Estimation method, device and equipment of state of charge of battery and storage medium

Abstract

The invention discloses a battery charge state estimation method and device, equipment and a storage medium. The method comprises the following steps: acquiring at least two groups of observation data of a target battery at a preset temperature, and determining an association relationship between a state of charge and an open-circuit voltage according to the at least two groups of observation data; acquiring battery end voltage data, current data and temperature data of the target battery in a working state according to a preset acquisition period; an RC equivalent circuit model matched with the target battery is determined according to the battery end voltage data, the current data, the temperature data, the at least two sets of observation data and the incidence relation between the state of charge and the open-circuit voltage; and determining an estimation result of the state of charge according to the RC equivalent circuit model. According to the technical scheme, the problem of low estimation accuracy of the state of charge of the battery is solved, the state equation of the lithium ion battery is established through the RC equivalent circuit model, and accurate estimation of the state of charge of the battery is realized.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and in particular to a method, apparatus, electronic device, and storage medium for estimating the state of charge of a battery. Background Technology

[0002] Lithium-ion batteries have become one of the mainstream batteries in the field of electrochemical energy storage, attracting much attention due to their high energy density, low self-discharge rate, and long cycle life. However, lithium-ion batteries still face challenges in terms of safety, stability, and performance lifespan, requiring regulation through a reliable battery management system (BMS).

[0003] In lithium-ion battery management, accurately estimating the battery's State of Charge (SOC) is a crucial task and the foundation for equalization control and State of Health (SOH) control. Currently, existing SOC estimation methods mainly include the open-circuit voltage method and the ampere-hour integral method. However, these methods struggle to guarantee accuracy, typically requiring the lithium-ion battery to rest for a sufficiently long period. The algorithm's accuracy is also susceptible to cycle life limitations, and in open-loop conditions, real-time corrections are impossible. Therefore, a new method for estimating battery state of charge is needed to improve the accuracy and reliability of SOC estimation. Summary of the Invention

[0004] This invention provides a method, apparatus, device, and storage medium for estimating the state of charge (SOC) of a battery, in order to solve the problem of low accuracy in estimating the SOC of a battery. It establishes the state equation of a lithium-ion battery through an RC equivalent circuit model, thereby achieving accurate estimation of the SOC of the battery.

[0005] According to one aspect of the present invention, a method for estimating the state of charge of a battery is provided, the method comprising:

[0006] Acquire at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open-circuit voltage based on the at least two sets of observation data; wherein, the observation data includes the open-circuit voltage and the state of charge matching the open-circuit voltage;

[0007] According to the preset acquisition cycle, acquire battery terminal voltage data, current data and temperature data of the target battery under working conditions;

[0008] Based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage, determine the RC equivalent circuit model matching the target battery.

[0009] Based on the RC equivalent circuit model, the estimated state of charge is determined.

[0010] According to another aspect of the present invention, a battery state of charge estimation apparatus is provided, the apparatus comprising:

[0011] The observation data acquisition module is used to acquire at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open circuit voltage based on the at least two sets of observation data; wherein, the observation data includes the open circuit voltage and the state of charge matching the open circuit voltage.

[0012] The data acquisition module is used to acquire battery terminal voltage data, current data, and temperature data of the target battery under its working state according to a preset acquisition cycle.

[0013] The circuit model determination module is used to determine the RC equivalent circuit model matching the target battery based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage.

[0014] The estimation result determination module is used to determine the estimation result of the state of charge based on the RC equivalent circuit model.

[0015] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0016] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the battery state-of-charge estimation method according to any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the battery state-of-charge estimation method according to any embodiment of the present invention.

[0018] The technical solution of this invention involves acquiring at least two sets of observation data of a target battery at a preset temperature, and determining the correlation between the state of charge (SOC) and open-circuit voltage based on these two sets of observation data. It also involves acquiring battery terminal voltage data, current data, and temperature data of the target battery under operating conditions according to a preset acquisition cycle. Based on the battery terminal voltage data, the current data, the temperature data, the at least two sets of observation data, and the correlation between SOC and open-circuit voltage, it determines a matching RC equivalent circuit model for the target battery. Finally, it determines the estimated SOC result based on the RC equivalent circuit model. This technical solution solves the problem of low accuracy in estimating the battery's SOC by establishing a state equation for a lithium-ion battery through an RC equivalent circuit model, thereby achieving accurate estimation of the battery's SOC.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for estimating the state of charge of a battery according to Embodiment 1 of the present invention;

[0022] Figure 2A This is a flowchart of a method for estimating the state of charge of a battery according to Embodiment 2 of the present invention;

[0023] Figure 2B This is a schematic diagram of a third-order RC equivalent circuit provided in Embodiment 2 of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of a battery state of charge estimation device provided in Embodiment 3 of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of an electronic device that implements the battery state of charge estimation method of the embodiments of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices. The acquisition, storage, use, and processing of data in the technical solutions of this application all comply with the relevant provisions of national laws and regulations.

[0028] Example 1

[0029] Figure 1 This is a flowchart illustrating a method for estimating the state of charge (SOC) of a battery according to Embodiment 1 of the present invention. This embodiment is applicable to the SOC estimation scenario of lithium-ion batteries. The method can be executed by a battery SOC estimation device, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1 As shown, the method includes:

[0030] S110. Obtain at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open circuit voltage based on the at least two sets of observation data.

[0031] This solution can be executed by a state of charge (SCC) estimation system, which may include electronic devices such as voltage measuring devices, current measuring devices, temperature measuring devices, and control devices. Voltage measuring devices, such as voltmeters and oscilloscopes, are used to measure voltage data associated with the target battery, such as open-circuit voltage and battery terminal voltage. Current measuring devices, such as ammeters and current sensors, are used to measure current data associated with the target battery, such as the current in the circuit containing the target battery. Temperature measuring devices, such as temperature sensors, are used to collect temperature data of the target battery under operating conditions. The control device can be used to control the connection state of the target battery and estimate its SCC based on the voltage data collected by the voltage measuring device, the current data collected by the current measuring device, and the temperature data collected by the temperature measuring device.

[0032] Understandably, the target battery may be a lithium-ion battery requiring state-of-charge (POC) estimation. The POC estimation system can acquire at least two sets of observation data for the target battery at a preset temperature, wherein the observation data includes open-circuit voltage and a POC matching the open-circuit voltage. Based on the at least two sets of observation data, the POC estimation system can fit the correlation between the POC and the open-circuit voltage to obtain a relationship curve characterizing the correlation between the POC and the open-circuit voltage.

[0033] S120. Acquire battery terminal voltage data, current data, and temperature data under the working state of the target battery according to the preset acquisition cycle.

[0034] After acquiring observation data of the target battery in offline mode, the state of charge estimation system can acquire battery terminal voltage data, current data, and temperature data of the target battery in its operating state through voltage measurement devices, current measurement devices, and temperature measurement devices, respectively, according to a pre-set acquisition cycle. The operating state can include the target battery's charging state, discharging state, standby state, and open circuit state.

[0035] S130. Based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage, determine the RC equivalent circuit model matching the target battery.

[0036] The state of charge (SOC) estimation system can establish a multi-order RC equivalent circuit to simulate the operating state of the target battery based on electrochemical principles, thereby obtaining a set of state equations matching the target battery. Based on the battery terminal voltage data, current data, temperature data, at least two sets of observation data, and the correlation between SOC and open-circuit voltage, the SOC estimation system can determine the matching RC equivalent circuit model of the target battery based on the matching set of state equations.

[0037] S140. Based on the RC equivalent circuit model, determine the estimated state of charge.

[0038] After obtaining the RC equivalent circuit model matching the target battery, the state of charge estimation system can use a Kalman filter to estimate the state of charge based on the RC equivalent circuit model, and obtain the estimated state of charge result.

[0039] The technical solution of this invention involves acquiring at least two sets of observation data of a target battery at a preset temperature, and determining the correlation between the state of charge (SOC) and open-circuit voltage based on these two sets of observation data. It also involves acquiring battery terminal voltage data, current data, and temperature data of the target battery under operating conditions according to a preset acquisition cycle. Based on the battery terminal voltage data, the current data, the temperature data, the at least two sets of observation data, and the correlation between SOC and open-circuit voltage, it determines a matching RC equivalent circuit model for the target battery. Finally, it determines the estimated SOC result based on the RC equivalent circuit model. This technical solution solves the problem of low accuracy in estimating the battery's SOC by establishing a state equation for a lithium-ion battery through an RC equivalent circuit model, thereby achieving accurate estimation of the battery's SOC.

[0040] Example 2

[0041] Figure 2A This is a flowchart of a battery state of charge estimation method provided in Embodiment 2 of the present invention. This embodiment is a refinement based on the above embodiment. Figure 2A As shown, the method includes:

[0042] S210. Obtain at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open circuit voltage based on the at least two sets of observation data.

[0043] S220: Acquire battery terminal voltage data, current data, and temperature data under the target battery's operating state according to the preset acquisition cycle.

[0044] S230. Based on electrochemical characteristics, construct the RC equivalent circuit equation and state-of-charge equation for the target battery.

[0045] In this scheme, optionally, the RC equivalent circuit equation is determined based on the RC equivalent circuit of a preset order, and the RC equivalent circuit equation includes the polarization circuit equation of a preset order.

[0046] In one feasible approach, the RC equivalent circuit equations are determined based on a third-order RC equivalent circuit, and the RC equivalent circuit equations include:

[0047]

[0048]

[0049]

[0050] U s,k =R s,k-1 I k-1 ;

[0051] U t,k =UOC k +U p1,k +U p2,k +U p3,k +U s,k ;

[0052] Where k represents the current acquisition period, Δt represents the acquisition period length, p1 represents the identifier of the first polarization circuit, p2 represents the identifier of the second polarization circuit, p3 represents the identifier of the third polarization circuit, and U p1,k U p2,k and U p3,k U represents the equivalent polarization voltage of the first, second, and third polarization circuits in the current acquisition cycle. p1,k-1 U p2,k-1 and U p3,k-1 I represents the equivalent polarization voltage of the first, second, and third polarization circuits in the previous acquisition cycle. k-1 C represents the main circuit current of the RC equivalent circuit in the previous sampling cycle. p1,k-1 C p2,k-1 and C p3,k-1 R represents the capacitance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. p1,k-1 R p2,k-1 and R p3,k-1 R represents the resistance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. s,k-1 UOC represents the main circuit resistance in the previous acquisition cycle. k U represents the equivalent open-circuit voltage of the target battery in the current acquisition period. s,k U represents the equivalent ohmic voltage of the current acquisition period. t,k This indicates the battery terminal voltage during the current data acquisition cycle.

[0053] Figure 2B This is a schematic diagram of a third-order RC equivalent circuit provided according to Embodiment 2 of the present invention, as shown below. Figure 2B As shown, C1 and R1 constitute the first polarization circuit, C2 and R2 constitute the second polarization circuit, and C3 and R3 constitute the third polarization circuit. The equivalent polarization voltages of the first, second, and third polarization circuits in the previous acquisition cycle are U, U, and U, respectively. p1 U p2 and Up3 I represents the main circuit current of the third-order RC equivalent circuit, and R... s R represents the resistance of the main circuit. s Voltage U across the terminals s UOC represents the equivalent ohmic voltage, and U represents the equivalent open-circuit voltage of the target battery. t This represents the battery terminal voltage. Based on electrochemical characteristics, the state-of-charge estimation system can obtain the polarization circuit equations corresponding to the three polarization circuits, the Ohmic circuit equation corresponding to the main circuit resistance, and the voltage equation.

[0054] Based on the above scheme, the charged state equation is an ampere-hour integral state equation with full charge-discharge correction. The charged state equation may include:

[0055]

[0056] Among them, SOC k State of charge (SOC) represents the current acquisition cycle. k-1 C represents the state of charge in the previous acquisition cycle, η represents the coulombic efficiency of the target battery during charge and discharge, and C represents the state of charge in the previous acquisition cycle. n This indicates the nominal capacity of the target battery.

[0057] S240. Based on the relationship between the state of charge and the open-circuit voltage, construct the open-circuit state equation.

[0058] It is easy to understand that the open-circuit state equation is obtained based on the relationship between the state of charge and the open-circuit voltage determined in S210. The open-circuit state equation is specifically expressed as follows:

[0059] UOC k =g(SOC) k );

[0060] Where g(·) represents the relationship between the state of charge and the open-circuit voltage.

[0061] S250. Generate a set of state equations based on the RC equivalent circuit equations, the charged state equations, and the open-circuit state equations.

[0062] The state of charge estimation system can combine the RC equivalent circuit equations in S230, the state of charge equations, and the open-circuit state equations in S240 into a set of state equations.

[0063] S260. Based on the battery terminal voltage data, the current data, the temperature data, and at least two sets of observation data, determine the capacitance and resistance parameters of the RC equivalent circuit based on the state equation set.

[0064] The state-of-charge estimation system can substitute battery terminal voltage data, current data, and at least two sets of observation data corresponding to the same temperature into a set of state equations to perform piecewise fitting of the parameters of the RC equivalent circuit, thereby obtaining the capacitance and resistance parameters of the RC equivalent circuit. The capacitance parameters are the capacitance values ​​of each polarization circuit in the RC equivalent circuit, and the resistance parameters include the resistance values ​​of each polarization circuit and the main circuit resistance value of the RC equivalent circuit.

[0065] S270. Based on the capacitance parameters, the resistance parameters, and the state equation set, determine the RC equivalent circuit model matching the target battery.

[0066] After obtaining the capacitance and resistance parameters, the state of charge estimation system can obtain the RC equivalent circuit model matching the target battery based on the capacitance parameters, resistance parameters, and the state equations.

[0067] S280. Based on the RC equivalent circuit model, use a Kalman filter to determine the state estimation data that matches each set of observation data.

[0068] The state of charge estimation system uses the state of charge from each set of observation data as observation values. Based on an RC equivalent circuit model, and utilizing a Kalman filter, it recursively obtains the state estimation data matching each set of observation data through state updates. The Kalman filter can be constructed based on the extended Kalman filter algorithm.

[0069] Specifically, the steps of the extended Kalman filter algorithm for state estimation are as follows:

[0070] (1) Determine the state transition equation and the measurement transition equation: x k =f(x) k-1 ,u k-1 )+w k ;y k =h(x k-1 )+v k ;

[0071] (2) Linearizing the equation yields the Jacobian matrix:

[0072] (3) Calculate the Kalman gain:

[0073] (4) Obtain new state estimates based on the observation data:

[0074] (5) Update the state covariance matrix:

[0075] Where k represents the current acquisition period, w kThe state prediction noise for the current acquisition period represents a normal distribution; v k The measurement noise in the current acquisition period represents a normal distribution; y k x represents the observed state of charge value in the current acquisition period. k x represents the state-of-charge variable in the current acquisition period. k-1 U represents the state-of-charge variable from the previous acquisition cycle. k-1 This represents the input of the Kalman filter in the previous acquisition cycle, where f(·) and h(·) represent the first and second nonlinear functions, respectively. k C represents the state transition matrix for the current acquisition cycle. k This represents the observation matrix for the current acquisition period. f represents the estimated state of charge from the previous acquisition cycle. ′ (·) represents the linearized function corresponding to f(·), h ′ (·) represents the linearization function corresponding to h(·), K k P represents the Kalman gain. k-1 R represents the state estimation covariance of the previous acquisition cycle, and R represents the measurement noise matrix. I represents the estimated state of charge for the current acquisition period, where I represents the identity matrix and Q represents the state noise matrix.

[0076] After obtaining the state estimation data corresponding to each set of observation data, the charge state estimation system can use the state estimation data as the estimation result of the charge state.

[0077] The technical solution of this invention involves acquiring at least two sets of observation data of a target battery at a preset temperature, and determining the correlation between the state of charge (SOC) and open-circuit voltage based on these two sets of observation data. It also involves acquiring battery terminal voltage data, current data, and temperature data of the target battery under operating conditions according to a preset acquisition cycle. Based on the battery terminal voltage data, the current data, the temperature data, the at least two sets of observation data, and the correlation between SOC and open-circuit voltage, it determines a matching RC equivalent circuit model for the target battery. Finally, it determines the estimated SOC result based on the RC equivalent circuit model. This technical solution solves the problem of low accuracy in estimating the battery's SOC by establishing a state equation for a lithium-ion battery through an RC equivalent circuit model, thereby achieving accurate estimation of the battery's SOC.

[0078] Example 3

[0079] Figure 3 This is a schematic diagram of a battery state of charge estimation device provided in Embodiment 3 of the present invention. Figure 3 As shown, the device includes:

[0080] The observation data acquisition module 310 is used to acquire at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open circuit voltage based on the at least two sets of observation data; wherein, the observation data includes the open circuit voltage and the state of charge matching the open circuit voltage.

[0081] The data acquisition module 320 is used to acquire battery terminal voltage data, current data and temperature data of the target battery under working conditions according to a preset acquisition cycle.

[0082] The circuit model determination module 330 is used to determine the RC equivalent circuit model matching the target battery based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage.

[0083] The estimation result determination module 340 is used to determine the estimation result of the state of charge based on the RC equivalent circuit model.

[0084] In this solution, optionally, the circuit model determination module 330 is specifically used for:

[0085] Based on electrochemical characteristics, the RC equivalent circuit equation and the state-of-charge equation for matching the target battery are constructed.

[0086] Based on the relationship between the state of charge and the open-circuit voltage, the open-circuit state equation is constructed;

[0087] Generate a set of state equations based on the RC equivalent circuit equations, the charged state equations, and the open-circuit state equations.

[0088] Based on the battery terminal voltage data, the current data, the temperature data, and at least two sets of observation data, the capacitance and resistance parameters of the RC equivalent circuit are determined according to the state equations.

[0089] Based on the capacitance parameters, the resistance parameters, and the set of state equations, determine the RC equivalent circuit model matching the target battery.

[0090] Based on the above scheme, optionally, the estimation result determination module 340 is specifically used for:

[0091] Based on the RC equivalent circuit model, the state estimation data matching each set of observation data is determined using a Kalman filter.

[0092] Optionally, the RC equivalent circuit equations are determined based on RC equivalent circuits of a preset order, and the RC equivalent circuit equations include a preset number of polarization circuit equations.

[0093] In one feasible approach, the RC equivalent circuit equations are determined based on a third-order RC equivalent circuit, and the RC equivalent circuit equations include:

[0094]

[0095]

[0096]

[0097] U s,k =R s,k-1 I k-1 ;

[0098] U t,k =UOC k +U p1,k +U p2,k +U p3,k +U s,k ;

[0099] Where k represents the current acquisition period, Δt represents the acquisition period length, p1 represents the identifier of the first polarization circuit, p2 represents the identifier of the second polarization circuit, p3 represents the identifier of the third polarization circuit, and U p1,k U p2,k and U p3,k U represents the equivalent polarization voltage of the first, second, and third polarization circuits in the current acquisition cycle. p1,k-1 U p2,k-1 and U p3,k-1 I represents the equivalent polarization voltage of the first, second, and third polarization circuits in the previous acquisition cycle. k-1 C represents the main circuit current of the RC equivalent circuit in the previous sampling cycle. p1,k-1 C p2,k-1 and C p3,k-1 R represents the capacitance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. p1,k-1 R p2,k-1 and R p3,k-1 R represents the resistance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. s,k-1 UOC represents the main circuit resistance in the previous acquisition cycle. k U represents the equivalent open-circuit voltage of the target battery in the current acquisition period. s,k U represents the equivalent ohmic voltage of the current acquisition period. t,k This indicates the battery terminal voltage during the current data acquisition cycle.

[0100] Based on the above scheme, optionally, the charge state equation includes:

[0101]

[0102] Among them, SOC k State of charge (SOC) represents the current acquisition cycle. k-1 C represents the state of charge in the previous acquisition cycle, η represents the coulombic efficiency of the target battery during charge and discharge, and C represents the state of charge in the previous acquisition cycle. n This indicates the nominal capacity of the target battery.

[0103] In this embodiment, optionally, the open-circuit state equation includes:

[0104] UOC k =g(SOC) k );

[0105] Where g(·) represents the relationship between the state of charge and the open-circuit voltage.

[0106] The battery state of charge estimation device provided in the embodiments of the present invention can execute the battery state of charge estimation method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of executing the method.

[0107] Example 4

[0108] Figure 4 A schematic diagram of an electronic device 410 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0109] like Figure 4As shown, the electronic device 410 includes at least one processor 411 and a memory, such as a read-only memory (ROM) 412 or a random access memory (RAM) 413, communicatively connected to the at least one processor 411. The memory stores computer programs executable by the at least one processor. The processor 411 can perform various appropriate actions and processes based on the computer program stored in the ROM 412 or loaded from storage unit 418 into the RAM 413. The RAM 413 may also store various programs and data required for the operation of the electronic device 410. The processor 411, ROM 412, and RAM 413 are interconnected via a bus 414. An input / output (I / O) interface 415 is also connected to the bus 414.

[0110] Multiple components in electronic device 410 are connected to I / O interface 415, including: input unit 416, such as keyboard, mouse, etc.; output unit 417, such as various types of displays, speakers, etc.; storage unit 418, such as disk, optical disk, etc.; and communication unit 419, such as network card, modem, wireless transceiver, etc. Communication unit 419 allows electronic device 410 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0111] Processor 411 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 411 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 411 performs the various methods and processes described above, such as methods for estimating the state of charge of a battery.

[0112] In some embodiments, the method for estimating the battery state of charge may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 418. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 410 via ROM 412 and / or communication unit 419. When the computer program is loaded into RAM 413 and executed by processor 411, one or more steps of the battery state of charge estimation method described above may be performed. Alternatively, in other embodiments, processor 411 may be configured to perform the battery state of charge estimation method by any other suitable means (e.g., by means of firmware).

[0113] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transferring data and instructions to the storage system, the at least one input device, and the at least one output device.

[0114] Computer programs used to implement the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable battery state-of-charge estimation device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The computer programs can be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0115] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0116] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0117] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0118] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0119] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0120] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for estimating the state of charge of a battery, characterized in that, The method includes: Acquire at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open-circuit voltage based on the at least two sets of observation data; wherein, the observation data includes the open-circuit voltage and the state of charge matching the open-circuit voltage; According to the preset acquisition cycle, acquire battery terminal voltage data, current data and temperature data of the target battery under working conditions; Based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage, determine the RC equivalent circuit model matching the target battery. Based on the RC equivalent circuit model, the estimated state of charge is determined.

2. The method according to claim 1, characterized in that, The step of determining the RC equivalent circuit model matching the target battery based on the battery terminal voltage data, the current data, the temperature data, and at least two sets of observation data includes: Based on electrochemical characteristics, the RC equivalent circuit equation and the state-of-charge equation for matching the target battery are constructed. Based on the relationship between the state of charge and the open-circuit voltage, the open-circuit state equation is constructed; Generate a set of state equations based on the RC equivalent circuit equations, the charged state equations, and the open-circuit state equations. Based on the battery terminal voltage data, the current data, the temperature data, and at least two sets of observation data, the capacitance and resistance parameters of the RC equivalent circuit are determined according to the state equations. Based on the capacitance parameters, the resistance parameters, and the set of state equations, determine the RC equivalent circuit model matching the target battery.

3. The method according to claim 2, characterized in that, The estimation result of determining the state of charge based on the RC equivalent circuit model includes: Based on the RC equivalent circuit model, the state estimation data matching each set of observation data is determined using a Kalman filter.

4. The method according to claim 2, characterized in that, The RC equivalent circuit equations are determined based on RC equivalent circuits of a preset order, and the RC equivalent circuit equations include a preset number of polarization circuit equations.

5. The method according to claim 4, characterized in that, The RC equivalent circuit equations are determined based on a third-order RC equivalent circuit, and the RC equivalent circuit equations include: U s,k =R s,k-1 I k-1 ; U t,k =UOC k +U p1,k +U p2,k +U p3,k +U s,k ; Where k represents the current acquisition period, Δt represents the acquisition period length, p1 represents the identifier of the first polarization circuit, p2 represents the identifier of the second polarization circuit, p3 represents the identifier of the third polarization circuit, and U p1,k U p2,k and U p3,k U represents the equivalent polarization voltage of the first, second, and third polarization circuits in the current acquisition cycle. p1,k-1 U p2,k-1 and U p3,k-1 I represents the equivalent polarization voltage of the first, second, and third polarization circuits in the previous acquisition cycle. k-1 C represents the main circuit current of the RC equivalent circuit in the previous sampling cycle. p1,k-1 C p2,k-1 and C p3,k-1 R represents the capacitance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. p1,k-1 R p2,k-1 and R p3,k-1 R represents the resistance of the first polarization circuit, the second polarization circuit, and the third polarization circuit in the previous sampling cycle. s,k-1 UOC represents the main circuit resistance in the previous acquisition cycle. k U represents the equivalent open-circuit voltage of the target battery in the current acquisition period. s,k U represents the equivalent ohmic voltage of the current acquisition period. t,k This indicates the battery terminal voltage during the current data acquisition cycle.

6. The method according to claim 5, characterized in that, The charge state equation includes: Among them, SOC k State of charge (SOC) represents the current acquisition cycle. k-1 C represents the state of charge in the previous acquisition cycle, η represents the coulombic efficiency of the target battery during charge and discharge, and C represents the state of charge in the previous acquisition cycle. n This indicates the nominal capacity of the target battery.

7. The method according to claim 6, characterized in that, The open-circuit state equations include: UOC k =g(SOC k ); Where g(·) represents the relationship between the state of charge and the open-circuit voltage.

8. A device for estimating the state of charge of a battery, characterized in that, The device includes: The observation data acquisition module is used to acquire at least two sets of observation data of the target battery at a preset temperature, and determine the correlation between the state of charge and the open circuit voltage based on the at least two sets of observation data; wherein, the observation data includes the open circuit voltage and the state of charge matching the open circuit voltage. The data acquisition module is used to acquire battery terminal voltage data, current data, and temperature data of the target battery under its working state according to a preset acquisition cycle. The circuit model determination module is used to determine the RC equivalent circuit model matching the target battery based on the battery terminal voltage data, the current data, the temperature data, at least two sets of observation data, and the correlation between the state of charge and the open circuit voltage. The estimation result determination module is used to determine the estimation result of the state of charge based on the RC equivalent circuit model.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the method for estimating the state of charge of a battery according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method for estimating the state of charge of a battery as described in any one of claims 1-7.

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