Battery management system, electric vehicle, and power battery protection method

Abstract

The present invention provides a battery management system, an electric vehicle, and a power battery protection method. The battery management system includes a detection board and a control board. The detection board is connected to an on-board power battery and is used to detect a thermal runaway state of a cell of the power battery. The control board is connected to the detection board, and the control board includes a power chip and a controller, and the detection board is provided independently from the control board, the detection board is connected to the power chip, and the power chip is connected to the controller. The power battery protection method includes the steps of detecting a thermal runaway state of a cell of the on-board power battery, generating a wake-up signal when the battery management system is offline and detecting thermal runaway of a cell of the power battery, and waking up the battery management system using the wake-up signal to issue a thermal runaway alarm. The present invention can provide excellent safety protection functions for the power battery.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to the technical field of electric vehicles, and more particularly to a battery management system, an electric vehicle, and a power battery protection method. [Background technology]

[0002] As gasoline energy continues to become scarce and environmental awareness grows, electric vehicles (EVs) are increasingly being adopted as a new, environmentally friendly form of transportation, replacing traditional energy vehicles. Power batteries are an important power source for EVs, and power battery safety is a key issue to be addressed during the development of EVs. Typically, EV power batteries require multiple battery units (cells) connected in series or parallel to be grouped together. Because the high energy content of grouped batteries can lead to thermal runaway and cell combustion under special conditions such as short circuits and collisions, cell combustion can occur. Cell combustion releases large amounts of heat, which, if not promptly or improperly treated, can lead to the entire battery system catching fire or exploding, potentially resulting in loss of life and property.

[0003] In recent years, there have been frequent cases of spontaneous combustion in electric vehicles. In light of this, it is necessary to improve the safety of power batteries in order to popularize new energy electric vehicles on a large scale. Therefore, how to prevent and reduce the occurrence of thermal runaway in batteries is currently a major issue in the electric vehicle field. Summary of the Invention

[0004] The embodiments of the present invention provide a battery management system, an electric vehicle, and a power battery protection method that can effectively protect a power battery.

[0005] According to one aspect of an embodiment of the present invention, there is provided a battery management system, the battery management system including a detection board and a control board, the detection board is connected to an on-board power battery and is used to detect a cell thermal runaway state of the power battery, the control board is connected to the detection board, the control board includes a power chip and a controller, the detection board is provided independently from the control board, the detection board is connected to the power chip, and the power chip is connected to the controller.

[0006] In one alternative embodiment, when the battery management system is offline, when thermal runaway of a cell of the power battery is detected, the detection plate is further used to generate a wake-up signal to wake up the controller via the power chip to operate the battery management system.

[0007] In one alternative embodiment, the controller is further adapted to issue a thermal runaway alarm when thermal runaway of a cell of the power battery occurs.

[0008] In one alternative embodiment, the detection plate includes a cell collection plate for collecting battery unit voltage and / or temperature of the power battery online and / or offline at a predetermined sampling period.

[0009] In one alternative embodiment, the cell collection board is used to compare the collected battery unit voltage of the power battery with a predetermined voltage limit value and / or compare the collected battery unit temperature of the power battery with a predetermined temperature limit value, and generate the wake-up signal when the battery unit voltage of the power battery exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery exceeds the predetermined temperature limit value.

[0010] In one alternative embodiment, the detection plate further includes a high voltage current collection plate for collecting current from the power battery.

[0011] In one alternative embodiment, the high-voltage current collection board is used to collect the voltage across a detection resistor connected in series to a load circuit, and obtain the current of the power battery by collecting the voltage across the detection resistor, and the load circuit includes the power battery and a load connected in series.

[0012] In one alternative embodiment, when the collected current of the power battery exceeds an overcurrent protection current limit value, the high voltage current collection board is further used to generate an overcurrent hardware signal to the controller, and the controller is used to provide overcurrent protection to the power battery.

[0013] In one alternative embodiment, when the collected current of the power battery exceeds a short circuit protection current limit value, the high voltage current collecting board is further used to generate a short circuit hardware signal to the controller, and the controller is used to control the blowing of an explosive fuse connected in series with the load circuit.

[0014] In one alternative embodiment, the control board further includes a low-voltage uninterruptible power supply and a pressure detection module, the low-voltage uninterruptible power supply is used to supply power to the pressure detection module, the pressure detection module is connected to the power chip, and the pressure detection module is used to detect the pressure of the power battery online and / or offline.

[0015] In one alternative embodiment, when the battery management system is offline, when the detected pressure of the power battery exceeds a predetermined pressure limit value, the pressure detection module is further used to generate a wake-up signal to wake up the controller via the power chip to operate the battery management system.

[0016] According to another aspect of the present invention, there is provided an electric vehicle including the battery management system according to any one of the above embodiments.

[0017] According to another aspect of the present invention, there is provided a power battery protection method, the method including: detecting a cell thermal runaway state of a power battery mounted on a vehicle; generating a wake-up signal when detecting thermal runaway of a cell of the power battery if a battery management system is offline; and waking up operation of the battery management system by the wake-up signal to issue a thermal runaway alarm.

[0018] In one alternative embodiment, the step of detecting a cell thermal runaway state of an on-board power battery includes the steps of collecting battery unit voltages and / or temperatures of the power battery online and / or offline at a predetermined sampling period, comparing the collected battery unit voltages of the power battery with a predetermined voltage limit value and / or comparing the collected battery unit temperatures of the power battery with a predetermined temperature limit value, and determining that thermal runaway has occurred in a cell of the power battery when the battery unit voltage of the power battery exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery exceeds the predetermined temperature limit value.

[0019] In one alternative embodiment, the step of detecting a cell thermal runaway condition of an on-board power battery includes the steps of collecting a current of the power battery, and determining that a thermal runaway has occurred in a cell of the power battery if the collected current of the power battery exceeds a short circuit protection current limit value.

[0020] In one alternative embodiment, the method further includes the steps of: when the collected current of the power battery exceeds an overcurrent protection current limit value, generating an overcurrent hardware signal to a battery management system to provide overcurrent protection to the power battery; and when the collected current of the power battery exceeds a short circuit protection current limit value, generating a short circuit hardware signal to the battery management system so that the battery management system controls the blowing of an explosive fuse connected in series to a load circuit, the load circuit including the power battery and a load connected in series.

[0021] In one alternative embodiment, the step of detecting a cell thermal runaway condition of an on-board power battery includes the steps of detecting a pressure of the power battery online and / or offline, comparing the detected pressure of the power battery with a predetermined pressure limit value, and determining that a thermal runaway has occurred in a cell of the power battery if the pressure of the power battery exceeds the predetermined pressure limit value.

[0022] The battery management system, electric vehicle, and power battery protection method according to one or more embodiments of the present invention can effectively protect the power battery. [Brief explanation of the drawings]

[0023] In order to more clearly explain the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings in the following description are only a part of the embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without any creative efforts. [Figure 1] 1 is a schematic block diagram of a battery management system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a structural block diagram of the internal part of the control board according to the embodiment of the present invention. [Figure 3] 2 is a flowchart of a power battery protection method according to an embodiment of the present invention. [Figure 4] 1 illustrates specific steps of a power battery protection method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention, but it is obvious that the described embodiments are only some embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the protection scope of the present invention.

[0025] Illustrative embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different drawings refer to the same or similar elements unless otherwise noted. The embodiments described in the following illustrative examples do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as set forth in the appended claims.

[0026] The terms used in the present invention are merely for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present invention and the appended claims, the singular forms "a," "the," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used refers to and includes any and all possible combinations of one or more of the associated listed items. Unless otherwise specified, similar terms such as "front," "rear," "lower," and / or "upper" are for descriptive purposes only and are not intended to limit a location or spatial orientation. Similar terms such as "connected" or "coupled" are not limited to physical or mechanical connections and may also include electrical connections, whether direct or indirect. In the present invention, "capable" may refer to having the ability.

[0027] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. Unless contradictory, the features in the following embodiments and embodiments can be combined with each other.

[0028] An embodiment of the present invention provides a battery management system (BMS) 10. FIG. 1 is a schematic block diagram of the battery management system 10 of an embodiment of the present invention. As shown in FIG. 1, the battery management system 10 of an embodiment of the present invention includes a detection board and a control board 13, and the detection board is provided independently from the control board 13. The detection board is connected to an on-board power battery 20 and can be used to detect a cell thermal runaway state of the power battery 20. The control board 13 is connected to the detection board, and the control board 13 includes a power chip 131 and a controller 132. The power chip 131 can be used to supply power to the entire BMS, and the power chip 131 is connected to the controller 132, and the detection board is connected to the power chip 131 in the control board 13.

[0029] The detection board can be used to detect the cell thermal runaway state of the power battery 20. When the battery management system 10 is offline, when the cell thermal runaway of the power battery 20 is detected, the detection board can generate a wake-up signal and send the wake-up signal to the control board 13, which turns on the power chip 131 of the control board 13 and wakes up the controller 132 through the power chip 131, which activates the BMS 10 and wakes up the entire vehicle.

[0030] In some embodiments, if thermal runaway occurs in a cell of the power battery 20, the controller 132 in the BMS can further issue a thermal runaway alarm to provide appropriate advance warning to the driver and passengers.

[0031] In some embodiments, the detection board of the present invention may include a cell collection board 11 that is provided independently from the control board 13 and connected to the power battery 20, and the cell collection board 11 is connected to the power chip 131 of the control board 13. The cell collection board 11 can collect the battery unit voltage and / or temperature of the power battery 20 online and / or offline at a predetermined sampling period.

[0032] The cell collection board 11 compares the collected battery unit voltage of the power battery 20 with a predetermined voltage limit value and / or compares the collected battery unit temperature of the power battery 20 with a predetermined temperature limit value. If the battery unit voltage of the power battery 20 exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery 20 exceeds the predetermined temperature limit value and the battery management system is offline, a wake-up signal can be generated. For example, the cell collection board 11 can continuously detect the battery unit voltage and / or temperature of the power battery 20 when the entire vehicle is in a sleep state. If the battery unit voltage of the power battery 20 exceeds a predetermined voltage upper limit or a predetermined voltage lower limit and / or the battery unit temperature of the power battery 20 exceeds a predetermined temperature upper limit or a predetermined temperature lower limit, the cell collection board 11 can generate a wake-up signal to turn on the power chip 131 in the control board 13 and wake up the controller 132 in the control board 13, which will activate the entire BMS 10 and wake up the entire vehicle, thereby issuing a thermal runaway warning.

[0033] The battery management system 10 according to the embodiment of the present invention can not only support online battery thermal runaway detection, but also offline thermal runaway detection, and can immediately issue a thermal runaway alarm in the event of offline thermal runaway.

[0034] In some embodiments, the sensing board of the present invention may further include a high voltage current collection board 12 that is provided independently of the control board 13 and that may be used to collect current from the power battery 20 .

[0035] As shown in Figure 1, the power battery 20 can provide power to a load 40. The power battery 20 and the load 40 connected in series constitute a load circuit. A sense resistor 50 is connected in series to the load circuit. In one embodiment, the high-voltage current collection board 12 can be used to collect the voltage across the sense resistor 50 connected in series to the load circuit, and obtain the current of the power battery 20 by collecting the voltage across the sense resistor 50.

[0036] In some embodiments, the battery management system 10 of the present invention can provide overcurrent protection. When the collected current of the power battery 20 exceeds the overcurrent protection current limit value, the high voltage current collection board 12 can generate an overcurrent hardware signal to the controller 132, and the controller 132 can provide overcurrent protection to the power battery 20.

[0037] A pyrotechnic fuse 30 is also connected in series with the load circuit. Unlike conventional fuses, the pyrotechnic fuse 30 can be actively controlled and is inexpensive. Therefore, adopting such a pyrotechnic fuse can significantly reduce costs and improve competitive advantage. In another embodiment, the battery management system 10 of the present invention can also provide short-circuit protection. When the collected current of the power battery 20 exceeds the short-circuit protection current limit value, the high-voltage current collection board 12 can generate a short-circuit hardware signal to the controller 132. The controller 132 can control the rapid blowing of the pyrotechnic fuse 30 connected in series with the load circuit. When the pyrotechnic fuse 30 blows, the high-voltage power supply to the entire vehicle is cut off, providing excellent short-circuit protection for the power battery 20.

[0038] The battery management system 10 of the embodiment of the present invention not only supports overcurrent protection, but also supports short circuit protection, and can complete the short circuit protection function in a short time (e.g., 5 ms), cut off the high voltage of the entire vehicle, and protect the power battery 20.

[0039] 2 is a structural block diagram of the internal part of the control board 13 according to one embodiment of the present invention. As shown in FIG. 2, in some embodiments, the control board 13 of the present invention may further include a low-voltage uninterruptible power supply 133 and a pressure detection module 134. The low-voltage uninterruptible power supply 133 may be, for example, a 5V uninterruptible power supply. The low-voltage uninterruptible power supply 133 may be used to supply power to the pressure detection module 134, which can detect the pressure of the power battery 20 online and / or offline. The pressure detection module 134 is connected to the power chip 131.

[0040] The pressure detection module 134 of the embodiment of the present invention can continuously detect the pressure of the power battery 20 even when the entire vehicle is in a sleep state.

[0041] The pressure detection module 134 can compare the detected pressure of the power battery 20 with a predetermined pressure limit value. If the pressure of the power battery 20 detected by the pressure detection module 134 exceeds the predetermined pressure limit value and the battery management system 10 is offline, the pressure detection module 134 can generate a wake-up signal to turn on the power chip 131 and wake up the controller 132, so that the entire BMS 10 is activated and the entire vehicle is woken up, and a thermal runaway alarm can be issued.

[0042] The battery management system 10 of the embodiment of the present invention integrates the pressure detection module 134 into the control board 13 and continuously supplies power to the pressure detection module 134 from a low-voltage uninterruptible power supply 133, thereby enabling real-time detection of the pressure of the power battery 20, achieving a detection cycle of, for example, 10 ms at the shortest, and supporting online and / or offline pressure detection and an offline automatic wake-up function.

[0043] The battery management system 10 according to the embodiment of the present invention can perform omnidirectional safety management and efficient detection of the power battery 20, realize detection of all operating states, and has a high degree of integration and low cost.

[0044] The battery management system 10 of the embodiment of the present invention can efficiently detect the safety state of the power battery 20, thereby effectively ensuring the personal safety of users, reducing the risk of thermal runaway in the entire vehicle, and protecting the safety of property.

[0045] An embodiment of the present invention further provides an electric vehicle, which includes the battery management system 10 described in each of the above embodiments.

[0046] The electric vehicle according to the embodiment of the present invention has beneficial technical effects similar to those of the battery management system 10 described above, and therefore a description thereof will be omitted here.

[0047] An embodiment of the present invention further provides a power battery protection method. Figure 3 is a flowchart of the power battery protection method of an embodiment of the present invention. As shown in Figure 3, the power battery protection method of an embodiment of the present invention may include steps S11 to S14.

[0048] In step S11, a cell thermal runaway state of the vehicle-mounted power battery 20 can be detected.

[0049] In step S12, it is determined whether thermal runaway has occurred in the cells of the power battery 20. If the result of the determination is "yes," the process proceeds to step S13. Otherwise, the process returns to continuous detection.

[0050] In step S13, if it is determined in step S12 that thermal runaway has occurred in the cells of the power battery 20, a wake-up signal can be generated when the battery management system 10 is offline.

[0051] In step S14, the operation of the battery management system 10 can be woken up by the wake-up signal generated in step S13, and a thermal runaway alarm can be issued.

[0052] In some embodiments, the step of detecting a cell thermal runaway state of the on-board power battery 20 in step S11 may include the steps of collecting battery unit voltages and / or temperatures of the power battery 20 online and / or offline at a predetermined sampling period, comparing the collected battery unit voltages of the power battery 20 with a predetermined voltage limit value and / or comparing the collected battery unit temperatures of the power battery 20 with a predetermined temperature limit value, and determining that thermal runaway has occurred in a cell of the power battery 20 if the battery unit voltage of the power battery 20 exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery 20 exceeds the predetermined temperature limit value.

[0053] In some embodiments, the step of detecting a cell thermal runaway state of the on-board power battery 20 in step S11 may include collecting a current of the power battery 20, and determining that a thermal runaway has occurred in a cell of the power battery 20 if the collected current of the power battery 20 exceeds a short circuit protection current limit value.

[0054] In some embodiments, the power battery protection method of the present invention may further include the steps of: when the collected current of the power battery 20 exceeds the overcurrent protection current limit value, generating an overcurrent hardware signal to the battery management system 10 to provide overcurrent protection for the power battery 20; and when the collected current of the power battery 20 exceeds the short circuit protection current limit value, generating a short circuit hardware signal to the battery management system 10 so that the battery management system 10 controls the blowout of the explosive fuse 30 connected in series to the load circuit, where the load circuit includes the power battery 20 and the load 40 connected in series.

[0055] In some embodiments, the step of detecting a cell thermal runaway state of the on-board power battery 20 in step S11 may include the steps of detecting the pressure of the power battery 20 online and / or offline, comparing the detected pressure of the power battery 20 with a predetermined pressure limit value, and determining that thermal runaway has occurred in a cell of the power battery 20 if the detected pressure of the power battery 20 exceeds the predetermined pressure limit value.

[0056] FIG. 4 shows the specific steps of a power battery protection method according to a specific embodiment of the present invention. As shown in FIG. 4, in step S21, online and / or offline battery unit voltage and / or temperature detection can be performed on the power battery 20 at a predetermined sampling period. In step S22, it is determined whether the collected battery unit voltage of the power battery 20 exceeds a predetermined voltage limit value and / or whether the collected battery unit temperature of the power battery 20 exceeds a predetermined temperature limit value. If the result of the determination is "yes," the process proceeds to step S23. Otherwise, the process returns. In step S23, if the battery unit voltage of the power battery 20 exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery 20 exceeds the predetermined temperature limit value and the BMS 10 is offline, a wake-up signal is generated. In step S24, the wake-up signal wakes up the BMS 10. In step S25, the BMS 10 can issue a thermal runaway alarm.

[0057] In step S31, current detection can be performed on the power battery 20. In step S32, it is determined whether the collected current of the power battery 20 exceeds the overcurrent protection current limit value. If the result of the determination is "yes," the process proceeds to step S33. Otherwise, the process returns. In step S33, if the current of the power battery 20 exceeds the overcurrent protection current limit value, an overcurrent hardware signal is generated to the BMS 10. In step S34, the BMS 10 can perform overcurrent protection on the power battery 20. In step S35, it is determined whether the collected current of the power battery 20 exceeds the short circuit protection current limit value. If the result of the determination is "yes," the process proceeds to step S36. Otherwise, the process returns. In step S36, if the current of the power battery 20 exceeds the short circuit protection current limit value, a short circuit hardware signal is generated to the BMS 10. In step S37, the BMS 10 can control the rapid melting of the pyrotechnic fuse 30 connected in series to the load circuit, thereby providing overcurrent protection to the power battery 20.

[0058] In step S41, online and / or offline pressure detection can be performed on the power battery 20. In step S42, it is determined whether the collected pressure of the power battery 20 exceeds a predetermined pressure limit value. If the result of the determination is "yes," the process proceeds to step S43. Otherwise, the process returns. In step S43, if the pressure of the power battery 20 exceeds the predetermined pressure limit value and the BMS 10 is offline, a wake-up signal is generated. In step S44, the wake-up signal wakes up the operation of the BMS 10. In step S45, the BMS 10 can issue a thermal runaway alarm.

[0059] The power battery protection method according to the embodiment of the present invention can provide good and versatile safety protection functions for the power battery.

[0060] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another and do not necessarily require or imply any actual relationship or order between those entities or operations. The terms "comprise," "contain," or any other variation thereof, are intended to include a non-exclusive inclusion, whereby a process, method, article, or device that includes a set of elements not only includes those elements, but also includes other elements not expressly listed, or includes the inherent elements of such process, method, article, or device. Absent more limitations, elements qualified by the phrase "comprises ..." do not exclude the presence of additional identical elements in a process, method, article, or device that includes said elements.

[0061] The battery management system, electric vehicle, and power battery protection method according to the embodiments of the present invention have been described in detail above. Although the principles and embodiments of the present invention have been described using specific examples in this specification, the description of the above examples is merely intended to facilitate understanding of the method and its core idea of ​​the present invention, and the contents of this specification do not limit the present invention. Furthermore, those skilled in the art may make any modifications, equivalent substitutions, or improvements to the specific embodiments and application scope based on the idea of ​​the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. a detection plate connected to the vehicle-mounted power battery for detecting a cell thermal runaway state of the power battery; a control board connected to the detection board and including a power chip and a controller; the detection board is provided independently of the control board, the detection board is connected to the power supply chip, and the power supply chip is connected to the controller; A battery management system characterized by:

2. When the battery management system is offline, when a thermal runaway of a cell of the power battery is detected, the detection board is further used to generate a wake-up signal to wake up the controller via the power chip to operate the battery management system. The battery management system according to claim 1 .

3. When thermal runaway occurs in a cell of the power battery, the controller is further used to issue a thermal runaway alarm. The battery management system according to claim 2 .

4. The detection plate includes a cell collection plate for collecting the battery unit voltage and / or temperature of the power battery online and / or offline at a predetermined sampling period; The battery management system according to claim 2 .

5. The cell collection board is used to compare the collected battery unit voltage of the power battery with a predetermined voltage limit value and / or compare the collected battery unit temperature of the power battery with a predetermined temperature limit value, and generate the wake-up signal when the battery unit voltage of the power battery exceeds the predetermined voltage limit value and / or the battery unit temperature of the power battery exceeds the predetermined temperature limit value and the battery management system is offline; The battery management system according to claim 4 .

6. the detection plate further includes a high voltage current collection plate for collecting current from the power battery; The battery management system according to claim 2 .

7. The high-voltage current collecting board is used to collect the voltage across a detection resistor connected in series to a load circuit, and obtain the current of the power battery by collecting the voltage across the detection resistor, and the load circuit includes the power battery and a load connected in series; The battery management system according to claim 6 .

8. When the collected current of the power battery exceeds an overcurrent protection current limit value, the high voltage current collecting board is further used to generate an overcurrent hardware signal to the controller, and the controller is used to provide overcurrent protection to the power battery; The battery management system according to claim 6 .

9. When the collected current of the power battery exceeds a short circuit protection current limit value, the high voltage current collecting board is further used to generate a short circuit hardware signal to the controller, and the controller is used to control the blowing of an explosive fuse connected in series with a load circuit; 9. The battery management system according to claim 6 or 8.

10. The control board further includes a low-voltage uninterruptible power supply and a pressure detection module, the low-voltage uninterruptible power supply is used to supply power to the pressure detection module, the pressure detection module is connected to the power chip, and the pressure detection module is used to detect the pressure of the power battery online and / or offline; The battery management system according to claim 1 .

11. When the battery management system is offline, when the detected pressure of the power battery exceeds a predetermined pressure limit value, the pressure detection module is further used to generate a wake-up signal to wake up the controller via the power chip to operate the battery management system. The battery management system according to claim 10 .

12. A battery management system according to any one of claims 1 to 11, An electric vehicle characterized by:

13. Detecting a cell thermal runaway condition of an on-board power battery; generating a wake-up signal when detecting a thermal runaway of a cell of the power battery if the battery management system is offline; and waking up the operation of the battery management system by the wake-up signal to issue a thermal runaway alarm. A power battery protection method.

14. The step of detecting a cell thermal runaway state of an on-board power battery includes: Collecting battery unit voltage and / or temperature of the power battery online and / or offline at a predetermined sampling period; comparing the collected battery unit voltage of the power battery with a predetermined voltage limit value and / or comparing the collected battery unit temperature of the power battery with a predetermined temperature limit value; determining that a thermal runaway has occurred in a cell of the power battery when a battery unit voltage of the power battery exceeds the predetermined voltage limit value and / or a battery unit temperature of the power battery exceeds the predetermined temperature limit value; 14. The power battery protection method of claim 13.

15. The step of detecting a cell thermal runaway state of an on-board power battery includes: collecting current from the power battery; determining that a thermal runaway has occurred in a cell of the power battery if the collected power battery current exceeds a short circuit protection current limit value; 14. The power battery protection method of claim 13.

16. When the collected current of the power battery exceeds an overcurrent protection current limit value, generating an overcurrent hardware signal to a battery management system to perform overcurrent protection for the power battery; If the collected current of the power battery exceeds a short circuit protection current limit value, generating a short circuit hardware signal to the battery management system, so that the battery management system controls the blowing of an explosive fuse connected in series to a load circuit, the load circuit including the power battery and a load connected in series.

16. The power battery protection method of claim 15.

17. The step of detecting a cell thermal runaway state of an on-board power battery includes: detecting the pressure of the power battery online and / or offline; comparing the detected pressure of the power battery to a predetermined pressure limit; determining that a thermal runaway has occurred in a cell of the power battery if the pressure in the power battery exceeds the predetermined pressure limit; 14. The power battery protection method of claim 13.

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