Fire early warning system and method for lithium ion battery of energy storage power station

Abstract

The invention provides a fire early warning system and method for a lithium ion battery of an energy storage power station, and belongs to the technical field of safety monitoring of an energy storage system. The system comprises a lithium ion battery of an energy storage power station, an optical fiber collimator, a photoelectric converter and a remote computer, a penetrating device is arranged on the side wall of the lithium ion battery, a fluorescent optical fiber probe is arranged in the lithium ion battery, the fluorescent optical fiber probe is connected with the input end of the penetrating device, the output end of the penetrating device is connected with an optical fiber collimator, the optical fiber collimator is connected with a photoelectric converter, and the photoelectric converter is connected with a remote computer; the fluorescent optical fiber probe is used for collecting an optical signal generated by a battery cell in the lithium ion battery due to abnormal discharge or chemical reaction, and sending the optical signal to the photoelectric converter through the through device and the optical fiber collimator; the photoelectric converter is used for converting the optical signal into an electric signal; and the remote computer is used for giving an alarm after receiving the optical signal, and starting a protection mechanism according to an analysis result by analyzing the amplitude or repetition rate of the optical signal.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage system safety monitoring, and more particularly to a fire early warning system and method for lithium-ion batteries in energy storage power stations. Background Art

[0002] With the continuous growth of energy storage demand and the continuous development of related technologies, lithium-ion has been widely used in energy storage power stations in recent years due to its excellent performance. However, a large amount of heat will inevitably be released during its own operation. Especially when a short circuit fault occurs, it will produce a thermal effect in a short period of time that is sufficient to cause the battery to explode, and even cause a fire in the entire energy storage power station, which seriously threatens the safe operation of the energy storage power station. Thermal runaway of lithium-ion batteries occurs because the internal heat generation rate is higher than the heat dissipation rate, and a large amount of heat is accumulated inside the lithium-ion battery, causing a chain reaction, resulting in battery fire and explosion. The main reason for the increase in heat generation rate is the short circuit or chemical reaction inside and outside the battery.

[0003] At present, many scientific research institutions have conducted a large number of tests and simulation tests on the thermal runaway of lithium batteries. Studies have shown that when lithium-ion batteries experience thermal runaway due to their own or external reasons, they will be accompanied by pressure relief, flammable gas release, electrolyte injection, smoke release, high temperature and flames. However, existing fire warning technologies (such as temperature sensors, smoke alarms, etc.) are not only unable to monitor the inside of the battery module in real time, but can only sound an alarm when the fire has already started, and cannot effectively detect the early signs of fire. When the system sounds an alarm, the lithium-ion battery fire has begun to spread, and the damage to the battery has reached a relatively serious level. It is impossible to extinguish the fire in time, and when the battery thermal runaway reaches a certain level, the residual heat inside the battery combined with the battery's own properties is very likely to re-ignite. Therefore, there is an urgent need for an early fire warning system that directly targets battery pack modules or even individual cells. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a fire warning system and method for lithium-ion batteries in energy storage power stations, which can issue a warning in time when thermal runaway occurs in the lithium-ion battery system, especially dangerous signals such as short circuit sparks and arcs.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions: In a first aspect, the present invention discloses a fire warning system for lithium-ion batteries in an energy storage power station, comprising a lithium-ion battery, an optical fiber collimator, a photoelectric converter and a remote computer arranged in the energy storage power station; a through hole is arranged on the side wall of the lithium-ion battery, a fluorescent optical fiber probe is arranged in the lithium-ion battery, a through-hole is installed in the through hole, the fluorescent optical fiber probe is connected to the input end of the through-hole, the output end of the through-hole is connected to the optical fiber collimator, the optical fiber collimator is connected to the photoelectric converter, and the photoelectric converter is connected to the remote computer; the fluorescent optical fiber probe is used to collect in real time the optical signal generated by the internal battery cell of the lithium-ion battery due to abnormal discharge or abnormal chemical reaction, and send the optical signal to the photoelectric converter through the through-hole and the optical fiber collimator; the photoelectric converter is used to convert the optical signal into an electrical signal and send it to the remote computer; the remote computer is used to issue an alarm after receiving the optical signal, and start a protection mechanism according to the analysis result by analyzing the amplitude or repetition rate of the optical signal.

[0006] Furthermore, the system also includes an analog-to-digital conversion module, the input end of the analog-to-digital conversion module is connected to the photoelectric converter, and the output end of the analog-to-digital conversion module is connected to a remote computer via a transmission bus; the analog-to-digital conversion module is used to convert the electrical signal into a digital signal and send it to the remote computer.

[0007] Furthermore, sealing rings are provided on both sides of the through-hole, threads are provided in the middle section of the through-hole, the through-hole is fixedly installed in the through-hole through the sealing ring and threads, a high-purity quartz lens is provided in the center of the through-hole, and the output end of the through-hole is connected to the optical fiber collimator through a quartz optical fiber.

[0008] Furthermore, both the input and output ends of the through-hole device adopt ST interfaces.

[0009] Furthermore, the fluorescent optical fiber probe is arranged at the proximal end of the electrode and the collector of the lithium-ion battery.

[0010] In a second aspect, the present invention further discloses a fire warning method for lithium-ion batteries in energy storage power stations, comprising: The fluorescent fiber optic probe is used to collect the optical signals generated by abnormal discharge or abnormal chemical reaction in the lithium-ion battery in real time, amplify and convert the optical signals with different spectrum lengths, and transmit them to the through-hole device; The optical signal is transmitted to the optical fiber collimator through the through-hole, and the optical signal is converted into a uniformly distributed parallel optical signal through the optical fiber collimator and then transmitted to the photoelectric converter; The optical signal is converted into an electrical signal through a photoelectric converter, and then converted into a digital signal through an analog-to-digital conversion module and sent to a remote computer; After receiving the digital signal, the remote computer immediately sends out an alarm message, analyzes the amplitude or repetition rate of the optical signal according to the digital signal, and activates the protection mechanism according to the analysis result.

[0011] Furthermore, the analyzing the amplitude or repetition rate of the optical signal and initiating the protection mechanism according to the analysis result includes: Analyze the amplitude or repetition rate of the optical signal through digital signal processing technology; Determine whether the amplitude or repetition rate is greater than a preset warning threshold: If so, an early warning signal and a control instruction are directly sent to the energy storage power station, and the energy storage power station performs a power-off operation on the corresponding lithium-ion battery according to the control instruction.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention realizes real-time monitoring of the internal environment of the battery through the highly sensitive fluorescent fiber probe sensing technology. This technology can capture the internal conditions of the battery cell in a timely manner, and respond to abnormalities through optical signals with high sensitivity, high signal-to-noise ratio, and obvious fault-normal state distinction, ensuring that early warnings can be issued in the early stages of fire risk or even in the development stage, greatly improving the safety of the battery.

[0013] 2. The present invention can accurately identify the fault signal of the battery and automatically start the protection mechanism when potential risks are found. This automated early warning and protection system not only reduces the risk of human operation, but also responds quickly at critical moments to avoid the expansion of accidents and ensure the safety of equipment and personnel.

[0014] 3. The design of the present invention has good adaptability and can be widely used in various energy storage systems, including electric vehicles, renewable energy storage, smart grids and other fields. With the growing global demand for renewable energy and efficient energy storage technology, the fire early warning method based on fluorescent fiber optic probes will play a more important role in future energy management and power systems.

[0015] It can be seen that compared with the prior art, the present invention has outstanding substantive features and significant progress, and the beneficial effects of its implementation are also obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0017] Figure 1 It is a schematic structural diagram of a lithium-ion battery according to a specific embodiment of the present invention.

[0018] Figure 2It is a system structure principle diagram of a specific implementation mode of the present invention.

[0019] Figure 3 It is a schematic diagram of the optical signal propagation path of a specific embodiment of the present invention.

[0020] Figure 4 It is a method flow chart of a specific implementation mode of the present invention. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] See also Figure 1 and Figure 2 As shown, this embodiment provides a fire warning system for lithium-ion batteries in an energy storage power station, including a lithium-ion battery 1 arranged in the energy storage power station, a fiber collimator 2, a photoelectric converter 3, an analog-to-digital conversion module 4 and a remote computer 5.

[0023] A through hole 6 is provided on the side wall of the lithium-ion battery 1, and a fluorescent fiber probe 7 is provided in the lithium-ion battery 1. The fluorescent fiber probe 7 is provided at the proximal end of the electrode and the collector of the lithium-ion battery 1. A through-hole 8 is installed in the through-hole 6. Sealing rings are provided on both sides of the through-hole 8, and the through-hole 8 is fixedly installed in the through-hole 6 through the sealing rings. A quartz fiber lens 9 is provided in the center of the through-hole 8, and the input end and the output end of the through-hole 8 both adopt ST interfaces.

[0024] The fluorescent fiber probe 7 is connected to the input end of the through hole 8, and the output end of the through hole 8 is connected to the fiber collimator 2 through the quartz fiber 10. The fiber collimator 2 is connected to the photoelectric converter 3, the input end of the analog-to-digital conversion module 4 is connected to the photoelectric converter 3, and the output end of the analog-to-digital conversion module 4 is connected to the remote computer 5 through the transmission bus 11.

[0025] like Figure 3 As shown, in this system, the fluorescent fiber optic probe 7 is used to collect the optical signal generated by the internal cell of the lithium-ion battery 1 due to abnormal discharge or chemical reaction in real time, and send the optical signal to the photoelectric converter 3 through the through-hole 8 and the fiber collimator 2. The photoelectric converter 3 is used to convert the optical signal into an electrical signal and send it to the analog-to-digital conversion module 4. The analog-to-digital conversion module 4 converts the electrical signal into a digital signal and sends it to the remote computer 5.

[0026] The remote computer 5 is used to issue an alarm after receiving the optical signal, and to analyze the amplitude or repetition rate of the optical signal and activate the protection mechanism according to the analysis result.

[0027] In this system, the fluorescent fiber probe 7 is cleverly arranged inside the lithium-ion battery 1 of the energy storage power station to achieve real-time monitoring of the early warning signal of battery fire. The arrangement position of the fluorescent fiber probe 7 inside the battery is precisely designed, and is usually placed in areas with a high risk of thermal runaway of the battery, especially in areas close to the electrodes and collectors, so as to maximize the capture of temperature rise, abnormal light signals and possible arc phenomena in the battery.

[0028] Among them, a through-hole 6 with internal threads is designed on the side of the lithium-ion battery 1. The design of the through-hole 6 ensures that the optical signal can be effectively drawn out from the inside of the battery without affecting the normal operation of the battery. A small through-hole 8 needs to be installed at the through-hole 6. Both sides of the through-hole 8 are equipped with sealing designs (such as sealing rings, etc.). The internal and external sealing is required to be good, and the through-hole is fixed to the outer wall of the battery cell through threads. The center of the through-hole 8 is a highly transparent quartz fiber lens 9, which is connected to the through-hole 8 through a quartz optical fiber 10. The quartz material has excellent light transmission performance and high-temperature stability, and can transmit the optical signal inside the battery to the outside under extremely low attenuation. This quartz optical fiber and quartz lens can not only withstand the high temperature environment inside the battery, but also maintain high-precision transmission of the optical signal, effectively improving the transmission efficiency and reliability of the optical signal. At the same time, in order to strengthen and bias the connection between the optical fiber and the through-hole 8, the internal fluorescent optical fiber probe, the external quartz optical fiber and the through-hole 8 can be made into a standard interface, such as a standard ST interface. This interface design makes the connection between the optical fiber and the through-hole 8 more stable, avoids environmental interference, and ensures high stability of optical signal transmission.

[0029] Finally, outside the battery, the quartz optical fiber 10 is connected to a highly sensitive micro photodiode through a fiber collimator 2, which is responsible for converting the optical signal from inside the battery into an electrical signal for subsequent processing.

[0030] In the above manner, the optical signal is converted and transmitted from the inside of the battery to the outside of the battery. Through this optical fiber layout design, this solution can effectively realize the monitoring and signal transmission of early signs of fire inside the battery, provide a reliable safety monitoring method for the battery pack, and greatly improve the safety and response efficiency of the energy storage power station.

[0031] After the optical signal is generated, it is first collected and converted by the fluorescent fiber optic probe 7, and the optical signals of different spectral lengths are amplified and converted into optical signals of sensitive wavelengths suitable for detection by the photoelectric conversion device, and then transmitted to the outside of the battery cell by the through-hole 8 with a high-purity quartz lens.

[0032] After the optical signal enters the outside of the battery cell, it passes through the optical fiber collimator 2 to convert the originally crossed or even chaotic optical signal into evenly distributed parallel light, and finally sends it to the photoelectric converter 3. The advantage of this is that it avoids the excessive concentration or dispersion of the signal light, evenly distributes the signal energy of the optical signal, thereby improving the overall utilization rate of the photosensitive area of ​​the photoelectric converter 3, avoiding the problem that a small part of the photoelectric converter 3 is saturated while most of it is almost unused, which is conducive to the selection and optimization of the photoelectric converter 3.

[0033] The photoelectric converter 3 of the present invention adopts a high-precision micro-photodiode. After the optical signal reaches the micro-photodiode, the optical signal is converted into an electrical signal. At the same time, the analog signal output by the micro-photodiode is converted into a digital signal through the analog-to-digital conversion module 4 (ADC), and then connected to the remote computer 5 through the signal transmission bus 11, and the fault diagnosis, alarm and recording based on the optical signal are completed on the remote computer 5.

[0034] The analog-to-digital conversion module 4 in the present invention should have high precision and fast sampling capabilities to ensure that when the temperature change inside the battery or the optical signal is detected, the signal status can be reflected in real time. At the same time, after the analog signal is converted into a digital signal, its anti-interference ability is greatly enhanced, avoiding various interference signals that may be coupled into the signal transmission process. This process ensures that the continuous changes of the optical signal inside the battery cell are accurately captured and finally converted into a digital electrical form that is easy for the computer to process.

[0035] The analog-to-digital conversion module 4 also transmits the processed data to the remote computer 5 via a wireless or wired network. As a monitoring center, the remote computer 5 can centrally receive and store data from multiple battery packs and conduct in-depth analysis and diagnosis. Through the computer system, operators can view the operating status, monitoring data, and early warning information of the battery in real time and take emergency measures in a timely manner. In addition, the computer system can also record and analyze data to help optimize the operation management and maintenance strategy of the battery, and further improve the safety and efficiency of the energy storage power station.

[0036] See also Figure 4 As shown, the present invention also discloses a fire warning method for lithium-ion batteries in energy storage power stations, comprising the following steps: S1: The fluorescent fiber optic probe is used to collect the optical signals generated by abnormal discharge or abnormal chemical reaction in the internal cells of the lithium-ion battery in real time, amplify and convert the wavelengths of the optical signals with different spectral lengths, and transmit them to the through-hole.

[0037] S2: The optical signal is transmitted to the fiber collimator through the through-hole, and the optical signal is converted into a uniformly distributed parallel optical signal through the fiber collimator and then transmitted to the photoelectric converter.

[0038] S3: The optical signal is converted into an electrical signal through a photoelectric converter, and then converted into a digital signal through an analog-to-digital conversion module and sent to a remote computer.

[0039] S4: After receiving the digital signal, the remote computer immediately issues an alarm message, analyzes the amplitude or repetition rate of the optical signal according to the digital signal, and activates the protection mechanism according to the analysis result.

[0040] In a specific implementation, the amplitude or repetition rate of the optical signal is first analyzed by digital signal processing technology; then it is determined whether the amplitude or repetition rate is greater than a preset warning threshold: if so, a warning signal and a control instruction are directly sent to the energy storage power station, and the energy storage power station performs a power-off operation on the corresponding lithium-ion battery according to the control instruction.

[0041] It should be noted that, under normal circumstances, the received signal generally remains at a stable 0 level, with occasional small pulses with extremely low repetition rate, indicating that the battery pack is in normal working condition.

[0042] As the fault gradually develops, the recombination of positive and negative ions inside the battery cell will generate radiation and release certain light-generating signal photons. At this time, the fire warning system provided by the present invention can detect certain impact signals, the amplitude and periodic repetition rate of which are usually much higher than normal (usually 10 to 100 times that of normal), which is sufficient to indicate potential risks. Once the system detects these impact signals, it will immediately issue a warning signal to prompt the operator to review. At this time, the system will require further confirmation based on devices monitoring signals such as temperature, voltage, and current to verify the true state of the fault. If the amplitude or repetition rate of the impact signal exceeds the preset threshold, the protection mechanism will be automatically activated to cut off the corresponding battery cell or battery compartment, thereby preventing further deterioration of the accident.

[0043] After a fault occurs, the number of optical signal photons radiated by the positive and negative ions in the battery cell will increase significantly (usually more than 1,000 times the normal level). At this time, the optical signal detected by the fluorescent fiber optic probe detection system may even appear in a continuous sheet, indicating that the battery is in a dangerous stage of near explosion. At this time, the fire warning system should immediately trigger the protection mechanism, quickly remove the battery compartment, and start the fire-fighting device to cool down to prevent the occurrence and spread of the accident.

[0044] It can be seen that the present invention can effectively identify and respond to the failure risk of battery packs and ensure the safe operation of energy storage power stations through the design of this early warning system. The combination of real-time monitoring, automatic alarm and protection mechanism of the fire early warning system enables rapid response measures to be taken when potential dangers occur, greatly reducing the risk of fire and explosion accidents and ensuring the safety of equipment and personnel.

[0045] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the method disclosed in the embodiment, since it corresponds to the system disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0046] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0047] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0048] The above is a detailed introduction to the fire warning system and method for lithium-ion batteries in energy storage power stations provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A fire warning system for lithium-ion batteries in energy storage power stations, characterized in that: It includes lithium-ion batteries, optical fiber collimators, photoelectric converters and remote computers installed in energy storage power stations; The side wall of the lithium-ion battery is provided with a through hole, a fluorescent fiber optic probe is provided in the lithium-ion battery, a through-hole is installed in the through hole, the fluorescent fiber optic probe is connected to the input end of the through-hole, the output end of the through-hole is connected to the fiber optic collimator, the fiber optic collimator is connected to the photoelectric converter, and the photoelectric converter is connected to the remote computer; The fluorescent optical fiber probe is used to collect in real time the optical signal generated by the abnormal discharge or abnormal chemical reaction of the internal battery of the lithium-ion battery, and send the optical signal to the photoelectric converter through the through-hole and the optical fiber collimator; The photoelectric converter is used to convert the optical signal into an electrical signal and send it to a remote computer; The remote computer is used to issue an alarm after receiving the optical signal, and to start a protection mechanism according to the analysis result by analyzing the amplitude or repetition rate of the optical signal.

2. The fire warning system for lithium-ion batteries in energy storage power stations according to claim 1, characterized in that: The system also includes an analog-to-digital conversion module, the input end of the analog-to-digital conversion module is connected to the photoelectric converter, and the output end of the analog-to-digital conversion module is connected to a remote computer via a transmission bus; The analog-to-digital conversion module is used to convert the electrical signal into a digital signal and send it to a remote computer.

3. The fire warning system for lithium-ion batteries in energy storage power stations according to claim 2, characterized in that: The through-hole is provided with sealing rings on both sides, and the through-hole is fixedly installed in the through-hole through the sealing rings. A quartz fiber lens is provided at the center of the through-hole, and the output end of the through-hole is connected to the fiber collimator through the quartz fiber.

4. The fire warning system for lithium-ion batteries in energy storage power stations according to claim 3 is characterized in that: The input and output ends of the through-hole device both adopt ST interfaces.

5. The fire warning system for lithium-ion batteries in energy storage power stations according to claim 1, characterized in that: The photoelectric converter adopts a photodiode.

6. The fire warning system for lithium-ion batteries in energy storage power stations according to claim 1, characterized in that: The fluorescent optical fiber probe is arranged at the proximal end of the electrode and the current collector of the lithium ion battery.

7. A fire warning method for lithium-ion batteries in energy storage power stations, characterized in that: The method adopts the fire warning system of lithium-ion battery of energy storage power station as claimed in any one of claims 1 to 6; The method comprises: The fluorescent fiber optic probe is used to collect the optical signals generated by abnormal discharge or abnormal chemical reaction in the lithium-ion battery in real time, and the optical signals with different spectral lengths are amplified and wavelength converted, and then transmitted to the through-hole device; The optical signal is transmitted to the optical fiber collimator through the through-hole, and the optical signal is converted into a uniformly distributed parallel optical signal through the optical fiber collimator and then transmitted to the photoelectric converter; The optical signal is converted into an electrical signal through a photoelectric converter, and then converted into a digital signal through an analog-to-digital conversion module and sent to a remote computer; After receiving the digital signal, the remote computer immediately sends out an alarm message, analyzes the amplitude or repetition rate of the optical signal according to the digital signal, and activates the protection mechanism according to the analysis result.

8. The fire warning method for lithium-ion batteries in energy storage power stations according to claim 7, characterized in that: The step of analyzing the amplitude or repetition rate of the optical signal and initiating a protection mechanism according to the analysis result includes: Analyze the amplitude or repetition rate of the optical signal through digital signal processing technology; Determine whether the amplitude or repetition rate is greater than a preset warning threshold: If so, an early warning signal and a control instruction are directly sent to the energy storage power station, and the energy storage power station performs a power-off operation on the corresponding lithium-ion battery according to the control instruction.

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