High-voltage power-down control method and device, BMS, battery pack, system, equipment, medium and program product

Abstract

The embodiment of the invention provides a high-voltage power-down control method and device, a BMS, a battery pack, a system, equipment, a medium and a program product. The method comprises the following steps: in response to a high-voltage power-off instruction, disconnecting a main positive relay of the battery pack and keeping a main negative relay of the battery pack closed; performing voltage relief on the filter capacitor through the voltage relief module; acquiring the current and the external voltage of the battery pack under the condition that the voltage relief duration reaches a preset duration; and based on the current and the external voltage, determining whether the voltage release module fails. The method is used for improving the stability and safety of the high-voltage system.

Description

Technical Field

[0001] This application relates to the technical field of power supply, and particularly to a high-voltage power-off control method, device, BMS, battery pack, system, equipment, medium and program product. Background Art

[0002] In the high-voltage system of new energy vehicles, a pressure relief module is used to provide a pressure relief path for a filter capacitor (a capacitor connected across the positive and negative poles of the high-voltage bus, also known as an X capacitor). The pressure relief module can release residual high-voltage charges during power-off, maintenance, or emergencies, avoiding the accumulation of high-voltage system voltage to a dangerous level, preventing electric shock to maintenance personnel and equipment damage, and at the same time avoiding accidental discharge, protecting sensitive components, and improving the stability and safety of the high-voltage system.

[0003] If the vehicle's pressure relief module fails, this may affect the stability and safety of the vehicle's high-voltage system, and it may also cause maintenance personnel to operate incorrectly, leading to safety accidents. Currently, there is no effective method to monitor the failure state of the pressure relief module. Summary of the Invention

[0004] Embodiments of this application provide a high-voltage power-off control method, device, BMS, battery pack, system, equipment, medium and program product, which can monitor whether the pressure relief module fails during the power-off process, thereby improving the stability and safety of the high-voltage system.

[0005] In a first aspect, embodiments of this application provide a high-voltage power-off control method. The high-voltage system of an electrical device includes: a battery pack, a pressure relief module, and a filter capacitor; the method includes:

[0006] In response to a high-voltage power-off command, disconnect the main positive relay of the battery pack and keep the main negative relay of the battery pack closed;

[0007] Discharge the filter capacitor through the pressure relief module;

[0008] When the pressure relief duration reaches a preset duration, obtain the current and external voltage of the battery pack;

[0009] Based on the current and external voltage, determine whether the pressure relief module fails.

[0010] In a possible implementation manner, the determining whether the pressure relief module fails based on the current and external voltage includes:

[0011] If the external voltage is less than or equal to a first threshold, determine that the pressure relief module has not failed;

[0012] If the external voltage is greater than the first threshold and the current is greater than a second threshold, determine that the pressure relief module has not failed;

[0013] If the external voltage is greater than the first threshold and the current is less than or equal to the second threshold, it is determined that the pressure relief module fails.

[0014] In a possible implementation, after determining that the pressure relief module fails, the method further includes:

[0015] Output a first fault message, where the first fault message is used to indicate that the pressure relief module fails.

[0016] In a possible implementation, if the current is greater than the second threshold, based on the current, determine the relay that has sintered in the battery pack.

[0017] In a possible implementation, the battery pack further includes: a pre-charge relay; determining the relay that has sintered in the battery pack based on the current includes:

[0018] If the current is greater than a third threshold, determine that the relay that has sintered is the main positive relay;

[0019] If the current is less than the third threshold, determine that the relay that has sintered is the pre-charge relay.

[0020] In a possible implementation, after determining the relay that has sintered in the battery pack, the method further includes:

[0021] Output a second fault message, where the second fault message is used to indicate the relay that has sintered.

[0022] In a possible implementation, the battery pack further includes: a high-voltage relay and a high-voltage module connected in series. After determining that the pressure relief module fails, the method further includes:

[0023] Control the high-voltage relay to conduct, so as to discharge the filter capacitor through the high-voltage module.

[0024] In a possible implementation, during the process of discharging the filter capacitor through the high-voltage module, based on the pressure difference of the high-voltage relay, determine whether the high-voltage relay fails.

[0025] In a possible implementation, determining whether the high-voltage relay fails based on the pressure difference of the high-voltage relay includes:

[0026] If the pressure difference is less than or equal to a fourth threshold, determine that the high-voltage relay has not failed;

[0027] If the pressure difference is greater than the fourth threshold, determine that the high-voltage relay fails.

[0028] In a possible implementation, after determining that the high-voltage relay fails, the method further includes:

[0029] Outputting third fault information, where the third fault information is used to indicate that the filtering capacitor has not completed pressure relief.

[0030] In a possible implementation, after determining that the high-voltage relay has not failed, the method further includes:

[0031] Based on the external voltage, determining whether the pressure relief of the filtering capacitor is completed;

[0032] If the pressure relief of the filtering capacitor is completed, the high-voltage relay and the main negative relay are disconnected in sequence.

[0033] In a possible implementation, after determining that the pressure relief module has not failed, the method further includes:

[0034] Based on the external voltage, determining whether the pressure relief of the filtering capacitor is completed;

[0035] If the pressure relief of the filtering capacitor is completed, the main negative relay is disconnected.

[0036] In a second aspect, an embodiment of the present application provides a high-voltage power-off control device. The high-voltage system of the electrical equipment includes: a battery pack, a pressure relief module, and a filtering capacitor; the device includes:

[0037] A control module, configured to disconnect the main positive relay of the battery pack and keep the main negative relay of the battery pack closed in response to a high-voltage power-off instruction;

[0038] A pressure relief module, configured to perform pressure relief on the filtering capacitor through the pressure relief module;

[0039] An acquisition module, configured to acquire the current and external voltage of the battery pack when the pressure relief duration reaches a preset duration;

[0040] A determination module, configured to determine whether the pressure relief module fails based on the current and external voltage.

[0041] In a third aspect, an embodiment of the present application provides a BMS of a battery pack. The BMS includes: a memory, a processor;

[0042] The memory stores computer execution instructions;

[0043] The processor executes the computer execution instructions stored in the memory, so that the processor executes the method according to any one of the first aspects above.

[0044] Fourth aspect, an embodiment of the present application provides a battery pack, which includes a BMS as described in the third aspect.

[0045] Fifth aspect, an embodiment of the present application provides a high-voltage system of an electrical device, which includes a pressure relief module, a filter capacitor, and a battery pack as described in the fourth aspect.

[0046] Sixth aspect, an embodiment of the present application provides an electrical device, which includes a high-voltage system as described in the fifth aspect.

[0047] Seventh aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in any item of the first aspect above.

[0048] Eighth aspect, an embodiment of the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the method described in any item of the first aspect above.

[0049] The high-voltage power-off control method, device, BMS, battery pack, system, device, medium, and program product provided by the embodiments of the present application can utilize the existing high-voltage sampling points and current sampling points in the battery pack to monitor the working state of the pressure relief module during the high-voltage power-off process, so that when the pressure relief module fails, its failure state can be timely known. This method does not require an additional hardware sampling unit, and can detect whether the pressure relief module fails by using the existing sampling function, without increasing additional hardware costs. By detecting the working state of the pressure relief module, corresponding treatment measures can be taken in time when the pressure relief module fails, preventing electric shock to maintenance personnel or users or potential safety hazards caused by the high-voltage residue of the X capacitor, and improving the stability and safety of the high-voltage system. Description of the Drawings

[0050] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0051] Figure 1 It is a schematic structural diagram of a high-voltage system;

[0052] Figure 2 It is a schematic flow diagram of the high-voltage power-off control method provided by the embodiment of the present application;

[0053] Figure 3 It is a schematic structural diagram of a high-voltage system provided by the embodiment of the present application;

[0054] Figure 4 It is a schematic flow diagram of the high-voltage power-off control method provided by the embodiment of the present application;

[0055] Figure 5 Schematic structural diagram of an electric control device under high voltage provided for this application;

[0056] Figure 6 Schematic structural diagram of the BMS of a battery pack provided for this application.

[0057] Through the above-mentioned drawings, specific embodiments of this application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0058] Here, exemplary embodiments will be described in detail, and examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0059] In this application, the term "including" and its variants may refer to non-limiting inclusion; the term "or" and its variants may refer to "and / or". In this application, terms such as "first" and "second" are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. In this application, "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0060] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, use, and processing of relevant data need to comply with relevant laws, regulations, and standards of relevant countries and regions, and corresponding operation entrances are provided for users to choose to authorize or reject.

[0061] With the rapid development of new energy vehicle technology, in order to ensure the stable operation and safety of electric vehicles, the high-voltage system of the vehicle is crucial. Figure 1 Schematic structural diagram of a high-voltage system, as Figure 1 shown, the high-voltage system may include a battery pack, a pressure relief module, and a filter capacitor.

[0062] Among them, the battery pack may include: a power battery, a main positive relay, a main negative relay, and a Battery Management System (BMS). The main positive relay is connected to the positive electrode of the power battery, and the main negative relay is connected to the negative electrode of the power battery. When the main negative relay is closed, the high-voltage reference ground of the battery pack is connected to the high-voltage reference ground of the vehicle body.

[0063] In some embodiments, the battery pack further includes a pre-charge relay and a pre-charge resistor. The pre-charge relay is closed when the power battery is connected to the load. By means of the pre-charge resistor, it is possible to avoid damaging the load due to excessive current when the load is connected to the power battery.

[0064] The filter capacitor generally refers to a capacitor connected across the positive and negative electrodes of the high-voltage bus, also known as an X capacitor. The filter capacitor can smooth the current supplied by the power battery to the load, improving the stability and reliability of the high-voltage system. The stability and reliability of the filter capacitor are crucial for the normal operation of the electric vehicle.

[0065] The pressure relief module is generally connected in parallel across the two ends of the filter capacitor, and is used to provide a pressure relief path for the filter capacitor.

[0066] The BMS is used to collect data such as the voltage, current, temperature, state of charge of the battery, and state of health of the battery of the battery pack, control the charge and discharge of the battery pack, control the temperature of the battery pack, and execute the high-voltage power-off process. It should be understood that only the content related to this application is described here, and no limitation is made on whether the BMS has other functions.

[0067] During high-voltage power-off, the X capacitor will retain high-voltage charges, and the high-voltage system may have unstable voltages, increasing the potential hazards of the high-voltage system and reducing the safety of the high-voltage system. Currently, during the high-voltage power-off process, the voltage of the X capacitor is discharged through the pressure relief module. The existing high-voltage power-off process will be described below.

[0068] When the Battery Management System (BMS) executes the high-voltage power-off process, it controls the main positive relay of the battery pack to disconnect, and controls the main negative relay of the battery pack to disconnect immediately after the main positive relay disconnects. The BMS requests the vehicle control unit (VCU) of the vehicle to activate the pressure relief function, and the vehicle VCU activates the pressure relief function so that the X capacitor discharges through the loop formed with the pressure relief module.

[0069] When the vehicle's power supply is cut off, the X capacitor still retains high-voltage charges. The pressure relief module can safely release these charges to prevent equipment damage caused by the residual voltage of the X capacitor. During vehicle maintenance, discharging the voltage of the X capacitor through the pressure relief module can prevent electric shock to maintenance personnel or users due to the residual voltage of the X capacitor. The pressure relief module can ensure that the voltage of the high-voltage system does not accumulate to a dangerous level, effectively improving the electrical safety of the high-voltage system. In addition, it can avoid accidental discharge phenomena caused by the X capacitor, protect other sensitive components in the high-voltage system, and improve the stability and safety of the high-voltage system.

[0070] In addition, in the event of an accidental power cut or an emergency in the high-voltage system, the pressure relief module can respond quickly to prevent the high voltage of the X capacitor from remaining, reduce potential safety hazards, and ensure that the vehicle can quickly return to a safe state under various accidental conditions.

[0071] However, in the existing technology methods, although the pressure relief module can provide a pressure relief path for the X capacitor, the normal operation of the pressure relief module is unknown. If the vehicle's pressure relief module fails, it may bring a series of potential risks and problems, mainly including:

[0072] 1. Increased risk of electric shock: During vehicle maintenance, the high-voltage charges on the X capacitor cannot be released in time, which may cause electric shock to maintenance personnel or users when they come into contact with the high-voltage system, resulting in personal safety risks.

[0073] 2. Damage to electrical equipment: The remaining high-voltage charges may impact low-voltage and sensitive equipment in the system, accelerating equipment aging and even damaging important electrical equipment, affecting the stability and service life of the high-voltage system.

[0074] 3. Shorter capacitor life: Long-term retention of high voltage will increase the pressure on the X capacitor, accelerate its aging, and reduce its service life. As the capacitor performance deteriorates, the filtering effect will also weaken, resulting in more electrical interference problems in the system.

[0075] 4. Decreased vehicle safety: In an emergency, if the X capacitor cannot be discharged in time, the high-voltage system may have unstable voltage, increasing the hidden dangers of the high-voltage system and reducing the safety of the whole vehicle.

[0076] 5. Increased risk of system misoperation: If maintenance personnel are not aware of the failure of the pressure relief module, misoperation may lead to serious safety accidents.

[0077] Therefore, the present application proposes an electric control method, device, BMS, battery pack, system, equipment, medium and program product under high-voltage power-off, which can utilize the existing high-voltage sampling points and current sampling points in the battery pack during the high-voltage power-off process to monitor the working state of the pressure relief module, so that when the pressure relief module fails, its failure state can be known in time. This method does not require an additional hardware sampling unit, and can detect whether the pressure relief module fails by using the existing sampling function, without increasing additional hardware costs. By detecting the working state of the pressure relief module, corresponding treatment measures can be taken in time when the pressure relief module fails, preventing electric shock to maintenance personnel or users or potential safety hazards caused by the high-voltage residue of the X capacitor, and improving the stability and safety of the high-voltage system.

[0078] The execution subject of the embodiment of the present application can be the BMS of the battery pack, for example, it can be the BMC in the BMS.

[0079] It should be understood that the method of the embodiment of the present application can be applied to any electrical equipment with a high-voltage system such as the one described above Figure 1 shown, including but not limited to electric vehicles.

[0080] The following will specifically describe the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems through specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0081] Figure 2 It is a schematic flowchart of the high-voltage power-off control method provided by the embodiment of the present application. As Figure 2 shown, the method includes:

[0082] S101. In response to a high-voltage power-off instruction, disconnect the main positive relay of the battery pack and keep the main negative relay of the battery pack closed.

[0083] Optionally, the BMS executes a high-voltage power-off process in response to a high-voltage power-off instruction and disconnects the main positive relay of the battery pack.

[0084] Exemplarily, as Figure 1 shown, the power battery can provide electrical energy for the load, and a shunt can be used to measure the current in the circuit. V PACK+ represents the internal voltage of the battery pack, and V LINK+ represents the external voltage of the battery pack. It should be noted that when the main negative relay is closed, the high-voltage reference ground of the battery pack is connected to the high-voltage reference ground of the vehicle body end, and at this time V LINK+ can represent the voltage across the X capacitor.

[0085] S102. Discharge the filter capacitor through the pressure relief module.

[0086] Optionally, the pressure relief module may include components such as a relay and a discharge resistor that perform the pressure relief function, and the present application does not limit this. For Figure 1 example, the pressure relief module discharges the filter capacitor through a loop formed with the X capacitor.

[0087] For example, the BMS requests the control unit of the electrical device to turn on the pressure relief function. Taking a vehicle as an example, the control unit may be a VCU for example. The control unit of the electrical device turns on the pressure relief function and discharges the filter capacitor through the pressure relief module.

[0088] S103. When the pressure relief duration reaches the preset duration, obtain the current and external voltage of the battery pack.

[0089] The present application uses the existing high-voltage sampling points and current sampling points in the battery pack to obtain the external voltage and current of the battery pack, without incurring additional hardware costs. For Figure 1 example, the current of the battery pack can be obtained using a shunt.

[0090] Optionally, the preset duration may be pre-stored by the BMS. The preset duration may be related to any one or more of the characteristics of the X capacitor, the pressure relief speed of the pressure relief module, etc., or may also be calibrated by historical sampling, and the present application does not limit this.

[0091] S104. Based on the current and external voltage of the battery pack, determine whether the pressure relief module fails.

[0092] As the pressure relief process progresses, the voltage across the X capacitor gradually decreases. As described above, the external voltage of the battery pack is the voltage across the X capacitor. Therefore, as the pressure relief process progresses, when the pressure relief module is working properly and the internal relay of the battery pack is normally disconnected, when the pressure relief duration reaches the preset duration, V LINK+ will show a significant decrease.

[0093] If V LINK+ does not decrease as expected, it may be that the pressure relief module fails. In addition, during the high-voltage power-down process, the main positive relay and the pre-charge relay should be in the off state. When at least one of the main positive relay and the pre-charge relay is abnormally closed (such as sintering), the power battery in the battery pack will continuously output voltage, which will also cause V LINK+ not to decrease as expected.

[0094] The current of the battery pack can reflect whether the circuit of the battery pack is conducting. Therefore, when V LINK+ does not decrease as expected, it is possible to determine whether the pressure relief module fails based on the current.

[0095] The embodiments of the present application can utilize the existing high-voltage sampling points and current sampling points in the battery pack during the high-voltage power-off process to monitor the working state of the pressure relief module, so as to be able to timely know its failure state when the pressure relief module fails. This method does not require an additional hardware sampling unit and can detect whether the pressure relief module fails by using the existing sampling function, without increasing additional hardware costs. By detecting the working state of the pressure relief module, timely treatment measures can be taken when the pressure relief module fails, preventing electric shock to maintenance personnel or users or potential safety hazards caused by the high-voltage residue of the X capacitor, and improving the stability and safety of the high-voltage system.

[0096] The determination of whether the pressure relief module fails based on current and external voltage will be further described in detail below.

[0097] Optionally, if the external voltage is less than or equal to the first threshold, it is determined that the pressure relief module has not failed.

[0098] Exemplarily, if the external voltage is less than or equal to the first threshold, it indicates that as the pressure relief process progresses, the external voltage gradually decreases. Figure 1 For example, that is, the voltage across the X capacitor, namely V LINK+ gradually decreases, indicating that the pressure relief module can work properly. Optionally, the first threshold can be pre-stored in the BMS. The first threshold can be related to any one or more of the characteristics of the X capacitor, the pressure relief speed of the pressure relief module, etc., or can be calibrated by historical sampling, and the present application does not limit this.

[0099] Further, after determining that the pressure relief module has not failed, the BMS can monitor whether the pressure relief of the filter capacitor is completed based on the external voltage. Optionally, the BMS can continuously obtain the value of the external voltage at a fixed time interval. If the value of the external voltage is less than the preset value, it can be explained that the pressure relief of the filter capacitor is completed. Further, if the pressure relief of the filter capacitor is completed, the main negative relay is disconnected to complete the high-voltage power-off.

[0100] If the external voltage is greater than the first threshold, at this time, there are two situations. One is that the external voltage is greater than the first threshold due to the failure of the pressure relief module, and the other is that there is a sintered relay in the battery pack, that is, the relay in the battery pack has not been normally disconnected.

[0101] To distinguish the above two situations, it can be determined based on the current of the battery pack. If the current in the battery pack is greater than the second threshold, it indicates that the circuit is in a conducting state. In addition to the main negative relay in the battery pack, there is also a relay that has not been normally disconnected, and it can be determined that there is a sintered relay in the battery pack. If the current in the battery pack is less than or equal to the second threshold, it indicates that the relays in the battery pack except the main negative relay are all normally disconnected. Therefore, the reason for the external voltage being greater than the first threshold is the failure of the pressure relief module.

[0102] Optionally, the second threshold value can be pre-stored in the BMS, and can be related to the design of the battery pack, for example, the output current of the power battery, the size of the pre-charge resistor, etc., or can be calibrated by historical sampling. The present application does not make any limitation in this regard.

[0103] After determining that the pressure relief module fails, the BMS can output a first fault message, and the first fault message is used to indicate the failure of the pressure relief module.

[0104] Exemplarily, taking the electric vehicle as an example of the electrical equipment, the BMS can upload the first fault message to the vehicle.

[0105] In the embodiment of the present application, by outputting the first fault message to indicate the failure of the pressure relief module, it can remind the user or the maintenance personnel to perform maintenance under the condition of ensuring personal safety.

[0106] Furthermore, when it is determined that there is a sintered relay in the battery pack, the sintered relay can be further determined according to the magnitude of the current in the battery pack. That is, since the pre-charge relay is in series with the pre-charge resistor, the current generated in the battery pack due to the sintering of the pre-charge relay is smaller than the current generated in the battery pack due to the sintering of the main positive relay. Exemplarily, if the current is greater than the third threshold value, it is determined that the sintered relay is the main positive relay. If the current is less than the third threshold value, it is determined that the sintered relay is the pre-charge relay.

[0107] Optionally, the third threshold value can be pre-stored in the BMS, and can be related to the design of the battery pack, for example, the output current of the power battery, the size of the pre-charge resistor, etc., or can be calibrated by historical sampling. The present application does not make any limitation in this regard.

[0108] Optionally, after determining the sintered relay in the battery pack, the BMS can output a second fault message, and the second fault message is used to indicate the sintered relay.

[0109] The embodiment of the present application can further determine the sintered relay in the battery pack based on the current and give feedback, which helps to quickly locate the problems existing in the battery pack and improves the fault response speed of the high-voltage system.

[0110] Figure 3 is a schematic structural diagram of a high-voltage system provided by an embodiment of the present application, as Figure 3 shown, there is a high-voltage module in the battery pack. Therefore, after determining that the pressure relief module fails, the present application can also control the high-voltage relay in the battery pack to conduct, so as to use the existing high-voltage module in the battery pack to replace the pressure relief module to relieve the pressure of the X capacitor.

[0111] Optionally, the high-voltage module and the high-voltage relay can be originally available in the battery pack, for example, they can be the heating film and the heating relay in the battery pack. Figure 3It is a schematic diagram taking the heating film and the heating relay as examples. The heating film in the battery pack is usually used to adjust the battery temperature. In this method, the heating film can also be used to achieve the pressure relief function, adding the use of discharging the X capacitor in addition to battery temperature control, realizing multiple uses of one thing and improving the utilization rate of the heating film.

[0112] After determining that the pressure relief module fails in the embodiment of the present application, the high-voltage module and the high-voltage relay already available in the battery pack are used to replace the pressure relief module to complete the pressure relief, that is, the present application can replace the pressure relief module to complete the pressure relief without adding hardware units in the high-voltage system, improving the reliability of the high-voltage system, reducing the cost required for the high-voltage system to achieve the pressure relief function, and the complexity of the structural design.

[0113] It should be understood that the above is to reuse the high-voltage module and the high-voltage relay already available in the battery pack to replace the pressure relief module to complete the pressure relief. Optionally, the high-voltage module and the high-voltage relay can also be additionally added to the high-voltage system, and the present application does not limit this.

[0114] Optionally, during the process of discharging the filter capacitor through the high-voltage module, the BMS can monitor whether the high-voltage relay fails based on the pressure difference of the high-voltage relay and using the existing high-voltage sampling points in the battery pack, so as to be able to timely know its failure state when the high-voltage relay fails. Further, taking Figure 3 as an example, the pressure difference of the high-voltage relay can be the difference between V LINK+ and V 加热 . If this pressure difference is less than or equal to the fourth threshold, it indicates that the high-voltage relay is normally closed. If this pressure difference is greater than the fourth threshold, it indicates that the high-voltage relay fails.

[0115] Optionally, the fourth threshold can be pre-stored in the BMS, can be related to the characteristics of the high-voltage relay, or can be calibrated by historical sampling. The present application does not limit this.

[0116] After the BMS determines that the high-voltage relay fails, it indicates that there is no way to discharge the X capacitor in the high-voltage system. At this time, the BMS can output the third fault information, and the third fault information is used to indicate that the filter capacitor has not completed the pressure relief.

[0117] After the BMS determines that the high-voltage relay has not failed, that is, when the high-voltage module can normally discharge the filter capacitor, the BMS can continue to monitor the external voltage to determine whether the pressure relief of the filter capacitor is completed.

[0118] Optionally, the BMS can continuously obtain the value of the external voltage at a fixed time interval. If the value of the external voltage is less than the preset value, it can indicate that the pressure relief of the filter capacitor is completed. Further, if the pressure relief of the filter capacitor is completed, the BMS disconnects the high-voltage relay and the main negative relay in sequence to complete the high-voltage power-down process.

[0119] Exemplarily, in combination with Figure 3 , the obtained external voltage is represented by V LINK+ , and the obtained current is represented by I. Figure 4 FIG. is a schematic flow chart of a high-voltage power-off control method provided by an embodiment of the present application. In combination with the above method, the second threshold, the fourth threshold, and the preset value are all taken as 0, and the process includes:

[0120] 1. Start.

[0121] 2. The BMS receives a high-voltage power-off command.

[0122] In response to the high-voltage power-off command, execute the high-voltage power-off process, that is, the subsequent steps.

[0123] 3. Disconnect the main positive relay.

[0124] 4. The BMS requests the vehicle VCU to activate the pressure relief function.

[0125] 5. The vehicle VCU activates the pressure relief function.

[0126] 6. Wait for time T 1 .

[0127] 7. Determine whether V LINK+ is less than the set threshold. If so, execute step 8; if not, execute step 10.

[0128] 8. Determine whether V LINK+ is 0. If so, execute step 7; if not, execute step 8.

[0129] 9. Determine that the X capacitor has completed discharge, and continue to execute step 21.

[0130] 10. Determine whether I is 0. If so, execute step 12; if not, execute step 11.

[0131] 11. Determine that the pressure relief module is normally activated, and determine whether the main positive relay or the pre-charge relay is sintered according to the magnitude of I.

[0132] Optionally, after determining the sintering fault of the main positive relay or the pre-charge relay, output the second fault information.

[0133] 12. Determine that the pressure relief module is operating abnormally.

[0134] Optionally, after determining that the pressure relief module is operating abnormally, output the first fault information.

[0135] 13. Close the heating relay.

[0136] 14. Determine V LINK+ and V 加热Whether the difference is less than the set threshold. If so, execute step 16; if not, execute step 15.

[0137] 15. Determine that the heating relay cannot close and a fault occurs.

[0138] Optionally, after determining the fault information that the heating relay cannot close, output the third fault information.

[0139] 16. Determine whether V LINK+ is 0. If so, execute step 19; if not, execute step 18.

[0140] 17. Determine that the vehicle X capacitor has completed discharging.

[0141] 18. Disconnect the heating relay.

[0142] 19. Disconnect the main negative relay.

[0143] 20. The high-voltage power-off is completed.

[0144] 21. End.

[0145] The embodiment of the present application designs a new high-voltage power-off process, which uses the existing high-voltage sampling points and current sampling points in the battery pack to add functions for the battery pack to assist in monitoring the state of the pressure relief module and the discharging of the capacitor. It not only realizes the monitoring of the state of the pressure relief module and the X capacitor, but also ensures the detection of the state of the internal relay of the battery pack, and has good feasibility.

[0146] In the existing high-voltage power-off process, the main negative relay usually disconnects immediately after the main positive relay disconnects. However, the embodiment of the present application designs a method for delaying the disconnection of the main negative relay. After disconnecting the main positive relay, by keeping the main negative relay in the closed state, the high-voltage reference ground of the battery pack is connected to the high-voltage reference ground of the vehicle end, realizing the function of collecting the vehicle-end voltage using V LINK+ .

[0147] This method does not require an additional hardware sampling unit, and can detect whether the pressure relief module fails by using the existing sampling function, without increasing additional hardware costs. By detecting the working state of the pressure relief module, timely treatment measures can be taken when the pressure relief module fails, preventing electric shock to maintenance personnel or users or potential safety hazards caused by the high-voltage residue of the X capacitor, and improving the stability and safety of the high-voltage system.

[0148] The above is the method embodiment provided by the present application. The device provided by the present application will be described below.

[0149] Figure 5 is a schematic structural diagram of a high-voltage power-off control device provided by the present application. The high-voltage system of the electrical equipment includes: a battery pack, a pressure relief module, and a filter capacitor; asFigure 5 As shown in Figure 5 , the high-voltage power-off control device 200 provided in this embodiment includes a control module 201, a pressure relief module 202, an acquisition module 203, and a determination module 204. Optionally, the high-voltage power-off control device 200 may further include an output module 205.

[0150] The control module 201 is configured to disconnect the main positive relay of the battery pack and keep the main negative relay of the battery pack closed in response to a high-voltage power-off instruction.

[0151] The pressure relief module 202 is configured to relieve the pressure of the filter capacitor through the pressure relief module.

[0152] The acquisition module 203 is configured to acquire the current of the battery pack and the external voltage when the pressure relief duration reaches a preset duration.

[0153] The determination module 204 is configured to determine whether the pressure relief module fails based on the current and the external voltage.

[0154] Optionally, the determination module 204 is specifically configured to determine that the pressure relief module has not failed when the external voltage is less than or equal to a first threshold. Determine that the pressure relief module has not failed when the external voltage is greater than the first threshold and the current is greater than a second threshold. When the external voltage is greater than the first threshold and the current is less than or equal to the second threshold, it is determined that the pressure relief module has failed.

[0155] Exemplarily, the control module 201 is further configured to determine whether the pressure relief of the filter capacitor is completed based on the external voltage after the determination module 204 determines that the pressure relief module has not failed. When the pressure relief of the filter capacitor is completed, disconnect the main negative relay.

[0156] Exemplarily, the output module 205 is configured to output a first fault message after the determination module 204 determines that the pressure relief module has failed, and the first fault message is used to indicate that the pressure relief module has failed.

[0157] Exemplarily, the determination module 204 is further configured to determine the relay in the battery pack that has sintered based on the current when the current is greater than the second threshold.

[0158] For example, the battery pack further includes a pre-charge relay. The determination module 204 is specifically configured to determine that the relay that has sintered is the main positive relay when the current is greater than a third threshold. When the current is less than the third threshold, it is determined that the relay that has sintered is the pre-charge relay.

[0159] In some embodiments, the output module 205 is further configured to output a second fault message after the determination module 204 determines the relay in the battery pack that has sintered, and the second fault message is used to indicate the relay that has sintered.

[0160] Exemplarily, the battery pack further includes: a high-voltage relay and a high-voltage module connected in series. The pressure relief module 202 is further configured to control the high-voltage relay to conduct, so as to relieve the pressure of the filter capacitor through the high-voltage module.

[0161] For example, the determination module 204 is further configured to determine whether the high-voltage relay fails based on the pressure difference of the high-voltage relay during the process of relieving the pressure of the filter capacitor through the high-voltage module.

[0162] In some embodiments, the determination module 204 is specifically configured to determine that the high-voltage relay has not failed when the pressure difference is less than or equal to the fourth threshold. When the pressure difference is greater than the fourth threshold, it is determined that the high-voltage relay fails.

[0163] Optionally, the output module 205 is further configured to output third fault information after the determination module 204 determines that the high-voltage relay fails. The third fault information is used to indicate that the pressure relief of the filter capacitor is not completed.

[0164] Optionally, the control module 201 is further configured to determine whether the pressure relief of the filter capacitor is completed based on the external voltage after the determination module 204 determines that the high-voltage relay has not failed. When the pressure relief of the filter capacitor is completed, the high-voltage relay and the main negative relay are disconnected in sequence. The high-voltage power-off control device provided in this embodiment can execute the method provided in any of the above method embodiments, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0165] Figure 6 It is a schematic structural diagram of a BMS of a battery pack provided by this application. As Figure 6 shown, the BMS 300 of the battery pack provided in this embodiment includes: at least one processor 301 and a memory 302. Optionally, the device 300 further includes a communication component 303. Among them, the processor 301, the memory 302, and the communication component 303 are connected through a bus 304.

[0166] In the specific implementation process, at least one processor 301 executes the computer-executable instructions stored in the memory 302, so that at least one processor 301 executes the above method.

[0167] The specific implementation process of the processor 301 can refer to the above method embodiment, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0168] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU for short), or other general-purpose processors, digital signal processors (DSP for short), application specific integrated circuits (ASIC for short), etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0169] The memory may include a random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0170] The bus may be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience in representation, the buses in the drawings of this application are not limited to only one bus or one type of bus.

[0171] The embodiment of the present application provides a battery pack, which includes the BMS of the above battery pack.

[0172] The embodiment of the present application provides a high-voltage system for an electrical device, which includes a pressure relief module, a filter capacitor, and the above battery pack.

[0173] The embodiment of the present application provides an electrical device, which includes the above high-voltage system.

[0174] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0175] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the processor executes the computer-executable instructions, the above method is implemented.

[0176] The above-readable storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disk. The readable storage medium may be any available medium accessible by a general-purpose or special-purpose computer.

[0177] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium may also be an integral part of the processor. The processor and the readable storage medium may be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium may also exist as discrete components in a device.

[0178] The division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other may be indirect couplings or communication connections through some interfaces, devices, or units, and may be in electrical, mechanical, or other forms.

[0179] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0180] In addition, in each embodiment of the present invention, the functional units may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0181] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs, and other various media that can store program codes.

[0182] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When this program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: ROMs, RAMs, magnetic disks, or optical discs, and other various media that can store program codes.

[0183] Finally, it should be noted that: After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily think of other implementation manners of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for controlling electricity under high voltage, characterized in that: The high-voltage system of the electric equipment includes: a battery pack, a pressure relief module and a filter capacitor; the method includes: In response to a high voltage power-down instruction, disconnecting a main positive relay of the battery pack and keeping a main negative relay of the battery pack closed; Relieve the pressure of the filter capacitor through the pressure relief module; When the pressure relief time reaches a preset time, obtaining the current and external voltage of the battery pack; Based on the current and the external voltage, it is determined whether the pressure relief module fails.

2. The method according to claim 1, characterized in that The determining whether the pressure relief module fails based on the current and the external voltage includes: If the external voltage is less than or equal to the first threshold, it is determined that the pressure relief module is not failed; If the external voltage is greater than the first threshold value, and the current is greater than the second threshold value, it is determined that the pressure relief module is not failed; If the external voltage is greater than a first threshold value, and the current is less than or equal to a second threshold value, it is determined that the pressure relief module has failed.

3. The method according to claim 2, characterized in that After determining that the pressure relief module fails, the method further includes: Outputting first fault information, where the first fault information is used to indicate that the pressure relief module fails.

4. The method according to claim 2, characterized in that: The method further comprises: If the current is greater than the second threshold, a relay in the battery pack that is burned is determined based on the current.

5. The method according to claim 4, characterized in that The battery pack further includes: a pre-charge relay; and the step of determining the relay that is sintered in the battery pack based on the current includes: If the current is greater than a third threshold, it is determined that the relay that is sintered is the main positive relay; If the current is less than the third threshold, it is determined that the relay that is sintered is the pre-charged relay.

6. The method according to claim 4, characterized in that After determining the relay that is sintered in the battery pack, the method further includes: The second fault information is outputted, wherein the second fault information is used to indicate a relay that has been sintered.

7. The method according to claim 2, characterized in that The battery pack further includes: a high-voltage relay and a high-voltage module connected in series. After determining that the pressure relief module fails, the method further includes: The high-voltage relay is controlled to be turned on so as to release the pressure of the filter capacitor through the high-voltage module.

8. The method according to claim 7, characterized in that The method further comprises: In the process of relieving the pressure of the filter capacitor through the high-voltage module, it is determined whether the high-voltage relay fails based on the pressure difference of the high-voltage relay.

9. The method according to claim 8, characterized in that The step of determining whether the high-voltage relay fails based on the pressure difference of the high-voltage relay comprises: If the pressure difference is less than or equal to a fourth threshold, it is determined that the high-voltage relay has not failed; If the pressure difference is greater than a fourth threshold, it is determined that the high-voltage relay has failed.

10. The method according to claim 9, characterized in that After determining that the high-voltage relay has failed, the method further includes: Output third fault information, where the third fault information is used to indicate that the filter capacitor has not completed pressure relief.

11. The method according to claim 9, characterized in that After determining that the high-voltage relay has not failed, the method further includes: Based on the external voltage, determining whether the pressure relief of the filter capacitor is completed; If the pressure relief of the filter capacitor is completed, the high-voltage relay and the main negative relay are disconnected in sequence.

12. The method according to claim 2, characterized in that: After determining that the pressure relief module is not failed, the method further includes: Based on the external voltage, determining whether the pressure relief of the filter capacitor is completed; If the pressure relief of the filter capacitor is completed, the main negative relay is disconnected.

13. A high voltage power control device, characterized in that: The high-voltage system of the electrical equipment includes: a battery pack, a pressure relief module and a filter capacitor; the device includes: a control module, configured to disconnect a main positive relay of the battery pack and keep a main negative relay of the battery pack closed in response to a high voltage power-down instruction; A pressure relief module, used for releasing pressure on the filter capacitor through the pressure relief module; An acquisition module, used for acquiring the current and external voltage of the battery pack when the pressure relief time reaches a preset time; A determination module is used to determine whether the pressure relief module fails based on the current and the external voltage.

14. A BMS for a battery pack, characterized in that: The BMS includes: a memory and a processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 12.

15. A battery pack, characterized in that: The battery pack comprises: the BMS as claimed in claim 14.

16. A high voltage system for electrical equipment, characterized in that: The high voltage system comprises: a pressure relief module, a filter capacitor, and a battery pack as claimed in claim 15.

17. An electrical equipment, characterized in that: The electrical equipment includes: a high voltage system as claimed in claim 16.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 12 when executed by a processor.

19. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 12 when being executed by a processor.

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