On-line monitoring device and on-line monitoring method based on impedance spectrum of storage battery

Abstract

The invention relates to the technical field of battery monitoring, and discloses an on-line monitoring device and an on-line monitoring method based on an impedance spectrum of a storage battery, the SOH of the storage battery can be determined by measuring internal resistance measurement result data corresponding to each frequency and generating the impedance spectrum of the storage battery according to the data, the accuracy is high, deep charging and discharging are avoided, and the reliability of the storage battery is improved. Therefore, frequent monitoring is facilitated, batteries with severely degraded performance can be found and identified in time, and the reliability of the storage battery pack serving as a standby power supply is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of battery monitoring, and in particular to an online monitoring device and an online monitoring method based on battery impedance spectrum. Background Art

[0002] Valve-regulated lead-acid batteries are widely used in substation systems due to their significant advantages, including no need for frequent maintenance, high rated capacity, stable and reliable operating performance, relatively long service life, and easy subsequent recycling and reuse. They are usually deployed in group configurations.

[0003] In order to ensure the reliability of such battery packs as critical backup power sources and accurately grasp their storage capacity, it is particularly important to conduct regular inspections of the battery packs. The inspection work mainly focuses on several core parameters: open circuit voltage, operating temperature, and DC internal resistance. However, to accurately evaluate the health status of the battery (i.e., SOH, State of Health), a more rigorous nuclear capacity test is required. However, since lead-acid batteries in substations play a key role as DC backup power sources, frequent nuclear capacity tests are not appropriate, which directly leads to an extension of the battery health status monitoring cycle. In this case, it is difficult for maintenance personnel to promptly discover and identify batteries whose performance has been severely degraded within the time window between two nuclear capacity tests.

[0004] Therefore, it is particularly urgent to innovate and upgrade current technical means.

[0005] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Summary of the invention

[0006] The present invention provides an online monitoring device and an online monitoring method based on battery impedance spectrum to solve the problems existing in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides an online monitoring device based on battery impedance spectrum, the device comprising a host, a terminal and a module; wherein:

[0009] The host is connected to the terminal, and is used to send an impedance spectrum statistics instruction to the terminal, and receive the internal resistance measurement result data corresponding to each frequency sent by the terminal, and generate the impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, so as to determine the SOH of the battery;

[0010] The terminal is connected to the module, and is used to forward the impedance spectrum statistics instruction to the module, and receive the internal resistance measurement result data corresponding to each frequency sent by the module, and forward it to the host

[0011] The module is connected to the single cells in the storage battery, and is used to measure the corresponding internal resistance at different frequencies after receiving the impedance spectrum statistics instruction, and send the corresponding internal resistance measurement result data at each frequency to the terminal.

[0012] Furthermore, in the online monitoring device based on battery impedance spectrum, the number of modules provided corresponds to the number of single cells in the battery, and one module corresponds to monitoring one single cell.

[0013] Furthermore, in the online monitoring device based on battery impedance spectrum, the host is also used to send an internal resistance measurement instruction to the terminal, and receive the internal resistance measurement result data sent by the terminal;

[0014] The terminal is also used to forward the internal resistance measurement instruction to the module, and receive the internal resistance measurement result data sent by the module and forward it to the host;

[0015] The module is also used to measure the internal resistance of the single cell after receiving the internal resistance measurement instruction, and send the internal resistance measurement result data to the terminal.

[0016] Furthermore, in the online monitoring device based on battery impedance spectrum, the module includes a sampling circuit, and the sampling circuit includes a switch tube K and a protection resistor R;

[0017] The switch tube K and the protection resistor R are connected in series and then connected to two ends of the single battery.

[0018] Furthermore, the online monitoring device based on battery impedance spectrum also includes a screen;

[0019] The screen is connected to the host and is used to display a human-computer interaction interface for users to perform human-computer interaction.

[0020] In a second aspect, the present invention provides an online monitoring method based on battery impedance spectrum, which is performed by using the online monitoring device based on battery impedance spectrum provided in the first aspect, and the method comprises:

[0021] The host sends an impedance spectrum statistics instruction to the terminal, and the terminal forwards the impedance spectrum statistics instruction to the module;

[0022] After receiving the impedance spectrum statistics instruction, the module measures the corresponding internal resistance at different frequencies, and sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host;

[0023] The host receives the internal resistance measurement result data corresponding to each frequency, and generates an impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, thereby determining the SOH of the battery.

[0024] Furthermore, in the online monitoring method based on battery impedance spectrum, after receiving the impedance spectrum statistics instruction, the module measures the corresponding internal resistance at different frequencies, and sends the corresponding internal resistance measurement result data at each frequency to the terminal, and the terminal forwards the corresponding internal resistance measurement result data at each frequency to the host, including:

[0025] After receiving the impedance spectrum statistics instruction, the module triggers the switch tube K therein with a multi-frequency sinusoidal signal, so that the single cells in the battery are discharged in a multi-frequency sinusoidal law;

[0026] The module samples the discharge voltage and calculates the discharge current, performs fast Fourier operation on the sampling information results, and generates the corresponding internal resistance at different frequencies; after completing a multi-frequency sine signal discharge, it automatically discharges with the next multi-frequency sine signal and measures the internal resistance;

[0027] After completing the internal resistance measurement of all multi-frequency sinusoidal signals, the module sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host.

[0028] Furthermore, the online monitoring method based on battery impedance spectrum further comprises:

[0029] The host sends an internal resistance measurement instruction to the terminal, and the terminal forwards the internal resistance measurement instruction to the module;

[0030] After receiving the internal resistance measurement instruction, the module measures the internal resistance corresponding to the single cell and sends the internal resistance measurement result data to the terminal, which then forwards the internal resistance measurement result data to the host.

[0031] Furthermore, in the online monitoring method based on battery impedance spectrum, after receiving the internal resistance measurement instruction, the module measures the internal resistance corresponding to the single cell and sends the internal resistance measurement result data to the terminal, and the terminal forwards the internal resistance measurement result data to the host, comprising:

[0032] After receiving the internal resistance measurement instruction, the module turns on the switch tube K of the single cell according to the required discharge frequency, so that the single cell discharges in a sinusoidal manner;

[0033] The module samples the voltage at both ends ab of the positive and negative electrodes of the single battery and at both ends cd of the protection resistor R in the module in real time, and performs fast Fourier transform on the sampled voltage signal to obtain the voltage effective value U ab , U cd , and the voltage phase angle φ ab ,φ cd , and then calculate the discharge current I DC , the internal resistance Z and direction θ of the single cell;

[0034] The module sends the internal resistance measurement result data to the terminal, and the terminal forwards the internal resistance measurement result data to the host.

[0035] Furthermore, in the online monitoring method based on battery impedance spectrum, the discharge current I is calculated according to the following formula: DC :

[0036] I DC =U cd / R;

[0037] The internal resistance Z of the single cell is calculated according to the following formula:

[0038] Z=U ab / I DC ;

[0039] The direction θ is calculated according to the following formula:

[0040] θ=φ cd -φ ab .

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention provides an online monitoring device and an online monitoring method based on battery impedance spectrum. By measuring the internal resistance measurement result data corresponding to each frequency and generating the impedance spectrum of the battery based on the data, the SOH of the battery can be determined. This method not only has high accuracy but also avoids deep charging and discharging. It is suitable for frequent monitoring, which is conducive to timely discovery and identification of batteries with severely degraded performance, thereby ensuring the reliability of the battery pack as a backup power supply.

[0043] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 1 is a schematic structural diagram of an online monitoring device based on battery impedance spectrum provided in Embodiment 1 of the present invention;

[0046] Figure 2 is a schematic diagram of the structure of the module provided in the first embodiment of the present invention;

[0047] Figure 3 This is one of the flow charts of an online monitoring method based on battery impedance spectrum provided in the second embodiment of the present invention.

[0048] Figure 4 This is the second flow chart of an online monitoring method based on battery impedance spectrum provided by the second embodiment of the present invention.

[0049] Reference numerals:

[0050] Host 1, terminal 2, module 3, screen 4. DETAILED DESCRIPTION

[0051] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0052] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0053] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0054] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0055] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0056] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0057] In this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0058] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0059] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0060] Embodiment 1

[0061] In view of the defects of the above-mentioned prior art, the applicant, based on many years of rich practical experience and professional knowledge in this field, and in conjunction with the application of theory, actively conducts research and innovation in the hope of creating a technology that can solve the defects of the prior art. After continuous research and design, and after repeated trial production and improvement, the present invention with real practical value was finally created.

[0062] Please refer to Figure 1 The embodiment of the present invention provides an online monitoring device based on battery impedance spectrum, the device includes a host 1, a terminal 2 and a module 3; wherein,

[0063] The host 1 is connected to the terminal 2, and is used to send an impedance spectrum statistics instruction to the terminal 2, and receive the internal resistance measurement result data corresponding to each frequency sent by the terminal 2, and generate the impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, and then determine the SOH of the battery;

[0064] The terminal 2 is connected to the module 3, and is used to forward the impedance spectrum statistics instruction to the module 3, and receive the internal resistance measurement result data corresponding to each frequency sent by the module 3, and forward it to the host 1

[0065] The module 3 is connected to the single cells in the battery, and is used to measure the corresponding internal resistance at different frequencies after receiving the impedance spectrum statistics instruction, and send the corresponding internal resistance measurement result data at each frequency to the terminal 2.

[0066] It should be noted that electrochemical impedance spectroscopy (EIS) is a non-destructive test and is closely related to the internal changes of the battery. Therefore, EIS is more suitable as a direct basis for rapid evaluation of battery SOH. The EIS method is a method of characterizing electrochemical properties by applying small-amplitude AC disturbances of different frequencies to the electrochemical system and measuring the spectrum of the ratio of AC electromotive force to AC current as the excitation frequency changes.

[0067] The embodiment of the present invention accurately measures and analyzes the internal resistance data of the single cells in the battery at different frequencies, and then constructs the impedance spectrum of the battery, providing a scientific basis for accurately evaluating the SOH of the battery. This method not only significantly improves the accuracy of the evaluation, but also effectively avoids the potential impact of deep charge and discharge tests on the battery life, making frequent monitoring possible. This is of great significance for timely discovering and identifying batteries with severe performance degradation and ensuring the reliability of the battery pack as a key backup power source.

[0068] In one implementation of this embodiment, the number of modules 3 corresponds to the number of cells in the battery, and one module 3 monitors one cell.

[0069] Specifically, the number of modules 3 completely corresponds to the number of cells inside the battery, that is, each cell is equipped with a dedicated module 3 for monitoring. This one-to-one monitoring mode not only allows the health status and performance changes of each cell to be captured in a timely and accurate manner, but also greatly improves the accuracy and reliability of the entire monitoring system. In this way, the status of each cell in the battery pack can be meticulously monitored, thereby more effectively ensuring the overall performance and stability of the battery pack as a backup power source.

[0070] In one implementation of this embodiment, the operation process of the device and the functional allocation of each component are further optimized to achieve accurate measurement and monitoring of the internal resistance of the single cells in the battery pack. The specific description is as follows:

[0071] The host 1 is also used to send an internal resistance measurement instruction to the terminal 2, and receive the internal resistance measurement result data sent by the terminal 2;

[0072] The terminal 2 is also used to forward the internal resistance measurement instruction to the module 3, and receive the internal resistance measurement result data sent by the module 3, and forward it to the host 1;

[0073] The module 3 is also used to measure the internal resistance of the single cell after receiving the internal resistance measurement instruction, and send the internal resistance measurement result data to the terminal 2.

[0074] Through this series of optimization measures, this embodiment can achieve accurate measurement of the internal resistance of the single cells in the battery pack.

[0075] In one implementation of this embodiment, the module 3 includes a sampling circuit, and the sampling circuit includes a switch tube K and a protection resistor R;

[0076] The switch tube K and the protection resistor R are connected in series and then connected to two ends of the single battery.

[0077] The internal structure of module 3 is designed in detail, especially the sampling circuit part. The sampling circuit is the key component of module 3 for measuring the internal resistance of single cells, and its design is directly related to the accuracy and reliability of the measurement.

[0078] Specifically, the sampling circuit in module 3 is mainly composed of a switch tube K and a protection resistor R. These two components are connected in series and directly connected to the two ends of the single battery. This design not only ensures that the current can smoothly pass through the sampling circuit to measure the internal resistance, but also effectively protects the circuit through the protection resistor R to prevent damage to the circuit components or single battery due to excessive current.

[0079] The switch tube K plays a role in controlling the on-off of the current in the sampling circuit. When the internal resistance measurement is required, the switch tube K will be closed to allow the current to pass through the sampling circuit; when the measurement is completed, the switch tube K will be opened to cut off the current and ensure the safety of the circuit.

[0080] The protective resistor R plays a dual role of current limiting and protection. On the one hand, it limits the current passing through the sampling circuit to prevent circuit damage or battery overheating caused by excessive current; on the other hand, it can also provide additional protection when the circuit is abnormal, such as short circuit or overload, to ensure the stable operation of the entire monitoring system.

[0081] Through such careful design, the sampling circuit of module 3 not only realizes the accurate measurement of the internal resistance of the single cell, but also ensures the safety and reliability of the entire monitoring system.

[0082] In one implementation of this embodiment, a screen 4 is further introduced as a user interaction interface, which greatly improves the operability of the system and the user experience.

[0083] As an important component of the entire online monitoring device based on battery impedance spectrum, the screen 4 establishes a stable connection with the host 1. Its main function is to display an intuitive and friendly human-computer interaction interface, so that users can easily perform various operations and information inquiries.

[0084] Through this interface, users can clearly see the overall health status of the battery pack, the internal resistance measurement results of each single cell, impedance spectrum and other key information. At the same time, users can also input commands, set parameters, query data and other operations through buttons or menu options on the interface.

[0085] The introduction of Screen 4 not only allows users to understand the operating status of the battery pack anytime and anywhere, but also enables them to detect and deal with potential problems in a timely manner. In addition, it also provides users with a convenient channel for adjusting and optimizing the settings of the monitoring system to suit different application scenarios and needs.

[0086] In summary, the addition of screen 4 greatly enhances the interactivity and practicality of the system, allowing users to manage and maintain the battery pack more efficiently and ensure the stable operation of the entire monitoring system and the health status of the battery.

[0087] Although the terms such as host, terminal, module, etc. are used more frequently in this application, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

[0088] An online monitoring device based on a battery impedance spectrum provided in an embodiment of the present invention measures the internal resistance measurement result data corresponding to each frequency, and generates an impedance spectrum of the battery based on the data, thereby determining the SOH of the battery. This device has high accuracy and avoids deep charge and discharge, and is therefore suitable for frequent monitoring, which is beneficial for timely discovery and identification of batteries whose performance has been severely degraded, thereby ensuring the reliability of the battery pack as a backup power source.

[0089] Embodiment 2

[0090] Please refer to Figure 3 Embodiment 2 of the present invention provides an online monitoring method based on battery impedance spectrum, which is performed by using the online monitoring device based on battery impedance spectrum provided in the above embodiment 1. The method specifically includes the following steps:

[0091] S101. The host sends an impedance spectrum statistics instruction to the terminal, and the terminal forwards the impedance spectrum statistics instruction to the module.

[0092] It should be noted that before this, the host will first determine whether the battery is in a stable state (floating charge or static). If so, it will send an impedance spectrum statistics instruction to the terminal. If not, it will be terminated and the impedance spectrum will not be allowed to be generated.

[0093] S102: After receiving the impedance spectrum statistics instruction, the module measures the internal resistance at different frequencies, and sends the internal resistance measurement result data at each frequency to the terminal, and the terminal forwards the internal resistance measurement result data at each frequency to the host.

[0094] S103: The host receives the internal resistance measurement result data corresponding to each frequency, and generates an impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, and further determines the SOH of the battery.

[0095] In one implementation of this embodiment, N multi-frequency sinusoidal signals synthesized by M different frequencies are preset in the module, and step S102 specifically includes:

[0096] After receiving the impedance spectrum statistics instruction, the module triggers the switch tube K therein with a multi-frequency sinusoidal signal, so that the single cells in the battery are discharged in a multi-frequency sinusoidal law;

[0097] The module samples the discharge voltage and calculates the discharge current, performs fast Fourier operation on the sampling information results, and generates the corresponding internal resistance at different frequencies; after completing a multi-frequency sine signal discharge, it automatically discharges with the next multi-frequency sine signal and measures the internal resistance;

[0098] After completing the internal resistance measurement of all multi-frequency sinusoidal signals, the module sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host.

[0099] Please refer to Figure 4 In one implementation of this embodiment, the online monitoring method based on battery impedance spectrum further includes:

[0100] S201: The host sends an internal resistance measurement instruction to the terminal, and the terminal forwards the internal resistance measurement instruction to the module.

[0101] It should be noted that before this, the host will first determine whether the battery is in a stable state (floating charge or static). If so, it will send an internal resistance measurement instruction to the terminal. If not, it will be terminated and impedance calculation is not allowed.

[0102] S202: After receiving the internal resistance measurement instruction, the module measures the internal resistance of the single cell and sends the internal resistance measurement result data to the terminal, which then forwards the internal resistance measurement result data to the host.

[0103] In one implementation of this embodiment, step S202 specifically includes:

[0104] After receiving the internal resistance measurement instruction, the module turns on the switch tube K of the single cell according to the required discharge frequency, so that the single cell discharges in a sinusoidal manner;

[0105] The module samples the voltage at both ends ab of the positive and negative electrodes of the single battery and at both ends cd of the protection resistor R in the module in real time, and performs fast Fourier transform on the sampled voltage signal to obtain the voltage effective value U ab , U cd , and the voltage phase angle φ ab ,φ cd , and then calculate the discharge current I DC , the internal resistance Z and direction θ of the single cell;

[0106] The module sends the internal resistance measurement result data to the terminal, and the terminal forwards the internal resistance measurement result data to the host.

[0107] In one implementation of this embodiment, the discharge current I is calculated according to the following formula: DC :

[0108] I DC =U cd / R;

[0109] The internal resistance Z of the single cell is calculated according to the following formula:

[0110] Z=U ab / I DC ;

[0111] The direction θ is calculated according to the following formula:

[0112] θ=φ cd -φ ab .

[0113] An online monitoring method based on battery impedance spectrum provided by an embodiment of the present invention measures the internal resistance measurement result data corresponding to each frequency, and generates the impedance spectrum of the battery based on the data, thereby determining the SOH of the battery. This method has high accuracy and avoids deep charge and discharge, and is therefore suitable for frequent monitoring, which is beneficial for timely discovery and identification of batteries with severely degraded performance, thereby ensuring the reliability of the battery pack as a backup power source.

[0114] Finally, it should be noted that although the above embodiments have been described in the specification and drawings of this application, this does not limit the scope of patent protection of this application. All technical solutions generated by replacing or modifying equivalent structures or equivalent processes based on the essential concept of this application using the contents recorded in the specification and drawings of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are included in the scope of patent protection of this application.

Claims

1. An online monitoring device based on battery impedance spectrum, characterized in that: The device comprises a host (1), a terminal (2) and a module (3); wherein: The host (1) is connected to the terminal (2) and is used to send an impedance spectrum statistics instruction to the terminal (2), receive internal resistance measurement result data corresponding to each frequency sent by the terminal (2), and generate an impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, thereby determining the SOH of the battery; The terminal (2) is connected to the module (3) and is used to forward the impedance spectrum statistics instruction to the module (3), and receive the internal resistance measurement result data corresponding to each frequency sent by the module (3), and forward it to the host (1). The module (3) is connected to the single cells in the storage battery and is used to measure the corresponding internal resistance at different frequencies after receiving the impedance spectrum statistics instruction, and send the corresponding internal resistance measurement result data at each frequency to the terminal (2).

2. The online monitoring device based on battery impedance spectrum according to claim 1, characterized in that: The number of modules (3) provided corresponds to the number of single cells in the battery, and one module (3) corresponds to monitoring one single cell.

3. The online monitoring device based on battery impedance spectrum according to claim 1, characterized in that: The host (1) is also used to send an internal resistance measurement instruction to the terminal (2), and receive internal resistance measurement result data sent by the terminal (2); The terminal (2) is also used to forward the internal resistance measurement instruction to the module (3), and to receive the internal resistance measurement result data sent by the module (3) and forward it to the host (1); The module (3) is also used to measure the corresponding internal resistance of the single cell after receiving the internal resistance measurement instruction, and send the internal resistance measurement result data to the terminal (2).

4. The online monitoring device based on battery impedance spectrum according to claim 1, characterized in that: The module (3) comprises a sampling circuit, wherein the sampling circuit comprises a switch tube K and a protection resistor R; The switch tube K and the protection resistor R are connected in series and then connected to two ends of the single battery.

5. The online monitoring device based on battery impedance spectrum according to claim 1, characterized in that: Also includes screens (4); The screen (4) is connected to the host (1) and is used to display a human-computer interaction interface for a user to perform human-computer interaction.

6. An online monitoring method based on battery impedance spectrum, performed by using the online monitoring device based on battery impedance spectrum as claimed in any one of claims 1 to 5, characterized in that: The method comprises: The host sends an impedance spectrum statistics instruction to the terminal, and the terminal forwards the impedance spectrum statistics instruction to the module; After receiving the impedance spectrum statistics instruction, the module measures the corresponding internal resistance at different frequencies, and sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host; The host receives the internal resistance measurement result data corresponding to each frequency, and generates an impedance spectrum of the battery according to the internal resistance measurement result data corresponding to each frequency, thereby determining the SOH of the battery.

7. The online monitoring method based on battery impedance spectrum according to claim 6 is characterized in that: After receiving the impedance spectrum statistics instruction, the module measures the corresponding internal resistance at different frequencies, and sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host, including: After receiving the impedance spectrum statistics instruction, the module triggers the switch tube K therein with a multi-frequency sinusoidal signal, so that the single cells in the battery are discharged in a multi-frequency sinusoidal law; The module samples the discharge voltage and calculates the discharge current, performs fast Fourier operation on the sampling information results, and generates the corresponding internal resistance at different frequencies; after completing a multi-frequency sine signal discharge, it automatically discharges with the next multi-frequency sine signal and measures the internal resistance; After completing the internal resistance measurement of all multi-frequency sinusoidal signals, the module sends the internal resistance measurement result data corresponding to each frequency to the terminal, and the terminal forwards the internal resistance measurement result data corresponding to each frequency to the host.

8. The online monitoring method based on battery impedance spectrum according to claim 6, characterized in that: The method further comprises: The host sends an internal resistance measurement instruction to the terminal, and the terminal forwards the internal resistance measurement instruction to the module; After receiving the internal resistance measurement instruction, the module measures the internal resistance corresponding to the single cell and sends the internal resistance measurement result data to the terminal, which then forwards the internal resistance measurement result data to the host.

9. The online monitoring method based on battery impedance spectrum according to claim 8, characterized in that: After receiving the internal resistance measurement instruction, the module measures the internal resistance corresponding to the single cell and sends the internal resistance measurement result data to the terminal, and the terminal forwards the internal resistance measurement result data to the host, including: After receiving the internal resistance measurement instruction, the module turns on the switch tube K of the single cell according to the required discharge frequency, so that the single cell discharges in a sinusoidal manner; The module samples the voltage at both ends ab of the positive and negative electrodes of the single battery and at both ends cd of the protection resistor R in the module in real time, and performs fast Fourier transform on the sampled voltage signal to obtain the voltage effective value U ab , U cd , and the voltage phase angle φ ab ,φ cd , and then calculate the discharge current I DC , the internal resistance Z and direction θ of the single cell; The module sends the internal resistance measurement result data to the terminal, and the terminal forwards the internal resistance measurement result data to the host.

10. The online monitoring method based on battery impedance spectrum according to claim 9, characterized in that: The discharge current I is calculated according to the following formula DC : I DC =U cd / R; The internal resistance Z of the single cell is calculated according to the following formula: Z=U ab / I DC ; The direction θ is calculated according to the following formula: θ=φ cd -f ab 。

Images