Method and system for detecting working abnormality of power battery
阅读说明：本技术 动力电池工作异常的检测方法及系统 (Method and system for detecting working abnormality of power battery ) 是由 任亚超 王明玉 吴靖 周国梁 廖佳音 于 2019-08-29 设计创作，主要内容包括：本发明提供了一种动力电池工作异常的检测方法及系统,包括：平均发热量获取步骤：计算动力电池在第一时刻到第二时刻内的平均发热量；发热量限值获取步骤：获取动力电池在生命周期内的发热量限值；决策步骤：判断所述发热量限值是否大于等于所述平均发热量,若判断结果为是,则动力电池工作正常,若判断结果为否,则动力电池工作异常。本发明有效的解决了当前技术中易出现的电池已处于异常状态,但由于电池热管理性能较好,电池未达到温度异常阈值从而未报警的检测死角问题。(The invention provides a method and a system for detecting the working abnormity of a power battery, which comprises the following steps: an average heating value acquisition step: calculating the average heating value of the power battery from the first moment to the second moment; a heating value limit value acquisition step: acquiring a calorific value limit value of the power battery in a life cycle; a decision making step: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally. The invention effectively solves the problem of detection dead angles which are easily caused in the prior art that the battery is in an abnormal state, but the battery does not reach the abnormal temperature threshold value due to better thermal management performance of the battery, so that no alarm is given.)
1. A method for detecting the abnormal operation of a power battery is characterized by comprising the following steps:
an average heating value acquisition step: calculating the average heating value of the power battery from the first moment to the second moment;
a heating value limit value acquisition step: acquiring a calorific value limit value of the power battery in a life cycle;
a decision making step: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally.
2. The method for detecting an operational abnormality of a power battery according to claim 1, characterized in that the calculation of the average heat generation amount includes:
wherein the content of the first and second substances,
3. The method for detecting an operational abnormality of a power battery according to claim 1, characterized in that the calculation of the heat generation amount limit value includes:
wherein the content of the first and second substances,
4. The method for detecting the power battery working abnormity according to the claim 3, wherein the heating value limit value is obtained by calculation according to a single battery or a battery module in the power battery or according to the whole power battery.
5. The method for detecting the power battery working abnormity according to the claim 1, characterized by further comprising the step of giving an alarm when the power battery works abnormally.
6. A power battery abnormal operation detection system is characterized by comprising:
an average heating value acquisition module: calculating the average heating value of the power battery from the first moment to the second moment;
a calorific value limit acquisition module: acquiring a calorific value limit value of the power battery in a life cycle;
a decision module: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally.
7. The power cell operation abnormality detection system according to claim 6, characterized in that the calculation of the average heat generation amount includes:
wherein the content of the first and second substances,
8. The power battery operation abnormality detection system according to claim 6, characterized in that the calculation of the heat generation amount limit value includes:
wherein the content of the first and second substances,
9. The system for detecting the power battery working abnormity according to claim 8, wherein the heating value limit value is calculated according to a single battery or a battery module in the power battery or according to the whole power battery.
10. The system for detecting the power battery working abnormity according to the claim 6, characterized by further comprising an alarm prompt when the power battery works abnormally.
Technical Field
The invention relates to the technical field of power batteries of electric vehicles, in particular to a method and a system for detecting working abnormity of a power battery.
Background
With the development of automobile technology, the occupancy rate of an electric automobile in a vehicle is higher and higher, and the electric automobile is powered by a battery, and in order to ensure that a power battery in a new energy automobile can provide and store energy in an optimal state, battery state information (including voltage, current, temperature and heat) of the power battery in a use state needs to be detected so as to judge whether the power battery is abnormal or not.
In the prior art, a method for directly detecting voltage, current and temperature of a battery body is usually adopted, whether the battery is abnormal or not is judged according to whether a detected value exceeds a set threshold value or not, however, even if the battery is abnormal under certain specific conditions, the battery does not show an over-temperature sign due to good thermal management performance of the battery, if the temperature is still used as a judgment condition, the optimal alarm time is easy to miss, the power battery cannot be used efficiently and safely, and even the safety of a driver is threatened. For example:
patent CN108603792A discloses that a temperature detection module (HM) includes: a thermistor that detects the temperature of the single cell; a thermistor wire led out from the thermistor; a thermistor holding unit that holds the thermistor so as to be movable in a direction toward or away from the cell in a state in which the thermistor is moved and urged toward the cell; and a wire routing channel in which the thermistor wire is routed toward one direction. A holding unit is provided in the wire routing channel, and the holding unit holds the midway position of the thermistor wire that is drawn out from the thermistor and routed along the wire routing channel in such a manner that a predetermined amount of excess length portion is provided on the drawn-out end side of the thermistor wire in order to allow movement of the thermistor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a method and a system for detecting the working abnormity of a power battery.
The invention provides a method for detecting the working abnormity of a power battery, which comprises the following steps:
an average heating value acquisition step: calculating the average heating value of the power battery from the first moment to the second moment;
a heating value limit value acquisition step: acquiring a calorific value limit value of the power battery in a life cycle;
a decision making step: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally.
Preferably, the calculation of the average calorific value includes:
wherein the content of the first and second substances,
Preferably, the calculation of the heat generation amount limit value includes:
wherein the content of the first and second substances,
Preferably, the heating value limit value is calculated according to a battery cell or a battery module in the power battery, or according to the whole power battery.
Preferably, the method further comprises the step of giving an alarm when the power battery works abnormally.
The invention provides a detection system for power battery working abnormity, which comprises:
an average heating value acquisition module: calculating the average heating value of the power battery from the first moment to the second moment;
a calorific value limit acquisition module: acquiring a calorific value limit value of the power battery in a life cycle;
a decision module: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally.
Preferably, the calculation of the average calorific value includes:
wherein the content of the first and second substances,
Preferably, the calculation of the heat generation amount limit value includes:
wherein the content of the first and second substances,
Preferably, the heating value limit value is calculated according to a battery cell or a battery module in the power battery, or according to the whole power battery.
Preferably, the method further comprises the step of giving an alarm when the power battery works abnormally.
Compared with the prior art, the invention has the following beneficial effects:
the invention effectively solves the problem of detection dead angles which are easily caused in the prior art that the battery is in an abnormal state, but the battery does not reach the abnormal temperature threshold value due to better thermal management performance of the battery, so that no alarm is given.
The battery safety detection is more comprehensive, and an alarm signal can be sent out before the battery is abnormal. And more escape time can be strived for the driver by giving an alarm in advance under an extreme condition. The problem can be found earlier by alarming in advance, so that the problem is solved more easily, and the economic loss is reduced.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a flow chart of the operation of the present invention;
FIG. 2 is a schematic structural diagram of a power battery pack thermal management system.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
As shown in fig. 1, the method for detecting the power battery working abnormality provided by the invention comprises the following steps:
an average heating value acquisition step: calculating the average heating value of the power battery from the first moment to the second moment;
a heating value limit value acquisition step: acquiring a calorific value limit value of the power battery in a life cycle;
a decision making step: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally, and giving an alarm.
The calculation of the average heating value includes:
wherein the content of the first and second substances,
The calculation of the heating value limit value includes:
wherein the content of the first and second substances,
The calorific value limit value is obtained by calculation according to a single battery or a battery module in the power battery or according to the whole power battery.
Referring to fig. 2, the temperature sensor 1, the power battery pack 2, the temperature sensor 3, the battery cooler 4, the water pump 5 and the air conditioning system 6.
The temperature T1 of the coolant entering the power battery pack 2 and the temperature T3 of the coolant flowing out of the power battery pack can be obtained by the temperature sensor 1 and the temperature sensor 3; the flow rate of the cooling liquid in the power battery pack 2 at the moment can be obtained according to the rotating speed of the water pump 5, so that the heat Q1 taken away by the cooling liquid is calculated; in conjunction with the temperature information of the battery in the BMS, the amount of change Δ T in the battery temperature over a period of time (e.g., from time a to time b) Ta-Tb can be obtained, and in conjunction with the characteristics of the battery pack itself, the amount of heat Q2 absorbed by the battery pack can be calculated; according to the data, the heat generation quantity Q3 in a battery pack in a short period of time, namely Q3-Q1 + Q2, can be calculated, and the heat generation quantity Q3 is one of the key parameters in the invention.
Referring to fig. 1, the battery thermal management system collects parameters (step 001) for calculating the current heat generation amount of the battery (step 002), sets a current heat generation amount threshold of the battery (step 003), determines the battery operation abnormality (step 004), and performs the battery operation abnormality determination (
The current heat production amount of the battery (step 002) is obtained by comprehensively calculating the temperature and the flow of the cooling liquid in the battery cooling plate and the temperature change condition of the battery in a period of time.
The current heat generation threshold value of the battery (step 003) is obtained according to the tests of the battery monomer, the battery module and the battery pack.
And judging the abnormal operation of the battery (step 004) to ensure that the heat generated by the battery does not exceed the threshold value, otherwise, indicating that the operation of the battery is abnormal.
The battery works abnormally (step 005), corresponding prompts such as sound, light source and characters exist, and alarm information is stored in the BMS for workers to check.
According to step 003, it is judged whether or not Q3 is satisfied at this time<Qx. If the inequality is true, the battery pack is in a normal state, if the inequality is false, the battery pack is in an abnormal state, a corresponding alarm signal is needed at the moment, corresponding sound, characters and light sources are generated to prompt a driver, and the judgment process information is stored for maintenance personnel to check.
On the basis of the method for detecting the working abnormity of the power battery, the invention also provides a system for detecting the working abnormity of the power battery, which comprises the following steps:
an average heating value acquisition module: calculating the average heating value of the power battery from the first moment to the second moment;
a calorific value limit acquisition module: acquiring a calorific value limit value of the power battery in a life cycle;
a decision module: and judging whether the calorific value limit value is larger than or equal to the average calorific value, if so, judging that the power battery works normally, and if not, judging that the power battery works abnormally.
Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, units provided by the present invention as pure computer readable program code, the system and its various devices, modules, units provided by the present invention can be fully implemented by logically programming method steps in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system and various devices, modules and units thereof provided by the invention can be regarded as a hardware component, and the devices, modules and units included in the system for realizing various functions can also be regarded as structures in the hardware component; means, modules, units for performing the various functions may also be regarded as structures within both software modules and hardware components for performing the method.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
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