4 and recorded in advance on the storage medium 60 .

[0145] If the determination in step S110 is YES, the diagnosis current value I diag The magnitude is relatively larger than the second threshold current value I th2 In this case, in step S120, the control unit 30 may diagnose the first main switch SW1 and the pre-charge switch SW FC Meanwhile, if the determination in step S110 is NO, the diagnostic current value I diag The magnitude is greater than the first threshold current value I th1 and is equal to or less than the second threshold current value I th2 In this case, in step S130, the control unit 30 may diagnose the first main switch SW1 and the pre-charge switch SW FC A welding failure has occurred in any of the .

[0146] After steps S120 and S130, step S140 is performed.

[0147] In step S140, the control unit 30 may record the switch fault diagnosis result in the storage medium 60. The switch fault diagnosis result may include identification information of the switch in which the welding failure has occurred. In step S150, the control unit 30 may also read the switch fault diagnosis result recorded in the storage medium 60, and visually display the switch fault diagnosis result through the output device 70. In step S160, the control unit 30 may also read the switch fault diagnosis result recorded in the storage medium 60, and transmit the switch fault diagnosis result to an external device through the communication interface 80. If step S160 is performed, the process of the battery management method according to an embodiment of the present disclosure is completed. At the same time, step S150 and / or step S160 are optional steps and may be omitted.

[0148] Figure 4 is a flowchart for illustrating a battery management method with a switch fault diagnosis function according to another embodiment of the present disclosure. Another embodiment of the present disclosure is characterized in that compared with the previous embodiment, Figure 3 Step S100 in .

[0149] See also Figure 4 Step S100a is performed after step S90. That is, the control unit 30 turns on the diagnosis switch SW diag , then in step S100a, the current flowing through the sensing resistor R is received from the current measuring unit 20 S The diagnostic current value I diag , and determine the diagnostic current value I diag Is the magnitude greater than the first sub-threshold current value I th1-1 The first sub-threshold current value I th1-1 may be set to a value determined by Formula 5 and may be recorded in advance on the storage medium 60 .

[0150] If the determination in step S100a is NO, the control unit 30 may proceed to Figure 3 The present invention further implements step S40 of the present invention, and performs steps S40 to S80 in substantially the same manner as the previous embodiment.

[0151] Meanwhile, if the determination in step S100a is yes, then in step S100b, the control unit 30 determines the diagnosis current value I diag Is the magnitude greater than the second sub-threshold current value I th1-2 The second sub-threshold current value I th1-2 can be set to be greater than the first sub-threshold current value I th1-1 The value of is determined by Formula 5 and can be pre-recorded on the storage medium 60.

[0152] If the determination in step S100b is NO, the diagnostic current value Idiag The magnitude is greater than the first sub-threshold current value I th1-1 and is equal to or less than the second sub-threshold current value I th1-2 In this case, in step S130b, the control unit 30 may diagnose that the pre-charge switch SW FC A welding failure has occurred.

[0153] If the determination in step S100b is YES, then in step S110, the control unit 30 determines the diagnostic current value I diag Is the magnitude greater than the second threshold current value I th2 The second threshold current value I th2 may be set to a value determined by Formula 4 and may be recorded in advance on the storage medium 60 .

[0154] If the determination in step S110 is NO, the diagnostic current value I diag The magnitude is greater than the second sub-threshold current value I th1-2 and is equal to or less than the second threshold current value I th2 In this case, the control unit 30 may diagnose that a welding failure has occurred in the first main switch SW1 in step S130a.

[0155] Meanwhile, if the determination in step S110 is yes, the diagnosis current value I diag The magnitude is greater than the second threshold current value I th2 In this case, in step S120, the control unit 30 may diagnose the first main switch SW1 and the pre-charge switch SW FC In both cases, a fusion failure has occurred.

[0156] After steps S120, S130a and S130b, the control unit 30 may perform the following steps in substantially the same manner as in the previous embodiment. Figure 3 Steps S140 to S160.

[0157] Meanwhile, in the modification, the second sub-threshold current value I th1-2 can be less than the first sub-threshold current value I th1-1 In this case, step S100b may be performed first, and then step S100a may be performed. Furthermore, if the determination in step S100b is no, steps S40 to S80 may be performed. Furthermore, if the determination in step S100a is no, it may be diagnosed that a welding failure has occurred in the first main switch SW1. Furthermore, when the determination in step S110 is no, it may be diagnosed that a welding failure has occurred in the pre-charge switch SW FC A welding failure has occurred.

[0158] According to the present disclosure, by installing a pre-charging circuit 10 in which a first pre-charging resistor, a pre-charging switch, and a second pre-charging resistor are sequentially connected in series, and a diagnostic switch on a branch line connecting one end of the pre-charging switch and a low-potential line of the battery, and analyzing the magnitude of the diagnostic current value measured immediately after the diagnostic switch is turned on, it is possible to reliably diagnose a welding fault of a main switch and / or a pre-charging switch installed on a high-potential line of the battery.

[0159] When describing various embodiments of the present disclosure, elements named "... unit" should be understood as functionally different elements rather than physically different elements. Therefore, each component can be selectively integrated with other components, or each component can be split into sub-components for efficiently executing control logic. However, it is obvious to those skilled in the art that even if the components are integrated or split, if the same function can be identified, the integrated or split components should also be interpreted as falling within the scope of the present disclosure.

[0160] The present disclosure has been described in detail. However, it should be understood that although the detailed description and specific examples indicate preferred embodiments of the present disclosure, these detailed descriptions and specific examples are given by way of illustration only, because various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art based on these detailed descriptions.

[0161] In addition, since those skilled in the art can make many substitutions, modifications and changes to the above-mentioned disclosure without departing from the technical aspects of the disclosure, the present disclosure is not limited to the above-mentioned embodiments and drawings, and all or some of these embodiments can be selectively combined to allow various modifications.

Claims

1. A battery management device with switch fault diagnosis function, comprising: a main switch mounted on a first line connected to one terminal of a battery; A pre-charging circuit, the pre-charging circuit comprising a first pre-charging resistor, a pre-charging switch and a second pre-charging resistor connected in series in sequence, the pre-charging circuit being connected in parallel with both ends of the main switch; a current measuring unit configured to measure a current flowing through a second line connected to another terminal of the battery; a diagnostic switch, the diagnostic switch being mounted on a branch line connecting one end of the pre-charging switch and the second line; as well as a control unit operatively coupled to the main switch, the pre-charge switch, the diagnostic switch and the current measuring unit, The control unit is configured to receive a diagnostic current value from the current measuring unit when the diagnostic switch is turned on or off, and diagnose whether at least one of the main switch and the pre-charging switch has a welding fault according to the magnitude of the diagnostic current value.

2. The battery management device with switch fault diagnosis function according to claim 1, further comprising: a first voltage measuring unit configured to measure a battery voltage between a first terminal and a second terminal of the battery; as well as a second voltage measuring unit configured to measure a voltage of the load between a first connection terminal and a second connection terminal of the load, Wherein, the control unit is configured as: receiving the battery voltage and the voltage of the load from the first voltage measuring unit and the second voltage measuring unit, respectively, and receiving the diagnostic current value from the current measuring unit in a state where the main switch and the pre-charge switch are turned off, and When the conditions that the difference between the battery voltage and the voltage of the load is greater than a preset threshold voltage value and the diagnosis current value is substantially 0 are satisfied, it is diagnosed that there is no welding fault in the main switch and the pre-charge switch.

3. The battery management device with switch fault diagnosis function according to claim 2, in, The control unit is optionally configured to: When a condition that a difference between the battery voltage and the voltage of the load is substantially 0 and the diagnostic current value is substantially 0 is satisfied, turning on the diagnostic switch and then receiving the diagnostic current value from the current measuring unit, and When a condition that the diagnostic current value is greater than a preset first threshold current value is satisfied, it is diagnosed that a welding fault has occurred in any one of the main switch and the pre-charge switch.

4. The battery management device with switch fault diagnosis function according to claim 3, in, The control unit may be optionally configured to diagnose that there is a welding fault in the main switch and the pre-charging switch when a condition that the diagnostic current value is greater than a preset second threshold current value (greater than the first threshold current value) is satisfied.

5. The battery management device with switch fault diagnosis function according to claim 4, in, The first pre-charging resistor and the second pre-charging resistor have a first resistance value and a second resistance value, respectively, wherein the first resistance value is greater than the second resistance value, The first threshold current value is divided into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnosis resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (greater than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnosis resistance of the main switch and the battery voltage. Wherein, the control unit is optionally configured as: When the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second sub-threshold current value, it is diagnosed that a welding fault has occurred in the pre-charging switch, When the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the second threshold current value, it is diagnosed that a welding fault has occurred in the main switch, and When the diagnosis current value is greater than the second threshold current value, it is diagnosed that a welding failure has occurred in both the main switch and the pre-charge switch.

6. The battery management device with switch fault diagnosis function according to claim 4, in, The first pre-charging resistor and the second pre-charging resistor have a first resistance value and a second resistance value, respectively, wherein the second resistance value is greater than the first resistance value, The first threshold current value is divided into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnosis resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (smaller than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnosis resistance of the main switch and the battery voltage. Wherein, the control unit is optionally configured as: When the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the first sub-threshold current value, it is diagnosed that a welding fault has occurred in the main switch, When the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second threshold current value, diagnosing that a welding fault has occurred in the pre-charge switch, and When the diagnosis current value is greater than the second threshold current value, it is diagnosed that a welding failure has occurred in both the main switch and the pre-charge switch.

7. The battery management device with switch fault diagnosis function according to claim 1, further comprising: a storage medium operatively coupled to the control unit, Wherein, the control unit is configured to record the fault diagnosis results of the main switch and the pre-charging switch on the storage medium.

8. The battery management device with switch fault diagnosis function according to claim 7, further comprising: an output device operatively coupled to the control unit, Wherein, the control unit is configured to read the fault diagnosis result from the storage medium and visually output the fault diagnosis result through the output device.

9. The battery management device with switch fault diagnosis function according to claim 7, further comprising: a communication interface operably coupled to the control unit, The control unit is configured to read the fault diagnosis result from the storage medium and transmit the fault diagnosis result to the outside through the communication interface.

10. A system comprising the battery management device according to any one of claims 1 to 9.

11. A vehicle comprising a system according to claim 10.

12. A battery management method having a switch fault diagnosis function using a main switch, a precharge circuit, a current measurement unit, and a diagnosis switch, wherein the main switch is installed on a first line connected to one terminal of a battery; the precharge circuit comprises a first precharge resistor, a precharge switch, and a second precharge resistor connected in series sequentially, the precharge circuit is connected in parallel to both ends of the main switch; the current measurement unit is configured to measure a current flowing through a second line connected to another terminal of the battery; The diagnostic switch is installed on a branch line connecting one end of the pre-charging switch and the second line, and the battery management method includes: (a) receiving a diagnostic current value from the current measuring unit in a state where the diagnostic switch is turned on or off; as well as (b) diagnosing whether at least one of the main switch and the pre-charge switch has a welding fault according to the magnitude of the diagnostic current value.

13. The battery management method according to claim 12, further comprising: In a state where the main switch and the pre-charging switch are turned off, measuring a battery voltage between a first terminal and a second terminal of the battery and a voltage of the load between a first connection terminal and a second connection terminal of the load, Wherein, in the step (b), optionally, when the condition that the difference between the battery voltage and the voltage of the load is greater than a preset threshold voltage value and the diagnostic current value is substantially 0 is satisfied, it is diagnosed that there is no welding fault in the main switch and the pre-charging switch.

14. The battery management method according to claim 12, further comprising: In a state where the main switch and the pre-charging switch are turned off, measuring a battery voltage between a first terminal and a second terminal of the battery and a voltage of the load between a first connection terminal and a second connection terminal of the load, wherein, in the step (a), when the conditions that the difference between the battery voltage and the voltage of the load is substantially 0 and the diagnostic current value is substantially 0 are satisfied, the diagnostic switch is turned on and then the diagnostic current value is received from the current measuring unit, and Wherein, in the step (b), when the condition that the diagnostic current value is greater than a preset first threshold current value is satisfied, it is diagnosed that a welding fault has occurred in any one of the main switch and the pre-charging switch.

15. The battery management method according to claim 12, further comprising: In a state where the main switch and the pre-charging switch are turned off, measuring a battery voltage between a first terminal and a second terminal of the battery and a voltage of the load between a first connection terminal and a second connection terminal of the load, wherein, in the step (a), when the conditions that the difference between the battery voltage and the voltage of the load is substantially 0 and the diagnostic current value is substantially 0 are satisfied, the diagnostic switch is turned on and then the diagnostic current value is received from the current measuring unit, and Wherein, in the step (b), when the condition that the diagnostic current value is greater than a preset second threshold current value (greater than the first threshold current value) is satisfied, it is diagnosed that both the main switch and the pre-charging switch have welding faults.

16. The battery management method according to claim 14, in, The first pre-charging resistor and the second pre-charging resistor have a first resistance value and a second resistance value, respectively, wherein the first resistance value is greater than the second resistance value, The first threshold current value is divided into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnosis resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (greater than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnosis resistance of the main switch and the battery voltage. Wherein, in the step (b), when the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second sub-threshold current value, it is diagnosed that a welding fault has occurred in the pre-charging switch, When the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the second threshold current value, it is diagnosed that a welding fault has occurred in the main switch, and When the diagnosis current value is greater than the second threshold current value, it is diagnosed that a welding failure has occurred in both the main switch and the pre-charge switch.

17. The battery management method according to claim 14, in, The first pre-charging resistor and the second pre-charging resistor have a first resistance value and a second resistance value, respectively, wherein the second resistance value is greater than the first resistance value, The first threshold current value is divided into a first sub-threshold current value determined by Ohm's law according to the first resistance value, the welding diagnosis resistance of the pre-charge switch and the battery voltage, and a second sub-threshold current value (smaller than the first sub-threshold current value) determined by Ohm's law according to the second resistance value, the welding diagnosis resistance of the main switch and the battery voltage. Wherein, in the step (b), when the diagnostic current value is greater than the second sub-threshold current value and equal to or less than the first sub-threshold current value, it is diagnosed that a welding fault has occurred in the main switch, When the diagnostic current value is greater than the first sub-threshold current value and equal to or less than the second threshold current value, diagnosing that a welding fault has occurred in the pre-charge switch, and When the diagnosis current value is greater than the second threshold current value, it is diagnosed that a welding failure has occurred in both the main switch and the pre-charge switch.

18. The battery management method according to claim 12, further comprising: The fault diagnosis results of the main switch and the pre-charge switch are recorded on a storage medium.

19. The battery management method according to claim 18, further comprising: The fault diagnosis result is read from the storage medium and visually output through an output device.

20. The battery management method according to claim 18, further comprising: The fault diagnosis result is read from the storage medium and transmitted to the outside through a communication interface.

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