CN116868072A

CN116868072A - Battery SOH detection method, device, equipment and storage medium

Info

Publication number: CN116868072A
Application number: CN202280007993.8A
Authority: CN
Inventors: 袁柱; 赵微; 张世昌; 李海力
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2023-10-10
Also published as: WO2024000145A1

Abstract

A battery SOH detection method, device, equipment and storage medium are provided, and the method, device and storage medium comprise the steps of responding to an SOH detection instruction, determining a target detection working condition (101) corresponding to the detection instruction, controlling a battery to operate the target detection working condition, and detecting the current SOH (102) of the battery under the target detection working condition, so that the detection requirements of SOH under various working conditions can be met. SOH recorded by the electric equipment is calibrated based on the detected SOH, parameters of an electrochemical model of the electric equipment and/or the cloud end are corrected, the control accuracy of the battery or the electric equipment is improved, and the service performance and the safety performance of the electric equipment are improved.

Description

Battery SOH detection method, device, equipment and storage medium

Technical Field

The present application relates to the field of battery technologies, and in particular, to a method, an apparatus, a device, and a storage medium for detecting SOH of a battery.

Background

The state of health SOH of a battery is one of important parameters of the battery, and influences the state of charge estimation, power estimation, charge rate estimation and the like of the battery, and plays an important role in active control of the whole life state of the battery. So that it is necessary to accurately detect SOH of the battery.

At present, in the related art, the SOH of a battery is monitored mainly through simple maintenance capacity, and the detection requirement of the SOH under various working conditions is difficult to meet. Moreover, the detection mode in the related art is only used for an energy storage system, and has a great limiting effect.

Disclosure of Invention

The embodiment of the application provides a battery SOH detection method, device, equipment and storage medium, which avoid the situation that the detection precision is increased along with battery aging under different aging paths by using the same detection mode. For different detection instructions, the SOH of the battery is detected under different target detection working conditions, and the detection requirements of SOH under various working conditions can be met. The method is not only suitable for the energy storage system, but also suitable for detection requests of the vehicle end, the server end or the user end, and has small limitation and high universality.

In a first aspect, an embodiment of the present application provides a battery SOH detection method, including:

responding to an SOH detection instruction, and determining a target detection working condition corresponding to the detection instruction;

and controlling the battery to run the target detection working condition, and detecting the current SOH of the battery under the target detection working condition.

In this embodiment, the target detection condition corresponding to the detection instruction is determined. And then controlling the battery to run under the target detection working condition, and detecting the SOH of the battery under the target detection working condition. If the battery aging path is used in different application scenes, different detection modes are adopted, and the situation that the detection precision is increased along with battery aging under different aging paths by using the same detection mode is avoided. For different detection instructions, the SOH of the battery is detected under different target detection working conditions, and the detection requirements of SOH under various working conditions can be met. The method is not only suitable for the energy storage system, but also suitable for detection requests of the vehicle end, the server end or the user end, and has small limitation and high universality.

In some embodiments, the determining the target detection condition corresponding to the detection instruction includes:

and determining a target detection working condition corresponding to the scene identification according to the scene identification included in the detection instruction, wherein the scene identification is used for identifying an application scene needing SOH detection currently.

In this embodiment, different application scenarios are represented by the scenario identifiers, and detection conditions corresponding to each scenario identifier are preconfigured. When the SOH detection instruction is received, determining a target detection working condition to be used according to a scene identifier carried by the detection instruction, and then detecting the current SOH of the battery based on the target detection working condition. So realized that different application scenes adopt different detection operating modes to detect SOH, avoided all using the same detection mode to lead to the problem that detection accuracy is low under the different application scenes, be applicable to various scenes that need to detect SOH moreover, the universality is very high.

In some embodiments, the controlling the battery to operate the target detection condition, detecting the current SOH of the battery under the target detection condition includes:

controlling the battery to run the target detection working condition based on the working condition parameters corresponding to the target detection working condition;

And determining the current SOH of the battery based on the electrical parameters of the battery under the target detection working condition.

In this embodiment, the battery is controlled to operate under the target detection condition, and the current SOH of the battery is calculated from the electrical parameters exhibited by the battery under the target detection condition. Because the target detection working condition is matched with the scene identification, SOH is detected through the electrical parameters of the battery under the target detection working condition, and the detection mode is suitable for the current application scene and is beneficial to improving the accuracy of SOH detection under the application scene.

In some embodiments, the target detection condition includes an electrochemical impedance spectroscopy EIS condition, and the controlling the battery to operate the target detection condition based on a condition parameter corresponding to the target detection condition includes:

adjusting the electric quantity of the battery to the preset electric quantity and adjusting the temperature of the battery to the first preset temperature based on the preset electric quantity and the first preset temperature included in the working condition parameters corresponding to the EIS working condition; and executing current negative pulse with preset frequency on the battery.

In this embodiment, in the process of detecting the SOH of the battery under the EIS condition, the current negative pulse discharging is performed on the battery according to the preset frequency, so that the battery is under the current negative pulse condition in the EIS condition, and there is a strong correlation between the cell impedance of the battery and the SOH of the battery under the condition, so that the control of the battery under the condition is helpful to accurately detect the current SOH of the battery.

In some embodiments, the determining the current SOH of the battery based on the electrical parameter exhibited by the battery under the target detection condition includes:

detecting the cell impedance exhibited by the battery under the current negative pulse; and acquiring corresponding SOH from a preset SOH lookup table according to the preset electric quantity, the first preset temperature and the battery cell impedance, wherein the preset SOH lookup table comprises the mapping relation between the battery cell impedance and the SOH under different battery electric quantities and battery temperatures.

In this embodiment, a preset SOH lookup table is preset, and the mapping relationship between the battery power and the battery temperature and the battery cell impedance and the SOH is stored in the lookup table. And when the battery is controlled to be under a current negative pulse working condition in an EIS working condition, inquiring SOH related to the preset electric quantity, the first preset temperature and the electric core impedance from a preset SOH inquiry table according to the preset electric quantity and the first preset temperature corresponding to the EIS working condition and the electric core impedance detected under the current working condition. The current SOH of the battery is obtained based on the battery cell impedance table look-up shown by the battery by controlling the battery to be in the current negative pulse working condition in the EIS working condition, so that the detection speed is high and the accuracy is high.

In some embodiments, the controlling the battery to operate the target detection condition based on the condition parameter corresponding to the target detection condition includes:

and controlling the battery to charge with the preset request current based on the preset request current included in the working condition parameters corresponding to the target detection working condition.

In this embodiment, when the electric device is connected to the charging device and the battery is in any state, the BMS may perform charging request to the charging device with a preset request current, so that the battery operates under a target detection working condition, and the battery is controlled to be in the working condition and can accurately calculate the current SOH of the battery based on the electrical parameters of the battery under the working condition.

detecting current, voltage, current electric quantity and current battery temperature of the battery in the charging process;

calculating the impedance of the battery core of the battery under the EIS working condition based on the detected current and voltage;

and acquiring corresponding SOH from a preset SOH lookup table according to the current electric quantity, the current battery temperature and the battery cell impedance, wherein the preset SOH lookup table comprises mapping relations between battery cell impedance and SOH under different battery electric quantities and battery temperatures.

In this embodiment, when the battery is not in the EIS working condition, the control current is charged with the preset request current, and the current working condition is converted into the EIS working condition by mathematical conversion according to the current and the voltage shown by the battery in the charging process, so as to simulate the impedance of the battery cell in the EIS working condition. Then based on the current temperature and the electric quantity of the battery and the simulated impedance of the battery core, the current SOH of the battery is obtained through table lookup, the detection speed is very fast, and the accuracy is high. The battery can conveniently detect SOH in any state by adopting the mode, and the application range is wide.

detecting electrical parameters of the battery in a charging process, wherein the electrical parameters comprise current, voltage and current electric quantity of the battery;

determining model parameters of a preset electrochemical model from a mapping relation between the preset electrical parameters and model parameters based on the electrical parameters;

and determining the current SOH of the battery based on the model parameters of the preset electrochemical model.

In this embodiment, when the battery is not under the EIS working condition, the control current is charged with the preset request current, according to the current, the voltage and the electric quantity shown by the battery in the charging process, the model parameter corresponding to the electrical parameter is determined from the mapping relation between the pre-configured electrical parameter and the model parameter, and then the current SOH of the battery is calculated based on the determined model parameter. The battery can conveniently detect SOH in any state by adopting the mode, the applicable application scene is wide, and the detection speed is high based on an electrochemical model, so that the accuracy is high.

In some embodiments, the determining the current SOH of the battery based on the model parameters of the preset electrochemical model includes:

calculating the current SOH of the battery through the preset electrochemical model according to the electrical parameters and the determined model parameters; or according to the determined model parameters, acquiring SOH corresponding to the model parameters from a preset mapping relation between the model parameters and the SOH as the current SOH of the battery.

In this embodiment, after determining the corresponding model parameters based on the electrical parameters of the battery, the model parameters are directly substituted into the corresponding preset electrochemical model to calculate the SOH, so that the SOH of the battery can be rapidly calculated, and the calculation accuracy is high. Based on the determined model parameters, the SOH of the battery is obtained by looking up a table from the mapping relation between the preconfigured model parameters and the SOH, so that the calculation resources of a control module are saved, the detection speed is faster, and the accuracy is higher.

controlling the battery to discharge to a preset cut-off state at a second preset temperature included in the working condition parameters corresponding to the target detection working condition; and after the first preset time period included in the working condition parameters is kept stand, the battery is charged to a preset full charge state based on the preset charging parameters included in the working condition parameters, and the second preset time period included in the working condition parameters is kept stand.

In this embodiment, the battery is controlled to be discharged to a preset cut-off state, and the battery is allowed to stand for a period of time, so that the electric quantity of each electric core in the battery reaches a stable state. And then controlling the battery to charge to a preset full charge state, and standing for a period of time to enable the electric quantity of each electric core in the battery to reach a stable state. So be convenient for detect the electric quantity difference condition of every electric core under the very low condition of electric quantity to and detect the electric quantity difference condition of every electric core under the very high condition of electric quantity, and calculate the SOH of battery based on this, realized that consumer and charge and discharge machine cooperation charge and discharge, and detect battery SOH under the charge and discharge operating mode, and can improve the precision that detects SOH greatly.

detecting a first residual electric quantity of each electric core in the battery when discharging and standing for the first preset time period; detecting the charging capacity of the battery and the second residual electric quantity of each electric core when the battery is charged to the preset full charge state and is kept stand for the second preset time period; and calculating the current SOH of the battery according to the charging capacity, the first residual electric quantity and the second residual electric quantity of each battery core.

In this embodiment, the first residual electric quantity of each electric core can represent the electric quantity difference between the electric cores when the electric cores are discharged to a preset cut-off state, the second residual electric quantity of each electric core can represent the current difference between the electric cores when the electric cores are charged to a preset full-charge state, the total charge capacity of the battery from the preset cut-off state to the preset full-charge state can represent the whole capacity of the battery, the current SOH of the battery is calculated based on the three electric cores, and the accuracy of the SOH can be improved to the greatest extent.

In some embodiments, before the responding to the SOH detection instruction, the method further comprises:

triggering an SOH detection instruction when the battery is detected to meet a first preset abnormal condition, wherein the first preset abnormal condition comprises that the battery has a battery core water jump phenomenon or the battery does not detect SOH when exceeding a preset time.

In this embodiment, the control module detects that the battery meets the first preset abnormal condition and triggers the SOH detection instruction, so that the SOH detection process can be automatically started when some abnormal conditions occur in the electric equipment or the battery, and the automation degree of equipment maintenance is improved. When the electric equipment or the battery is abnormal, SOH detection is timely carried out, so that the accuracy of calculation processes such as charge state estimation, power estimation, charging rate determination and the like based on SOH can be improved, and the condition that the battery or the electric equipment is damaged due to inaccurate SOH is reduced. Specifically, for example, when the battery core water-jump phenomenon is detected, an SOH detection instruction is triggered, so that the SOH of the battery can be timely detected and calibrated when the battery core water-jump phenomenon is detected, the battery core water-jump cause can be diagnosed based on the calibrated SOH, and the battery can be more accurately controlled based on the calibrated SOH. For another example, when it is detected that the battery does not detect SOH for a long time, it indicates that the SOH recorded in the current control module is likely to be inconsistent with the current actual situation of the battery, and at this time, the SOH detection instruction is triggered, so that the SOH recorded in the control module can be calibrated, the accuracy of the recorded SOH is improved, and the accuracy of battery control based on the SOH is further improved.

receiving an SOH detection instruction sent by a user; or receiving an SOH detection instruction sent by the server when a second preset abnormal condition is detected to be met, wherein the second preset abnormal condition comprises that the battery has a battery core water jump phenomenon, and the deviation between the server and SOH detected by equipment where the battery is located exceeds a preset threshold value, or the battery has an outlier phenomenon under a certain working condition.

In the embodiment, when the user needs to perform SOH detection, the SOH detection instruction can be sent through the user terminal, or the SOH detection instruction is directly submitted by operation on the electric equipment, so that the requirement of the user on SOH detection in any scene can be met, and the convenience of SOH detection triggered by the user is improved. SOH is detected and calibrated in time when a user needs, so that the user can grasp the SOH of the battery in time, and the method is beneficial to evaluating the residual value of the electric equipment or the battery based on the calibrated SOH. Meanwhile, the SOH recorded in the control module can be calibrated, so that the accuracy of the recorded SOH is improved, and the accuracy of battery control based on the SOH is further improved. Or the server monitors that the second preset abnormal condition is met and issues an SOH detection instruction, so that the server side triggers the detection of the SOH of the battery when the electric equipment or the battery is detected to be abnormal, and the degree of automation of equipment maintenance is improved. When abnormal conditions occur, SOH detection is timely carried out, so that the accuracy of calculation processes such as charge state estimation, power estimation, charging multiplying power determination and the like based on SOH can be improved, and the condition that faults of batteries or electric equipment are caused due to inaccurate SOH is reduced. And the method is beneficial to keeping the consistency of the electric equipment and the SOH of the battery recorded by the server, improving the accuracy of controlling the electric equipment by the server side based on the SOH, and improving the accuracy of data analysis and model optimization by the server side based on the SOH.

In some embodiments, after detecting the current SOH of the battery under the target detection condition, the method further includes:

and modifying the SOH of the battery which is currently stored into the SOH which is currently detected.

In this embodiment, the SOH of the currently stored battery is modified to the currently detected SOH. Therefore, SOH recorded in the electric equipment is corrected, and SOH precision of the electric equipment is calibrated, so that the service performance and safety performance of the electric equipment are better.

and correcting model parameters of a preset electrochemical model according to the SOH currently detected.

In the embodiment, based on the currently detected battery SOH, the model parameters of the preset electrochemical model in the electric equipment are reversely corrected, so that the accuracy of the model parameters is improved, the accuracy of calculation based on the preset electrochemical model is further improved, and the accuracy of battery control is improved.

and sending the SOH currently detected to a server so that the server trains a neural network model for detecting the SOH based on the SOH to correct model parameters of a preset electrochemical model in the server.

In this embodiment, the currently detected SOH is sent to the server. And the server receives the SOH detected by the electric equipment terminal and replaces the currently recorded SOH of the electric equipment with the currently received SOH corresponding to the electric equipment. In addition, the server corrects the model parameters of each preset electrochemical model in the server based on the received SOH, and the specific correction mode is the same as the mode of correcting the model parameters at the electric equipment end, which is not described herein again. In addition, the server also records the mapping relation between the current operation working condition of the electric equipment and the current detected SOH, and can specifically record the mapping relation between the working condition parameters of the current operation working condition and the detected SOH. The server can receive SOH sent by a plurality of electric equipment and record the mapping relation between a plurality of working condition parameters and SOH. The server may use each operating mode parameter and SOH as one sample, and form a training set from a plurality of samples, and train a neural network model for estimating SOH through the training set. After the server trains the neural network model, the neural network model can be configured on electric equipment or the server, and then the corresponding SOH can be automatically output only by inputting working condition parameters into the neural network model, so that the SOH detection efficiency and convenience are improved. And as the mapping relation between the collected working condition parameters and the detected SOH is more and more, the neural network model trained before can be optimized based on the collected data, so that the accuracy of the neural network model is improved.

In a second aspect, an embodiment of the present application provides a battery SOH detection apparatus, including:

the determining module is used for responding to the SOH detection instruction and determining a target detection working condition corresponding to the detection instruction;

the detection module is used for controlling the battery to run the target detection working condition and detecting the current SOH of the battery under the target detection working condition.

In a third aspect, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the method according to the first aspect when executing the computer program.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program which, when executed by a processor, implements a method according to the first aspect.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flowchart of a battery SOH detection method according to an embodiment of the present application.

Fig. 2 is another flowchart of a battery SOH detection method according to an embodiment of the present application.

Fig. 3 is a schematic diagram of a discharging process in the process of detecting SOH under the charging and discharging conditions according to the embodiment of the present application.

Fig. 4 is a schematic diagram of a charging process in the process of detecting SOH under a charging and discharging condition according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a battery SOH detection device according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like are merely used for convenience in describing the present application and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

The directional terms appearing in the following description are those directions shown in the drawings and do not limit the specific structure of the application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

Currently, the more widely the battery is used in view of the development of market situation. The battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles, and the like, as well as a plurality of fields such as military equipment, aerospace, and the like. In the fields of electric traffic supply, military equipment, aerospace, etc., power is typically provided by batteries.

The state of health SOH of a battery is one of important parameters of the battery, and plays an important role in estimating the state of charge of the battery, estimating power, determining the charging rate, controlling the whole life state of the battery, and the like. Therefore, the SOH of the battery is often required to be detected in the process of using the battery by the electric equipment. In the related art, when the capacity decay of the battery is detected to reach a certain threshold, the battery is subjected to charge-discharge calibration to obtain a new capacity value, and the SOH of the battery is determined according to the new capacity value.

The inventors of the present application have found that, in the course of studying the detection method of SOH of a battery, under different aging paths, the accuracy of estimating SOH in the above-described related art may become larger as the battery ages. In addition, the SOH of the battery is monitored through simple maintenance capacity, and the SOH detection requirement under various working conditions is difficult to meet. Moreover, the detection mode of the related art is only used for an energy storage system, and has a great limiting effect.

In order to provide a battery SOH detection method suitable for various working conditions aiming at different ageing paths. Through intensive research, the inventor of the application designs a battery SOH detection method, and the method responds to an SOH detection instruction to determine a target detection working condition corresponding to the detection instruction; and controlling the battery to run the target detection working condition, and detecting the current SOH of the battery under the target detection working condition.

The method designs different target detection working conditions for SOH detection instructions in different application scenes. After receiving a detection instruction triggered in a certain application scene, determining a target detection working condition corresponding to the detection instruction. And then controlling the battery to run under the target detection working condition, and detecting the SOH of the battery under the target detection working condition. Therefore, the adopted detection strategy for detecting the SOH of the battery is matched with the current application scene, and the aging paths of the battery in different application scenes are different, so that the adopted detection strategy is matched with the aging paths of the battery, and the situation that the detection precision is increased along with the aging of the battery in different aging paths by using the same detection mode is avoided. And for different detection instructions, the SOH of the battery is detected under different target detection working conditions, so that the detection requirements of SOH under various working conditions can be met. And the method is not only suitable for the energy storage system, but also suitable for detection requests of a vehicle end, a server end or a user end, and has the advantages of small limitation and high universality.

The battery SOH detection method provided by the embodiment of the application can be applied to any battery, and the battery can be a single battery core, a battery pack or a battery pack formed by a plurality of single battery cores, and the like. The electric equipment to which the method provided by the embodiment of the application can be applied can be, but is not limited to, an electric toy with a battery, an electric tool, a battery car, an electric car, a ship, a spacecraft and the like. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

The electric equipment can be in communication connection with a server, and the server can be a single physical server device, a server cluster formed by a plurality of devices, or cloud servers of public cloud and private cloud, and the like. The electric equipment can receive the SOH detection instruction sent by the server and detect the SOH of the battery by the method of the embodiment of the application. The electric equipment can also be in communication connection with user terminals such as mobile phones, tablet computers and notebook computers of users, and can receive SOH detection instructions sent by the users through the user terminals and detect SOH of the battery through the method of the embodiment of the application. Or, the control module in the electric equipment can also provide an interface for triggering the SOH detection instruction for the user, and the user can submit the SOH detection instruction to the electric equipment through the interface. For example, a key to initiate SOH detection may be displayed on a center console of the electric vehicle, which a user may click to submit SOH detection instructions to the electric vehicle. The electric equipment can be connected with charge and discharge equipment in places such as a charging station or a power exchange station and the like, and receives SOH detection instructions triggered by the charge and discharge equipment. The charging and discharging equipment can be a charging pile, a charging and discharging machine and the like. The electric equipment can be connected with maintenance equipment, and receives an SOH detection instruction triggered by the maintenance equipment.

The above-mentioned electric equipment is listed as a plurality of application scenarios in which the electric equipment is connected with other equipment and receives SOH detection instructions triggered by other equipment, but the application is not limited to the above-mentioned application scenarios, and any other application scenario capable of triggering SOH detection can be used for detecting SOH of the battery according to the method provided by the embodiment of the application, including SOH detection actively triggered by the control module of the electric equipment based on the states of the electric equipment and/or the battery.

The specific process of detecting SOH of a battery according to the present application will be described in detail by means of specific examples. The embodiment of the application provides a battery SOH detection method, which comprises the steps of firstly determining a target detection working condition corresponding to a detection instruction after receiving the SOH detection instruction. And then controlling the battery to run under the target detection working condition, and detecting the SOH of the battery under the target detection working condition. If the battery aging path is used in different application scenes, different detection modes are adopted, and the situation that the detection precision is increased along with battery aging under different aging paths by using the same detection mode is avoided. For different detection instructions, the SOH of the battery is detected under different target detection working conditions, and the detection requirements of SOH under various working conditions can be met. The method is not only suitable for the energy storage system, but also suitable for detection requests of the vehicle end, the server end or the user end, and has small limitation and high universality.

Referring to a flowchart of a battery SOH detection method shown in fig. 1, the method specifically includes the following steps:

and 101, responding to the SOH detection instruction, and determining a target detection working condition corresponding to the detection instruction.

The execution main body of the embodiment of the application is electric equipment or a control module in the electric equipment and the like. The control module may be a BMS (Battery Managment System, battery management system), VCU (Vehicle Control Unit ), DC (Domain Controller, domain controller), or the like. The embodiment of the application takes the execution main body as a control module as an example for detailed description.

The SOH detection method of the embodiment of the application can be applied to various application scenes needing to detect the SOH of the battery, and the embodiment of the application divides the various application scenes into three types of electric equipment, a user side and a server side according to different sources of detection instructions, wherein the division mode is only used as an example, other division modes can be adopted in practical application, and application scenes from other sources except the three ends can be adopted in practical application, so that the method is not enumerated one by one.

The detection instruction from the end of the electric equipment where the battery is located can be monitored in real time by the control module of the electric equipment, and the SOH detection instruction is triggered when the battery is monitored to meet the first preset abnormal condition. The first preset abnormal condition comprises that the battery has a battery core water jump phenomenon or the battery exceeds a preset time period and SOH detection is not carried out. The preset time period can be 3 months, 5 months or half a year, etc.

For example, when the BMS monitors that the battery cell has an electrical quantity suddenly decreasing in a short time, it confirms that a cell water jump phenomenon occurs, and at this time, the BMS triggers an SOH detection command. For another example, a preset calculation condition required to be met by triggering the SOH detection battery is preconfigured in the BMS, the preset calculation condition may include a certain state of charge SOC, a specific battery temperature, and the like, and if the BMS monitors that the battery does not reach the preset calculation condition for a preset time, the SOH detection instruction is triggered.

The first preset abnormal condition may further include any other situation that the electric device actively triggers the SOH detection instruction, for example, when the VCU monitors that the electric vehicle has a running mileage decay, the SOH detection instruction is triggered, which is not listed here.

The control module monitors that the battery meets the first preset abnormal condition and triggers the SOH detection instruction, so that the SOH detection process can be automatically started when electric equipment or the battery has some abnormal conditions, and the degree of automation of equipment maintenance is improved. When the electric equipment or the battery is abnormal, SOH detection is timely carried out, so that the accuracy of calculation processes such as charge state estimation, power estimation, charging rate determination and the like based on SOH can be improved, and the condition that the battery or the electric equipment is damaged due to inaccurate SOH is reduced. Specifically, for example, when the battery core water-jump phenomenon is detected, an SOH detection instruction is triggered, so that the SOH of the battery can be timely detected and calibrated when the battery core water-jump phenomenon is detected, the battery core water-jump cause can be diagnosed based on the calibrated SOH, and the battery can be more accurately controlled based on the calibrated SOH. For another example, when it is detected that the battery does not detect SOH for a long time, it indicates that the SOH recorded in the current control module is likely to be inconsistent with the current actual situation of the battery, and at this time, the SOH detection instruction is triggered, so that the SOH recorded in the control module can be calibrated, the accuracy of the recorded SOH is improved, and the accuracy of battery control based on the SOH is further improved.

And when the user finds that the electric equipment can not calibrate the SOH of the battery under the condition that the SOH detection instruction is from the user side. Alternatively, the user does not use the powered device for a long time, resulting in the BMS being powered off for a long time. Alternatively, for an electric vehicle, the user finds that the electric vehicle is experiencing a mileage decay. Alternatively, when the user needs to purchase or sell a second-hand electric vehicle, the SOH of the battery needs to be evaluated. The SOH detection command originates from the user side, and is not limited to those listed here, but any other case triggered by the user is applicable.

An application program associated with the electric equipment can be installed on a user terminal such as a mobile phone or a computer of a user, and an interface for triggering an SOH detection instruction is arranged in the application program. Under the condition that any user needs to detect SOH, the user triggers an SOH detection instruction through an interface provided by the application program on the user terminal, and the user terminal sends the SOH detection instruction to the electric equipment.

Or, a mechanical key for triggering SOH detection is arranged on the electric equipment, or a key for triggering SOH detection is arranged in an interface displayed on a display screen of the electric equipment. Under the condition that any user needs to detect SOH, the user triggers SOH detection by operating the keys, and when the electric equipment detects the operation events of the keys, the SOH detection instruction submitted by the user is determined to be received.

When the user needs to detect SOH, the SOH detection instruction can be sent through the user terminal, or the SOH detection instruction is directly submitted by operation on the electric equipment, so that the requirement of the user for detecting SOH in any scene can be met, and the convenience of the user for triggering detection of SOH is improved. SOH is detected and calibrated in time when a user needs, so that the user can grasp the SOH of the battery in time, and the method is beneficial to evaluating the residual value of the electric equipment or the battery based on the calibrated SOH. Meanwhile, the SOH recorded in the control module can be calibrated, so that the accuracy of the recorded SOH is improved, and the accuracy of battery control based on the SOH is further improved.

And when the server detects that the second preset abnormal condition is met, sending the SOH detection instruction to the electric equipment. And the electric equipment receives the SOH detection instruction sent by the server. The second preset abnormal condition comprises that the battery generates a battery core water jump phenomenon, the deviation between the server and SOH detected by the electric equipment where the battery is located exceeds a preset threshold value, or the SOH of the battery under a certain working condition generates an outlier phenomenon, and the like.

In the embodiment of the application, for the batteries with the same model applied to the same type of electric equipment, the server counts SOH of the batteries under various working conditions. For the same conditions, the SOH of these cells will be concentrated in a span smaller than the span. If the server detects that the SOH of the battery of the electric equipment under a certain working condition is not in the SOH interval of the battery of the same type under the working condition, the server determines that the SOH of the battery under the working condition is in an outlier phenomenon.

The second preset abnormal condition may further include any other situation that the server issues an SOH detection instruction, for example, when the server monitors that the electric vehicle has a running mileage decay, the embodiment of the present application is not listed here.

And when the server monitors that the second preset abnormal condition is met, a SOH detection instruction is issued, so that the server triggers the detection of the SOH of the battery when the electric equipment or the battery is detected to be abnormal, and the degree of automation of equipment maintenance is improved. When abnormal conditions occur, SOH detection is timely carried out, so that the accuracy of calculation processes such as charge state estimation, power estimation, charging multiplying power determination and the like based on SOH can be improved, and the condition that faults of batteries or electric equipment are caused due to inaccurate SOH is reduced. And the method is beneficial to keeping the consistency of the electric equipment and the SOH of the battery recorded by the server, improving the accuracy of controlling the electric equipment by the server side based on the SOH, and improving the accuracy of data analysis and model optimization by the server side based on the SOH.

And for the SOH detection instruction triggered in any scene such as the electric equipment side, the server side, the user side and the like, the control module of the electric equipment responds to the SOH detection instruction and starts to detect the current SOH of the battery. First, the control module determines a target detection condition corresponding to the detection instruction.

In the embodiment of the application, the precision requirements of different application scenes on SOH detection are different, the precision requirements of some application scenes on SOH detection are very high, the time required for detection is relatively long under the condition of high precision requirements, and if the battery SOH needs to be accurately detected under the scene that the consumer residual value needs to be evaluated in the business of second-hand consumers. The accuracy requirement of the application scene on SOH detection is not so high, the detection time is relatively short under the condition of relatively low accuracy requirement, if a user does not use electric equipment for a long time, and the battery SOH needs to be detected rapidly when the user uses the battery SOH again.

Considering that the requirements of different application scenes on the detection precision are different, the application scenes are divided into two types, one type is the application scene requiring very high detection precision, and the other type is the application scene with less high detection precision requirement. The embodiment of the application is pre-configured with the scene identifications corresponding to the two types of application scenes, wherein the scene identifications are used for identifying the application scenes needing SOH detection currently, and the scene identifications can be character strings. For example, 00 identifies an application scenario with high accuracy requirements, and 01 identifies an application scenario with relatively low accuracy requirements. Corresponding to the classification situation of the application scene, the embodiment of the application classifies a plurality of detection working conditions for detecting the SOH of the battery, wherein one type of detection working conditions is used for rapidly detecting the SOH of the battery, and the detection precision is relatively low. Another type of detection condition is for accurately detecting SOH of the battery, with high accuracy, but relatively long detection times. Each type of detection condition includes at least one detection condition.

The server and the electric equipment can be preset with the discrimination conditions of the application scene requiring very high precision, and the discrimination conditions can be the phenomenon of battery core diving, mileage attenuation and the like. When the server and the electric equipment detect that the current application scene meets the preset judging conditions, the current application scene is determined to be the application scene requiring very high precision, otherwise, the current application scene belongs to the application scene with relatively low precision requirements. After the server or the electric equipment determines the category to which the current application scene belongs, the triggered SOH detection instruction carries the scene identifier corresponding to the determined category.

For the SOH detection instruction from the user side, because the detection instruction is actively triggered by the user, the user can determine whether higher detection precision is required or battery SOH is required to be obtained quickly according to own requirements, and the requirement on precision is not so high. The interface of the application program in the user terminal can provide a scene selection interface for the user, and the user can select the scene identification meeting the own requirements through the scene selection interface. Or, keys corresponding to scenes with different precision requirements can be set on the electric equipment, or the interface displayed by the display screen of the electric equipment can comprise selection keys corresponding to the scenes with different precision requirements, and a user can autonomously select keys meeting the precision requirements when submitting the SOH detection instruction directly from the electric equipment. The SOH detection instruction triggered by the user also carries a corresponding scene identifier.

After receiving the SOH detection instruction, the control module of the electric equipment analyzes the scene identification from the detection instruction. And determining a target detection working condition corresponding to the scene identifier according to the scene identifier included in the detection instruction. The control module of the electric equipment is preconfigured with mapping relations between different scene identifications and at least one detection working condition. After determining the scene identifier carried in the current detection instruction, the control module can acquire each detection working condition corresponding to the scene identifier from the preset mapping relation, and then randomly select one detection working condition from each detection working condition corresponding to the scene identifier as the target detection working condition to be adopted currently.

In the embodiment of the application, the working condition refers to the working state of the battery, and in the mapping relation between the scene identifier and the detection working condition, the working condition parameters of the detection working condition are stored, wherein the working condition parameters comprise parameters such as the temperature, the current, the voltage, the SOC and the like of the battery when the battery runs under the detection working condition.

The application scenes are classified according to the precision requirement, and at least one detection working condition corresponding to each type of application scene is set. In the embodiment, the application scene can be classified according to other classification conditions in practical application, and detection working conditions corresponding to each type can be set. Different application scenes are represented by scene identifiers, and detection working conditions corresponding to each scene identifier are preconfigured. When the SOH detection instruction is received, determining a target detection working condition to be used according to a scene identifier carried by the detection instruction, and then detecting the current SOH of the battery based on the target detection working condition. So realized that different application scenes adopt different detection operating modes to detect SOH, avoided all using the same detection mode to lead to the problem that detection accuracy is low under the different application scenes, be applicable to various scenes that need to detect SOH moreover, the universality is very high.

And 102, controlling the battery to run the target detection working condition, and detecting the current SOH of the battery under the target detection working condition.

After determining the target detection working condition corresponding to the current detection command through step 101, working condition parameters of the target detection working condition are obtained, and the battery is controlled to run under the target detection working condition based on the working condition parameters corresponding to the target detection working condition. And determining the current SOH of the battery based on the electrical parameters of the battery under the target detection working condition.

And controlling the battery to run under a target detection working condition, and calculating the current SOH of the battery through the electrical parameters shown by the battery under the target detection working condition. Because the target detection working condition is matched with the scene identification, SOH is detected through the electrical parameters of the battery under the target detection working condition, and the detection mode is suitable for the current application scene and is beneficial to improving the accuracy of SOH detection under the application scene.

The embodiment of the application exemplarily provides a plurality of detection working conditions for detecting SOH, and the following specific description is given respectively.

In a first embodiment, the target detection regime includes an EIS (Electrochemical Impedance Spectroscopy ) regime. After determining that the target detection working condition corresponding to the current detection instruction is the EIS working condition through step 101, working condition parameters of the EIS working condition are obtained from a mapping relation between a pre-configured scene identifier and the detection working condition, wherein the working condition parameters comprise preset electric quantity and first preset temperature which are required to be reached by the battery under the EIS working condition. The control module adjusts the electric quantity of the battery to the preset electric quantity and adjusts the temperature of the battery to the first preset temperature based on the preset electric quantity and the first preset temperature included in the working condition parameters corresponding to the EIS working condition.

The preset electric quantity can be represented by a battery charge State (SOC), and the preset electric quantity can represent 50% or 60% of SOC and the like. The first preset temperature may be 25 ℃ or 28 ℃ or the like. The embodiment of the application does not limit the specific value of the preset electric quantity and the first preset temperature, and can be set according to the requirements in practical application.

Specifically, if the current electric quantity of the battery is greater than the preset electric quantity, the control module can control the battery to discharge so as to reduce the electric quantity of the battery to the preset electric quantity. If the current of the battery is smaller than the preset electric quantity, the control module can control the battery to charge so that the current of the battery is increased to the preset electric quantity. If the current temperature of the battery is higher than the first preset temperature, the control module can control the cooling module in the electric equipment to cool the battery, so that the temperature of the battery is reduced to the first preset temperature. If the current temperature of the battery is lower than the first preset temperature, the control module can control the heating module in the electric equipment to heat the battery, so that the temperature of the battery is increased to the first preset temperature. The heating module and the battery form a charge-discharge loop, and the battery is self-heated by alternately charging or discharging. Alternatively, the heating module may be an external heating module.

Under EIS working condition, the control module adjusts the battery electric quantity to the preset electric quantity, and after adjusting the battery temperature to the first preset temperature, executes current negative pulse with preset frequency on the battery. The preset frequency range may be 1-100hz, and the specific value of the preset frequency is related to the battery core characteristics of the battery.

In the process of executing the current negative pulse with the preset frequency on the battery, the electric energy emitted by the battery can be discharged to electric loads such as electric lamps, air conditioners, sound equipment and the like on the electric equipment. Or the electric equipment can be connected with the charging and discharging machine, and the charging and discharging machine can charge the battery and also can receive the discharge of the battery. The electric energy discharged by the battery executing the current negative pulse can be discharged to the charging and discharging machine.

In the process of detecting the SOH of the battery under the EIS working condition, the negative current pulse discharging is performed on the battery according to the preset frequency, so that the battery is under the negative current pulse working condition in the EIS working condition, and the battery cell impedance and the SOH of the battery have strong correlation under the working condition, so that the battery is controlled to be under the working condition, and the current SOH of the battery can be accurately detected.

And controlling the battery to be in an EIS working condition, detecting the impedance of the battery cell under the current negative pulse in the process of executing the current negative pulse on the battery according to the preset frequency, and particularly, calculating the impedance of the battery cell under the current negative pulse according to the detected impedance phase angle and impedance amplitude by detecting the impedance phase angle and the impedance amplitude of the battery cell under the current negative pulse. And acquiring corresponding SOH from a preset SOH lookup table according to the preset electric quantity, the first preset temperature and the battery cell impedance under the EIS working condition, and determining the acquired SOH as the current SOH of the battery. The preset SOH lookup table comprises mapping relations between battery cell impedance and SOH under different battery electric quantity and battery temperature.

The embodiment of the application presets a preset SOH lookup table, and the mapping relation of the battery electric quantity, the battery temperature, the battery core impedance and the SOH is stored in the lookup table. And when the battery is controlled to be under a current negative pulse working condition in an EIS working condition, inquiring SOH related to the preset electric quantity, the first preset temperature and the electric core impedance from a preset SOH inquiry table according to the preset electric quantity and the first preset temperature corresponding to the EIS working condition and the electric core impedance detected under the current working condition. The current SOH of the battery is obtained based on the battery cell impedance table look-up shown by the battery by controlling the battery to be in the current negative pulse working condition in the EIS working condition, so that the detection speed is high and the accuracy is high.

In a second embodiment, the battery is controlled to be charged with the preset request current based on the preset request current included in the working condition parameters corresponding to the target detection working condition. Namely, when the electric equipment is connected with the charging equipment (such as a charging pile or a charging and discharging machine) and the battery is in any state, the battery can be charged by the BMS through a request of a preset current, so that the battery runs under a target detection working condition, and the battery is controlled to be in the working condition and can accurately calculate the current SOH of the battery based on the electrical parameters of the battery under the working condition.

In one implementation manner of the second embodiment, during the process of charging the battery with a preset request current, electrical parameters such as current, voltage, current electric quantity and current battery temperature of the battery during the charging process are detected, based on the detected current and voltage, the current working condition is converted into the EIS working condition through a wavelet transformation algorithm, and the cell impedance of the battery under the EIS working condition is calculated. The control module is pre-configured with a preset SOH lookup table which comprises mapping relations between battery cell impedance and SOH under different battery electric quantity and battery temperature. And acquiring corresponding SOH from a preset SOH lookup table according to the current electric quantity, the current battery temperature and the battery cell impedance, and taking the acquired SOH as the current SOH of the battery.

When the battery is not in the EIS working condition, the control current is charged with a preset request current, the current working condition is converted into the EIS working condition through mathematical transformation according to the current and the voltage shown by the battery in the charging process, and the impedance of the battery core under the EIS working condition is simulated. Then based on the current temperature and the electric quantity of the battery and the simulated impedance of the battery core, the current SOH of the battery is obtained through table lookup, the detection speed is very fast, and the accuracy is high. The battery can conveniently detect SOH in any state by adopting the mode, and the application range is wide.

In another implementation manner of the second embodiment, during the process of charging the battery with the preset request current, an electrical parameter of the battery during the charging process is detected, where the electrical parameter includes a current, a voltage, a current electric quantity of the battery, and the current electric quantity may be a current SOC of the battery. Based on the detected electrical parameters, determining model parameters of a preset electrochemical model from a mapping relation between the preset electrical parameters and the model parameters. And determining the current SOH of the battery based on model parameters of a preset electrochemical model.

The preset electrochemical model may be any model configured in the control module, such as an electrochemical model for estimating SOH, an electrochemical model for internally fusing SOH, an aging experience model for estimating battery aging, an impedance model for researching cell impedance, a characteristic parameter model for estimating characteristic parameters of the battery, and the like.

The mapping relation between the electrical parameters and the model parameters of the battery is pre-configured in the control module, and the mapping relation between the electrical parameters and the electrochemical models can be respectively configured for different electrochemical models. The expression form of the mapping relation can be a list, a mapping curve, a calculation formula or the like.

When the battery is not in the EIS working condition, the control current is charged with a preset request current, according to the current, voltage and electric quantity shown by the battery in the charging process, the model parameters corresponding to the electrical parameters are determined from the mapping relation between the pre-configured electrical parameters and the model parameters, and then the current SOH of the battery is calculated based on the determined model parameters. The battery can conveniently detect SOH in any state by adopting the mode, the applicable application scene is wide, and the detection speed is high based on an electrochemical model, so that the accuracy is high.

The method for determining the current SOH of the battery based on the model parameters of the preset electrochemical model specifically includes calculating the current SOH of the battery through the preset electrochemical model according to the current electrical parameters of the battery and the determined model parameters. In the implementation mode, the preset electrochemical model is an electrochemical model for estimating SOH, after the model parameters of the electrochemical model for estimating SOH are determined according to the current electrical parameters, the parameters of the electrochemical model are replaced by the determined model parameters, and then the current electrical parameters of the battery are substituted into the electrochemical model with the replaced model parameters, so that the current SOH of the battery is calculated.

Or, in another specific implementation manner, the mapping relation between the model parameters and the SOH, which is obtained through a plurality of experimental tests, is preconfigured in the control module. After the model parameters of the preset electrochemical model are determined according to the current electrical parameters of the battery, according to the determined model parameters, SOH corresponding to the model parameters is obtained from the mapping relation between the preset model parameters and the SOH to serve as the current SOH of the battery.

After the corresponding model parameters are determined based on the electrical parameters of the battery, the model parameters are directly substituted into the corresponding preset electrochemical model to calculate SOH, so that the SOH of the battery can be rapidly calculated, and the calculation accuracy is high. Based on the determined model parameters, the SOH of the battery is obtained by looking up a table from the mapping relation between the preconfigured model parameters and the SOH, so that the calculation resources of a control module are saved, the detection speed is faster, and the accuracy is higher.

In a third embodiment, battery SOH is calculated based on electrical parameters of the charge-discharge process by controlling the charge-discharge of the battery. Specifically, when the electric equipment is connected with the charging and discharging machine, the battery is controlled to discharge to a preset cut-off state at a second preset temperature included in the working condition parameters corresponding to the target detection working condition; after a first preset time period included in the standing working condition parameters, charging the battery to a preset full charge state based on a preset charging parameter included in the working condition parameters, and a second preset time period included in the standing working condition parameters.

Wherein the second preset temperature may be 25 ℃ or 28 ℃ or the like. The first preset time length and the second preset time length can be the same or different, and the first preset time length and the second preset time length can be 3h, 3.5h, 4h and the like. The preset charging parameters may include charging rates in charging stages of constant-current charging, constant-voltage charging, and the like, for example, the charging rates in the constant-current charging stages may be 0.30c, 0.33c, and the like, and the constant-current charging rates after the constant-voltage charging is completed may be 0.04c, 0.05c, and the like. The embodiment of the application does not limit the specific values of the second preset temperature, the first preset time, the second preset time and the preset charging parameters, and can be set according to the requirements in practical application.

The preset cut-off state is that a first empty cell appears in a plurality of cells included in the battery. When the first discharged battery cell appears, the battery is determined to reach a preset cut-off state, and the discharge is stopped at the moment, so that the over-discharge condition of the discharged battery cell is avoided. The preset full charge state is that a first full charge core appears in a plurality of battery cores included in the battery, when the first full charge core appears, the battery is determined to reach the preset full charge state, and charging is stopped at the moment, so that the situation that the full charge core is overcharged is avoided.

For example, at 25 ℃, the battery is controlled to discharge until the first empty cell appears, at this time, the discharge is stopped, the battery is charged after standing for 3 hours, and the battery is charged to the cut-off voltage at a charging rate of 0.33 c. And then constant voltage charging is carried out, the request current of the battery is regulated in real time through electrochemical performance in the constant voltage charging process until the charging multiplying power is reduced to 0.05c, the charging is stopped when the first full cell appears in the battery, and the battery is kept stand for 3h.

The cut-off voltage is a voltage threshold value measured through a large number of tests, and when the battery voltage reaches the cut-off voltage in the constant-current charging process, the constant-current charging is continued, so that the charging speed becomes very slow, and the constant-voltage charging is needed to be carried out instead.

The battery is controlled to discharge to a preset cut-off state, and the battery is kept stand for a period of time, so that the electric quantity of each electric core in the battery reaches a stable state. And then controlling the battery to charge to a preset full charge state, and standing for a period of time to enable the electric quantity of each electric core in the battery to reach a stable state. So be convenient for detect the electric quantity difference condition of every electric core under the very low condition of electric quantity to and detect the electric quantity difference condition of every electric core under the very high condition of electric quantity, and calculate the SOH of battery based on this, realized that consumer and charge and discharge machine cooperation charge and discharge, and detect battery SOH under the charge and discharge operating mode, and can improve the precision that detects SOH greatly.

And in the process of controlling the battery to operate under the charge and discharge working conditions, when discharging and standing for a first preset period of time, detecting the first residual electric quantity of each electric core in the battery. And detecting the charge capacity of the battery and the second residual electric quantity of each battery core when the battery is charged to a preset full charge state and is kept stand for a second preset time period. The charge capacity of a battery is the capacity that the battery charges during the entire charging process. And calculating the current SOH of the battery according to the charging capacity, the first residual electric quantity and the second residual electric quantity of each battery core. Specifically, the charging capacity, the first remaining capacity and the second remaining capacity of each battery cell may be added, and the obtained sum value is used as the current SOH of the battery.

The first residual electric quantity of each electric core can represent electric quantity difference between the electric cores when the electric cores are discharged to a preset cut-off state, the second residual electric quantity of each electric core can represent current difference between the electric cores when the electric cores are charged to a preset full-charge state, the total charge capacity of the battery from the preset cut-off state to the preset full-charge state can represent the whole capacity of the battery, the current SOH of the battery is calculated based on the three electric quantities, and the accuracy of the SOH can be improved to the greatest extent.

The detection accuracy of the third embodiment is higher than that of the first and second implementations of the first and second embodiments, and the detection time of the third embodiment is longer than that of the first and second implementations of the first and second embodiments. In practical application, classifying the application scenes according to the detection precision and/or detection time consumption requirements of the application scenes, setting scene identifiers corresponding to each type of application scene, and setting detection working conditions corresponding to each scene identifier. When SOH needs to be detected, determining which mode of the multiple detection modes is adopted for detection according to a scene identifier carried by a triggered SOH detection request and the scene identifier. For example, in a scenario where a second-hand electric vehicle needs to evaluate battery capacity fade, the SOH of the second-hand electric vehicle battery may be accurately detected using the manner of the third embodiment described above. In a scenario where the user does not use the electric vehicle for a long time, the SOH of the electric vehicle battery may be detected using the first or second implementation of the second embodiment described above. When the electric vehicle is currently in the EIS working condition and needs to detect SOH, the mode of the first embodiment can be adopted to detect SOH of the battery.

After the current SOH of the battery is detected by the method provided by the embodiment of the application, the SOH of the battery stored currently is modified into the current detected SOH. Therefore, SOH recorded in the electric equipment is corrected, and SOH precision of the electric equipment is calibrated, so that the service performance and safety performance of the electric equipment are better.

In some embodiments of the application, the control module further corrects model parameters of the preset electrochemical model based on the currently detected SOH. The control module is pre-configured with the mapping relation between the model parameters of each electrochemical model and SOH, after detecting the current SOH of the battery through the process, the control module determines the model parameters corresponding to the SOH based on the mapping relation between the model parameters and the SOH, and then corrects the model parameters of the corresponding electrochemical model according to the determined model parameters. Specifically, the parameters of the internal model at the BMS end, such as the coefficient of the repair aging experience model, the parameters in the electrochemical model for estimating SOH, the parameters of the impedance model, the calculated parameters of the characteristic parameter model, the coefficient of the internal SOH fusion model, and the like can be reversely corrected according to the method.

Based on the currently detected battery SOH, model parameters of a preset electrochemical model in electric equipment are reversely corrected, the accuracy of the model parameters is improved, the accuracy of calculation based on the preset electrochemical model is further improved, and the accuracy of battery control is improved.

In other embodiments of the present application, the control module also sends the currently detected SOH to the server. And the server receives the SOH detected by the electric equipment terminal and replaces the currently recorded SOH of the electric equipment with the currently received SOH corresponding to the electric equipment. In addition, the server corrects the model parameters of each preset electrochemical model in the server based on the received SOH, and the specific correction mode is the same as the mode of correcting the model parameters at the electric equipment end, which is not described herein again. In addition, the server also records the mapping relation between the current operation working condition of the electric equipment and the current detected SOH, and can specifically record the mapping relation between the working condition parameters of the current operation working condition and the detected SOH. The server can receive SOH sent by a plurality of electric equipment and record the mapping relation between a plurality of working condition parameters and SOH. The server may use each operating mode parameter and SOH as one sample, and form a training set from a plurality of samples, and train a neural network model for estimating SOH through the training set. After the server trains the neural network model, the neural network model can be configured on electric equipment or the server, and then the corresponding SOH can be automatically output only by inputting working condition parameters into the neural network model, so that the SOH detection efficiency and convenience are improved. And as the mapping relation between the collected working condition parameters and the detected SOH is more and more, the neural network model trained before can be optimized based on the collected data, so that the accuracy of the neural network model is improved.

In order to facilitate an understanding of the complete process of the method provided by the embodiments of the present application, the following description is provided with reference to the accompanying drawings. As shown in fig. 2, the BMS may request to calculate SOH internally, or some early warning models in the cloud server may request to calculate SOH, and the user may also actively request to calculate SOH. The control module of the electric equipment can be used for carrying out rapid detection based on the impedance of the battery cell under the EIS working condition, or carrying out rapid detection through wavelet analysis, or carrying out detection based on the capacity of the battery cell under the charging and discharging working condition, or carrying out detection based on model parameters of a preset electrochemical model. After detecting the current SOH of the battery, updating and correcting model parameters of each preset electrochemical model in the control module, such as correcting parameters of an SOH attenuation empirical model, updating parameters of an aging electrochemical model, correcting parameters of an electrochemical impedance module, correcting parameters of an SOH characteristic calculation model, correcting parameters of an SOH data fusion model, and the like. The control module also sends the calculated and calibrated SOH to a cloud server, and the cloud server updates and corrects parameters of a preset electrochemical model of the cloud based on the SOH and records data labels between the SOH and corresponding working condition parameters thereof so as to train a neural network model for estimating the SOH based on the collected data labels.

In the embodiment of the application, the target detection working condition corresponding to the SOH detection instruction is determined. And controlling the battery to run under the target detection working condition, and detecting the SOH of the battery under the target detection working condition. Different application scenes and battery aging paths adopt different detection modes, so that the situation that the detection precision is increased along with battery aging under different aging paths by using the same detection mode is avoided. For different detection instructions, the SOH of the battery is detected under different target detection working conditions, so that the detection requirements of SOH under various working conditions can be met, the method is not only suitable for an energy storage system, but also suitable for detection requests of a vehicle end, a server end or a user end, and the detection method is small in limitation and high in universality. SOH recorded by the electric equipment is calibrated based on the detected SOH, and model parameters of an electrochemical model of the electric equipment and/or a cloud end are corrected, so that the control accuracy of the battery or the electric equipment is improved, and the use performance and the safety performance of the electric equipment are improved.

The following specifically describes an example of a method of detecting the SOH of the battery based on the battery capacity of the electric vehicle under the charge/discharge condition. And when the electric vehicle is positioned in the power exchange station or the charging station, the electric vehicle is connected with a charging and discharging machine in the station and a host machine in the station. As shown in fig. 3, the BMS of the electric vehicle wakes up, determines whether the current charge/discharge mode is the in-station mode, and if not, proceeds with the determination step. If so, judging whether the driving mileage, the electricity changing times, the BMS running time and the charge and discharge cycle number are respectively larger than or equal to corresponding threshold values, and judging whether a request of cloud detection SOH is received. As shown in fig. 4, it is determined whether the driving mileage is equal to or more than 10000Km, whether the number of battery replacement times is equal to or more than 90 times, whether the BMS operation time is equal to or more than 3 months, and whether the charge and discharge cycle number is equal to or more than 100. The thresholds may be other values. When the BMS judges that the plurality of judging conditions are not met, the BMS continues to judge the plurality of conditions and sends the state bit of the battery health examination to the host in the station, and when the judging conditions are not met, the sent state bit can be 0. And if one or more of the conditions are judged to be met, sending a state bit of battery health examination to the host computer in the station, wherein the state bit can be 1. After judging that SOH detection is needed to be carried out on the battery of the electric vehicle, the host computer in the station sends an SOH maintenance discharge instruction to the charging and discharging motor, and carries the battery to a maintenance bin, at the moment, the SOH detection instruction can be initiated manually, and the battery is started to discharge through the charging and discharging motor. In this case, the BMS determines whether an SOH detection command transmitted from the in-station host is received, and determines whether the BMS fault level is equal to or less than a set level (e.g., level 5 in fig. 4). If the SOH detection command is received or if the failure level is equal to or lower than the set level, the state machine of the BMS jumps from standby to precharge, and after the precharge is completed, the state machine jumps from precharge to station discharge (discharges). The BMS judges whether the current lowest cell temperature is within a preset interval, such as 23 ℃ -27 ℃. If not, judging whether the time length from the state machine to station discharge to start timing exceeds 30min, and if not, continuously judging whether the lowest cell temperature is within the preset interval. If the time exceeds 30 minutes, the discharging process is ended, the BMS controls the state machine to jump to standby, and reports the maintenance state to the host in the station, wherein the maintenance state indicates that the detecting process is wrong.

And if the lowest battery cell temperature is in the preset temperature interval, controlling the running state of the charge-discharge machine to enter a discharge state, starting to input a negative pulse working condition to the battery for discharging, controlling the discharge multiplying power of the charge-discharge machine to be 0.33 ℃, and controlling the charge-discharge machine to allow the lowest discharge voltage and the highest charge voltage. Reporting the condition of the negative pulse working condition to a host in the station. And judging whether the discharge current I of each electric core in the battery is greater than 0A in the discharge process, if not, further judging whether the duration of the discharge current I which is less than or equal to 0A exceeds the preset duration, and if not, returning to continuously judging whether the discharge current I is greater than 0A. If the duration of the discharge current I is less than or equal to 0A and exceeds the preset duration, ending the discharge and sending a notification message for ending the discharge to the host in the station. If the above-mentioned judgment shows that the discharge current I of each electric core is greater than 0A, then continue discharging, and judge in real time in the course of discharging whether the preset discharge abnormal condition appears, the preset discharge abnormal condition includes receiving the instruction of stopping SOH detection, or whether the A+/A-wake-up source disappears for more than a certain period of time (for example 5 s), or whether the BMS fault level is greater than or equal to a certain level (for example 6 level), or whether the connection with the charging and discharging machine is disconnected, etc. And judging the preset discharge abnormal condition, if a certain condition is met, ending the discharge, and sending a notification message for ending the discharge to the host in the station. If none of the above conditions is satisfied, it is further determined whether the lowest voltage of the battery is equal to or less than a threshold (e.g., whether the lowest voltage of the lithium iron phosphate battery LFP is equal to or less than 2.5v, and whether the lowest voltage of the ternary lithium battery NCM is equal to or less than 2.8 v), and if not, it is returned to continue determining whether the above conditions are satisfied. If yes, the discharging is ended, the running state of the charging and discharging motor is controlled to enter a standby state, and a notification message of the completion of maintenance discharging is reported to a host in the station. After the discharging is finished, the main relay corresponding to the battery is disconnected, and the state machine is jumped to shutdown. After reporting the notification message of the completion of maintenance discharge to the in-station host, the in-station host issues a request instruction for requesting to cut off the low-voltage auxiliary power supply. After the BMS judges that the request instruction is received, the BMS sends a notification of allowing the low-voltage auxiliary power supply to be cut off to the host in the station, and the BMS is powered down at low voltage.

After the above-described discharging process shown in fig. 3 is completed, the charging process shown in fig. 4 is entered. As shown in fig. 4, first the BMS wakes up, and the in-station host transmits an SOH maintenance standby instruction to the BMS. The host computer in the station judges whether the standing time after the discharge is over or not more than a certain time (T is more than or equal to 65min in the figure 4), if not, the host computer in the station continues to stand. If yes, the host in the station sends an SOH maintenance charging instruction to the BMS and the charging and discharging machine. After the BMS judges that the SOH maintenance charging instruction is received, the BMS interactively starts a charging flow with the charging and discharging machine, the state machine of the BMS jumps from standby to precharge, and after the precharge is finished, the state machine jumps to station charge. The BMS judges whether a main charging loop of the battery is closed, if not, the BMS continuously judges whether the main charging loop is closed, if so, a notification message for maintaining charging is sent to a host in the station, and the charging working condition is started. And judging whether a preset charging abnormal condition occurs in real time in the charging process, wherein the preset charging abnormal condition comprises the disconnection of the charging and discharging machine, whether the A+/A-awakening source disappears for more than a certain period of time (such as 5 s), whether a serious charging fault occurs, whether the charging and discharging machine finishes charging, whether an instruction for finishing SOH maintenance is received or not, and the like. If the preset abnormal charging conditions are judged to occur, the charging is ended, the running state of the charging and discharging machine is controlled to enter a standby state, and maintenance state information of maintenance errors is sent to the host in the station. If any abnormal condition is judged not to occur, judging whether the preset full charge state is reached, and if not, continuing to judge whether the abnormal condition occurs in real time. If the state reaches the preset full charge state, the charging is ended, whether an instruction for ending SOH maintenance is received or not is judged, if so, the running state of the charging and discharging machine is controlled to enter a standby state, and maintenance state information of the maintenance end is sent to the host in the station. If the instruction for ending SOH maintenance is not received, standing for a certain period of time (for example, waiting for 65min in fig. 4) after the charging is ended, judging whether the SOH calculation completion flag bit is detected, and if the completion flag bit is not detected, returning to continue waiting. If the completion flag bit is detected, the running state of the charging and discharging machine is controlled to enter a standby state, and maintenance state information of maintenance charging completion is sent to the host in the station. Then the BMS clears the calculation of the driving mileage, the number of battery replacement times, the BMS running time, the number of charge and discharge cycles and the like, and restarts the counting. The BMS turns off the main relay of the battery and the state machine jumps to shutdown. The in-station host may issue a request command requesting to shut down the low voltage auxiliary power. After the BMS judges that the request instruction is received, the BMS sends a notification of allowing the low-voltage auxiliary power supply to be cut off to the host in the station, and the BMS is powered down at low voltage.

In the charging and discharging process, the battery is controlled to be discharged to a preset cut-off state, and the battery is kept stand for a period of time, so that the electric quantity of each electric core in the battery reaches a stable state. And then controlling the battery to charge to a preset full charge state, and standing for a period of time to enable the electric quantity of each electric core in the battery to reach a stable state. So be convenient for detect the electric quantity difference condition of every electric core under the very low condition of electric quantity to and detect the electric quantity difference condition of every electric core under the very high condition of electric quantity, and calculate the SOH of battery based on this, realized that consumer and charge-discharge machine cooperate to charge-discharge, and detect battery SOH under the charge-discharge operating mode, and can improve the precision that detects SOH greatly.

The embodiment of the application also provides a battery SOH detection device, which is used for executing the battery SOH detection method provided by the above embodiments, as shown in fig. 5, and comprises:

a determining module 201, configured to determine a target detection condition corresponding to the detection instruction in response to the SOH detection instruction;

the detection module 202 is configured to control a target detection condition of battery operation, and detect a current SOH of the battery under the target detection condition.

The determining module 201 is configured to determine, according to a scene identifier included in the detection instruction, a target detection working condition corresponding to the scene identifier, where the scene identifier is used to identify an application scene that needs to be currently detected by SOH.

The detection module 202 is configured to control a battery to operate according to a target detection condition; and determining the current SOH of the battery based on the electrical parameters of the battery under the target detection working condition.

The target detection working condition comprises an Electrochemical Impedance Spectrum (EIS) working condition, and the detection module 202 is used for adjusting the electric quantity of the battery to the preset electric quantity and adjusting the temperature of the battery to the first preset temperature based on the preset electric quantity and the first preset temperature included in the working condition parameters corresponding to the EIS working condition; a negative current pulse of a preset frequency is performed on the battery.

A detection module 202 for detecting a cell impedance exhibited by the battery under a negative current pulse; and acquiring corresponding SOH from a preset SOH lookup table according to the preset electric quantity, the first preset temperature and the battery cell impedance, wherein the preset SOH lookup table comprises mapping relations between the battery cell impedance and the SOH under different battery electric quantities and battery temperatures.

The detection module 202 is configured to control the battery to charge with the preset request current based on the preset request current included in the working condition parameters corresponding to the target detection working condition.

The detection module 202 is configured to detect a current, a voltage, a current electric quantity and a current battery temperature of the battery during a charging process; based on the detected current and voltage, calculating the impedance of the battery core of the battery under the EIS working condition; and acquiring corresponding SOH from a preset SOH lookup table according to the current electric quantity, the current battery temperature and the battery cell impedance, wherein the preset SOH lookup table comprises the mapping relation between the battery cell impedance and the SOH under different battery electric quantities and battery temperatures.

The detection module 202 is configured to detect electrical parameters of the battery during the charging process, where the electrical parameters include current, voltage and current electric quantity of the battery; determining model parameters of a preset electrochemical model from a mapping relation between the preset electrical parameters and model parameters based on the electrical parameters; and determining the current SOH of the battery based on model parameters of a preset electrochemical model.

The detection module 202 is configured to calculate a current SOH of the battery according to the electrical parameter and the determined model parameter through a preset electrochemical model; or according to the determined model parameters, acquiring SOH corresponding to the model parameters from a preset mapping relation between the model parameters and the SOH as the current SOH of the battery.

The detection module 202 is configured to control the battery to discharge to a preset cut-off state at a second preset temperature included in the working condition parameters corresponding to the target detection working condition; after a first preset time period included in the standing working condition parameters, charging the battery to a preset full charge state based on a preset charging parameter included in the working condition parameters, and a second preset time period included in the standing working condition parameters.

The detection module 202 is configured to detect a first remaining power of each cell in the battery when discharging and standing for a first preset period of time; detecting the charging capacity of the battery and the second residual electric quantity of each battery core when the battery is charged to a preset full charge state and is kept stand for a second preset time period; and calculating the current SOH of the battery according to the charging capacity, the first residual electric quantity and the second residual electric quantity of each battery core.

The apparatus further comprises: the SOH detection instruction receiving module is used for triggering the SOH detection instruction when the battery is detected to meet a first preset abnormal condition, wherein the first preset abnormal condition comprises that the battery has a battery core water jump phenomenon or the battery exceeds a preset time period and SOH detection is not carried out.

The SOH detection instruction receiving module is used for receiving SOH detection instructions sent by a user; or receiving an SOH detection instruction sent by the server when the second preset abnormal condition is detected to be met, wherein the second preset abnormal condition comprises a battery cell water jump phenomenon, and the deviation between the server and SOH detected by equipment where the battery is located exceeds a preset threshold value, or an outlier phenomenon of the SOH of the battery under a certain working condition.

The apparatus further includes an SOH calibration module for modifying the SOH of the currently stored battery to the currently detected SOH.

The device also comprises a model parameter correction module which is used for correcting the model parameters of the preset electrochemical model according to the currently detected SOH.

The model parameter correction module is further used for sending the currently detected SOH to the server so that the server trains a neural network model for detecting the SOH based on the SOH to correct model parameters of a preset electrochemical model in the server.

The battery SOH detection device provided by the above embodiment of the present application and the battery SOH detection method provided by the embodiment of the present application have the same beneficial effects as the method adopted, operated or implemented by the application program stored therein, because of the same inventive concept.

Fig. 6 shows a schematic block diagram of an electronic device 700 of an embodiment of the application. As shown in fig. 6, the electronic device 700 includes a processor 710, and optionally, the electronic device 700 further includes a memory 720, wherein the memory 720 is used for storing a computer program, and the processor 710 is used for reading the computer program and executing the battery SOH detection method of the foregoing various embodiments of the present application based on the computer program.

The embodiments of the present application also provide a computer readable storage medium storing a computer program which, when executed by a processor, implements the methods of the various embodiments of the present application described above.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery state of health SOH detection method, comprising:

2. The method of claim 1, wherein the determining the target detection condition corresponding to the detection instruction comprises:

3. The method of claim 1, wherein the controlling the battery to operate the target detection condition at which the current SOH of the battery is detected comprises:

4. The method of claim 3, wherein the target detection operating condition comprises an electrochemical impedance spectroscopy, EIS, operating condition, the controlling the battery to operate the target detection operating condition based on operating condition parameters corresponding to the target detection operating condition comprising:

Adjusting the electric quantity of the battery to the preset electric quantity and adjusting the temperature of the battery to the first preset temperature based on the preset electric quantity and the first preset temperature included in the working condition parameters corresponding to the EIS working condition;

and executing current negative pulse with preset frequency on the battery.

5. The method of claim 4, wherein determining the current SOH of the battery based on the electrical parameter exhibited by the battery under the target detection condition comprises:

detecting the cell impedance exhibited by the battery under the current negative pulse;

and acquiring corresponding SOH from a preset SOH lookup table according to the preset electric quantity, the first preset temperature and the battery cell impedance, wherein the preset SOH lookup table comprises the mapping relation between the battery cell impedance and the SOH under different battery electric quantities and battery temperatures.

6. The method of claim 3, wherein controlling the battery to operate the target detection condition based on the condition parameter corresponding to the target detection condition comprises:

7. The method of claim 6, wherein determining the current SOH of the battery based on the electrical parameter exhibited by the battery under the target detection condition comprises:

8. The method of claim 6, wherein determining the current SOH of the battery based on the electrical parameter exhibited by the battery under the target detection condition comprises:

9. The method of claim 8, wherein the determining the current SOH of the battery based on model parameters of the preset electrochemical model comprises:

calculating the current SOH of the battery through the preset electrochemical model according to the electrical parameters and the determined model parameters; or alternatively, the process may be performed,

and according to the determined model parameters, acquiring SOH corresponding to the model parameters from a preset mapping relation between the model parameters and the SOH as the current SOH of the battery.

10. The method of claim 3, wherein controlling the battery to operate the target detection condition based on the condition parameter corresponding to the target detection condition comprises:

controlling the battery to discharge to a preset cut-off state at a second preset temperature included in the working condition parameters corresponding to the target detection working condition;

and after the first preset time period included in the working condition parameters is kept stand, the battery is charged to a preset full charge state based on the preset charging parameters included in the working condition parameters, and the second preset time period included in the working condition parameters is kept stand.

11. The method of claim 10, wherein the determining the current SOH of the battery based on the electrical parameter exhibited by the battery under the target detection condition comprises:

detecting a first residual electric quantity of each electric core in the battery when discharging and standing for the first preset time period;

detecting the charging capacity of the battery and the second residual electric quantity of each electric core when the battery is charged to the preset full charge state and is kept stand for the second preset time period;

and calculating the current SOH of the battery according to the charging capacity, the first residual electric quantity and the second residual electric quantity of each battery core.

12. The method of any one of claims 1-11, wherein prior to responding to the SOH detection instruction, further comprising:

13. The method of any one of claims 1-11, wherein prior to responding to the SOH detection instruction, further comprising:

receiving an SOH detection instruction sent by a user; or alternatively, the process may be performed,

And receiving an SOH detection instruction sent by the server when a second preset abnormal condition is detected to be met, wherein the second preset abnormal condition comprises a battery core water jump phenomenon, and the deviation between the server and SOH detected by equipment where the battery is located exceeds a preset threshold value, or an outlier phenomenon of the SOH of the battery under a certain working condition.

14. The method of any one of claims 1-11, wherein after detecting the current SOH of the battery under the target detection condition, further comprising:

15. The method of any one of claims 1-11, wherein after detecting the current SOH of the battery under the target detection condition, further comprising:

16. The method of any one of claims 1-11, wherein after detecting the current SOH of the battery under the target detection condition, further comprising:

17. A battery SOH detection device, characterized by comprising:

18. A powered device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method of any of claims 1-16 when the computer program is executed by the processor.

19. A computer readable storage medium storing a computer program, which when executed by a processor, implements the method of any one of claims 1-16.