CN110276925B - A kind of lithium battery short-circuit thermal runaway fire detection and early warning method - Google Patents
A kind of lithium battery short-circuit thermal runaway fire detection and early warning method Download PDFInfo
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- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 45
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 13
- 238000001514 detection method Methods 0.000 title claims abstract description 10
- 230000002159 abnormal effect Effects 0.000 claims description 15
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 230000006378 damage Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005779 cell damage Effects 0.000 description 1
- 208000037887 cell injury Diseases 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011076 safety test Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000010926 waste battery Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B17/00—Fire alarms; Alarms responsive to explosion
- G08B17/06—Electric actuation of the alarm, e.g. using a thermally-operated switch
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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Abstract
本发明涉及一种锂电池短路热失控火灾探测预警方法，包括：判断同一时间采集的锂电池的电压、工作电流和电池表面温度是否均不在安全区间内，如果均不在安全区间内，一级报警时间增加1；判断一级报警时间是否超过预设时间，如果超过，发出一级报警；二级报警判断步骤，根据预设时段内采集的锂电池的电压、工作电流和电池表面温度获得电压变化率、电流变化率及温度变化率；判断预设时段内的电压变化率、电流变化率和温度变化率是否均不在合理区间内，如果均不在合理区间内，发出二级报警。本发明一种锂电池短路热失控火灾探测预警方法，能够对锂电池当前的短路安全状态进行实时监测，并产生预警，保证了锂电池的使用安全。
The invention relates to a short-circuit thermal runaway fire detection and early warning method for a lithium battery, comprising: judging whether the voltage, operating current and battery surface temperature of the lithium battery collected at the same time are all within a safe range, and if they are not within the safe range, a first-level alarm The time is increased by 1; it is judged whether the first-level alarm time exceeds the preset time, and if it exceeds, the first-level alarm is issued; the second-level alarm judgment step is to obtain the voltage change according to the voltage, working current and battery surface temperature of the lithium battery collected within the preset time period. rate, current change rate and temperature change rate; judge whether the voltage change rate, current change rate and temperature change rate within the preset period are all within the reasonable range, and if they are not within the reasonable range, a secondary alarm will be issued. The invention provides a short-circuit thermal runaway fire detection and early warning method for a lithium battery, which can monitor the current short-circuit safety state of the lithium battery in real time and generate an early warning, thereby ensuring the safety of the lithium battery.
Description
Technical Field
The invention belongs to the technical field of lithium batteries, and particularly relates to a lithium battery short circuit thermal runaway fire detection and early warning method.
Background
Since the first lithium ion battery in the world in the 70 s of the 20 th century, the lithium ion battery has been developed to have the advantages of cleanness, no pollution, high energy density ratio, long cycle service life and the like, and is widely applied to new energy automobiles, solar energy storage and mobile communication equipment. However, improper use or destructive operation of lithium batteries can cause certain hazards and even thermal runaway explosions.
Among the numerous causes of thermal runaway of lithium batteries, the thermal runaway hazard of lithium batteries caused by short circuits is particularly serious. The collision of a new energy automobile, the water immersion of a battery box, the falling extrusion of lithium battery communication equipment, the treatment of waste batteries and the like can cause the short circuit damage of the lithium battery, and the short circuit of the lithium battery refers to the strong discharge behavior caused by the fact that a conductor with smaller resistance is directly connected to the two ends of the positive electrode and the negative electrode of the battery.
When the lithium cell rationally uses, battery self heat production reaches dynamic balance with external heat dissipation, in case the lithium cell takes place the short circuit, voltage drops rapidly, in case reduce to discharge when cutoff voltage the lithium cell will produce the overdischarge damage, the short circuit will make the lithium cell produce great short-circuit current rapidly simultaneously, then produce a large amount of joule heat, the lithium cell heaies up rapidly, after the temperature surpassed the reasonable use temperature of lithium cell, the lithium cell damages and produces thermal runaway. The short-circuit thermal runaway of the lithium battery seriously threatens the life and property safety of people, and the national standard committee also promulgates corresponding lithium battery short-circuit safety test standards of lithium ion batteries and battery pack safety requirements for GB 31241-2014 portable electronic products and GB/T31485-2015 power storage battery safety requirements and test methods for electric automobiles, so that the detection and early warning of the short circuit of the lithium battery are particularly necessary.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a lithium battery short circuit thermal runaway fire detection and early warning method which can monitor the current short circuit safety state of a lithium battery in real time, generate early warning and ensure the use safety of the lithium battery.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a lithium battery short circuit thermal runaway fire detection early warning method comprises the following steps:
a first-level alarm judging step, namely judging whether the voltage, the working current and the surface temperature of the lithium battery collected at the same time are not in a safety interval, and if not, increasing the first-level alarm time by 1; judging whether the primary alarm time exceeds the preset time, and if so, sending a primary alarm;
a secondary alarm judgment step, namely acquiring a voltage change rate, a current change rate and a temperature change rate according to the voltage, the working current and the battery surface temperature of the lithium battery collected in a preset time period; and judging whether the voltage change rate, the current change rate and the temperature change rate in the preset time period are all not in a reasonable interval, and if not, sending out a secondary alarm.
Preferably, the first-level alarm judging step specifically includes:
setting a voltage safety parameter SU, a current safety parameter SI and a temperature safety parameter ST as 1, and collecting characteristic parameter values of the nth second; the characteristic parameter values comprise voltage, working current and battery surface temperature;
judging whether the voltage is within the range of the upper and lower voltage safety limits, if so, judging that the voltage is normal, and setting SU to 1, otherwise, judging that the voltage is abnormal, and setting SU to 0; judging whether the working current is within the range of the upper and lower current safety limits, if so, judging the working current to be normal, setting SI as 1, otherwise, judging the working current to be abnormal, and setting SI as 0; judging whether the surface temperature of the battery is within the upper and lower temperature safety limits, if so, judging the battery to be normal, setting ST to be 1, otherwise, judging the battery to be abnormal, and setting ST to be 0;
judging whether the voltage safety parameter SU, the current safety parameter SI and the temperature safety parameter ST are all 0, if so, adding 1 to the primary alarm accumulated time SUM;
and judging whether the SUM is greater than or equal to a preset value, if so, generating a primary alarm, and otherwise, not generating the primary alarm.
Preferably, the secondary alarm determining step specifically includes:
setting a secondary alarm voltage safety parameter SKU, a current safety parameter SKI and a temperature safety parameter SKT as 1, and collecting characteristic parameter values per second in preset time; the characteristic parameter values comprise voltage, working current and battery surface temperature;
performing linear fitting on the characteristic parameters within the preset time, namely performing linear fitting on the characteristic parameters of the nth second, (n +1) second, (n +2) second, (n +3) second and (n +4) second to obtain a voltage change rate KU, a current change rate KI and a temperature change rate KT;
judging whether the voltage change rate KU is within the range of the upper and lower voltage safety limits of the voltage change rate, if so, judging that the voltage change rate KU is normal, and setting the SKU to be 1, otherwise, judging that the voltage change rate KU is abnormal, and setting the SKU to be 0; judging whether the current change rate KI is within the safe upper and lower limit ranges of the current change rate, if so, judging that the current change rate KI is normal, setting SKI to be 1, otherwise, judging that the current change rate KI is abnormal, and setting SKI to be 0; judging whether the temperature change rate is within the safety upper and lower limits of the temperature change rate, if so, judging that the temperature change rate is normal, setting SKT to be 1, otherwise, judging that the temperature change rate is abnormal, and setting SKT to be 0;
and judging whether the voltage safety parameter SKU, the current safety parameter SKI and the temperature safety parameter SKT are all 0, if so, generating a secondary alarm, otherwise, not generating the secondary alarm.
After the scheme is adopted, the invention has the beneficial effects that:
the method for detecting and early warning the short-circuit thermal runaway fire of the lithium battery can monitor the current short-circuit safety state of the lithium battery in real time, carry out primary early warning judgment according to the currently acquired characteristic parameters, and simultaneously carry out secondary early warning judgment according to the change rate of the characteristic parameters in a preset time period, wherein the secondary early warning judgment ensures the use safety of the lithium battery.
The invention is further described in detail with reference to the drawings and the embodiments, but the method for detecting and warning a short-circuit thermal runaway fire of a lithium battery is not limited to the embodiments.
Drawings
FIG. 1 is a first level alarm flow diagram of the present invention;
FIG. 2 is a flow chart of a secondary alarm of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described and discussed in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention discloses a lithium battery short circuit thermal runaway fire detection and early warning method, which comprises the following steps:
a first-level alarm judging step, namely judging whether the voltage, the working current and the surface temperature of the lithium battery collected at the same time are not in a safety interval, and if not, increasing the first-level alarm time by 1; judging whether the primary alarm time exceeds the preset time, and if so, sending a primary alarm;
a secondary alarm judgment step, namely acquiring a voltage change rate, a current change rate and a temperature change rate according to the voltage, the working current and the battery surface temperature of the lithium battery collected in a preset time period; and judging whether the voltage change rate, the current change rate and the temperature change rate in the preset time period are all not in a reasonable interval, and if not, sending out a secondary alarm.
It should be noted that the primary alarm determination and the secondary alarm determination are performed simultaneously.
Specifically, referring to fig. 1, the first-stage alarm determining step is implemented as follows.
In the first-level alarm judging step, the SUM is the first-level alarm accumulated time with the unit of s; the primary alarm safety parameters comprise a voltage safety parameter SU, a current safety parameter SI and a temperature safety parameter ST, and the values of the SU, the SI and the ST are 1 or 0(1 is safe, and 0 is unsafe); u shapeHAnd ULRespectively, a safe upper limit and a safe lower limit of voltage, IHAnd ILRespectively, a current safety upper limit and a current safety lower limit, THAnd TLRespectively, a safe upper limit and a safe lower limit of temperature, wherein UH、UL、IH、IL、THAnd TLThe upper and lower limit values can be changed according to the type of the specific lithium battery or the use environment.
When the process is judged to start, firstly, the SUM is assigned to be 0, the SU, the SI and the ST are all assigned to be 1, characteristic parameter values of n s are collected, whether the voltage is in the upper and lower reasonable use limit ranges is judged, if the voltage is in the upper and lower reasonable use limit ranges, the voltage is judged to be normal, the SU is assigned to be 1, and if the voltage is not in the upper and lower reasonable use limit ranges, the voltage is judged to be abnormal, and the SU is assigned to be 0.
The current and temperature are determined as well as the voltage. And then, performing an AND operation on SU, SI and ST, wherein if SU & SI & ST is 0, SUM +1, and if SU & SI & ST is 1, SUM is 0.
If the SUM is 3s and the characteristic parameters are abnormal, the SUM is more than or equal to 3, a first-level alarm is sent out, otherwise, the alarm is not sent out. And resetting SU, SI and ST to 1, and starting to acquire the characteristic parameters of the (n +1) th s.
Specifically, referring to fig. 2, the secondary alarm determining step is implemented as follows.
In the secondary alarm judging step, the secondary alarm safety parameters comprise a voltage safety parameter SKU, a current safety parameter SKI and a temperature safety parameter SKT, and the values of the SKU, the SKI and the SKT are 1 or 0(1 is safe and 0 is unsafe); kU、KIAnd KTRespectively the rate of change of voltage, current and temperature over a certain time, KUHAnd KULRespectively, a safe upper limit and a safe lower limit of the voltage change rate, KIHAnd KILRespectively, a safe upper limit and a safe lower limit of the rate of change of the current, KTHAnd KTLRespectively a safe upper limit and a safe lower limit of the temperature change rate, wherein KUH、KUL、KIH、KIL、KTHAnd KTLThe upper and lower limit values can be changed according to the type of the specific lithium battery or the use environment.
When the starting of the judging process is carried out, setting two-stage alarm safety parameters SKU, SKI and SKT to 1, acquiring the characteristic parameter value of every 1s, and carrying out linear fitting on the characteristic parameters within 5s (the time can be changed according to different lithium batteries and specific use environments), namely carrying out linear fitting on the characteristic parameters of ns, (n +1) s, (n +2) s, (n +3) s and (n +4) s to obtain the change rate KU、KIAnd KTAnd judging whether the voltage change rate is in the reasonable upper and lower limit ranges, if so, judging the voltage change rate to be normal, and assigning the SKU value to be 1, otherwise, judging the voltage change rate to be abnormal, and if not, assigning the SKU value to be 0.
The judgment of the current change rate and the temperature change rate is the same as the judgment of the voltage change rate. And performing AND operation on the SKU, the SKI and the SKT, if the SKU, the SKI and the SKT are 0, giving a secondary alarm, and if the SKU, the SKI and the SKT are 1, not giving the alarm.
And then, setting SKU, SKI and SKT to be 1, and starting the analysis and judgment of the change rates of the characteristic parameters of (n +1) th s, (n +2) th s, (n +3) th s, (n +4) th s and (n +5) th s.
The above is only one preferred embodiment of the present invention. However, the present invention is not limited to the above embodiments, and any equivalent changes and modifications made according to the present invention, which do not bring out the functional effects beyond the scope of the present invention, belong to the protection scope of the present invention.
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| CN112038716B (en) * | 2020-08-14 | 2022-06-07 | 合肥国轩高科动力能源有限公司 | Early warning method for thermal runaway of lithium ion battery pack |
| CN117452276A (en) * | 2023-12-15 | 2024-01-26 | 深圳市力生美半导体股份有限公司 | Switch power supply performance test method and device and switch power supply |
| CN119024196B (en) * | 2024-10-28 | 2025-02-07 | 深圳市云控新技术有限公司 | Fire detection method and system for lithium ion battery |
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| JP2007257334A (en) * | 2006-03-23 | 2007-10-04 | Nohmi Bosai Ltd | Fire alarm |
| KR100929036B1 (en) * | 2007-09-27 | 2009-11-30 | 삼성에스디아이 주식회사 | Protection circuit of battery pack, battery pack having same and operation method thereof |
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