A power supply detection method for a power battery of a new energy vehicle

Abstract

The present invention discloses a power supply detection method for a power battery of a new energy vehicle, which relates to the technical field of battery power supply detection and includes the following steps: S1, emitting sound waves by an ultrasonic transceiver attached to the surface of the power battery of the new energy vehicle; S2, collecting the real-time density of the electrolyte inside the power battery, calculating several dynamic ratios of the power battery, and generating an internal mobility; S3, determining whether the power supply state of the power battery is normal according to the emitted sound waves of the ultrasonic transceiver and the internal mobility. The present invention provides multi-faceted guidance for the power supply detection of the battery, improves the accuracy of judging whether the power battery bulges, and avoids safety problems caused by battery bulging.

Description

Technical Field

[0001] The present invention relates to the technical field of battery power supply detection, and in particular to a method for detecting power supply of a power battery of a new energy vehicle. Background Art

[0002] With the increasing global awareness of environmental protection and the transformation of energy structure, the new energy vehicle industry has developed rapidly. One of the core components of new energy vehicles is its power battery, which directly determines the vehicle's endurance, safety and service life. The performance status of the power battery, especially the integrity and health of its internal structure, is crucial to ensure the normal operation of the vehicle.

[0003] During long-term use, power batteries may experience internal structural changes due to factors such as charge and discharge cycles, temperature changes, and material aging, such as uneven electrolyte density distribution, active material shedding, and plate expansion. The most direct and serious manifestation is battery bulging. Battery bulging not only affects the sealing of the battery package, causing electrolyte leakage, but may also cause internal short circuits, resulting in thermal runaway or even explosions and other safety hazards.

[0004] Traditional power battery detection methods mostly rely on monitoring external parameters such as voltage, current and temperature, but these methods are often difficult to directly reflect the changes in the microstructure and physical and chemical state of the battery, and lack the ability to warn of early bulging. Therefore, it is particularly important to develop a technology that can non-destructively and in real time monitor the internal state of power batteries, especially to accurately identify battery bulging. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a new energy vehicle power battery power supply detection method.

[0006] The technical solution of the present invention is: a new energy vehicle power battery power supply detection method comprises the following steps:

[0007] S1. Using an ultrasonic transceiver attached to the surface of the power battery of a new energy vehicle to emit sound waves;

[0008] S2. Collect the real-time density of the electrolyte inside the power battery, calculate several dynamic ratios of the power battery, and generate the internal mobility;

[0009] S3. Determine whether the power supply status of the power battery is normal based on the transmitted sound waves of the ultrasonic transceiver and the internal mobility.

[0010] As a non-destructive testing technology, ultrasonic testing technology can reflect the internal structure information of materials due to its advantages such as sensitivity to internal defects of materials, high detection efficiency, and simple operation. Applying ultrasonic testing technology to the state monitoring of power batteries for new energy vehicles, especially in combination with the unique electrochemical characteristics of power batteries (such as changes in electrolyte density), can achieve early detection and accurate evaluation of internal abnormal phenomena such as battery swelling.

[0011] Further, S2 includes the following sub-steps:

[0012] S21. Collect the density of the electrolyte inside the power battery at each moment, and calculate the flow field distribution quantity of the power battery at each moment;

[0013] S22. Calculate the dynamic ratio of the power battery at each moment according to the size of the power battery and the flow field distribution quantity at each moment;

[0014] S23. Generate the internal mobility for the power battery according to the dynamic ratios at all moments of the power battery.

[0015] The beneficial effects of the above further solution are: In the present invention, by collecting the density of the electrolyte inside the power battery in real time, the internal state of the battery can be monitored in real time, the change in the electrolyte density can be captured in time, so as to reflect the performance of the battery. The calculation of the flow field distribution quantity takes into account the flow situation of the electrolyte at each moment, providing a comprehensive view of the internal dynamic changes of the battery; while the calculation of the dynamic ratio takes into account the change in the flow field distribution quantity, which can more accurately evaluate the performance state of the battery at different moments, providing a more accurate basis for battery monitoring.

[0016] Further, in S21, the flow field distribution quantity of the power battery at the th moment

[0017] ;

[0018] In the formula, represents the density of the electrolyte at the th moment, represents the initial density of the electrolyte, represents a constant, represents the porosity of the positive electrode plate, represents the length of the th positive electrode plate, represents the width of the th positive electrode plate, represents the height of the th positive electrode plate, represents the number of positive electrode plates, represents the porosity of the th negative electrode plate, Represents the length of the th negative electrode plate, Represents the th negative electrode plate width, Represents the th negative electrode plate height, Represents the number of negative electrode plates, Represents the diaphragm pore volume.

[0019] Furthermore, in S22, the dynamic ratio at the moment of the power battery is calculated as follows:

[0020] ;

[0021] In the formula, Represents the volume of the power battery, Represents the density of the electrolyte at the moment, Represents the density of the electrolyte at the moment, Represents the density of the electrolyte at the moment, Represents the flow field distribution quantity of the power battery at the moment.

[0022] Furthermore, S23 includes the following sub-steps:

[0023] S231. Arrange all dynamic ratios in chronological order to obtain a dynamic ratio sequence;

[0024] S232. Extract the LOF sequence of the dynamic ratio sequence;

[0025] S233. Generate an internal mobility for the power battery according to the LOF sequence.

[0026] The beneficial effect of the above further solution is: In the present invention, LOF is a local outlier factor of a data point, representing the ratio of the local density of the point to the local density of its neighboring points. The LOF method does not require assuming that the data follows a specific distribution, so it is applicable to the dynamic ratios with chronological connections, can detect the dynamic ratios located in different density regions, and can identify the abnormal changes in the performance parameters of the power battery by using the LOF sequence, thereby determining the influence parameters of the electrolyte on the battery power supply.

[0027] Furthermore, in S233, the internal mobility is calculated as follows:

[0028] ;

[0029] In the formula, Indicates the th element of the LOF sequence, represents the number of elements in the LOF sequence, Indicates the th element in the LOF sequence that is less than or equal to the set threshold, represents the number of elements in the LOF sequence that are less than or equal to the set threshold, Indicates generating a random number between 0 and 1.

[0030] Furthermore, S3 includes the following sub-steps:

[0031] S31. Calculate the time difference between transmission and reception based on the transmission time of the emitted sound wave and the reception time of the received sound wave;

[0032] S32. Use the internal mobility to correct the time difference between transmission and reception to obtain an accurate time difference;

[0033] S33. When the accurate time difference is less than the set time threshold, determine that the power supply situation of the power battery is abnormal.

[0034] The beneficial effect of the above further solution is: In the present invention, the internal mobility reflects the parameter situation of the electrolyte inside the power battery. Using this parameter to correct the time difference between transmission and reception can compensate for the error caused by the change in the internal state of the battery, further improve the accuracy of the time difference, and can be applied to power batteries in different states.

[0035] Furthermore, for S32, the accurate time difference is calculated by the formula:

[0036] ;

[0037] In the formula, represents the internal mobility, represents the time difference between transmission and reception.

[0038] The beneficial effect of the present invention is: The present invention uses an ultrasonic transceiver to emit sound waves, without the need to disassemble or damage the power battery, which is a non-invasive detection method, avoiding possible damage to the battery during the disassembly process; at the same time, by collecting the real-time density of the electrolyte inside the power battery, the internal state of the battery can be accurately understood, calculating multiple dynamic ratios and generating the internal mobility, which can comprehensively reflect the performance changes of the power battery, correct the time difference between transmission and reception, and finally the obtained time difference between transmission and reception combines the influence of the internal situation of the battery on the bulge judgment, providing multi-faceted guidance for the power supply detection of the battery, improving the accuracy of judging whether the power battery bulges, and avoiding safety problems caused by battery bulging. Description of the Drawings

[0039] Figure 1 It is a flow chart of a power supply detection method for a power battery of a new energy vehicle. Specific embodiments

[0040] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0041] As Figure 1 shown, the present invention provides a power supply detection method for a power battery of a new energy vehicle, including the following steps:

[0042] S1. Use an ultrasonic transceiver attached to the surface of the power battery of the new energy vehicle to emit sound waves;

[0043] S2. Collect the real-time density of the electrolyte inside the power battery, calculate several dynamic ratios of the power battery, and generate an internal mobility;

[0044] S3. Determine whether the power supply state of the power battery is normal according to the emitted sound waves of the ultrasonic transceiver and the internal mobility.

[0045] As a non-destructive testing technology, ultrasonic testing technology can reflect the internal structure information of materials due to its advantages such as sensitivity to internal defects of materials, high detection efficiency, and simple operation. Applying ultrasonic testing technology to the state monitoring of power batteries of new energy vehicles, especially in combination with the unique electrochemical characteristics of power batteries (such as changes in electrolyte density), can realize the early detection and accurate assessment of internal abnormal phenomena such as battery bulging.

[0046] In the embodiment of the present invention, S2 includes the following sub-steps:

[0047] S21. Collect the density of the electrolyte inside the power battery at each moment, and calculate the flow field distribution quantity of the power battery at each moment;

[0048] S22. Calculate the dynamic ratios of the power battery at each moment according to the size of the power battery and the flow field distribution quantity at each moment;

[0049] S23. Generate an internal mobility for the power battery according to the dynamic ratios of all moments of the power battery.

[0050] In the present invention, by collecting the density of the electrolyte inside the power battery in real time, the internal state of the battery can be monitored in real time, the change of the electrolyte density can be captured in time, so as to reflect the performance of the battery. The calculation of the flow field distribution quantity takes into account the flow situation of the electrolyte at each moment, providing a comprehensive view of the internal dynamic changes of the battery; while the calculation of the dynamic ratio takes into account the change of the flow field distribution quantity, which can more accurately evaluate the performance state of the battery at different moments and provide a more accurate basis for the monitoring of the battery.

[0051] In the embodiment of the present invention, in S21, for the power battery at the Flow field distribution quantity at a moment The calculation formula is as follows:

[0052] ;

[0053] In the formula, represents the density of the electrolyte at the th moment, represents the initial density of the electrolyte, represents a constant, represents the porosity of the positive electrode plate, represents the th length of the positive electrode plate, represents the th width of the positive electrode plate, represents the th height of the positive electrode plate, represents the number of positive electrode plates, represents the th porosity of the negative electrode plate, represents the th length of the negative electrode plate, represents the th width of the negative electrode plate, represents the th height of the negative electrode plate, represents the number of negative electrode plates, represents the pore volume of the separator.

[0054] In the embodiment of the present invention, in S22, the dynamic ratio of the power battery at the th moment has the following calculation formula:

[0055] ;

[0056] In the formula, represents the volume of the power battery, represents the density of the electrolyte at the th moment, represents the density of the electrolyte at the th moment, represents the density of the electrolyte at the th moment, represents the flow field distribution quantity of the power battery at the th moment.

[0057] In the embodiment of the present invention, S23 includes the following sub-steps:

[0058] S231. Arrange all the dynamic ratios in chronological order to obtain a dynamic ratio sequence;

[0059] S232. Extract the LOF sequence of the dynamic ratio sequence;

[0060] S233. Generate the internal mobility for the power battery according to the LOF sequence.

[0061] In the present invention, LOF is the local outlier factor of a data point, representing the ratio of the local density of this point to the local density of its neighboring points. The LOF method does not require assuming that the data follows a specific distribution, so it is applicable to dynamic ratios with temporal connections, can detect dynamic ratios located in different density regions, and can identify abnormal changes in the performance parameters of the power battery by using the LOF sequence, thereby determining the influence parameters of the electrolyte on the battery power supply.

[0062] In the embodiment of the present invention, in S233, the internal mobility has the following calculation formula:

[0063] ;

[0064] In the formula, represents the th element of the LOF sequence, represents the number of elements of the LOF sequence, represents the th element of the LOF sequence that is less than or equal to the set threshold, represents the number of elements of the LOF sequence that are less than or equal to the set threshold, represents generating a random number between 0 and 1.

[0065] In the embodiment of the present invention, S3 includes the following sub-steps:

[0066] S31. Calculate the time difference between transmission and reception according to the transmission time of the emitted sound wave and the reception time of the received sound wave;

[0067] S32. Use the internal mobility to correct the time difference between transmission and reception to obtain the accurate time difference;

[0068] S33. When the accurate time difference is less than the set time threshold, determine that the power supply situation of the power battery is abnormal.

[0069] In the present invention, the internal mobility reflects the parameter situation of the electrolyte inside the power battery. Using this parameter to correct the time difference between transmission and reception can compensate for the error caused by the change of the internal state of the battery, can further improve the accuracy of the time difference, and is applicable to power batteries in different states.

[0070] In the embodiment of the present invention, in S32, the accurate time difference has the following calculation formula:

[0071] ;

[0072] In the formula, represents the internal mobility, represents the time difference between transmission and reception.

[0073] Those of ordinary skill in the art will realize that the embodiments described herein are for helping the reader understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not depart from the essence of the present invention based on these technical revelations disclosed in the present invention, and these deformations and combinations are still within the scope of protection of the present invention.

Claims

1. A method for detecting the power supply of a power battery for a new energy vehicle, characterized in that, Including the following steps: S1. Use an ultrasonic transceiver attached to the surface of a new energy vehicle power battery to emit sound waves; S2. Collect the real-time density of the electrolyte inside the power battery, calculate several dynamic ratios of the power battery, and generate an internal mobility; S3. Determine whether the power supply status of the power battery is normal based on the emitted sound waves of the ultrasonic transceiver and the internal mobility; The S2 includes the following sub-steps: S21. Collect the density of the electrolyte inside the power battery at each moment, and calculate the flow field distribution quantity of the power battery at each moment; S22. Calculate the dynamic ratios of the power battery at each moment according to the size of the power battery and the flow field distribution quantity at each moment; S23. Generate an internal mobility for the power battery according to the dynamic ratios of all moments of the power battery; The S3 includes the following sub-steps: S31. Calculate the transceiver time difference according to the emission time of the emitted sound wave and the reception time of the received sound wave; S32. Use the internal mobility to correct the transceiver time difference to obtain an accurate time difference; S33. When the accurate time difference is less than the set time threshold, determine that the power supply situation of the power battery is abnormal.

2. The power supply detection method for the power battery of a new energy vehicle according to claim 1, characterized in that In S21, the flow field distribution quantity at the th moment of the power battery is calculated by the following formula: ； Wherein, represents the density of the electrolyte at the th moment, represents the initial density of the electrolyte, represents a constant, represents the porosity of the positive electrode sheet, represents the length of the th positive electrode sheet, represents the width of the th positive electrode sheet, represents the height of the th positive electrode sheet, represents the number of positive electrode sheets, represents the porosity of the th negative electrode sheet, represents the length of the th negative electrode sheet, represents the width of the th negative electrode sheet, represents the height of the th negative electrode sheet, represents the number of negative electrode sheets, represents the pore volume of the separator.

3. The power supply detection method for the power battery of a new energy vehicle according to claim 1, wherein In S22, the dynamic ratio at the moment of the power battery is calculated as follows: ； Wherein, represents the volume of the power battery, represents the density of the electrolyte at the th moment, represents the density of the electrolyte at the th moment, represents the density of the electrolyte at the th moment, represents the flow field distribution quantity of the power battery at the th moment.

4. The power supply detection method for the power battery of a new energy vehicle according to claim 1, wherein, The S23 includes the following sub-steps: S231. Arrange all dynamic ratios in chronological order to obtain a dynamic ratio sequence; S232. Extract the LOF sequence of the dynamic ratio sequence; S233. Generate an internal mobility for the power battery according to the LOF sequence.

5. The power supply detection method for the power battery of a new energy vehicle according to claim 4, characterized in that, In the above S233, the internal migration rate is calculated by the following formula: ； In the formula, represents the th element of the LOF sequence, represents the number of elements in the LOF sequence, represents the th element in the LOF sequence that is less than or equal to the set threshold, represents the number of elements in the LOF sequence that are less than or equal to the set threshold, represents generating a random number between 0 and 1.

6. The power supply detection method for the power battery of a new energy vehicle according to claim 1, wherein The said S32, precise time difference The calculation formula is as follows: ； In the formula, represents the internal mobility, represents the time difference between transmission and reception.

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