Battery apparatus and partial discharge monitoring method

Abstract

The present disclosure discloses a battery apparatus and a partial discharge monitoring method. The battery apparatus comprises: a single-cell battery, an insulating layer being provided on a surface of the single-cell battery; an ultrasonic sensor, the ultrasonic sensor being arranged on the side of the insulating layer away from the single-cell battery; a signal acquisition assembly, the signal acquisition assembly being provided separately from the ultrasonic sensor and coupled to the ultrasonic sensor; and a detection assembly, the detection assembly being coupled to the signal acquisition assembly. The ultrasonic sensor is used for converting an ultrasonic signal generated by partial discharge of the single-cell battery into a first voltage signal. The signal acquisition assembly is used for processing the first voltage signal and then outputting same to the detection assembly. The detection assembly is used for performing computational processing on the processed first voltage signal, so as to obtain a monitoring result characterizing the partial discharge of the single-cell battery.

Description

Battery device and partial discharge monitoring method

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202411396160.2, filed on September 30, 2024, entitled “Battery device and partial discharge monitoring method”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of batteries, and in particular to a battery device and a partial discharge monitoring method. BACKGROUND

[0004] With the rapid development of batteries, the application range extends not only to power batteries but also to energy storage batteries, and the safety of battery systems is increasingly valued. Among them, partial discharge is an important parameter reflecting the insulation performance of the battery, which is a sign and form of insulation deterioration.

[0005] At present, the commonly used partial discharge online monitoring mainly includes ultrahigh frequency method and ultrasonic method. However, the multi-layer metal shell of the battery module has a shielding effect on the ultrahigh frequency electromagnetic wave of the internal partial discharge, especially under the complex electromagnetic wave and vibration working conditions of the battery module, the anti-interference ability of the ultrahigh frequency sensor is poor; and the ultrasonic sensor fixed outside has poor coupling effect, which is not conducive to realizing the partial discharge monitoring of the battery. SUMMARY

[0006] The present disclosure provides a battery device and a partial discharge monitoring method, which can not only realize the partial discharge monitoring of single batteries, but also have fast response speed and can realize real-time early warning of whether the insulation state of the battery deteriorates.

[0007] The technical solution of the present disclosure is implemented as follows:

[0008] In a first aspect, the present disclosure provides a battery device, comprising:

[0009] a single battery, the surface of the single battery being provided with an insulation layer;

[0010] an ultrasonic sensor, the ultrasonic sensor being arranged on a side of the insulation layer away from the single battery;

[0011] a signal acquisition assembly, the signal acquisition assembly being arranged separately from the ultrasonic sensor and coupled to the ultrasonic sensor;

[0012] a detection assembly, the detection assembly being coupled to the signal acquisition assembly;

[0013] The ultrasonic sensor is used to convert an ultrasonic signal generated by the local discharge of the single battery into a first voltage signal; the signal acquisition component is used to output the first voltage signal after processing to the detection component; and the detection component is used to perform operation processing on the processed first voltage signal to obtain a monitoring result representing the local discharge of the single battery.

[0014] Through the above technical means, since the ultrasonic sensor is arranged on the insulating layer of the surface of the single battery, the distance between the ultrasonic sensor and the single battery is small at this time, so that the signal attenuation generated by the local discharge is small, thereby facilitating the realization of the local discharge monitoring of the single battery; then the signal acquisition component arranged separately from the ultrasonic sensor is used to process the first voltage signal, the signal acquisition component is arranged separately from the ultrasonic sensor, which solves the component space occupation problem, so that the ultrasonic sensor can be placed inside the battery device, and the local discharge signal of the single battery inside the battery device can be detected without increasing the size of the battery device; and then the detection component is used to perform operation processing on the processed first voltage signal, thereby being able to monitor the local discharge of the single battery, not only realizing the online monitoring of the local discharge of the single battery, but also the ultrasonic sensor has a faster response speed than the insulation resistance monitoring, and can more timely prevent the insulation failure inside the single battery, thereby being able to real-time early warn whether the insulation state of the battery deteriorates.

[0015] In some embodiments, the ultrasonic sensor comprises a piezoelectric film structure, wherein the piezoelectric film structure comprises a lower electrode sheet, a piezoelectric material layer and an upper electrode sheet which are sequentially stacked.

[0016] Through the above technical means, the ultrasonic sensor comprises the piezoelectric film structure, which occupies a small space when attached to the single battery, is tightly combined, and can well match the outer contour of the single battery. Based on the characteristics of high sensitivity, fast response speed and good stability of the piezoelectric film structure, it is beneficial to realize the local discharge monitoring of the single battery, thereby being able to real-time early warn whether the insulation state of the battery deteriorates.

[0017] In some embodiments, the piezoelectric film structure is a flexible structure.

[0018] Through the above technical means, since the piezoelectric film structure is a flexible structure, it can be better attached to the single battery to occupy a small space, be tightly combined, and well match the outer contour of the single battery, thereby being beneficial to realize the local discharge monitoring of the single battery.

[0019] In some embodiments, the ultrasonic sensor is arranged below the R-angle region of the bottom of the single battery, and / or below the bottom planar region of the single battery.

[0020] Through the technical means, the vibration process of the partial discharge can be transmitted, but the signal attenuation is relatively serious, and considering that the vibration direction is up and down vibration, the ultrasonic sensor is arranged below the bottom of the single battery (for example, below the bottom flat area and / or below the bottom R corner area), at this time, the pressure generated by the partial discharge vibration is transmitted to the piezoelectric film structure in the ultrasonic sensor, so that the piezoelectric film structure is more susceptible to deformation, thereby more easily detecting the vibration, and the measurement of the ultrasonic sensor is more accurate, and based on the characteristics of the piezoelectric film, such as high sensitivity, fast response speed, good stability, etc., thereby facilitating the partial discharge monitoring of the single battery.

[0021] In some embodiments, the number of single batteries is a plurality, and the plurality of single batteries are connected in series to form a battery module; the ultrasonic sensor is arranged at least one of the following positions inside the battery module:

[0022] below the bottom R corner area of the battery at the preset position inside the battery module;

[0023] below the bottom flat area of the battery at the preset position inside the battery module;

[0024] below the bottom R corner area of the battery at the non-preset position inside the battery module;

[0025] below the bottom flat area of the battery at the non-preset position inside the battery module;

[0026] The preset position battery includes: a first single battery and / or a last single battery.

[0027] Through the technical means, considering that the vibration process of the partial discharge can be transmitted, and the vibration direction is up and down vibration, in order to avoid the signal attenuation being relatively serious, the ultrasonic sensor is usually arranged at the bottom of the single battery inside the battery module, at this time, the pressure generated by the partial discharge vibration is transmitted to the ultrasonic sensor, so that the ultrasonic sensor is more susceptible to deformation, thereby more easily detecting the vibration, so that the measurement of the ultrasonic sensor is more accurate, and based on the characteristics of the piezoelectric film, such as high sensitivity, fast response speed, good stability, etc., thereby facilitating the partial discharge monitoring of the single battery.

[0028] In some embodiments, the signal acquisition assembly is coupled with the ultrasonic sensor through a signal shielding channel.

[0029] Through the technical means, since the signal detected by the ultrasonic sensor is weak (for example, in the order of millivolts), it is easy to be disturbed, at this time, the signal acquisition assembly and the ultrasonic sensor are coupled through the signal shielding channel, so as to realize signal shielding transmission and improve the anti-interference ability.

[0030] In some embodiments, the ultrasonic sensor is coupled to the signal acquisition component through a first acquisition line; wherein: the battery device further comprises a shielding element, and the shielding element is located around the first acquisition line.

[0031] Through the above technical means, since the signal detected by the ultrasonic sensor is weak (for example, in the order of millivolts), it is easy to be disturbed. The measures taken here are to add a shielding element, so as to realize signal shielding transmission and improve the anti-interference ability.

[0032] In some embodiments, the signal acquisition component comprises a signal amplification circuit and an acquisition filtering circuit, wherein: the signal amplification circuit comprises a first filtering circuit, a first operational amplifier circuit and a second operational amplifier circuit, and the input end of the first filtering circuit is coupled to the ultrasonic sensor, the output end of the first filtering circuit is connected to the first operational amplifier circuit, the first operational amplifier circuit is cascaded with the second operational amplifier circuit, for signal amplification and filtering processing of the first voltage signal, and outputting a second voltage signal; the acquisition filtering circuit comprises a signal acquisition circuit and a second filtering circuit, and the signal acquisition circuit is connected between the output end of the second operational amplifier circuit and the input end of the second filtering circuit, for signal acquisition and filtering processing of the second voltage signal, and outputting the processed first voltage signal.

[0033] Through the above technical means, through the signal amplification circuit, signal amplification and filtering processing of the first voltage signal can be realized. The signal filtering here can filter out the low-frequency signal in the first voltage signal. Moreover, the signal amplification adopts a two-stage amplification circuit design, which can better realize signal amplification and enhancement of a preset multiple, so as to ensure the stability and reliability of the signal and reduce the probability of signal interference. Then, through the acquisition filtering circuit for signal acquisition and filtering processing, the continuous analog signal can be first converted into a discrete digital signal by analog-to-digital conversion, and then the high-frequency noise signal in the first voltage signal is filtered out through signal filtering, so as to not only meet the sampling demand of the cell local discharge frequency band, but also obtain the voltage signal (i.e. the processed first voltage signal) finally used for local discharge identification, which is conducive to realizing the local discharge monitoring of the single battery.

[0034] In some embodiments, the signal acquisition circuit adopts a data acquisition element with a sampling rate not less than 10 million times per second.

[0035] Through the above technical means, according to the Nyquist theorem, based on the actual test of the cell local discharge frequency band, it is usually required that the signal sampling rate is not less than 10 million times per second, so as to meet the sampling demand of the cell local discharge frequency band.

[0036] In some embodiments, the battery device further comprises an alarm circuit, wherein: the alarm circuit is connected with the detection component, for generating alarm information according to the monitoring result, and the alarm information is used to indicate the local discharge degree of the single battery.

[0037] Through the technical means, after obtaining the monitoring result representing the partial discharge of the single battery, the alarm component can generate corresponding alarm information, which can indicate the degree of the partial discharge of the single battery and notify the manager to maintain the fault caused by the partial discharge in time, so as to prevent the insulation failure in time.

[0038] In some embodiments, the signal acquisition component is integrated into the battery detection device, and / or the detection component is integrated into the cluster-level battery management unit or the battery management system.

[0039] Through the technical means, the signal acquisition component and the ultrasonic sensor are separately arranged, which solves the problem of component space occupation, so that the ultrasonic sensor can be placed inside the battery device, the signal acquisition component can be integrally arranged with the existing battery detection device, and the detection component can be integrally arranged with the cluster-level battery management unit or the battery management system, so that the existing control board can be reused, resources can be reasonably utilized, and the cost can be reduced.

[0040] In a second aspect, the embodiments of the present disclosure provide a partial discharge monitoring method applied to the battery device of any one of the first aspect; the method comprises:

[0041] obtaining a first voltage signal output by the ultrasonic sensor, wherein the first voltage signal is converted from an ultrasonic signal generated by the ultrasonic sensor based on the partial discharge of the single battery;

[0042] processing the first voltage signal by using the signal acquisition component and outputting the processed first voltage signal to the detection component;

[0043] performing operation processing on the processed first voltage signal by using the detection component to obtain a monitoring result representing the partial discharge of the single battery.

[0044] Through the technical means, since the ultrasonic sensor is arranged on the insulation layer of the single battery, the distance between the ultrasonic sensor and the single battery is small at this time, so that the signal attenuation caused by the partial discharge is small, which is beneficial to realize the partial discharge monitoring of the single battery; the signal acquisition component and the ultrasonic sensor are separately arranged, which not only solves the problem of component space occupation, but also processes the first voltage signal by using the signal acquisition component, such as signal amplification, acquisition and filtering processing, so as to improve the anti-interference ability in the signal transmission process and improve the signal-to-noise ratio; then, the detection component performs operation processing on the processed first voltage signal to obtain the monitoring result representing the partial discharge of the single battery, so as to not only realize the online monitoring of the partial discharge of the single battery, but also make the ultrasonic sensor have a faster response speed than the insulation resistance monitoring, so as to more timely prevent the insulation failure inside the single battery, and further realize the real-time early warning of whether the insulation state of the battery is deteriorated.

[0045] In some embodiments, the detection component is configured to perform operation processing on the processed first voltage signal to obtain a monitoring result representing the local discharge of the single battery, including: performing time domain feature extraction on the processed first voltage signal to obtain a first time domain feature; matching the first time domain feature with a preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery; and wherein the preset time domain feature library is configured to store a correspondence relationship between different time domain features and monitoring results.

[0046] Through the above technical means, after obtaining the time domain signal (i.e., the "processed first voltage signal"), the first time domain feature can be obtained by performing time domain feature extraction on the time domain signal; the extracted first time domain feature is matched with the preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery, so that whether the local discharge exceeds the standard can be determined according to the extracted time domain feature, and the local discharge monitoring of the single battery can be realized.

[0047] In some embodiments, the detection component is configured to perform operation processing on the processed first voltage signal to obtain a monitoring result representing the local discharge of the single battery, including: performing time domain feature extraction on the processed first voltage signal to obtain a first time domain feature; matching the first time domain feature with a preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery; and wherein the preset time domain feature library is configured to store a correspondence relationship between different time domain features and monitoring results.

[0048] Through the above technical means, after obtaining the time domain signal (i.e., the "processed first voltage signal"), the first time domain feature can be obtained by performing time domain feature extraction on the time domain signal; the extracted first time domain feature is matched with the preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery, so that whether the local discharge exceeds the standard can be determined according to the extracted time domain feature, and the local discharge monitoring of the single battery can be realized.

[0049] In some embodiments, when the first time domain feature is a signal average amplitude, the method further includes: when the signal average amplitude of the processed first voltage signal is less than a first threshold, the monitoring result indicates that the single battery does not have local discharge; and when the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold, the monitoring result indicates that the single battery has local discharge.

[0050] By means of the above technical means, taking the first time domain feature as the signal average amplitude as an example, for the signal average amplitude of the processed first voltage signal, if the signal average amplitude is less than the first threshold value, it indicates that the insulation is normal, at this time the monitoring result indicates that the single battery does not exist local discharge; if the signal average amplitude is greater than or equal to the first threshold value, it indicates that the insulation is not normal, at this time the monitoring result indicates that the single battery exists local discharge, at this time the first alarm information can be further generated to notify the management personnel to timely repair the fault caused by local discharge, so as to timely prevent insulation failure.

[0051] In some embodiments, when the monitoring result indicates that the single battery exists local discharge, the method further comprises: when the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold value and less than the second threshold value, the alarm component generates the first alarm information; when the signal average amplitude of the processed first voltage signal is greater than or equal to the second threshold value and less than the third threshold value, the alarm component generates the second alarm information; when the signal average amplitude of the processed first voltage signal is greater than or equal to the third threshold value, the alarm component generates the third alarm information; wherein the first alarm information, the second alarm information and the third alarm information are used to indicate different degrees of local discharge of the single battery.

[0052] By means of the above technical means, still taking the first time domain feature as the signal average amplitude as an example, after obtaining the signal average amplitude of the processed first voltage signal, according to the range interval where the signal average amplitude is located, the different degrees of local discharge of the single battery can be further judged. Among them, if the signal average amplitude is in the first interval, the first alarm information is generated at this time, indicating that the single battery occurs mild local discharge; if the signal average amplitude is in the second interval, the second alarm information is generated at this time, indicating that the single battery occurs moderate local discharge; if the signal average amplitude is in the third interval, the third alarm information is generated at this time, indicating that the single battery occurs severe local discharge, leading to insulation failure, which needs to be removed immediately; in this way, different alarm information can be used to indicate different degrees of local discharge of the single battery, and the management personnel can also be notified to timely repair the fault caused by local discharge, so as to timely prevent insulation failure.

[0053] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, but not limiting the technical solutions of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0054] FIG. 1 is a schematic diagram of a battery device according to an embodiment of the present disclosure;

[0055] FIG. 2 is a schematic diagram of an application scenario of an ultrasonic sensor attachment position according to an embodiment of the present disclosure;

[0056] FIG. 3 is a schematic diagram of an application scenario of a piezoelectric film sensor according to an embodiment of the present disclosure;

[0057] FIG. 4 is a schematic diagram of a component structure of a battery device according to an embodiment of the present disclosure;

[0058] FIG. 5 is a schematic diagram of a component structure of a signal acquisition assembly according to an embodiment of the present disclosure;

[0059] FIG. 6 is a schematic diagram of a component structure of a signal amplification circuit according to an embodiment of the present disclosure;

[0060] FIG. 7 is a schematic diagram of a component structure of a battery device according to an embodiment of the present disclosure;

[0061] FIG. 8 is a schematic diagram of an application scenario of a battery device according to an embodiment of the present disclosure;

[0062] FIG. 9 is a schematic diagram of a flow of a partial discharge monitoring method according to an embodiment of the present disclosure;

[0063] FIG. 10 is a schematic diagram of a flow of a partial discharge monitoring method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0064] In order to enable a person skilled in the art to more fully understand the features and technical contents of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, which are only used for reference and are not intended to limit the embodiments of the present disclosure.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terminology used herein is for the purpose of describing the embodiments of the present disclosure only and is not intended to limit the present disclosure.

[0066] In the following description, "some embodiments" are described, which describe a subset of all possible embodiments, but it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0067] It should also be noted that the terms "first", "second", "third" involved in the embodiments of the present disclosure are only used to distinguish similar objects, and do not represent a specific order of the objects. It can be understood that "first", "second", "third" can be interchanged with a specific order or sequence as allowed, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0068] In addition, reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the disclosure. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is expressly understood that the embodiments described herein are combinable with each other.

[0069] The related technologies of the present disclosure are described below.

[0070] The battery cell is an important part of the battery. New energy batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also increasingly used in energy storage fields and the like.

[0071] At present, new energy batteries are increasingly widely used in life and industry. New energy batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles, and other electric vehicles, and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also increasing.

[0072] In the embodiments of the present disclosure, the battery can be a battery cell, or can also be a battery pack (Pack) composed of a plurality of battery cells. The battery cell refers to a basic unit capable of realizing mutual conversion between chemical energy and electrical energy, and can be used to make a battery module or a battery pack, thereby being used to supply power to a power consumption device. The battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging. The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., which is not limited here.

[0073] In the embodiments of the present disclosure, the battery can also be a single physical module including one or more battery cells to provide higher voltage and capacity. When there are a plurality of battery cells, the plurality of battery cells are connected in series, in parallel, or in a mixed connection through a busbar component.

[0074] With the wide application of batteries in the fields of power batteries and energy storage, new energy vehicles (such as electric vehicles) have become a trend in the development of the automobile industry to replace fuel vehicles. In addition to the concern about the cruising range of electric vehicles, consumers also pay great attention to the safety of the battery system. Timely and effective discovery of safety hazards in the battery system is an important measure to protect the safety of consumers and the sustainable development of battery enterprises.

[0075] Exemplarily, taking high-voltage power equipment as an example, partial discharge online monitoring mainly adopts: ultra-high frequency method and ultrasonic method. Among them, the ultrasonic method (also known as "acoustic emission method") monitors the ultrasonic signals generated when the power equipment generates partial discharge through the piezoelectric sensor installed on the shell. It has no any connection with the electrical circuit of the power equipment and is not interfered by the electrical aspect, and has strong anti-electromagnetic interference ability. The ultra-high frequency method is a method for monitoring the high-frequency electromagnetic wave signals generated by partial discharge by using an antenna sensor. The monitored electromagnetic wave frequency band is mainly 300MHz-3GHz. Since the interference electromagnetic pulse energy of the power field of the substation is mainly concentrated below 200MHz, the ultra-high frequency method has strong anti-electromagnetic interference ability.

[0076] However, whether it is the ultra-high frequency method or the ultrasonic method, the corresponding monitoring device has a large volume and the structure design is not suitable for being arranged on the battery module. In addition, the multi-layer metal shell of the battery module has a shielding effect on the ultra-high frequency electromagnetic waves of the internal partial discharge, especially under the complex electromagnetic wave and vibration working conditions of the battery module, the anti-interference ability of the ultra-high frequency sensor is poor; and the piezoelectric sensor fixed outside has poor coupling effect, which is not conducive to realizing the online monitoring of the partial discharge of the battery, and cannot timely warn whether the insulation state is deteriorated.

[0077] Based on this, the battery device and the partial discharge monitoring method provided by the embodiments of the present disclosure. In the battery device, since the ultrasonic sensor is arranged on the insulation layer of the monomer battery surface, the distance between the ultrasonic sensor and the monomer battery is small at this time, and based on the piezoelectric effect of the ultrasonic sensor, the signal attenuation generated by the partial discharge is small, thereby facilitating the realization of the partial discharge monitoring of the monomer battery; then the signal acquisition assembly and the ultrasonic sensor are arranged separately, and the signal acquisition assembly is used to process the first voltage signal, which not only solves the problem of component space occupation, but also enables the ultrasonic sensor to be placed inside the battery device, and the partial discharge signal of the monomer battery inside the battery device can be detected without increasing the size of the battery device. Moreover, the processed first voltage signal has been processed by signal amplification, acquisition and filtering, thereby the anti-interference ability in the signal transmission process can be improved, and the signal-to-noise ratio is improved; and then the processed first voltage signal is processed by the detection assembly, thereby the partial discharge of the monomer battery can be monitored, not only realizing the online monitoring of the partial discharge of the monomer battery, but also the ultrasonic sensor has a faster response speed than the insulation resistance monitoring, which can more timely prevent the insulation failure inside the monomer battery, and thereby the battery insulation state can be timely warned whether it is deteriorated.

[0078] The various embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0079] In an embodiment of the present disclosure, FIG. 1 is a schematic diagram of a structural composition of a battery device provided by an embodiment of the present disclosure. As shown in FIG. 1, the battery device 10 can include:

[0080] a single battery 101, the surface of the single battery 101 being provided with an insulation layer;

[0081] an ultrasonic sensor 102, the ultrasonic sensor 102 being arranged on a side of the insulation layer away from the single battery;

[0082] a signal acquisition component 103, the signal acquisition component 103 being arranged separately from the ultrasonic sensor 102 and coupled to the ultrasonic sensor 102;

[0083] a detection component 104, the detection component 104 being coupled to the signal acquisition component 103.

[0084] In an embodiment of the present disclosure, the ultrasonic sensor 102 is configured to convert an ultrasonic signal generated by partial discharge of the single battery 101 into a first voltage signal; the signal acquisition component 103 is configured to output the first voltage signal after processing to the detection component 104; and the detection component 104 is configured to perform operation processing on the processed first voltage signal to obtain a monitoring result representing the partial discharge of the single battery 101.

[0085] In an embodiment of the present disclosure, the battery device 10 can be applied to a medium-high voltage energy storage scene. For example, the battery device 10 can be applied to an energy storage scene with a rated direct current voltage of ≥1000V.

[0086] In addition, in an embodiment of the present disclosure, the battery device 10 is mainly configured to realize online monitoring of partial discharge of the single battery 101. The partial discharge refers to discharge occurring only in a local area of the single battery, without penetrating the applied voltage on the entire surface of the insulation layer of the single battery. That is, the discharge occurs in a certain area or near the area of an electrical device or an insulation structure, which is referred to as partial discharge, or simply referred to as “partial discharge”. In addition, the partial discharge usually refers to a discharge or breakdown phenomenon in a local range of an insulation medium due to uneven electric field distribution and excessively high local field strength in the insulation structure, which is the main cause of insulation deterioration and an important sign and form of deterioration, and is closely related to the deterioration and breakdown of the insulation material.

[0087] According to different monitoring principles and methods, the commonly used partial discharge monitoring methods include a very high frequency method and an ultrasonic wave method. However, the monitoring device corresponding to either the very high frequency method or the ultrasonic wave method has a large volume and a structure design that is not suitable for being arranged on the single battery. Especially for the online monitoring scene of the partial discharge, the existing monitoring method needs to arrange many ultrasonic probes, is easily disturbed, and needs to constantly adjust the position and direction of the probes during testing, which is not conducive to realizing the online monitoring of the partial discharge of the battery.

[0088] Thus, in the embodiments of the present disclosure, a battery device 10 is provided herein, which comprises an ultrasonic sensor 102. The ultrasonic sensor 102 can employ a piezoelectric film material, for example, a Poly Vinyli Dene Fluoride (PVDF) piezoelectric film material.

[0089] In some embodiments, the ultrasonic sensor 102 can comprise a piezoelectric film structure, wherein the piezoelectric film structure comprises a lower electrode sheet, a piezoelectric material layer and an upper electrode sheet which are sequentially stacked.

[0090] In the embodiments of the present disclosure, the piezoelectric film structure can be attached to the single battery with small space occupation, tight combination and good matching of the outer contour of the single battery. Thus, based on the characteristics of the piezoelectric film such as high sensitivity, fast response speed, good stability and the like, it is beneficial to realize the local discharge monitoring of the single battery 101, so as to realize real-time early warning of whether the insulation state of the battery is deteriorated.

[0091] In some embodiments, the piezoelectric film structure can be a flexible structure. In this way, since the piezoelectric film structure is a flexible structure, it can be better attached to the single battery with small space occupation, tight combination and good matching of the outer contour of the single battery, which is beneficial to realize the local discharge monitoring of the single battery.

[0092] In the embodiments of the present disclosure, the ultrasonic sensor 102 can also be referred to as a piezoelectric film sensor or simply a piezoelectric sensor. The ultrasonic sensor 102 can comprise a lower electrode sheet, a piezoelectric material layer and an upper electrode sheet which are sequentially stacked, and is mainly used to convert the generated ultrasonic signal into an electric signal.

[0093] It can be understood that in the embodiments of the present disclosure, when a piece of piezoelectric PVDF polymer film (piezoelectric film) is stretched or bent, an electric signal (charge or voltage) will be generated between the upper and lower electrode surfaces of the film, and is proportional to the deformation of stretching or bending. That is, for the piezoelectric film, a small force is applied in the longitudinal direction, and a large stress is generated in the transverse direction, thereby converting into an electric signal.

[0094] In addition, due to the characteristics of high sensitivity, fast response speed, good stability, wide frequency band and the like, the piezoelectric film is often used to measure dynamic or high-frequency signals. For example, the response speed of the piezoelectric film is very fast, and the change of the measured physical quantity can be measured in real time, which is very suitable for application scenarios that need to be monitored in real time; the measurement accuracy of the piezoelectric film is high, which can reach millimeter or micrometer, thereby being beneficial to realize the local discharge monitoring of the single battery.

[0095] It can also be understood that, in the embodiments of the present disclosure, the ultrasonic sensor 102 can further include a charge conversion circuit, which is configured to convert the charge signal corresponding to the ultrasonic signal into a first voltage signal after the charge signal is obtained. The charge conversion circuit can be arranged on an electrode layer (for example, an upper electrode sheet or a lower electrode sheet) of the ultrasonic sensor 102.

[0096] In a possible implementation, in order to avoid damage and pollution of the PVDF piezoelectric film in use, a protective film is added on the surface of the PVDF piezoelectric film; and since the PVDF piezoelectric film is a high polymer material, the electrode cannot be directly welded, and the electrode is introduced on the PVDF piezoelectric film by riveting. When the ultrasonic signal propagates in the single battery, it causes a slight deformation of the surface of the single battery, generates mechanical stress on the PVDF piezoelectric film attached to the surface of the single battery 101, and converts the mechanical stress into a charge signal. The first voltage signal can be obtained after the charge signal passes through the charge conversion circuit, and the first voltage signal is transmitted to the signal acquisition assembly for signal processing.

[0097] In addition, in the embodiments of the present disclosure, the signal acquisition assembly 103 and the ultrasonic sensor 102 adopt a split structure, and are not integrated in one component; or in other words, the signal acquisition assembly 103 and the ultrasonic sensor 102 are independently arranged, and the signal acquisition assembly 103 and the ultrasonic sensor 102 are arranged in different components. For example, the ultrasonic sensor 102 and the single battery 101 can be arranged in a battery module or a battery box that carries the single battery 101, and considering the size and layout of the battery module or the battery box, the signal acquisition assembly 103 and / or the detection assembly 104 can be arranged in a component outside the battery module or the battery box.

[0098] In this way, the ultrasonic sensor 102 is placed in the battery box, and the distance between the ultrasonic sensor 102 and the single battery is relatively short, so that the signal attenuation caused by the partial discharge is small; at the same time, the signal acquisition assembly 103 and the detection assembly 104 are arranged in a component outside the battery module or the battery box, which can also reduce the volume of the battery module or the battery box and reduce the cost.

[0099] In a possible implementation, the signal acquisition assembly 103 can be integrated in a battery detection device (Cell Supervision Circuit, CSC), or in other words, the signal acquisition assembly 103 can be integrally arranged with the CSC component. For the CSC component, the internal signal acquisition assembly 103 can be connected with the ultrasonic sensor 102 through a first acquisition line, for obtaining the first voltage signal generated by the partial discharge. In addition, the CSC component can be connected with the single battery 101 through a second acquisition line, for performing voltage, current, temperature and other sampling processing on the single battery 101.

[0100] In a possible implementation, the detection component 104 can be integrated into a slave battery management unit (SBMU) or a battery management system (BMS). That is, the detection component 104 can be integrally arranged with the SBMU component, or the detection component 104 can be integrally arranged with the BMS component. For the SBMU component or the BMS component, in addition to being able to identify the local discharge through the detection component 104, the SBMU component or the BMS component can also implement other battery state monitoring, such as battery current, battery total voltage, ambient temperature sampling, state of charge (SOC) estimation, insulation detection, and the like for the single battery.

[0101] That is, in the embodiment of the present disclosure, the signal acquisition component 103 is separately arranged from the ultrasonic sensor 102, and the signal acquisition component 103 can be integrally arranged with an existing battery detection device, and the detection component 104 can be integrally arranged with a slave battery management unit or a battery management system, thereby solving the component space occupation problem, enabling the ultrasonic sensor to be placed inside the battery device, and enabling the signal acquisition component and the detection component to reuse the existing control board without occupying additional space, and enabling resources to be reasonably utilized, thereby reducing costs.

[0102] In this case, the signal detected by the ultrasonic sensor 102 can be first transmitted to the CSC component and then aggregated to the SBMU or BMS component. In this way, since the ultrasonic sensor 102 is arranged on the insulation layer of the single battery, the distance between the ultrasonic sensor 102 and the single battery 101 is small at this time, and based on the piezoelectric effect of the ultrasonic sensor, the signal attenuation generated by the local discharge is small, and based on the characteristics of the piezoelectric film, such as high sensitivity, fast response speed, and good stability, the local discharge monitoring of the single battery can be facilitated; the signal acquisition component 103 is separately arranged from the ultrasonic sensor 102, which not only solves the component space occupation problem, but also enables the local discharge signal of the single battery inside the battery device to be detected without increasing the size of the battery device; and the first voltage signal is processed by the signal acquisition component 103, and at this time, the processed first voltage signal has been subjected to signal amplification, acquisition, and filtering, thereby also being able to improve the anti-interference capability in the signal transmission process, so that the signal-to-noise ratio is improved; and the processed first voltage signal is processed by the detection component 104, thereby being able to monitor the local discharge of the single battery, not only realizing the online monitoring of the local discharge of the single battery, but also enabling the ultrasonic sensor to have a faster response speed than the insulation resistance monitoring, so that the insulation failure inside the single battery can be more timely prevented, and thus the battery insulation state can be timely warned to be deteriorated.

[0103] It is also understood that, in the embodiments of the present disclosure, for the single battery 101, the surface of the single battery 101 has a layer of blue film (referred to as "blue film" for short), also known as isolation film, anti-adhesion film, etc., which is the insulation layer described in the foregoing embodiments, and serves as a protective film for the surface of the single battery. The main material is a polyethylene terephthalate (PET) film, which can play a good protective role as an insulation material between batteries, and can block the adverse effects of single battery failures on other single battery components. The ultrasonic sensor 102 can be attached to the outer surface of the blue film of the single battery 101.

[0104] In other embodiments, the insulation layer can also include an adhesive glue layer on the surface of the single battery, such as a polymer glue layer.

[0105] In addition, in the embodiments of the present disclosure, the ultrasonic sensor 102 should be arranged at a suitable position of the single battery 101, so that the captured partial discharge signals can effectively reflect the insulation failure process of the battery. In some embodiments, the arrangement position of the ultrasonic sensor 102 on the single battery 101 can include at least one of the following positions: the top of the single battery 101, the bottom of the single battery 101, the side of the single battery 101, etc., but is not limited thereto. For the bottom (or "lower side") of the single battery 101, for example, it can be below the R corner area of the bottom of the single battery 101, or it can be below the planar area of the bottom of the single battery 101, etc.

[0106] In a possible implementation, the ultrasonic sensor 102 can be arranged below the R corner area of the bottom of the single battery 101 and / or below the planar area of the bottom of the single battery 101.

[0107] Here, the R corner area generally refers to the four corners of the bottom of the battery. The battery R corner is a key parameter in lithium batteries, which relates to the included angle between the migration path of lithium ions in the positive and negative electrode materials and the migration path of lithium ions in the electrolyte. This angle is crucial for describing the internal structure and ion migration characteristics of the battery. The size of the R corner determines the directness of the ion migration path, thereby affecting the internal resistance and performance of the battery. Specifically, the smaller the R corner, the more direct the migration path of lithium ions, the smaller the internal resistance of the battery, and the better the performance. Therefore, in the embodiments of the present disclosure, the effect of arranging the ultrasonic sensor 102 below the R corner area of the bottom of the single battery 101 is better than that of arranging the ultrasonic sensor 102 below the planar area of the bottom of the single battery 101.

[0108] It is also to be noted that, in the embodiments of the present disclosure, the vibration process of partial discharge can be transmitted, but the signal attenuation is relatively large. If the ultrasonic sensor 102 is arranged at the bottom of the single battery 101, the distance between the ultrasonic sensor and the single battery is small at this time, and according to the piezoelectric effect of the ultrasonic sensor 102, the signal attenuation generated by the partial discharge is small. In addition, considering that the vibration direction is up and down vibration, it is not recommended to arrange the ultrasonic sensor 102 at the side of the single battery at this time, that is, the vibration direction is parallel to the placement direction of the piezoelectric film, so that the vibration cannot be accurately sensed. Moreover, it is also not recommended to arrange the ultrasonic sensor 102 at the top of the single battery at this time, that is, the signal attenuation generated by the partial discharge is large. In actual application, it is generally recommended to arrange the ultrasonic sensor 102 below the bottom of the single battery 101 (for example, below the bottom planar region and / or below the bottom R corner region), at this time, the pressure generated by the partial discharge vibration is transmitted to the piezoelectric film structure, so that the piezoelectric film structure is more likely to sense the deformation, thereby more easily detecting the vibration, and further making the measurement of the ultrasonic sensor 102 more accurate. Moreover, based on the characteristics of the piezoelectric film such as high sensitivity, fast response speed, good stability and the like, the partial discharge monitoring of the single battery can be realized.

[0109] Exemplarily, FIG. 2 is a schematic diagram of an application scenario of an ultrasonic sensor attachment position provided by the embodiments of the present disclosure. As shown in FIG. 2, the ultrasonic sensor 102 is taken as an example of a piezoelectric film, and there is a polyurethane (PU) adhesive 105 between the single battery 101 and the metal base plate 106, which is used to fix the bottom of the single battery 101 to the metal base plate 106. The ultrasonic sensor 102 can be placed below the bottom of the single battery 101. Exemplarily, the ultrasonic sensor 102 can be placed between the blue film outer surface of the single battery 101 and the PU adhesive 105, or can also be placed between the PU adhesive 105 and the metal base plate 106.

[0110] In some embodiments, the number of single batteries 101 inside the battery device 10 can be one or more. When the number of single batteries 101 is multiple, the multiple single batteries 101 are connected in series to form a battery module. In some embodiments, the ultrasonic sensor 102 is arranged at least one of the following positions inside the battery module:

[0111] the bottom R corner region of the battery at the preset position inside the battery module;

[0112] the bottom planar region of the battery at the preset position inside the battery module;

[0113] the bottom R corner region of the battery at the non-preset position inside the battery module;

[0114] the bottom planar region of the battery at the non-preset position inside the battery module.

[0115] In the embodiments of the present disclosure, the preset position battery can include: a first-end single battery and / or a last-end single battery. In addition, the preset position battery can also be a single battery at a certain position inside the battery module, which is not limited here.

[0116] It also needs to be explained that, in the embodiments of the present disclosure, for the battery module, the battery module can be placed in an electric box. In this way, according to the common energy storage electric box and cell structure, the ultrasonic sensor 102 can be arranged at a suitable position, for example, including but not limited to the following positions:

[0117] Position 1: below the bottom R corner area of the first-end and last-end single batteries inside the battery module, the ultrasonic sensor 102 is attached to the outer surface of the blue film or the upper and lower surfaces of the electric box bottom plate;

[0118] Position 2: below the bottom flat area of the first-end and last-end single batteries inside the battery module, the ultrasonic sensor 102 is attached to the outer surface of the blue film or the upper and lower surfaces of the electric box bottom plate;

[0119] Position 3: below the bottom R corner area of the non-first-end and non-last-end single batteries inside the battery module, the ultrasonic sensor 102 is attached to the outer surface of the blue film or the upper and lower surfaces of the electric box bottom plate;

[0120] Position 4: below the bottom flat area of the non-first-end and non-last-end single batteries inside the battery module, the ultrasonic sensor 102 is attached to the outer surface of the blue film or the upper and lower surfaces of the electric box bottom plate;

[0121] Position 5: the ultrasonic sensor 102 is attached to the inner side or outer surface of the battery module end plate;

[0122] Position 6: the ultrasonic sensor 102 is attached to the surface of the heat insulation pad between two adjacent single batteries in the same battery module, or embedded in the heat insulation pad.

[0123] Here, the battery module end plate is used to be arranged opposite to the large surface of the single battery, the end plate is a key component connecting the single battery, and the main function is to conduct electrical communication and mechanical fixation inside the battery module. The ultrasonic sensor 102 can be arranged above the top of the single battery, below the bottom of the single battery, or between two adjacent single batteries, or can also be arranged inside or on the outer surface of the battery module end plate. Among them, when the ultrasonic sensor 102 is arranged above the top of the single battery, it can be specifically attached to the outer surface of the blue film on the top of the single battery, or attached to the upper and lower surfaces of the top plate of the electric box, at this time the ultrasonic sensor 102 is arranged above the top of the single battery; Correspondingly, when the ultrasonic sensor 102 can be arranged below the bottom of the single battery, it can be specifically attached to the outer surface of the blue film on the bottom of the single battery (for example, the outer surface of the blue film on the R corner area of the bottom or the outer surface of the blue film on the bottom flat area), or attached to the upper and lower surfaces of the bottom plate of the electric box, at this time the ultrasonic sensor 102 is arranged below the bottom of the single battery, which is not limited here.

[0124] It also needs to be explained that in the embodiment of the present disclosure, the arrangement position of the ultrasonic sensor 102 can also be directly related to the battery insulation failure mode, and the captured signal can truly and effectively reflect the insulation failure process. For the above six positions, based on the vibration process and vibration direction of the partial discharge, the effect of positions 5 and 6 is the worst. That is, in the embodiment of the present disclosure, considering that the vibration process of the partial discharge can be transmitted, and the vibration direction is up and down vibration, in order to avoid the signal attenuation being relatively severe, the ultrasonic sensor 102 is usually arranged at the bottom of the single battery inside the battery module, at this time the pressure generated by the partial discharge vibration is transmitted to the ultrasonic sensor 102, so that the ultrasonic sensor 102 is more likely to feel deformation, thereby more easily detecting vibration, so that the measurement of the ultrasonic sensor 102 is more accurate, and based on the characteristics of the piezoelectric film such as high sensitivity, fast response speed, good stability, etc., thereby facilitating the realization of the partial discharge monitoring of the single battery.

[0125] It should also be noted that in the embodiments of the present disclosure, the number of ultrasonic sensors 102 placed inside the battery module can be one or more. Among them, ideally, an ultrasonic sensor 102 can be placed at the bottom of each single battery. Considering the cost factor, ultrasonic sensors 102 can also be placed only at the bottom of the first and last single batteries, because these two single batteries include the two cases of the lowest battery voltage and the highest battery voltage, that is, the setting position of the ultrasonic sensor 102 is usually recommended to choose position 1 and position 2. In addition, considering that the R corner area is crucial to describe the internal structure and ion migration characteristics of the battery, therefore, based on the comprehensive consideration of cost and monitoring effect, the embodiments of the present disclosure can choose (position 1): below the R corner area at the bottom of the first and last single batteries inside the battery module, the ultrasonic sensor 102 is attached to the outer surface of the respective blue film.

[0126] Exemplarily, taking the piezoelectric film sensor as an example, the size of the piezoelectric film sensor can be 25mmx13mmx28μm. In addition, there are many parameter types of piezoelectric film sensors, and Table 1 provides a range of performance parameters of an exemplary piezoelectric film sensor.

[0127] Table 1

[0128] It can also be understood that in the embodiments of the present disclosure, for the piezoelectric film sensor, the piezoelectric film has no polarization direction in the initial state, and polarization only occurs under certain conditions. After applying pressure or an electric field, the positive and negative charges in the piezoelectric material will be rearranged, so that different polarities are formed at the upper and lower ends of the material. This process is called polarization of the material.

[0129] In the embodiments of the present disclosure, the piezoelectric film sensor can include a piezoelectric material layer and an electrode layer placed in a stacked manner, and the electrode layer includes an upper electrode sheet and a lower electrode sheet, which are respectively arranged on the upper and lower surfaces of the piezoelectric material layer. In one possible implementation, assuming that the piezoelectric material layer is subjected to downward pressure, according to the piezoelectric effect, the positive and negative charges inside the electrode layer will be redistributed, the positive charges will concentrate upwards, and the negative charges will concentrate downwards, thereby forming an upward polarization direction. In the application of the piezoelectric film sensor, when external pressure or tension is applied, the polarization direction of the electrode layer will change accordingly, thereby generating a charge output signal, which is used to realize local discharge monitoring of the single battery.

[0130] Exemplarily, FIG. 3 is a schematic diagram of an application scenario of the piezoelectric thin film sensor according to the embodiments of the present disclosure. As shown in FIG. 3, the piezoelectric thin film sensor can include a lower electrode sheet 302, a piezoelectric material layer 301 and an upper electrode sheet 303 which are stacked, and a signal line 304 is led out through the upper electrode sheet 303. When a local discharge occurs in the single battery 101, an ultrasonic signal 305 is generated, thereby causing the piezoelectric material layer 301 to deform, so that the polarization directions of the lower electrode sheet 302 and the upper electrode sheet 303 are changed accordingly, and then the generated electric charge is converted into a first voltage signal and led out through the signal line 304 to be transmitted to the signal acquisition component 103.

[0131] It can also be understood that, in the embodiments of the present disclosure, the signal acquisition component 103 can be coupled with the ultrasonic sensor 102 through a signal shielding channel.

[0132] The signal shielding channel can be a wired channel or a wireless channel. Exemplarily, the wired channel can include a metal line on a flexible substrate, and the metal line covers a shielding layer; or a collection line can be used, and a shielding element is arranged around the collection line.

[0133] In the embodiments of the present disclosure, since the signal detected by the ultrasonic sensor is weak (for example, in the order of millivolts), it is easy to be disturbed, and therefore the signal shielding transmission can be achieved and the anti-interference capability can be improved by coupling the signal acquisition component with the ultrasonic sensor through the signal shielding channel.

[0134] In a possible implementation, the ultrasonic sensor 102 can be coupled with the signal acquisition component 103 through a first collection line. Based on the battery device 10 shown in FIG. 1, referring to FIG. 4, the battery device 10 can further include a shielding element 107, and the shielding element 107 is arranged around the first collection line.

[0135] It should be noted that, since the piezoelectric thin film sensor is capacitive by nature, the anti-electromagnetic interference capability is not strong, and therefore it can be ignored in the case of high output signal or low data precision requirement. However, in the embodiments of the present disclosure, since the signal detected by the ultrasonic sensor 102 is weak (for example, in the order of millivolts), it is easy to be disturbed, and therefore measures need to be taken to shield the electromagnetic interference. The measure taken here is to add the shielding element 107. In addition, the first collection line can also use a coaxial cable, so that the signal shielding transmission can be achieved and the anti-interference capability can be improved.

[0136] It should be further noted that, in the embodiments of the present disclosure, considering that the thickness of the piezoelectric film sensor is very small, and the flexibility is very large, and the electrode on the surface is very thin, the conventional welding and other methods are not suitable for the piezoelectric film. In the embodiments of the present disclosure, in order to prevent the piezoelectric film sensor from being affected by the lead joint, the signal line of the piezoelectric film sensor is led out in the same direction and on the same plane, so that the connection of the signal line and the first collection line can be conveniently led out, and then the signal can be ensured to enter the signal collection assembly 103 without interference in the maximum limit. The connection method can be two methods of using crimping terminals to crimp and using hollow rivets to rivet, but is not limited to any method.

[0137] In some embodiments, referring to FIG. 5, the signal collection assembly 103 can include a signal amplification circuit 501 and a collection filtering circuit 502, wherein:

[0138] The signal amplification circuit 501 can include a first filtering circuit 5011, a first operational amplifier circuit 5012 and a second operational amplifier circuit 5013, and the input end of the first filtering circuit 5011 is coupled to the ultrasonic sensor 102, the output end of the first filtering circuit 5011 is connected with the first operational amplifier circuit 5012, the first operational amplifier circuit 5012 is cascaded with the second operational amplifier circuit 5013, and is used for signal amplification and filtering processing of the first voltage signal, and outputs a second voltage signal.

[0139] The collection filtering circuit 502 can include a signal collection circuit 5021 and a second filtering circuit 5022, and the signal collection circuit 5021 is connected between the output end of the second operational amplifier circuit 5013 and the input end of the second filtering circuit 5022, and is used for signal collection and filtering processing of the second voltage signal, and outputs a processed first voltage signal.

[0140] In a possible implementation, for the signal amplification circuit 501, referring to FIG. 6, the first filter circuit 5011 can include the fifth resistor R5 and the first capacitor C1, the first operational amplifier circuit 5012 can include the first operational amplifier element U1, the first resistor R1, the third resistor R3, the sixth resistor R6, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4, and the second operational amplifier circuit 5013 can include the second operational amplifier element U2, the second resistor R2, the seventh resistor R7, the eighth resistor R8, and the fifth capacitor C5. The power supply VCC is connected to the positive input end of the first operational amplifier element U1 through the first resistor R1, the first filter circuit 5011 is connected to the negative input end of the first operational amplifier element U1, the output end of the first operational amplifier element U1 is connected to the positive input end of the second operational amplifier element U2, and the power supply VCC also supplies power to the power supply ends of the first operational amplifier element U1 and the second operational amplifier element U2. The third capacitor C3 has a filtering effect, so that the voltage of the power supply VCC is more smooth and stable. In addition, the connection relationship between the components is shown in FIG. 6.

[0141] In the embodiment of the present disclosure, the fifth resistor R5 and the first capacitor C1 are connected in series, which can realize the filtering processing of the low-frequency signal in the first voltage signal and only retain the high-frequency signal in the first voltage signal. Specifically, the cutoff frequency design can be realized by reasonably selecting the RC parameters, so as to filter out the low-frequency signal.

[0142] In the embodiment of the present disclosure, the first operational amplifier circuit 5012 and the second operational amplifier circuit 5013 are connected in cascade, so that a two-stage amplifier circuit design can be realized to better realize signal amplification. In terms of the selection of the operational amplifier element, whether the first operational amplifier element U1 or the second operational amplifier element U2, LF412, TL072, LF356, etc. can be selected according to the cost. For the second operational amplifier circuit 5013, the adjustable resistor R2 can be used to realize the adjustable amplification factor of 1-100 times.

[0143] In a possible implementation, for the component parameters in FIG. 6, the resistance of the fifth resistor R5 can be set to 5kΩ, the capacitance of the first capacitor C1 can be set to 0.01uF, the resistance of the first resistor R1 can be set to 100kΩ, the resistance of the third resistor R3 can be set to 100kΩ, the resistance of the sixth resistor R6 can be set to 10MΩ, the capacitance of the second capacitor C2 can be set to 1uF, the capacitance of the third capacitor C3 can be set to 1uF, the capacitance of the fourth capacitor C4 can be set to 100pF, the resistance of the second resistor R2 can be set to 100kΩ and adjustable, the resistance of the seventh resistor R7 can be set to 1kΩ, the resistance of the eighth resistor R8 can be set to 100kΩ, and the capacitance of the fifth capacitor C5 can be set to 0.01uF, but not limited thereto.

[0144] In another possible implementation, for the signal acquisition circuit 502, the signal acquisition circuit 5021 should select a synchronous signal acquisition card with a high sampling rate, a low resolution, and a short response time, such as PXI-8512B, and the like, and after converting the continuous analog voltage signal into a discrete digital signal by using an analog-to-digital conversion, the signal is sent to the second filtering circuit 5022 for processing, to filter out the high-frequency noise signal therefrom.

[0145] In some embodiments, the signal acquisition circuit 5021 adopts a data acquisition element with a sampling rate of not less than 10 million times per second (MS / s). Exemplarily, the data acquisition element can be a synchronous signal acquisition card with a high sampling rate, such as PXI-8512B, and the like.

[0146] In this way, in the embodiments of the present disclosure, according to the Nyquist theorem, the signal sampling rate is required to be not less than 10 million times per second based on the actual test frequency band of the battery cell, so as to meet the sampling requirement of the battery cell local discharge frequency band.

[0147] That is to say, in the embodiments of the present disclosure, the signal amplification and filtering processing of the first voltage signal can be realized by the signal amplification circuit 501, the signal filtering can filter out the low-frequency signal in the first voltage signal, and the signal amplification adopts a two-stage amplification circuit design, which can better realize the signal amplification and enhancement of the preset multiple, amplify the signal from the minimum range that can be received to the range that can be perceived, and increase the strength of the signal, so as to guarantee the stability and reliability of the signal and reduce the probability of signal interference; then the signal acquisition and filtering processing can be performed by the acquisition filtering circuit 502, which can first convert the continuous analog signal into a discrete digital signal by using an analog-to-digital conversion, and then filter out the high-frequency noise signal in the first voltage signal by using signal filtering, so as to not only meet the sampling requirement of the battery cell local discharge frequency band, but also obtain the voltage signal (i.e., the processed first voltage signal) for local discharge identification, which is conducive to realizing the local discharge monitoring of the single battery.

[0148] It can also be understood that, in the embodiments of the present disclosure, after the detection component 104 receives the processed first voltage signal, the processed first voltage signal can be operated and processed to obtain a monitoring result representing the local discharge of the single battery 101.

[0149] In a possible implementation, the detection component 104 can be based on the time domain feature to perform the local discharge identification. In some embodiments, the detection component 104 can be configured to perform time domain feature extraction on the processed first voltage signal to obtain a first time domain feature, match the first time domain feature with a preset time domain feature library to obtain a monitoring result representing the local discharge of the single battery, and the preset time domain feature library is configured to store a corresponding relationship between different time domain features and monitoring results.

[0150] In the embodiments of the present disclosure, the time domain features can include, but are not limited to, a peak signal repetition rate (times per minute) exceeding a local discharge allowed level threshold, a signal average amplitude, and the like. In addition, the preset time domain feature library can be constructed according to experimental results and simulation calculations of a large number of local discharge tests.

[0151] In this way, after obtaining the processed first voltage signal (i.e., a "time domain signal"), the first time domain features can be obtained by performing time domain feature extraction on the processed first voltage signal; and the extracted first time domain features are matched with the preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery. Thus, whether the local discharge exceeds the standard can be determined according to the extracted time domain features, and the local discharge monitoring of the single battery can be implemented.

[0152] In another possible implementation, the detection component 104 can perform local discharge identification based on frequency domain features. In some embodiments, the detection component 104 can be configured to perform Fourier transform on the processed first voltage signal to determine a frequency spectrum of the processed first voltage signal; perform frequency domain feature extraction according to the frequency spectrum of the processed first voltage signal to obtain first frequency domain features; match the first frequency domain features with a preset frequency domain feature library to obtain a monitoring result representing the local discharge of the single battery; and the preset frequency domain feature library is configured to store a corresponding relationship between different frequency domain features and the monitoring result.

[0153] In the embodiments of the present disclosure, the frequency domain features can include, but are not limited to, a frequency spectrum maximum amplitude (or referred to as a "feature frequency band peak value"), a mean square frequency (MSF), a centroid frequency (FC), a frequency spectrum variance (VF), a frequency spectrum standard deviation (RVF), and the like. In addition, the preset frequency domain feature library can also be constructed according to experimental results and simulation calculations of a large number of local discharge tests, and is configured to represent the corresponding relationship between different frequency domain features and the monitoring result.

[0154] In this way, after obtaining the processed first voltage signal (i.e., a "time domain signal"), the time domain signal can be converted to a frequency domain by performing a frequency domain transformation on the processed first voltage signal, such as a wavelet transformation, a Fourier Transform (FT), a Fast Fourier Transform (FFT), etc., so as to extract frequency spectrum components, such as a first frequency domain feature; the extracted first frequency domain feature is matched with a preset frequency domain feature library to obtain a monitoring result representing the local discharge of the single battery, so as to determine whether the local discharge exceeds a threshold according to the extracted frequency domain feature, thereby achieving the local discharge monitoring of the single battery.

[0155] In some embodiments, based on the battery device 10 shown in FIG. 1, referring to FIG. 7, the battery device 10 can further include an alarm component 108, wherein:

[0156] The alarm component 108 is connected with the detection component 104, and is configured to generate alarm information according to the monitoring result, the alarm information being used to indicate the degree of local discharge of the single battery 101.

[0157] In the embodiments of the present disclosure, after obtaining the monitoring result of the local discharge of the single battery, the alarm component 108 can generate alarm information according to the monitoring result, the alarm information being used to indicate the degree of local discharge of the single battery 101.

[0158] In the embodiments of the present disclosure, according to the degree of local discharge of the single battery 101, the alarm information can be divided into first alarm information, second alarm information and third alarm information, which are used to indicate different degrees of local discharge of the single battery, for example, the first alarm information represents mild local discharge, the second alarm information represents moderate local discharge, and the third alarm information represents severe local discharge (i.e., a serious fault).

[0159] In the embodiments of the present disclosure, the alarm component 108 can include a voice broadcaster, an indicator light, etc., and is further configured to send the alarm information to the manager. For example, taking the indicator light as an example, if the indicator light is yellow, it is used to indicate that the single battery 101 has mild local discharge, and at this time, the insulation resistance needs to be checked; if the indicator light is orange, it is used to indicate that the single battery 101 has moderate local discharge, and at this time, the local discharge continues to occur, and if the local discharge has not decreased for 30 minutes, the fault point is requested to be removed; if the indicator light is red, it indicates that the single battery 101 has a serious fault, and at this time, the insulation fails, and the fault point is immediately removed. In addition, if the indicator light is green or the indicator light is off, it indicates that the single battery 101 has no local discharge, and at this time, the insulation is normal.

[0160] That is, in the embodiments of the present disclosure, after obtaining the monitoring result representing the local discharge of the single battery 101, the corresponding alarm information can be generated by using the alarm component 108, according to which the degree of local discharge of the single battery 101 can be indicated, and the management personnel can also be notified to timely repair the fault caused by the local discharge, so as to timely prevent insulation failure.

[0161] Exemplarily, FIG. 8 is a schematic diagram of an application scenario of a battery device provided by the embodiments of the present disclosure. As shown in FIG. 8, here, there are an SBMU component 803, two electric cabinets and two CSC components corresponding to the two electric cabinets respectively, the two electric cabinets can include a first electric cabinet 801-1 and a second electric cabinet 801-2, and the two CSC components can include a first CSC component 802-1 and a second CSC component 802-2. The first electric cabinet 801-1 includes a first battery module B1, and the outer surface of the blue film at the R corner region of the bottom of the first and last single batteries inside the first battery module B1 is respectively arranged with an ultrasonic sensor 1; the second electric cabinet 801-2 includes a second battery module B2, and the outer surface of the blue film at the R corner region of the bottom of the first and last single batteries inside the second battery module B2 is respectively arranged with an ultrasonic sensor 2. The first CSC component 802-1 includes a first signal acquisition component 103-1 and a first communication module D1, and the first signal acquisition component 103-1 is coupled to the ultrasonic sensor 1 in the first electric cabinet 801-1; the ultrasonic sensor 1 converts the ultrasonic signal generated by the local discharge of the first battery module B1 into a first voltage signal, and then the first voltage signal is processed by the first signal acquisition component 103-1 and transmitted to the third communication module D3 in the SBMU component 803 based on the communication link between the first communication module D1 and the third communication module D3. The second CSC component 802-2 includes a second signal acquisition component 103-2 and a second communication module D2, and the second signal acquisition component 103-2 is coupled to the ultrasonic sensor 2 in the second electric cabinet 801-2; the ultrasonic sensor 2 converts the ultrasonic signal generated by the local discharge of the second battery module B2 into a first voltage signal, and then the first voltage signal is processed by the second signal acquisition component 103-2 and transmitted to the third communication module D3 in the SBMU component 803 based on the communication link between the first communication module D1 and the third communication module D3. Finally, in the SBMU component 803, the third communication module D3 outputs the processed first voltage signal to the detection component 104 for operation processing of the processed first voltage signal, so as to obtain the monitoring result representing the local discharge of the single battery.

[0162] That is to say, in the embodiment of the present disclosure, the ultrasonic sensor can be arranged in each electric box where the single battery is located, the signal acquisition component is arranged in the CSC component, and the detection component is arranged in the SBMU component. Then the signal detected by the ultrasonic sensor is first input into the CSC component and then is collected into the SBMU component. Finally, the time domain feature extraction / frequency domain feature extraction is performed by the detection component 104, and the monitoring of whether the partial discharge is excessive is realized according to the extracted corresponding features.

[0163] The embodiment of the present disclosure provides a battery device 10, the ultrasonic sensor is arranged on the insulating layer of the surface of the single battery, at this time, the distance between the ultrasonic sensor and the single battery is small, so that the signal attenuation generated by the partial discharge is small, thereby facilitating the realization of the partial discharge monitoring of the single battery; the signal acquisition component and the ultrasonic sensor are arranged separately, which solves the problem of component space occupation, so that the ultrasonic sensor can be placed inside the battery device; and after the ultrasonic signal generated by the partial discharge is converted into the first voltage signal and is subjected to signal amplification, collection and filtering processing, the processed first voltage signal has been subjected to signal amplification, collection and filtering processing, thereby the anti-interference ability in the signal transmission process can be further improved, and the signal-to-noise ratio is improved; after the detection component performs operation processing on the processed first voltage signal, whether the partial discharge of the single battery is excessive is determined according to the obtained monitoring result, thereby not only realizing the online monitoring of the partial discharge of the single battery, but also the response speed of the ultrasonic sensor is faster than that of the insulation resistance monitoring, the internal insulation failure of the single battery can be prevented more timely, and the real-time early warning of whether the battery insulation state is deteriorated can be realized.

[0164] In another embodiment of the present disclosure, FIG. 9 is a flow diagram of a partial discharge monitoring method provided by the embodiment of the present disclosure. As shown in FIG. 9, the method comprises:

[0165] S901, obtaining a first voltage signal output by an ultrasonic sensor, wherein the first voltage signal is an ultrasonic signal generated by the partial discharge of a single battery and converted by the ultrasonic sensor.

[0166] S902, processing the first voltage signal by using a signal acquisition component and outputting the processed first voltage signal to a detection component.

[0167] S903, performing operation processing on the processed first voltage signal by using the detection component to obtain a monitoring result representing the partial discharge of the single battery.

[0168] In the embodiments of the present disclosure, the method can be applied to the battery device as in the foregoing embodiments to realize online monitoring of local discharge of the single battery. The battery device comprises a single battery, an ultrasonic sensor, a signal acquisition assembly and a detection assembly. The single battery is provided with an insulating layer, and the ultrasonic sensor is arranged on the side of the insulating layer away from the single battery; the signal acquisition assembly is arranged separately from the ultrasonic sensor and coupled to the ultrasonic sensor, and the detection assembly is coupled to the signal acquisition assembly.

[0169] In the embodiments of the present disclosure, the signal acquisition assembly and the ultrasonic sensor adopt a separate structure and are not integrated in one component; or in other words, the signal acquisition assembly and the ultrasonic sensor are arranged independently, and the signal acquisition assembly and the ultrasonic sensor are arranged in different components. For example, the ultrasonic sensor and the single battery can be arranged in an electric box that carries the single battery, and considering the size and layout of the electric box, the signal acquisition assembly and the detection assembly can be arranged in components outside the electric box. For example, the signal acquisition assembly can be arranged in a CSC component, and the detection assembly can be arranged in an SBMU component, or the detection assembly can also be arranged in a BMS component. In this way, the signal detected by the ultrasonic sensor can be transmitted to the CSC component first and then aggregated to the SBMU component.

[0170] That is, in the embodiments of the present disclosure, since the ultrasonic sensor is arranged on the insulating layer of the surface of the single battery, the distance between the ultrasonic sensor and the single battery is small at this time, so that the signal attenuation caused by local discharge is small, which is conducive to realizing the monitoring of local discharge of the single battery; the signal acquisition assembly and the ultrasonic sensor are arranged separately, which not only solves the problem of component space occupation, but also enables the detection of the local discharge signal of the single battery inside the battery device without increasing the size of the battery device; and the first voltage signal is processed by the signal acquisition assembly, such as signal amplification, acquisition and filtering, etc., so as to further improve the anti-interference ability in the signal transmission process and improve the signal-to-noise ratio; and the processed first voltage signal is processed by the detection assembly, so as to obtain the monitoring result representing the local discharge of the single battery, thereby realizing not only the online monitoring of the local discharge of the single battery, but also the faster response speed of the ultrasonic sensor compared with the insulation resistance monitoring, which can more timely prevent the insulation failure inside the single battery, and further realize the real-time early warning of whether the insulation state of the battery deteriorates.

[0171] In some embodiments, the processed first voltage signal is processed by the detection assembly to obtain the monitoring result representing the local discharge of the single battery, which can comprise:

[0172] The processed first voltage signal is subjected to time domain feature extraction to obtain a first time domain feature;

[0173] The first time domain feature is matched with a preset time domain feature library to obtain a monitoring result representing the local discharge of the single battery; the preset time domain feature library is used to store a corresponding relationship between different time domain features and monitoring results.

[0174] In the embodiments of the present disclosure, the time domain feature can include but is not limited to a peak signal repetition rate (times / minute) corresponding to an exceeding local discharge allowable level threshold, a signal average amplitude, etc. In addition, the preset time domain feature library can be constructed according to a large number of local discharge test experimental results and simulation calculations.

[0175] In this way, after obtaining the processed first voltage signal (i.e., a time domain signal), the first time domain feature can be obtained by performing time domain feature extraction on the processed first voltage signal; the extracted first time domain feature is matched with the preset time domain feature library to obtain the monitoring result representing the local discharge of the single battery, so that whether the local discharge exceeds the standard can be determined according to the extracted time domain feature, and the local discharge monitoring of the single battery can be implemented.

[0176] In some embodiments, the processed first voltage signal is processed by the detection component to obtain the monitoring result representing the local discharge of the single battery, which can include:

[0177] The processed first voltage signal is subjected to Fourier transform to determine a frequency spectrum of the processed first voltage signal.

[0178] The first frequency domain feature is obtained by performing frequency domain feature extraction according to the frequency spectrum of the processed first voltage signal.

[0179] The first frequency domain feature is matched with a preset frequency domain feature library to obtain the monitoring result representing the local discharge of the single battery; the preset frequency domain feature library is used to store a corresponding relationship between different frequency domain features and monitoring results.

[0180] In the embodiments of the present disclosure, the frequency domain feature can include but is not limited to a frequency spectrum maximum amplitude (or referred to as a "feature frequency band peak value"), a mean square frequency, a center of gravity frequency, a frequency spectrum variance, a frequency spectrum standard deviation, etc. In addition, the preset frequency domain feature library can also be constructed according to a large number of local discharge test experimental results and simulation calculations, and is used to represent the corresponding relationship between different frequency domain features and monitoring results.

[0181] Thus, after obtaining the processed first voltage signal (i.e., a "time domain signal"), the time domain signal can be converted to a frequency domain by performing a frequency domain transformation on the processed first voltage signal, such as a wavelet transformation, a Fourier transformation, a fast Fourier transformation, etc., so as to extract a frequency spectrum component, such as a first frequency domain feature. The extracted first frequency domain feature is matched with a preset frequency domain feature library to obtain a monitoring result representing the local discharge of the single battery, so as to determine whether the local discharge exceeds a threshold according to the extracted frequency domain feature, thereby realizing the local discharge monitoring of the single battery.

[0182] In some embodiments, when the first time domain feature is the signal average amplitude, the method further comprises:

[0183] When the signal average amplitude of the processed first voltage signal is less than the first threshold, the monitoring result indicates that the single battery does not have local discharge.

[0184] When the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold, the monitoring result indicates that the single battery has local discharge.

[0185] In the embodiments of the present disclosure, the first threshold is a judgment index for measuring whether the single battery has local discharge. For example, the first threshold can be set to 5V, but can be adaptively adjusted according to actual conditions, which is not limited here.

[0186] That is, in the embodiments of the present disclosure, taking the signal average amplitude as the first time domain feature as an example, the signal average amplitude of the processed first voltage signal, i.e., the "voltage signal average amplitude", can be represented by U. If the signal average amplitude is less than the first threshold, for example, U<5V, it indicates that the insulation is normal, and at this time the monitoring result indicates that the single battery does not have local discharge. If the signal average amplitude is greater than or equal to the first threshold, for example, U≥5V, it indicates that the insulation is not normal, and at this time the monitoring result indicates that the single battery has local discharge, and at this time a warning information can be further generated to notify the management personnel to timely repair the fault caused by the local discharge, so as to timely prevent the insulation failure.

[0187] In some embodiments, when the monitoring result indicates that the single battery has local discharge, the method can further comprise:

[0188] When the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold and less than a second threshold, the warning component generates a first warning information;

[0189] When the signal average amplitude of the processed first voltage signal is greater than or equal to the second threshold and less than a third threshold, the warning component generates a second warning information;

[0190] When the signal average amplitude of the processed first voltage signal is greater than or equal to a third threshold value, the warning component generates third warning information.

[0191] In the embodiments of the present disclosure, the first warning information, the second warning information and the third warning information can be used to indicate different degrees of local discharge of the single battery. For example, the first warning information represents mild local discharge, the second warning information represents moderate local discharge, and the third warning information represents severe local discharge (i.e. serious failure).

[0192] In the embodiments of the present disclosure, the second threshold value and the third threshold value are judgment indexes for measuring the severity of local discharge of the single battery. For example, the second threshold value can be set to 10V, and the third threshold value can be set to 15V, but can also be adaptively adjusted according to actual conditions, which is not limited here.

[0193] In a possible implementation, taking the first threshold value as 5V, the second threshold value as 10V and the third threshold value as 15V as an example, FIG. 2 shows a monitoring state example of local discharge of the single battery.

[0194] Table 2

[0195] In the embodiments of the present disclosure, the warning component here can include a voice broadcaster, an indicator light and the like, and is also used to issue warning information to the management personnel. For example, taking the indicator light as an example, if the indicator light is yellow, it is used to indicate that the single battery has mild local discharge, and at this time the insulation resistance needs to be checked; if the indicator light is orange, it is used to indicate that the single battery has moderate local discharge, and at this time the local discharge continues to occur, and if it still does not decrease for 30 minutes, the fault point is requested to be cut off; if the indicator light is red, it indicates that the single battery has serious failure, and at this time the insulation fails, and the fault point is immediately cut off. In addition, if the indicator light is green or the indicator light is off, it indicates that the single battery does not have local discharge, and at this time the insulation is normal.

[0196] In other words, in this embodiment of the disclosure, taking the average amplitude of the signal as the first time-domain feature as an example, after obtaining the average amplitude of the processed first voltage signal, the degree of partial discharge of a single battery cell can be further determined based on the range of the average amplitude. Specifically, if the average amplitude is in the first range, for example, 5V≤U<10V, a first alarm message is generated, indicating that the single battery cell has experienced mild partial discharge; if the average amplitude is in the second range, for example, 10V≤U<15V, a second alarm message is generated, indicating that the single battery cell has experienced moderate partial discharge; if the average amplitude is in the third range, for example, U≥15V, a third alarm message is generated, indicating that the single battery cell has experienced severe partial discharge, leading to insulation failure, and the fault point needs to be immediately disconnected. In this way, different alarm messages can indicate different degrees of partial discharge of the single battery cell, and can also notify management personnel to repair the fault caused by partial discharge in a timely manner, thereby preventing insulation failure in a timely manner.

[0197] In another embodiment of this disclosure, an apparatus and method for online monitoring of partial discharge in a battery, which can be a lithium battery, lead-acid battery, or other energy storage battery. To achieve online monitoring of partial discharge in the energy storage battery and provide real-time early warning of whether insulation degradation has occurred, in this embodiment, a flexible PVDF patch piezoelectric sensor (i.e., the aforementioned "ultrasonic sensor") can be arranged at a suitable location on the energy storage battery to convert the ultrasonic signal generated by partial discharge into a voltage signal, which is then sent to the detection component after passing through a signal amplification circuit and a data acquisition and filtering circuit.

[0198] In one possible implementation, the detection component can use FFT transformation to obtain the spectrum of partial discharge, filter out low-frequency interference, and extract the spectrum information that is strongly correlated with the partial discharge characteristics of the insulating layer on the surface of the single cell (i.e., the aforementioned "first frequency domain feature"); based on the extracted first frequency domain feature, it can determine whether the partial discharge exceeds the standard and issue an alarm message, thereby preventing insulation failure in a timely manner.

[0199] In this embodiment of the disclosure, Figure 10 is a second schematic flowchart of a partial discharge monitoring method provided in this embodiment. As shown in Figure 10, the method may include:

[0200] S1001, the ultrasonic signal generated by partial discharge is converted into the first voltage signal.

[0201] S1002, the first voltage signal is transmitted in a shielded manner.

[0202] S1003 is a signal amplification circuit that performs signal amplification and filtering.

[0203] S1004 is a signal acquisition and filtering circuit that performs signal acquisition and filtering.

[0204] S1005, performing spectrum conversion and frequency domain feature extraction.

[0205] S1006, issuing an alarm information.

[0206] It should be noted that if the detection component is not set in the BMS component, the alarm information can also be sent to the BMS component to prevent insulation failure in time.

[0207] It should be further noted that, taking a piezoelectric film sensor as an example, the piezoelectric film sensor can be arranged at a suitable position. According to the common energy storage battery box and cell structure, the following positions are included but not limited to:

[0208] Position 1: below the bottom R corner area of the first and last single batteries inside the battery module, the piezoelectric film sensor is attached to the outer surface of the blue film or the upper and lower surfaces of the battery box bottom plate;

[0209] Position 2: below the bottom flat area of the first and last single batteries inside the battery module, the piezoelectric film sensor is attached to the outer surface of the blue film or the upper and lower surfaces of the battery box bottom plate;

[0210] Position 3: below the bottom R corner area of the non-first and last single batteries inside the battery module, the piezoelectric film sensor is attached to the outer surface of the blue film or the upper and lower surfaces of the battery box bottom plate;

[0211] Position 4: below the bottom flat area of the non-first and last single batteries inside the battery module, the piezoelectric film sensor is attached to the outer surface of the blue film or the upper and lower surfaces of the battery box bottom plate;

[0212] Position 5: the piezoelectric film sensor is attached to the inside or outer surface of the battery module end plate;

[0213] Position 6: the piezoelectric film sensor is attached to the surface of the heat insulation pad between two adjacent single batteries in the same battery module, or embedded in the heat insulation pad.

[0214] It should be further noted that the parameter setting requirements of the piezoelectric film sensor can refer to the content of Table 1 described above.

[0215] In a possible implementation, the specific structure of the signal amplification circuit is shown in the foregoing FIG. 6. Here, the signal amplification circuit can adopt a two-stage amplification circuit design, after completing the conversion of the charge signal into a voltage signal, a high cutoff frequency design can be realized by reasonably selecting the RC parameters; the latter stage can realize the adjustable amplification ratio of 1-100 times through the adjustability of the second resistor R2.

[0216] In addition, the selection of the operational amplifier element is flexible, and LF412, TL072, LF356, etc. can be selected according to the cost. The front-stage amplification part (i.e. the first operational amplifier circuit 5012) in FIG. 6 can include circuit elements connected between the input and output terminals of the first operational amplifier element; and the rear-stage amplification part (i.e. the second operational amplifier circuit 5013) in FIG. 6 can include circuit elements connected between the input and output terminals of the second operational amplifier element.

[0217] In a possible implementation, for the signal acquisition filter circuit, a synchronous signal acquisition card with high sampling rate, low resolution and short response time, such as PXI-8512B, is selected for the signal acquisition circuit. After the continuous analog signal is converted into a discrete digital signal by the analog-to-digital conversion, the signal is sent to the second filter circuit for processing. Exemplarily, the second filter circuit can also be arranged in the BMS component.

[0218] In the embodiments of the present disclosure, according to the Nyquist theorem, the signal sampling rate is required to be not less than 10 MS / s based on the actual test frequency band of the battery cell.

[0219] In a possible implementation, after the time-domain signal is extracted, fast Fourier transform can be performed to further extract the frequency spectrum component and determine whether the partial discharge occurs. The frequency domain features include, but are not limited to, the maximum amplitude of the frequency spectrum, the center of gravity frequency, the frequency spectrum variance, etc. Alternatively, time domain features can also be extracted for recognition. The time domain features include, but are not limited to, the peak signal repetition rate (times / minute) exceeding the allowable level threshold of the partial discharge and the average amplitude of the signal.

[0220] Exemplarily, the embodiments can be executed according to the steps of the above technical solutions. The process includes:

[0221] The size of the piezoelectric film sensor is selected as 25 mm x 13 mm x 28 μm, and the performance parameters meet the related requirements listed in Table 1.

[0222] The arrangement position of the piezoelectric film sensor can be arranged below the R corner area at the bottom of the first and last single batteries in the battery module. Specifically, the piezoelectric film sensor is attached to the outer surface of the blue film of the single battery.

[0223] The signal amplification circuit shown in FIG. 6 is adopted, and the amplification multiple is adjusted according to the field electromagnetic noise.

[0224] According to the 10 MHz sampling frequency, the voltage signal output by the piezoelectric film sensor is collected in real time, the time domain features extracted from the time domain signal are used for partial discharge recognition, the monitoring result representing the partial discharge of the single battery is obtained, and the alarm information can also be generated and sent out.

[0225] In the embodiments of the present disclosure, through signal calibration, combined with a large number of test and simulation calculation experiences, the monitoring threshold of the battery partial discharge can be formulated as shown in Table 2.

[0226] The embodiments of the present disclosure provide a partial discharge monitoring method, and the specific implementation of the foregoing embodiments is described in detail in the foregoing embodiments. It can be seen from the foregoing embodiments that, on the one hand, for online monitoring of the partial discharge index, insulation failure can be prevented more timely than insulation resistance monitoring, and the voltage fluctuation is not affected. On the other hand, compared with the RC charging and discharging process (second level) of the insulation resistance monitoring, the response speed of the present technical solution is faster (millisecond level). In addition, the arrangement position of the piezoelectric film sensor is directly related to the insulation failure mode of the battery cell, and the captured signal can truly and effectively reflect the insulation failure process. Moreover, combined with signal amplification, acquisition, and filtering, the anti-interference ability in the signal transmission process can be improved, so that the signal-to-noise ratio is improved. In this way, not only the component space occupation problem is solved, but also the online monitoring of the partial discharge of the single battery is realized. Moreover, compared with the response speed of the insulation resistance monitoring, the ultrasonic sensor has a faster response speed, which can more timely prevent insulation failure in the single battery, and thus the real-time early warning of whether the insulation state of the battery is deteriorated can be realized.

[0227] In still another embodiment of the present disclosure, the embodiments of the present disclosure provide a computer readable storage medium having a computer program stored thereon, the computer program being executable to implement the partial discharge monitoring method of the foregoing embodiments.

[0228] The embodiments of the present disclosure also provide a computer program product comprising a computer program or instructions, which, when executed, can implement the partial discharge monitoring method as in the foregoing embodiments.

[0229] It should be noted that the embodiments of the present disclosure can be provided as a method, a system, or a computer program product. Therefore, the present disclosure can be in the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present disclosure can be in the form of a computer program product implemented on one or more computer readable storage media (including but not limited to disk storage and optical storage, etc.) containing computer usable program code.

[0230] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0231] It should also be noted that, in the present disclosure, the terms "comprising" and "including" or any other variation thereof are intended to cover non-exclusive inclusions, such that the process, method, article, or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or further includes elements inherent in such process, method, article, or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or device including the element.

[0232] The above-mentioned sequence numbers of the embodiments of the present disclosure are only for description, and do not represent advantages or disadvantages of the embodiments.

[0233] The methods disclosed in the several method embodiments provided by the present disclosure can be combined arbitrarily without conflict, to obtain new method embodiments.

[0234] The features disclosed in the several product embodiments provided by the present disclosure can be combined arbitrarily without conflict, to obtain new product embodiments.

[0235] The features disclosed in the several method or device embodiments provided by the present disclosure can be combined arbitrarily without conflict, to obtain new method embodiments or device embodiments.

[0236] The above is merely specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A battery device, comprising: a single battery, a surface of the single battery being provided with an insulation layer; an ultrasonic sensor, the ultrasonic sensor being arranged on a side of the insulation layer away from the single battery; a signal acquisition assembly, the signal acquisition assembly being arranged separately from the ultrasonic sensor and coupled to the ultrasonic sensor; a detection assembly, the detection assembly being coupled to the signal acquisition assembly; wherein the ultrasonic sensor is configured to convert an ultrasonic signal generated by local discharge of the single battery into a first voltage signal; the signal acquisition assembly is configured to output the first voltage signal after processing to the detection assembly, and the detection assembly is configured to perform operation processing on the processed first voltage signal to obtain a monitoring result representing the local discharge of the single battery.

2. The battery device of claim 1, wherein, The ultrasonic sensor comprises a piezoelectric thin film structure, wherein the piezoelectric thin film structure comprises a lower electrode sheet, a piezoelectric material layer and an upper electrode sheet arranged in sequence.

3. The battery device of claim 2, wherein, The piezoelectric thin film structure is a flexible structure.

4. The battery device according to any one of claims 1 to 3, wherein The ultrasonic sensor is arranged below a bottom R corner region of the single battery and / or below a bottom planar region of the single battery.

5. The battery device of claim 4, wherein, The number of the single batteries is a plurality, and the plurality of single batteries are connected in series to form a battery module. The ultrasonic sensor is arranged at at least one of the following positions inside the battery module: below a bottom R corner region of a battery at a preset position inside the battery module; below a bottom planar region of the battery at the preset position inside the battery module; below a bottom R corner region of a battery at a non-pre-set position inside the battery module; below a bottom planar region of the battery at the non-pre-set position inside the battery module; The battery at the preset position comprises a first single battery and / or a last single battery.

6. The battery device according to any one of claims 1 to 5, wherein The signal acquisition assembly is coupled to the ultrasonic sensor through a signal shielding channel.

7. The battery device of claim 6, wherein, The ultrasonic sensor is coupled to the signal acquisition assembly through a first acquisition line; wherein: The battery device further comprises a shielding element, and the shielding element is located around the first acquisition line.

8. The battery device according to any one of claims 1 to 7, wherein The signal acquisition assembly comprises a signal amplification circuit and an acquisition filtering circuit, wherein: The signal amplification circuit comprises a first filtering circuit, a first operational amplifier circuit and a second operational amplifier circuit, and an input end of the first filtering circuit is coupled to the ultrasonic sensor, an output end of the first filtering circuit is connected to the first operational amplifier circuit, the first operational amplifier circuit is cascaded with the second operational amplifier circuit, and is configured to perform signal amplification and filtering processing on the first voltage signal to output a second voltage signal; The acquisition filtering circuit comprises a signal acquisition circuit and a second filtering circuit, and the signal acquisition circuit is connected between an output end of the second operational amplifier circuit and an input end of the second filtering circuit, and is configured to perform signal acquisition and filtering processing on the second voltage signal to output the processed first voltage signal.

9. The battery device of claim 8, wherein, The signal acquisition circuit adopts a data acquisition element with a sampling rate of no less than 10 million times per second.

10. The battery device according to any one of claims 1 to 9, wherein The battery device further comprises an alarm circuit, wherein: The alarm circuit is connected with the detection component, and is configured to generate alarm information according to the monitoring result, the alarm information being used to indicate the local discharge degree of the single battery.

11. The battery device according to any one of claims 1 to 10, wherein The signal collection component is integrated in a battery detection device, and / or the detection component is integrated in a cluster-level battery management unit or a battery management system.

12. A local discharge monitoring method applied to the battery device of any one of claims 1 to 11, the method comprising: acquiring a first voltage signal output by an ultrasonic sensor, wherein the first voltage signal is converted from an ultrasonic signal generated by the ultrasonic sensor based on the local discharge of the single battery; outputting the first voltage signal to a detection component after processing by a signal collection component; performing operation processing on the processed first voltage signal by the detection component to obtain a monitoring result representing the local discharge of the single battery.

13. The method of claim 12, wherein, The operation processing on the processed first voltage signal by the detection component to obtain the monitoring result representing the local discharge of the single battery comprises: performing time-domain feature extraction on the processed first voltage signal to obtain a first time-domain feature; matching the first time-domain feature with a preset time-domain feature library to obtain the monitoring result representing the local discharge of the single battery, wherein the preset time-domain feature library is configured to store a corresponding relationship between different time-domain features and monitoring results.

14. The method of claim 12, wherein, The operation processing on the processed first voltage signal by the detection component to obtain the monitoring result representing the local discharge of the single battery comprises: performing Fourier transform on the processed first voltage signal to determine a frequency spectrum of the processed first voltage signal; performing frequency-domain feature extraction according to the frequency spectrum of the processed first voltage signal to obtain a first frequency-domain feature; matching the first frequency-domain feature with a preset frequency-domain feature library to obtain the monitoring result representing the local discharge of the single battery, wherein the preset frequency-domain feature library is configured to store a corresponding relationship between different frequency-domain features and monitoring results.

15. The method of claim 13, wherein, When the first time-domain feature is a signal average amplitude, the method further comprises: when the signal average amplitude of the processed first voltage signal is less than a first threshold, the monitoring result indicates that the single battery has no local discharge; when the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold, the monitoring result indicates that the single battery has local discharge.

16. The method of claim 15, wherein, When the monitoring result indicates that the single battery has local discharge, the method further comprises: when the signal average amplitude of the processed first voltage signal is greater than or equal to the first threshold and less than a second threshold, an alarm component generates first alarm information; when the signal average amplitude of the processed first voltage signal is greater than or equal to the second threshold and less than a third threshold, the alarm component generates second alarm information; when the signal average amplitude of the processed first voltage signal is greater than or equal to the third threshold, the alarm component generates third alarm information; The first alarm information, the second alarm information and the third alarm information are used for indicating different degrees of local discharge of the single battery.

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