Early warning method and system for thermal runaway of battery

Abstract

The invention discloses a battery thermal runaway early warning method and system, and relates to the technical field of battery monitoring and early warning, and the method comprises the steps: transmitting the measurement distance and laser signal receiving conditions to a controller, transmitting the measurement distance and laser signal receiving conditions to an upper computer, and recognizing the position of a fault cell when the measurement distance is smaller than a preset value; when the first laser correlation device and the second laser correlation device receive laser signals, the first-stage early warning signal lamp is controlled to flicker, and the first-stage early warning signal is used for controlling the thermal management system to be started; when the first laser correlation device does not receive the laser signal and the second laser correlation device receives the laser signal, the second-level early warning signal lamp is controlled to flicker; using the secondary early warning signal to control the battery management system to execute a power-off action; when the first laser correlation device and the second laser correlation device do not receive the laser signal, the third-level early warning signal lamp is controlled to flicker; and the fire extinguishing equipment is controlled to be started by using the third-level early warning According to the invention, the abnormal position of the battery can be confirmed in time and corresponding early warning measures can be carried out on the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of battery monitoring and early warning, and in particular to a battery thermal runaway early warning method and system. Background Art

[0002] The proposal of the dual carbon target has promoted the rapid development of new energy. As the mainstream energy storage carrier, lithium-ion batteries have been widely used in energy storage power stations and electric vehicles. In the battery energy storage system composed of lithium-ion batteries, multiple layers can be formed from the smallest energy storage unit, including lithium-ion battery cells-battery modules-battery packs / clusters-battery stations. However, due to the characteristics of lithium-ion batteries, they can trigger thermal runaway and cause fires or explosions under conditions of thermal abuse, mechanical abuse, and electrical abuse.

[0003] In the prior art, the fire warning system of electrochemical energy storage stations mostly uses temperature sensing detection equipment and characteristic gas detection equipment to detect fire signals. When the temperature sensing detection equipment is in use, the detection of temperature signals requires the placement of sensors on the surface of each battery cell. When the battery has thermal runaway, it takes a certain amount of time for the internal temperature to be transmitted to the surface, and the warning has a certain lag; when the characteristic gas detection equipment is in use, the gas production signal can only be detected after the battery safety valve is opened, and the warning is very delayed. In addition, the gas production warning cannot accurately locate the position of the abnormal battery.

[0004] In summary, in the energy storage system of lithium-ion battery cell-battery module-battery pack / cluster-battery station layer, once the battery suffers thermal runaway, the existing technology cannot provide early warning of the energy storage system failure and accurately locate the abnormal position of the battery. Summary of the invention

[0005] The embodiments of the present invention provide a battery thermal runaway warning method and system, which can solve the problem in the prior art that it is impossible to provide an early warning of a failure of an energy storage system and simultaneously accurately locate the abnormal position of the battery.

[0006] The embodiment of the present invention provides an early warning method for battery thermal runaway, comprising the following steps: arranging a laser distance measuring device on an inner side wall of a battery module housing, and the laser emitted by the laser distance measuring device is parallel to the side surfaces of all single cells in the battery module; arranging one end of a first laser irradiation device and one end of a second laser irradiation device on the same inner side wall as the laser distance measuring device, and the distance between one end of the first laser irradiation device and the battery module is greater than the distance between the laser distance measuring device and the battery module, and the distance between one end of the second laser irradiation device and the laser distance measuring device is greater than the distance between one end of the first laser irradiation device and the laser distance measuring device; arranging the other end of the first laser irradiation device and the other end of the second laser irradiation device on the inner side wall opposite to the laser distance measuring device; when the laser emitted by the laser distance measuring device is blocked When the laser is blocked, it means that the laser distance measuring device detects that the battery module has caused expansion deformation on the side of the single battery due to thermal runaway, and the laser distance measuring device is used to obtain the measured distance between the expansion deformation and the laser distance measuring device; if the measured distance is less than the preset value, the measured distance is input into the position recognition model to identify the position of the single battery with expansion deformation, and the corresponding preliminary warning and processing behavior is triggered; when the laser emitted by the first laser matching device is blocked, it means that the preliminary warning and processing behavior cannot suppress the continuous expansion of the expansion deformation, so that the first laser matching device detects the expansion deformation; the laser emitted by the first laser matching device is blocked by the expansion deformation before the laser emitted by the second laser matching device, and different in-depth warnings and processing behaviors are triggered according to the situation that the laser emitted by the second laser matching device is blocked by the expansion deformation.

[0007] Furthermore, the step of identifying the position of the single battery that has undergone expansion deformation specifically includes:

[0008] Use the position recognition model to determine the number of the single battery that has expanded and deformed in the battery module. The formula is:

[0009]

[0010] Wherein, δ is the measurement distance of the laser ranging device, L is the distance from the laser ranging device installed on the inner wall of the battery module shell to the inner wall of the shell on the opposite side, d is the thickness of each single battery in the battery module, s is the distance between the battery module and the module shell; i means that the single batteries in the battery module are numbered starting from 1 from the end farthest from the laser ranging device.

[0011] Furthermore, the triggering of the corresponding preliminary warning and processing behavior includes the following specific steps: triggering a first-level warning, wherein the first-level warning includes: controlling the flashing of the first-level warning signal light through a controller; and controlling the start of a thermal management system for cooling by using the first-level warning signal through a host computer.

[0012] Furthermore, the triggering of different in-depth warnings and processing behaviors includes the following specific steps: when the laser emitted by the first laser shooting device is blocked by the expansion deformation, and the laser emitted by the second laser shooting device is not blocked by the expansion deformation, a second-level warning is performed; when the lasers emitted by the first laser shooting device and the second laser shooting device are both blocked by the expansion deformation, a third-level warning is performed.

[0013] Furthermore, the second-level warning specifically includes the following steps: controlling the second-level warning signal light to flash through a controller; and controlling the battery management system used to manage whether the battery is powered on to execute a power-off action through a host computer using the second-level warning signal.

[0014] Furthermore, the three-level warning specifically includes the following steps: controlling the three-level warning signal light to flash through a controller; and controlling the fire extinguishing equipment to start using the three-level warning signal through a host computer.

[0015] An embodiment of the present invention provides a battery thermal runaway warning system, comprising: a battery module, wherein the battery module is arranged in a battery module housing; a laser distance measuring device is arranged on an inner side wall of the battery module housing, and the laser emitted by the laser distance measuring device is parallel to the side surfaces of all the single cells in the battery module; one end of a first laser emitting device and one end of a second laser emitting device are arranged on the inner side wall where the laser distance measuring device is located; the other end of the first laser emitting device and the other end of the second laser emitting device are both arranged on the inner side wall opposite to the laser distance measuring device; the laser distance measuring device, the first laser emitting device and the second laser emitting device are all connected to a controller for communication, and the controller is connected to a host computer and a warning signal light for communication respectively;

[0016] The distance between one end of the first laser irradiation device and the battery module is greater than the distance between the laser ranging device and the battery module; the distance between one end of the second laser irradiation device and the laser ranging device is greater than the distance between one end of the first laser irradiation device and the laser ranging device.

[0017] The embodiment of the present invention provides a battery thermal runaway early warning method and system, which has the following beneficial effects compared with the prior art:

[0018] The laser distance measuring device is arranged on an inner side wall of the battery module housing, and the distance between one end of the first laser emitting device and the battery module is larger than the distance between the laser emitting device and the battery module, and the distance between one end of the second laser emitting device and the laser distance measuring device is larger than the distance between one end of the first laser emitting device and the laser distance measuring device. When the laser emitted by the laser distance measuring device is blocked, it indicates that the battery module has caused expansion deformation on the side of the single battery due to thermal runaway and has been detected by the laser distance measuring device. At this time, the laser distance measuring device is used to obtain the measured distance between the expansion deformation location and the laser distance measuring device; if the measured distance is less than the preset value, the measured distance is input into the position recognition model to identify the location of the single battery with expansion deformation, and the corresponding preliminary warning and processing behavior is triggered; if the preliminary warning and processing behavior cannot suppress the expansion deformation, the expansion deformation will continue to expand, and then the laser emitted by the first laser emitting device is blocked first, and then the laser emitted by the second laser emitting device is blocked; at this time, according to the blocking situation of the two laser emitting devices, different in-depth warning and processing behaviors are triggered, and the expansion deformation that cannot be suppressed by the preliminary warning and processing behavior is deeply processed.

[0019] In summary, in the energy storage system of lithium-ion battery cell-battery module-battery pack / cluster-battery station layer, once thermal runaway occurs, in the early stage of thermal runaway in the entire energy storage system, the side of the lithium-ion battery cell will first undergo expansion deformation. At this time, the laser ranging device, the first laser shooting device and the second laser shooting device can be used according to the expansion deformation to provide early warning of thermal runaway of the energy storage system and accurately locate the position of the faulty lithium-ion battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the overall structure of a battery thermal runaway early warning system provided by an embodiment of the present invention;

[0021] Figure 2 A partial top view of a battery module, a battery module housing, a laser rangefinder, a laser warning device, and a warning signal light of a battery thermal runaway warning system provided by an embodiment of the present invention;

[0022] Figure 3 An overall structural connection block diagram of a battery thermal runaway early warning system provided by an embodiment of the present invention;

[0023] Figure 4 A hierarchical warning logic diagram of a battery thermal runaway warning method provided in an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1-battery module, 2-battery module shell, 3-laser warning device, 4-warning signal light, 5-host computer, 6-controller, 31-laser ranging device, 32-first laser shooting device, 33-second laser shooting device, 321-first laser transmitter, 322 first laser receiver, 331-second laser transmitter, 332 second laser receiver, 41-first warning signal light, 42-second warning signal light, 43-third warning signal light. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0027] An embodiment of the present invention provides a battery thermal runaway early warning method, comprising the following steps:

[0028] Step 1: Set the laser distance measuring device on an inner wall of the battery module housing, and the laser emitted by the laser distance measuring device is parallel to the side surfaces of all the single cells in the battery module; set one end of the first laser irradiation device and one end of the second laser irradiation device on the same inner wall as the laser distance measuring device, and the distance between one end of the first laser irradiation device and the battery module is larger than the distance between the laser distance measuring device and the battery module, and the distance between one end of the second laser irradiation device and the laser distance measuring device is larger than the distance between one end of the first laser irradiation device and the laser distance measuring device; set the other end of the first laser irradiation device and the other end of the second laser irradiation device on the inner wall opposite to the laser distance measuring device.

[0029] Step 2: When the laser emitted by the laser ranging device is blocked, it means that the laser ranging device detects that the battery module has caused expansion deformation on the side of the single battery due to thermal runaway. The laser ranging device is used to obtain the measured distance between the expansion deformation point and the laser ranging device; if the measured distance is less than the preset value, the measured distance is input into the position recognition model to identify the position of the single battery that has undergone expansion deformation, and trigger the corresponding preliminary warning and processing behavior.

[0030] Step three: When the laser emitted by the first laser shooting device is blocked, it indicates that the initial warning and processing actions cannot suppress the continued expansion of the expansion deformation, so that the first laser shooting device detects the expansion deformation; the laser emitted by the first laser shooting device is blocked by the expansion deformation before the laser emitted by the second laser shooting device, and different in-depth warnings and processing actions are triggered according to the situation that the laser emitted by the second laser shooting device is blocked by the expansion deformation.

[0031] The system of the present invention is mainly composed of a battery module 1, a battery module housing 2, a laser warning device 3, a warning signal light 4, a host computer 5 and a controller 6. The laser warning device 3 transmits the detected signal to the controller 6 in real time, the controller 6 is connected to the warning signal light and the host computer 5, and the host computer 5 displays the safety status of the battery module in real time and has a three-level warning function.

[0032] The battery module 1 of the present invention is arranged in a battery module housing 2 and is composed of a plurality of battery cells.

[0033] The laser warning device of the present invention is composed of a laser distance measuring device 31, a first laser aiming device 32, and a second laser aiming device 33. The laser aiming device includes a laser transmitter and a receiver. The laser transmitter is the transmitting end, and the receiver is the receiving end. The laser distance measuring device 31, the first laser aiming device 32, and the second laser aiming device 33 are sequentially arranged on the side wall inside the module housing, flush with the horizontal center line of the battery side, and monitor the expansion deformation size of the battery side in real time. Among them, the laser distance measuring device 31 can monitor the distance from the device to the abnormal battery cell, so the specific position of the faulty battery cell can be calculated to achieve accurate positioning of the faulty battery. Figure 1 and Figure 2 shown.

[0034] The host computer of the present invention is arranged outside the battery module 1 and connected to the controller 6 through a signal line. When an abnormal signal occurs, the host computer will pop up a warning signal and display the location of the faulty battery, locating the fault to a specific battery cell.

[0035] The system has a three-level warning function. When the distance measured by the laser distance measuring device 31 is less than the preset value, the controller 6 receives an abnormal signal and transmits the data to the host computer 5. The host computer 5 can identify the specific location of the faulty battery cell through calculation based on the battery cell size and the received data. At the same time, the controller 6 controls the first-level warning signal light 41 to operate, and the host computer 5 also sends out a first-level warning signal at the same time. The warning signal can guide the thermal management system to operate; when the first laser receiver 322 in the first laser shooting device 32 does not receive the laser signal emitted by the first laser transmitter 321, the controller 6 controls the second-level warning signal light 42 to operate, and the host computer 5 sends out a second-level warning signal, which can guide the staff to cut off the power and deal with the abnormal battery; if the expansion deformation of the battery side continues to increase, and the second laser receiver 332 does not receive the laser signal emitted by the second laser transmitter 331, a third-level warning will be triggered. The third-level warning signal light 43 sends out a warning signal under the action of the controller 6, and the host computer 5 also displays a third-level warning information, which can guide the action of the fire extinguishing facilities. Figure 3 to Figure 4 shown.

[0036] An embodiment of the present invention provides a battery thermal runaway early warning system, comprising:

[0037] A battery module 1 is arranged in a battery module housing 2; a laser distance measuring device 31 is arranged on an inner side wall of the battery module housing 2, and the laser emitted by the laser distance measuring device 31 is parallel to the side surfaces of all the single cells in the battery module 1; one end of a first laser emitting device 32 and one end of a second laser emitting device 33 are arranged on the inner side wall where the laser distance measuring device 31 is located; the other end of the first laser emitting device 32 and the other end of the second laser emitting device 33 are both arranged on the inner side wall opposite to the laser distance measuring device 31; the laser distance measuring device 31, the first laser emitting device 32 and the second laser emitting device 33 are all connected to the controller 6 for communication, and the controller 6 is connected to the host computer 5 and the warning signal light 4 for communication respectively.

[0038] The distance between one end of the first laser irradiation device 32 and the battery module 1 is greater than the distance between the laser distance measuring device 31 and the battery module 1 ; the distance between one end of the second laser irradiation device 33 and the laser distance measuring device 31 is greater than the distance between one end of the first laser irradiation device 32 and the laser distance measuring device 31 .

[0039] A specific embodiment is as follows:

[0040] Conduct a battery module thermal runaway monitoring and early warning test:

[0041] 1. Before the test, the battery module 1 is neatly arranged on the experimental table, and the two sides of the battery module 1 are clamped with fixed fixtures. The laser ranging device 31 and the laser shooting device are arranged on both sides of the module and flush with the center line of the module side. A 500W heating sheet is used to heat the battery cell on one side of the module to trigger thermal runaway.

[0042] 2. Under overheating conditions, a series of exothermic side reactions occur inside the battery cell close to the heating plate, accompanied by gas production, causing the side of the battery cell to expand and deform. The laser rangefinder 31 arranged on both sides of the battery module 1 is closest to the side of the battery module 1, and the signal changes first, the monitoring distance becomes smaller, and the faulty battery cell is determined to be the battery cell close to the heating plate, and a first-level warning signal is issued; but as the heating continues and the self-heating rate inside the battery accelerates, the gas production inside the battery accelerates, and the side expansion intensifies, causing the first laser shooting device 32 next to the laser rangefinder to change its signal and issue a second-level warning signal; at this time, the battery cell pressure relief valve has not yet opened, the internal gas continues to accumulate, and the deformation continues to increase. When the battery bulge blocks the laser signal of the second laser shooting device 33, a third-level warning is issued. After a few tens of seconds, the safety valve opens, creating a fire risk.

[0043] 3. When the sides of multiple battery cells expand and deform, although the laser ranging devices 31 arranged on both sides of the battery module 1 cannot monitor the distance between the expansion deformation of a single battery cell sandwiched in the middle and the laser ranging device 31, an early warning signal can still be generated at this time, which does not affect the early warning effect. In this case, there is no need to measure the distance between the expansion deformation of the single battery cell sandwiched in the middle and the laser ranging device 31, it only needs to be able to generate an early warning effect.

[0044] Therefore, this early warning technology method can better predict the timing of early warning and accurately locate the faulty battery cell.

[0045] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A battery thermal runaway early warning method, characterized in that: The following steps are involved: The laser distance measuring device is arranged on an inner side wall of the battery module housing, and the laser emitted by the laser distance measuring device is parallel to the side surfaces of all the single cells in the battery module; One end of the first laser irradiation device and one end of the second laser irradiation device are both arranged on the same inner side wall as the laser distance measuring device, and the distance between one end of the first laser irradiation device and the battery module is greater than the distance between the laser distance measuring device and the battery module, and the distance between one end of the second laser irradiation device and the laser distance measuring device is greater than the distance between one end of the first laser irradiation device and the laser distance measuring device; the other end of the first laser irradiation device and the other end of the second laser irradiation device are both arranged on the inner side wall opposite to the laser distance measuring device; When the laser emitted by the laser ranging device is blocked, it means that the laser ranging device detects that the battery module has expanded and deformed on the side of the single battery due to thermal runaway, and the laser ranging device is used to obtain the measured distance between the expansion deformation and the laser ranging device; if the measured distance is less than the preset value, the measured distance is input into the position recognition model to identify the position of the single battery that has expanded and deformed, and the corresponding preliminary warning and processing behavior are triggered; When the laser emitted by the first laser shooting device is blocked, it means that the initial warning and processing behavior cannot suppress the continued expansion of the expansion deformation, so that the first laser shooting device detects the expansion deformation; the laser emitted by the first laser shooting device is blocked by the expansion deformation before the laser emitted by the second laser shooting device. According to the situation that the laser emitted by the second laser shooting device is blocked by the expansion deformation, different in-depth warnings and processing behaviors are triggered.

2. A battery thermal runaway early warning method as claimed in claim 1, characterized in that: The specific steps of identifying the position of the single battery that has undergone expansion deformation include: Use the position recognition model to determine the number of the single battery that has expanded and deformed in the battery module. The formula is: Wherein, δ is the measurement distance of the laser ranging device, L is the distance from the laser ranging device installed on the inner wall of the battery module shell to the inner wall of the shell on the opposite side, d is the thickness of each single battery in the battery module, s is the distance between the battery module and the module shell; i means that the single batteries in the battery module are numbered starting from 1 from the end farthest from the laser ranging device.

3. A battery thermal runaway early warning method as claimed in claim 1, characterized in that: The triggering corresponding preliminary warning and handling behavior, the specific steps include: Triggering a first-level warning, the first-level warning includes: The first-level warning signal light is controlled to flash through the controller; The host computer uses a first-level warning signal to control the start of the thermal management system used for cooling.

4. The battery thermal runaway early warning method according to claim 1, characterized in that: The triggering of different in-depth warnings and processing behaviors includes the following specific steps: When the laser emitted by the first laser irradiation device is blocked by the expansion deformation, and the laser emitted by the second laser irradiation device is not blocked by the expansion deformation, a second-level warning is issued; When the lasers emitted by the first laser irradiation device and the second laser irradiation device are both blocked by expansion deformation, a third-level warning is issued.

5. A battery thermal runaway early warning method as claimed in claim 4, characterized in that: The specific steps of the second-level warning include: The secondary warning signal light is controlled to flash through the controller; The host computer uses the secondary warning signal to control the battery management system used to manage whether the battery is powered on to execute a power-off action.

6. A battery thermal runaway early warning method as claimed in claim 4, characterized in that: The three-level warning includes the following specific steps: The three-level warning signal lights are controlled to flash through the controller; The fire extinguishing equipment is turned on by using the three-level early warning signal through the host computer.

7. A battery thermal runaway early warning system, characterized in that: include: A battery module (1), wherein the battery module is arranged in the battery module housing (2); a laser distance measuring device (31) is arranged on an inner side wall of the battery module housing (2), and the laser emitted by the laser distance measuring device (31) is parallel to the side surfaces of all the single batteries in the battery module (1); one end of a first laser irradiation device (32) and one end of a second laser irradiation device (33) are arranged on the inner side wall where the laser distance measuring device (31) is located; the other end of the first laser irradiation device (32) and the other end of the second laser irradiation device (33) are both arranged on the inner side wall opposite to the laser distance measuring device (31); the laser distance measuring device (31), the first laser irradiation device (32) and the second laser irradiation device (33) are all connected to a controller (6) for communication, and the controller (6) is connected to a host computer (5) and a warning signal light (4) for communication respectively; The distance between one end of the first laser irradiation device (32) and the battery module (1) is greater than the distance between the laser distance measuring device (31) and the battery module (1); the distance between one end of the second laser irradiation device (33) and the laser distance measuring device (31) is greater than the distance between one end of the first laser irradiation device (32) and the laser distance measuring device (31).

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