A battery self-heating temperature detection method, device, equipment and storage medium

Abstract

The present application relates to a kind of battery self-heating temperature detection method, device, equipment and storage medium, the method comprises: S1, the battery to be measured is placed in the middle of clamp, controllable and with temperature feedback heater is arranged on one side of clamp, temperature sensor is arranged on the other side;S2, superimposed setting speed linear signal and set amplitude, frequency AC signal as the set temperature signal of heater, alternating temperature control is carried out to the battery to be measured, while temperature sensor real-time monitoring temperature signal;S3, the AC part in set temperature signal is used as the reference signal of lock-in amplifier;Temperature amplitude curve is obtained by processing after temperature detection signal is input to lock-in amplifier, find the time of the wave trough between two peaks on the curve, the temperature of the same time linear part on reference signal is corresponding, it is the self-heating temperature of battery to be measured.Compared with prior art, the self-heating condition can be continuously detected in the process of heating, and noise suppression is more excellent.

Description

Technical Field

[0001] This invention relates to the field of battery temperature detection technology, and in particular to a method for detecting the self-heating temperature of a battery. Background Technology

[0002] Lithium-ion batteries possess numerous advantages, such as high operating voltage, high energy density, and long cycle life, leading to their widespread application in fields like communications, new energy vehicles, and smart grids in recent years. The safety of lithium-ion batteries is paramount. In recent years, thermal runaway incidents involving electric vehicles have been frequent, endangering lives and property and negatively impacting the development of new energy vehicles. The battery's self-heating temperature represents a crucial point in the early stages of thermal runaway, making accurate measurement of this temperature essential.

[0003] Currently, the most widely used method for detecting battery self-heating temperature is the "heat-wait-search" cycle of an adiabatic accelerated calorimeter (ARC). First, the ARC heats the chamber and sample according to a program; then, it waits for sufficient heat exchange between the different parts of the sample chamber until all parts reach the same temperature; finally, it searches for the sample's temperature rise rate. If it is greater than a set value (common value: 0.02℃ / min), the temperature is considered the sample's self-heating temperature; otherwise, it proceeds to the next cycle.

[0004] The accuracy of the self-heating temperature measurement using the above technology depends in part on the step size set for each heating cycle, typically 5°C or 10°C. Another challenge in practical applications is noise interference. The temperature rise rate is obtained by dividing the temperature difference between adjacent intervals by the time interval. In high-frequency temperature sampling, due to the short time intervals, even minor noise can easily result in a large temperature rise rate, leading to inaccurate determination of the self-heating temperature.

[0005] Therefore, there is a need for a detection method and device that can continuously detect self-heating during the heating process and has good noise suppression. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the prior art and provide a method, apparatus, device and storage medium for detecting battery self-heating temperature with continuous detection and excellent noise suppression during the heating process.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] According to a first aspect of the present invention, a method for detecting the self-heating temperature of a battery is provided, the method comprising the following steps:

[0009] Step S1: Place the battery to be tested in the middle of the fixture, wherein a controllable heater with temperature feedback is provided on one side of the fixture, and a temperature sensor is provided on the other side of the fixture.

[0010] Step S2: Superimpose the linear signal of the set speed and the AC signal of the set amplitude and frequency as the set temperature signal of the heater to perform alternating heating control on the battery under test. At the same time, the temperature sensor monitors the temperature signal in real time.

[0011] Step S3: Use the AC part of the set temperature signal as the reference signal of the lock-in amplifier; input the detected temperature signal measured by the temperature sensor into the lock-in amplifier, process it to obtain the temperature amplitude curve, find the time of the trough between the two peaks on the curve, and the temperature of the linear part of the reference signal at the same time is the self-heating temperature of the battery under test.

[0012] Preferably, the temperature sensor in step S1 is located at the geometric center of the clamp on the other side.

[0013] Preferably, the temperature sensor and heater are disposed on the side of the clamp closest to the battery under test.

[0014] Preferably, the speed of the linear signal, the amplitude and frequency of the AC signal in step S2 are determined according to the thickness of the battery under test, the maximum power of the heater and the actual heat dissipation conditions.

[0015] Preferably, the AC signal in step S2 is a sinusoidal AC signal.

[0016] Preferably, in step S3, the temperature signal measured by the temperature sensor is input to the lock-in amplifier and processed to obtain the temperature amplitude curve. Specifically, the temperature signal measured by the temperature sensor is processed by blocking the DC part with a capacitor and bandpass filtering, convolved with the shifted reference signal, and then low-pass filtered to obtain the amplitude change curve of the AC part of the temperature signal.

[0017] Preferably, the shifted reference signal specifically involves shifting the phase of the reference signal so that its phase matches that of the detected temperature signal.

[0018] According to a second aspect of the present invention, a device for detecting the self-heating temperature of a battery is provided, employing any of the methods described herein, the device comprising a clamp, a heater, a temperature sensor, a lock-in amplifier, and a signal processing terminal;

[0019] The battery under test is placed in the middle of the fixture, wherein a controllable heater with temperature feedback is provided on one side of the fixture, and a temperature sensor is provided on the other side of the fixture; the heater is a heater with controllable temperature rise rate, amplitude, and frequency; the lock-in amplifier is connected to the heater and the temperature sensor respectively, and is used to perform lock-in amplification processing on the detected temperature data measured by the temperature sensor; the signal processing terminal is connected to the lock-in amplifier, and is used to obtain the self-heating temperature of the battery under test from the temperature amplitude data after lock-in amplification processing.

[0020] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement any of the methods described above.

[0021] According to a fourth aspect of the invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements any of the methods described herein.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1) In the process of detecting the self-heating temperature of the battery sample, the present invention performs heating and monitoring simultaneously, which can continuously detect the self-heating temperature, rather than the step-by-step detection in the traditional solution.

[0024] 2) This invention is based on mature lock-in amplification technology, which has good noise immunity when detecting small self-heating signals, making the test results more reliable. Lock-in amplification technology is based on the orthogonality of trigonometric functions. After long-term convolution of the signal formed by noise of no fixed frequency and heating source of specific frequency, it approaches zero, which effectively suppresses the influence of noise in the measurement.

[0025] 3) Based on the characteristic that the background signal generated by the heating source is far from the temperature detector and attenuates more, while the sample is close to the temperature detector and attenuates less, the heat transfer equation is a parabolic second-order partial differential equation. Its solution is a linear superposition of several Green's functions, rather than a superposition of traveling waves, which is beneficial for the identification of self-heating signals.

[0026] 4) The present invention has a shorter detection time for batteries with smaller thickness, which has better practical significance and commercial value in this case. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the experimental apparatus for the battery detection method of the present invention;

[0028] Figure 2 This is a schematic diagram of the signal control and detection method of the present invention;

[0029] Figure 3The temperature vibration graphs are generated by the heater temperature and the sensor detection. Figure 3 (a) is a waveform of heater temperature vibration. Figure 3 (b) is a temperature vibration diagram detected by the temperature sensor;

[0030] Figure 4 A schematic diagram for detecting the amplitude change of the temperature AC component;

[0031] Figure labels: 1-Battery under test, 2-Clamp, 3-Heater, 4-Temperature sensor. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0033] Example

[0034] like Figure 1 As shown, the battery sample to be tested is placed between two clamps, one of which has a controllable heater, and the other clamp has a temperature sensor positioned at its geometric center. The heater has temperature feedback, and its heating power is controlled by a computer. A relatively slow temperature rise rate and a temperature alternating mode with appropriate amplitude and frequency are set, meaning the temperature on the left side of the sample satisfies the superposition of a linear signal and a small sinusoidal AC signal. The frequency and amplitude of the signal are determined based on the thickness of the battery sample, the maximum power of the heater, heat dissipation conditions, and other practical factors. The AC component of the temperature signal set above serves as the reference signal for the lock-in amplifier.

[0035] Heat flows through the battery, causing temperature fluctuations on the other side. These fluctuations are monitored by a temperature sensor. The temperature signal consists of two parts: one part reflects the temperature fluctuations from the heat source, and the other part reflects the temperature rise caused by the battery's own heating. As the temperature rises from low to high across the self-heating temperature, the temperature of different parts of the battery repeatedly crosses this temperature at the frequency of the heating source. Therefore, the frequency of the self-heating portion of the temperature signal is also the oscillation frequency of the heating source.

[0036] Figure 3 A temperature-time graph (temperature-time graph) simulating heater temperature and sensor-detected temperature vibration was used. To achieve a better visual effect, a larger temperature rise rate and a non-realistic battery self-heating power were employed; this is solely for illustrative purposes. The battery's self-heating temperature is defined as the zero point on the vertical axis in the graph. Figure 4To detect the curve of temperature AC amplitude changing over time, during the process of the temperature rising from low to high across the self-heating temperature, the AC amplitude will show two peaks, with the amplitude being the same and relatively small before and after the crossing.

[0037] like Figure 2 As shown, the temperature signal is processed by blocking the DC portion with a capacitor and bandpass filtering, and the reference signal is phase-shifted to match the phase of the detected temperature signal. The two signals are then convolved and passed through a low-pass filter to obtain the amplitude variation curve of the AC component of the detected temperature signal. This part uses a mature lock-in amplification technique and will not be elaborated upon here. The time at the trough between the two peaks on the amplitude curve is found. Since the linear temperature rise rate of the sample is relatively small in actual testing, the linear temperature components on both sides of the battery are almost identical. This temperature can be directly correlated with the temperature of the linear component on the reference signal at the same time, which is the battery's self-heating temperature.

[0038] This invention uses lock-in amplification technology, which also inherits the advantages of lock-in amplification. Since the frequencies of noise and reference signals are inconsistent, noise is greatly suppressed according to the orthogonality of trigonometric functions, resulting in a good signal-to-noise ratio.

[0039] This invention requires a longer testing time for batteries with greater thickness (such as prismatic batteries), while the testing time is shorter for batteries with less thickness (such as pouch or blade batteries). In this case, it has better practical significance and commercial value.

[0040] The electronic device of this invention includes a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) or loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0041] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0042] The processing unit executes the various methods and processes described above, such as methods S1 to S3. For example, in some embodiments, methods S1 to S3 may be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of methods S1 to S3 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S1 to S3 by any other suitable means (e.g., by means of firmware).

[0043] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload programmable logic devices (CPLDs), and so on.

[0044] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0045] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0046] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting the self-heating temperature of a battery, characterized in that, The method includes the following steps: Step S1: Place the battery to be tested in the middle of the fixture, wherein a controllable heater with temperature feedback is provided on one side of the fixture, and a temperature sensor is provided on the other side of the fixture. Step S2: Superimpose the linear signal of the set speed and the AC signal of the set amplitude and frequency as the set temperature signal of the heater to perform alternating temperature control on the battery under test. At the same time, the temperature sensor monitors the temperature signal in real time. Step S3: Use the AC part of the set temperature signal as the reference signal of the lock-in amplifier; input the detected temperature signal measured by the temperature sensor into the lock-in amplifier, process it to obtain the temperature amplitude curve, find the time of the trough between the two peaks on the curve, and the temperature of the linear part of the reference signal at the same time is the self-heating temperature of the battery under test.

2. The battery self-heating temperature detection method according to claim 1, characterized in that, The temperature sensor in step S1 is located at the geometric center of the clamp on the other side.

3. The method for detecting the self-heating temperature of a battery according to claim 1, characterized in that, The temperature sensor and heater are positioned on the side of the fixture closest to the battery under test.

4. The battery self-heating temperature detection method according to claim 1, characterized in that, The speed of the linear signal, the amplitude and frequency of the AC signal in step S2 are determined based on the thickness of the battery under test, the maximum power of the heater, and the actual heat dissipation conditions.

5. The method for detecting the self-heating temperature of a battery according to claim 1, characterized in that, The AC signal in step S2 is a sinusoidal AC signal.

6. The method for detecting the self-heating temperature of a battery according to claim 1, characterized in that, In step S3, the temperature signal measured by the temperature sensor is input to the lock-in amplifier and processed to obtain the temperature amplitude curve. Specifically, the temperature signal measured by the temperature sensor is processed by blocking the DC part with a capacitor and bandpass filtering, convolved with the shifted reference signal, and then low-pass filtered to obtain the amplitude change curve of the AC part of the temperature signal.

7. The battery self-heating temperature detection method according to claim 6, characterized in that, The shifted reference signal specifically refers to shifting the phase of the reference signal so that its phase is consistent with the detected temperature signal.

8. A battery self-heating temperature detection device, characterized in that, The device, which employs the method described in any one of claims 1 to 7, comprises a clamp (2), a heater (3), a temperature sensor (4), a lock-in amplifier, and a signal processing terminal; The battery under test (1) is placed in the middle of the fixture (2), wherein a controllable heater (3) with temperature feedback is provided on one side of the fixture (2), and a temperature sensor (4) is provided on the other side of the fixture; the heater (3) is a heater with controllable temperature rise rate, amplitude and frequency; the lock-in amplifier is connected to the heater (3) and the temperature sensor (4) respectively, and is used to perform lock-in amplification processing on the detection temperature data measured by the temperature sensor (4); the signal processing terminal is connected to the lock-in amplifier and is used to obtain the self-heating temperature of the battery under test from the temperature amplitude data after lock-in amplification processing.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 7.

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