Battery Impedance Detection Device

Abstract

A battery impedance detection device is provided, the device including: a first processing module (501) configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal, and to apply the excitation signal to the battery, the first signal being an original signal used to generate the excitation signal; a sampler (502) coupled to the battery and configured to sample a voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal; and a second processing module (503) configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, perform a second code conversion on a current signal of the battery based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal. According to the above method, EIS detection can be performed when the battery is in a charging state or when the battery is in a load discharging state.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present application relate to the field of batteries, and in particular to a battery impedance detection device. [Background technology]

[0002] As the charging speed and battery energy density increase, the safety risk of the battery continues to rise. Especially for ternary lithium batteries, the initial oxygen generated during the temperature rise is very likely to cause an explosion, which poses a serious threat to the safety of the user's personal and property. Therefore, advance detection and prevention by technical means before the spontaneous combustion of the battery is the key to the safe use of high energy density lithium-ion batteries.

[0003] Electrochemical impedance spectroscopy (EIS) is an effective method for detecting battery safety, contains rich basic electrochemical information and physical process information of the battery, and can be used to detect exceptions such as short circuit, lithium metal deposition, overheating, and swelling in the battery, which is an effective method for detecting and preventing battery failure in advance.

[0004] However, EIS detection is a static detection method, i.e., detection can only be performed when there is no interference current on the battery. Therefore, a method is needed to perform EIS detection in scenarios where there is load interference on the battery. Summary of the Invention

[0005] The present application provides a battery impedance detection apparatus for performing EIS detection in scenarios where a load interference is present on a battery.

[0006] According to a first aspect, the present application provides a battery impedance detection apparatus, the apparatus including: a first processing module configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal and apply the excitation signal to a battery, the first signal being an original signal used to generate the excitation signal; a sampler coupled to the battery and configured to sample a voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal; and a second processing module configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, perform a second code conversion on a current signal of the battery based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal.

[0007] According to the above-mentioned method, by using the first code conversion and the second code conversion, the interference signal spectrum can be removed from the test frequency of EIS detection, and EIS detection can be performed when the battery is in a charging state or when the battery is in a load discharging state. In addition, the above-mentioned method has the characteristics of strong interference resistance and high accuracy.

[0008] In a possible design, the first processing module includes a first code conversion module configured to multiply the first signal by a preset code to obtain the excitation signal.

[0009] The first code conversion is carried out in the above manner to obtain the excitation signal. This solution is simple and easy to implement. In addition, the excitation signal may be obtained in another manner, which is not limited in this application. The frequency domain waveform of the excitation signal obtained by the first code conversion is different from the frequency domain waveform of the first signal.

[0010] In a possible design, the first processing module includes a digital-to-analog converter DAC configured to perform a digital-to-analog conversion on the excitation signal to obtain an analog signal, and a current generator configured to generate an excitation current based on the analog signal and apply the excitation current to the battery.

[0011] According to the above design, the excitation signal may be converted into an excitation current, and the excitation current may be applied to the positive or negative terminal of the battery.

[0012] In a possible design, the sampler is further configured to sample the battery current to obtain a current signal, or the current signal is determined by a calculation based on the excitation signal.

[0013] According to the above design, the current signal may be acquired in several ways.

[0014] In a possible design, the second processing module includes a second code conversion module configured to multiply the sampled voltage signal by a preset code to obtain a first voltage signal, and to multiply the current signal by the preset code to obtain a first current signal.

[0015] The second code conversion is performed in the manner described above to obtain the first voltage signal and the first current signal. This solution is simple and easy to implement.

[0016] In a possible design, the product of a preset code and a preset code is a sequence of all ones.

[0017] In a possible design, the preset code is a sequence containing +1 and -1.

[0018] In a possible design, the preset code is a periodic sequence, the sampler is further configured to sample the voltage of the battery to obtain an interference voltage signal before the first processing module applies the excitation signal to the battery, and the second processing module is further configured to determine the periodicity of the preset code based on the sampled interference voltage signal.

[0019] In a possible design, the preset code is a non-periodic sequence, in which case the periodicity of the preset code does not need to be determined.

[0020] According to a second aspect, the present application provides a battery impedance detection device, the device comprising: The battery includes a processor configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal, and apply the excitation signal to the battery, the first signal being an original signal used to generate the excitation signal; and a sampler coupled to the battery and configured to sample a voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal, the processor further configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, perform a second code conversion on the battery current signal based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal.

[0021] In a possible design, the processor is configured to multiply the first signal by a preset code to obtain the excitation signal when performing a first code conversion on the first signal based on the preset code to obtain the excitation signal.

[0022] In a possible design, the processor is configured to perform digital-to-analog conversion on the excitation signal to obtain an analog signal when applying the excitation signal to the battery, generate an excitation current based on the analog signal, and apply the excitation current to the battery.

[0023] In a possible design, the sampler is further configured to sample the battery current to obtain a current signal, or the current signal is determined by a calculation based on the excitation signal.

[0024] In a possible design, the processor is further configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, and when performing the second code conversion on the battery current signal based on the preset code to obtain a first current signal, multiply the sampled voltage signal by the preset code to obtain the first voltage signal, and multiply the current signal by the preset code to obtain the first current signal.

[0025] In a possible design, the product of a preset code and a preset code is a sequence of all ones.

[0026] In a possible design, the preset code is a sequence containing +1 and -1.

[0027] In a possible design, the preset code is a periodic sequence, the sampler is further configured to sample the voltage of the battery to obtain an interference voltage signal before the first processing module applies the excitation signal to the battery, and the processor is further configured to determine the periodicity of the preset code based on the sampled interference voltage signal.

[0028] In a possible design, the preset code is a non-periodic sequence, in which case the periodicity of the preset code does not need to be determined.

[0029] According to a third aspect, the present application provides an electronic system, the system comprising a device according to the first aspect or a device according to the second aspect and a battery.

[0030] According to a fourth aspect, the present application provides a battery impedance detection method, the method includes: performing a first code conversion on a first signal based on a preset code to obtain an excitation signal, and applying the excitation signal to a battery, where the first signal is an original signal used to generate the excitation signal; sampling a voltage of the battery by using a sampler after the excitation signal is applied to the battery to obtain a sampled voltage signal; performing a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal; performing a second code conversion on a current signal of the battery based on the preset code to obtain a first current signal; and determining an impedance corresponding to the battery based on the first voltage signal and the first current signal.

[0031] In a possible design, when a first code conversion is performed on a first signal based on a preset code to obtain an excitation signal, the first signal is multiplied by a preset code to obtain the excitation signal.

[0032] In a possible design, when an excitation signal is applied to the battery, a digital-to-analog conversion is performed on the excitation signal to obtain an analog signal, an excitation current is generated based on the analog signal, and the excitation current is applied to the battery.

[0033] In a possible design, the battery current is sampled by using a sampler to obtain a current signal, or the current signal is determined by calculation based on the excitation signal.

[0034] In a possible design, a second code conversion is performed on the sampled voltage signal based on the preset code to obtain a first voltage signal, and when a second code conversion is performed on the battery current signal based on the preset code to obtain a first current signal, the sampled voltage signal is multiplied by the preset code to obtain the first voltage signal, and the current signal is multiplied by the preset code to obtain the first current signal.

[0035] In a possible design, the product of a preset code and a preset code is a sequence of all ones.

[0036] In a possible design, the preset code is a sequence containing +1 and -1.

[0037] In a possible design, the preset code is a periodic sequence, and before the excitation signal is applied to the battery, the voltage of the battery is sampled by using a sampler to obtain an interference voltage signal, and the periodicity of the preset code is determined based on the sampled interference voltage signal.

[0038] In a possible design, the preset code is a non-periodic sequence, in which case the periodicity of the preset code does not need to be determined.

[0039] According to a fifth aspect, the present application further provides an apparatus. The apparatus can perform the method design in the fourth aspect. The apparatus can be a chip or circuit that can perform the function corresponding to the above-mentioned method, or a device that includes a chip or circuit.

[0040] In one possible implementation, an apparatus includes a memory configured to store computer executable program code and a processor coupled to the memory, the program code stored in the memory including instructions that, when executed by the processor, enable the apparatus, or a device in which the apparatus is installed, to perform a method according to any one of the possible designs described above.

[0041] In one possible embodiment, the device may further include a communication interface. The communication interface may be a transceiver. Alternatively, if the device is a chip or circuit, the communication interface may be an input / output interface of the chip, such as an input / output pin.

[0042] In a possible design, the apparatus includes corresponding functional units that are separately configured to implement the steps of the aforementioned method. The functions may be implemented by hardware or by the hardware executing corresponding software. The hardware or software includes one or more units corresponding to the aforementioned functions.

[0043] According to a sixth aspect, the present application provides a computer readable storage medium. The computer readable storage medium stores a computer program. When the computer program is run on an apparatus, the method in any one of the possible designs of the fourth aspect is performed.

[0044] According to a seventh aspect, the present application provides a computer program product, the computer program product comprising a computer program which, when run on an apparatus, performs the method in any one of the possible designs of the fourth aspect. [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is a schematic diagram of EIS detection according to the present application. [Diagram 2] FIG. 2 is a schematic diagram of a VCCS circuit according to the present application. [Diagram 3] FIG. 1 is a schematic diagram of EIS detection failure when the battery is operating online according to the present application. [Figure 4] FIG. 2 is a schematic diagram of the structure of a terminal device according to the present application; [Diagram 5] 1 is a schematic diagram of a battery impedance detection device according to the present application; [Figure 6] FIG. 5 is a schematic diagram of components included in a first processing module 501 according to the present application. [Figure 7] 3A-3C are schematic diagrams of time and frequency domain waveforms of preset codes according to the present application; [Figure 8] FIG. 2 is a schematic diagram of the signals passing through the module when the impedance of the battery is detected according to the present application. [Figure 9] 2A-2C are schematic diagrams of time and frequency domain waveforms of an excitation signal according to the present application; [Figure 10] FIG. 5 is a schematic diagram of components included in a second processing module 503 according to the present application. [Figure 11] 4A-4C are schematic diagrams of time and frequency domain waveforms of a first voltage signal according to the present application; [Figure 12] 4A-4C are schematic diagrams of time and frequency domain waveforms of a first current signal according to the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] The technical solutions of the embodiments of the present application will be described below clearly and completely with reference to the accompanying drawings of the embodiments of the present application. It is clear that the described embodiments are only some, not all, of the embodiments of the present application. In the specification, claims, and accompanying drawings of the present application, the terms "first", "second", corresponding term numbers, etc. are intended to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the terms so used are interchangeable in appropriate circumstances, and this is merely a distinguishing manner used when objects having the same attributes are described in the embodiments of the present application. Furthermore, the terms "include", "have" and any other variations are meant to cover a non-exclusive inclusion, so that a process, method, system, product, or device that includes a set of units is not necessarily limited to those units, but may include other units that are not expressly listed or inherent in such a process, method, system, product, or device.

[0047] In the description of this application, unless otherwise stated, " / " means "or". For example, A / B may indicate A or B. In the present application, "and / or" only describes the association relationship to describe the associated object, and indicates that three relationships may exist. For example, A and / or B may indicate the following three cases: when only A exists, when both A and B exist, and when only B exists. In addition, in the description of this application, "at least one item" means one or more items, and "multiple items" means two or more items. "At least one item of" or similar expressions means any combination of these, including a singular item, or any combination of multiple items. For example, at least one item of a, b, or c may indicate a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be singular or plural.

[0048] To facilitate understanding of the embodiments of the present application, a brief description of EIS detection is provided below.

[0049] As shown in FIG. 1, an excitation signal S(n), for example, S(n)=A*sin(2πf0n / f s ), an analog excitation signal S(t) corresponding to S(n) is first generated via a digital-to-analog conversion performed by a digital-to-analog converter (DAC), where f0 is the test frequency, fs is the sampling rate, and A is the amplitude of the excitation signal. In this application, * represents a multiplication symbol.

[0050] Then, S(t) is input to a current generator, for example, a voltage-controlled current source (VCCS). The current generator generates an excitation current I(t) corresponding to S(t) and applies the excitation current I(t) to the battery. As shown in FIG. 1, I(t) is applied to the positive terminal of the battery. Also, the excitation current I(t) may alternatively be applied to the negative terminal of the battery. Here, only the example in which the excitation current I(t) is applied to the positive terminal of the battery is used for explanation. For example, the VCCS circuit includes an operational amplifier and a power MOS transistor, as shown in FIG. 2. Therefore, I(t) is proportional to S(t). For example, I(t)=α*S(t), where α is a constant.

[0051] After I(t) is applied to the battery, a sampler detects the voltage V(t) across the battery and performs analog-to-digital conversion to obtain V(n) corresponding to V(t). Since I(t) is a fixed periodic function, I(n) may be obtained by sampling the battery current online by a sampler, or it may be a constant after a Fourier transform is performed on the current value obtained by pre-sampling, e.g.

number

[0052] Furthermore, an N-point fast Fourier transform (FFT) is performed on V(n) to obtain V(k), where

number

number

number

[0053] N is the number of sampling points, f0 is the test frequency, and fs is the sampling rate. Therefore,

number

number

[0054] According to the above method, sinusoidal excitation signals with test frequencies f0, f1, ..., and fm are successively applied to obtain Z(ω0), Z(ω1), ..., and Z(ω m ) are determined to form an EIS impedance spectrum, where m is a positive integer.

[0055] 1, the excitation signal is described by taking a sine wave excitation signal as an example, and the excitation signal may also be a square wave signal, a triangular wave signal, etc.

[0056] However, the aforementioned EIS detection is a static detection method, and EIS detection cannot be performed in a scenario where there is load interference on the battery, in other words, dynamic detection cannot be performed when the battery is in an online working state. The battery being in an online working state may include the battery being in a charging state or the battery being in a load discharging state. As shown in FIG. 3, when the battery is working online, an interference current I_noise(t) is generated during charging or discharging, so if EIS detection is still performed, the voltage Vsn(t) across the battery is a voltage corresponding to the excitation response including both the current I(t) and the current I_noise(t), and an accurate result of the impedance of the battery at the test frequency f0 cannot be obtained. As a result, the EIS detection method fails.

[0057] Therefore, in scenarios where EIS detection needs to be performed when the battery is in a charging state or a load discharging state, the EIS detection method cannot meet the requirements. For example, to ensure the safety of the battery, EIS detection may need to be performed on the batteries in new energy vehicles, the large number of batteries in a solar power station, and the batteries contained in terminal devices such as mobile phones, watches, or tablet computers when the batteries are operating online. However, the EIS detection method cannot meet the aforementioned requirements.

[0058] The embodiments of the present application may be applied to a variety of different terminal devices, such as mobile phones, personal computers (PCs), tablets, wearable devices, new energy vehicles, and solar power plants, etc. In the following, the terminal device shown in FIG. 4 is used as an example to describe a specific application scenario of this embodiment of the present application.

[0059] 4 is a schematic diagram of the structure of a terminal device. The terminal device may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, a headset jack 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display 194, a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, an optical proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

[0060] It will be understood that the structure shown in this embodiment of the present invention does not impose any particular limitation on the terminal device. In some other embodiments of the present application, the terminal device may include more or less components than those shown in the figure, or some components may be combined, or some components may be divided, or a different component arrangement may be used. The components shown in the figure may be implemented by hardware, software, or a combination of software and hardware.

[0061] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent components or may be integrated into one or more processors. The processor 110 may be located on one or more chips.

[0062] The controller may be the central part and command center of the terminal device. The controller may generate an operation control signal according to the instruction operation code and the time series signal to complete the control of reading the instruction and executing the instruction.

[0063] A memory may further be disposed in the processor 110 and configured to store instructions and data. In some embodiments, the memory in the processor 110 is a cache. The memory may store instructions or data that have been used or have been used periodically by the processor 110. When the processor 110 needs to use the instructions or data again, the processor may retrieve the instructions or data directly from the memory. This avoids repeated accesses, reduces the latency of the processor 110, and improves system efficiency.

[0064] In some embodiments, the processor 110 may include one or more interfaces, which may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0065] The charging management module 140 is configured to receive a charging input from a charger. The charger may be a wireless charger or a wired charger. In some embodiments of wired charging, the charging management module 140 may receive a charging input from the wired charger via the USB interface 130. In some embodiments of wireless charging, the charging management module 140 may receive a wireless charging input via a wireless charging coil of the terminal device. While charging the battery 142, the charging management module 140 may further power the terminal device by using the power management module 141.

[0066] The power management module 141 is configured to connect to the battery 142, the charging management module 140, and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140 and provides power to the processor 110, the internal memory 121, the external memory, the display 194, the camera 193, the wireless communication module 160, etc. The power management module 141 may be further configured to monitor parameters such as battery capacity, battery cycle count, battery health (leakage or impedance), etc. In some other embodiments, the power management module 141 may be alternatively disposed in the processor 110. In some other embodiments, the power management module 141 and the charging management module 140 may alternatively be disposed in the same device.

[0067] The external memory interface 120 may be configured to connect to an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device. The external memory card communicates with the processor 110 through the external memory interface 120 to implement data storage functions. For example, music files or video files are stored in the external memory card.

[0068] The internal memory 121 may be configured to store computer executable program code. The executable program code includes instructions. The processor 110 runs the instructions stored in the internal memory 121 to perform various functional applications and data processing of the terminal device. The internal memory 121 may include a program storage area and a data storage area. The program storage area may store an operating system, applications required by at least one function (e.g., a sound playback function or an image playback function), and the like. The data storage area may store data (such as audio data and a phone book) created during the use of the terminal device, and the like. In addition, the internal memory 121 may include a high-speed random access memory or may include a non-volatile memory, for example, at least one magnetic disk storage device, a flash memory, or a universal flash storage (UFS).

[0069] For example, the internal memory 121 is configured to store a computer executable program code corresponding to this embodiment of the present application, and the processor 110 is coupled to the internal memory 121. The computer executable program code stored in the internal memory 121 includes instructions. When the processor 110 executes the instructions, the terminal device is enabled to perform an impedance spectrum detection method of the battery 142 provided in one embodiment of the present application. The method includes: performing a first code conversion on a first signal based on a preset code to obtain an excitation signal, applying the excitation signal to the battery, sampling the voltage of the battery 142 by using a sampler after applying the excitation signal to the battery to obtain a sampled voltage signal, performing a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, performing a second code conversion on the current signal of the battery 142 based on the preset code to obtain a first current signal, and determining an impedance corresponding to the battery 142 based on the first voltage signal and the first current signal. The aforementioned method will be described below with reference to the apparatus shown in FIG. 5.

[0070] As shown in FIG. 5, the present application provides a battery impedance spectrum detection device for performing EIS detection in a scenario where load interference exists on the battery. The device includes a first processing module 501, a sampler 502, and a second processing module 503. For example, the first processing module 501 and the second processing module 503 may be two functional modules in a processor. Optionally, the first processing module 501 and the second processing module 503 may be integrated into the same module. Optionally, the first processing module 501 and the second processing module 503 may reuse some modules. The sampler 502 may be a hardware accelerator in the processor 110 or may be an independent hardware component. Alternatively, the sampler 502 may be located inside the battery 142. This is not limited in the embodiment. For example, the first processing module 501 and the second processing module 503 are two functional modules in the processor 110 shown in FIG. 4, or the first processing module 501 and the second processing module 502 are disposed in two processors 110, respectively. The first processing module 501 and the second processing module 503 may be implemented by hardware, software, or a combination thereof. This is not limited in the present application. For example, the first processing module 501 and the second processing module 503 may be a hardware accelerated logic computing circuit in the processor 110. Alternatively, the first processing module 501 and the second processing module 503 may be a software module executed by the processor 110.

[0071] It will be understood that the impedance detection device provided in the present application may be used to measure the impedance of the battery 142 at a test frequency corresponding to the first signal. Furthermore, the impedance of the battery 142 at a series of test frequencies may be obtained by changing the test frequency to form an EIS impedance spectrum. It is noted that this embodiment of the present application may also be applied to a scenario in which the battery has a load interference, for example, the impedance of the battery is measured when the battery is in a charging state or a load discharging state, and may also be applied to a scenario in which the impedance of the battery is measured when the battery is in a resting state. The detected impedance value or the detected EIS impedance spectrum is used by the processor 110 to manage the battery 142 to implement safety control on the battery 142.

[0072] Referring to FIG. 5, the first processing module 501 is configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal, and apply the excitation signal to the battery, where the first signal is an original signal used to generate the excitation signal; the sampler 502 is coupled to the battery and configured to sample the voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal; the second processing module 503 is configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, and perform a second code conversion on the current signal of the battery based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal. When the first processing module 501 and the second processing module 503 are implemented by using hardware circuits, the first processing module 501 and the second processing module 503 may reuse some circuits, for example, may reuse circuits used for multiplication calculations. This is not limited in this embodiment. When the first processing module 501 and the second processing module 503 are implemented by using software, the first processing module 501 and the second processing module 503 may reuse some programs or functions, for example, may reuse programs or functions used for multiplication calculation. This is not limited in this embodiment.

[0073] The following describes each component of the aforementioned device. Figure 6 is a schematic diagram of each component included in the first processing module 501. It will be understood that the structure shown in Figure 6 does not constitute a specific limitation for the first processing module 501. In some other embodiments of the present application, the first processing module 501 may include more or less components than those shown in the figure, or may combine some components, or may split some components, or may have a different component arrangement.

[0074] 6, the first processing module 501 includes a first code conversion module 601, a digital-to-analog converter 602, and a current generator 603. The first code conversion module 601 shown in the figure may be implemented by hardware, software, or a combination of software and hardware. The digital-to-analog converter 602 and the current generator 603 may be hardware.

[0075] The first code conversion module 601 is configured to multiply the first signal by a preset code C(n) to obtain an excitation signal.

[0076] For example, as an original signal, the first signal may be a single-frequency signal or a multi-frequency signal, and is used to generate an excitation signal. For example, the first signal may be a sine wave signal, a square wave signal, a triangular wave signal, etc. This is not limited in this application. In the following, we only use an example in which the first signal is a sine wave signal for explanation. For example, the first signal is s(n)=A*sin(2πf0n / f s ), f0 is the test frequency and fs is the sampling rate. f0=125 Hz, f s = 32 kHz, then the first signal is s(n) = A * sin(2πn / 256).

[0077] For example, the preset code C(n) is a sequence including +1 and -1. For example, the preset code may be a periodic sequence including +1 and -1, and the preset code may be an aperiodic sequence including +1 and -1. For example, the preset code may be a random sequence including +1 and -1. It is understood that the preset code in this application is different from a typical binary code. In this application, a high electric level is represented as 1 and a low electric level is represented as -1, resulting in a sequence including +1 and -1. In addition, the product of the preset code and the preset code is a sequence of all ones.

[0078] For example, the preset code C(n) may be generated by a code generator, the output of which is connected to the first processing module 501 and the second processing module 503, respectively.

[0079] For example, the preset code C(n) is a periodic square wave sequence.

number

[0080] Where:

number

[0081] For P=2048 and N=8192, C(n) can be expressed as follows:

number

[0082] As shown in FIG. 7, the upper part of FIG. 7 is the time domain waveform C(n) of the preset code, and the lower part of FIG. 7 is the frequency domain waveform C(ω) of the preset code.

[0083] It should be understood that the first code conversion can also be called wave code conversion. In addition to the multiplication method, other methods may alternatively be used in the first code conversion to obtain the excitation signal Sc(n). This is not limited in the present application. Please note that the excitation signal obtained in this case is a digital signal.

[0084] The digital-to-analog converter 602 is configured to perform digital-to-analog conversion on the excitation signal Sc(n) to obtain an analog signal Sc(t).

[0085] The current generator 603 is configured to generate an excitation current Ic(t) based on the analog signal Sc(t) and apply the excitation current Ic(t) to the battery.

[0086] For example, the current generator 603 may be a VCCS or other module configured to generate a current, which is not limited in this embodiment.

[0087] In the following, with reference to FIG. 8, the signals passing through the modules in the first processing module 501 when the impedance of the battery is detected will be described.

[0088] For example, the first signal is s(n)=A*sin(2πf0n / f s ), and the preset code is Equation (1). The first code conversion module 601 multiplies s(n) by C(n) to obtain an excitation signal Sc(n). As shown in Fig. 8, the excitation signal output by the first code conversion module 601 is Sc(n), and Sc(n) is a digital signal.

number

[0089] f0=125 Hz, f s = 32 kHz, P = 2048, N = 8192.

number

[0090] As shown in Fig. 9, the upper part of Fig. 9 is the time domain waveform Sc(n) of the excitation signal shown in Equation (2), and the lower part of Fig. 9 is the frequency domain waveform Sc(ω) of the excitation signal shown in Equation (2). From Sc(n), it can be seen that Sc(n) is no longer a perfect sine wave waveform, and from Sc(ω), it can be seen that two harmonics (x=109.315, x=140.625) of Sc(ω) are separately located on both sides of the fundamental frequency (x=125) of s(n) (i.e., the test frequency).

[0091] Then, the digital-to-analog converter 602 performs digital-to-analog conversion on the excitation signal Sc(n) shown in equation (2) to generate an analog signal Sc(t). As shown in Figure 8, the signal output by the digital-to-analog converter 602 is Sc(t), where Sc(t) is an analog signal.

number

[0092] The current generator 603 is assumed to be a VCCS. As shown in Fig. 8, the current generator 603 generates an excitation current Ic(t) based on the analog signal Sc(t) shown in equation (3) and applies the excitation current Ic(t) to a battery, for example, to the positive terminal of the battery.

number

[0093] Here, α is a constant coefficient.

[0094] The sampler 502 is configured to sample the voltage Vcn(t) across the battery after the excitation signal is applied to the battery, and perform analog-to-digital conversion on the collected voltage Vcn(t) of the battery to obtain a sampled voltage signal Vcn(n). The sampled voltage signal Vcn(n) is a digital signal.

[0095] For example, as shown in Fig. 8, after an excitation signal Ic(t) is applied to the battery, a sampler 502 samples the battery voltage Vcn(t) and performs analog-to-digital conversion on Vcn(t) to obtain a sampled voltage signal Vcn(n). The sampled voltage signal Vcn(n) is a digital signal corresponding to the battery voltage Vcn(t).

[0096] In addition, the sampler 502 may be further configured to sample the battery current to obtain a current signal Ic(n). For example, as shown in FIG. 8, the current signal obtained by sampling the battery current by the sampler 502 is Ic(n).

[0097] Alternatively, in another implementation solution, the current signal Ic(n) may be determined by calculation based on the excitation signal. Also, when the current signal Ic(n) is determined by calculation based on the excitation signal, the interference current is not considered for the current signal in this case. For example, the current of the battery is the excitation current Ic(t), and the current signal Ic(n) is a digital signal corresponding to Ic(t). Since Ic(t)=α*Sc(t), Ic(n)=α*Sc(n), where α is a constant.

[0098] It should be noted that the current signal Ic(n) obtained by using the sampler 502 or determined by calculation based on the excitation signal is a digital signal.

[0099] Figure 10 is a schematic diagram of components included in the second processing module 503. It will be understood that the structure shown in Figure 10 does not constitute a particular limitation on the second processing module 503. In some other embodiments of the present application, the second processing module 503 may include more or fewer components than those shown in the figure, or some components may be combined, or some components may be split, or a different component arrangement may be used.

[0100] As shown in Fig. 10, the second processing module 503 includes a second code conversion module 1001, a Fourier transform module 1002, and a calculation module 1003. The components shown in the figure may be implemented by hardware, software, or a combination of software and hardware. For example, the second code conversion module 1001, the Fourier transform module 1002, and the calculation module 1003 may be hardware or software.

[0101] The second code conversion module 1001 is configured to multiply the preset code C(n) by the sampled voltage signal Vcn(n) to obtain a first voltage signal V(n), and to multiply the preset code C(n) by the current signal Ic(n) to obtain a first current signal I(n).

[0102] It should be understood that the second code conversion may also be called an inverse wave code conversion. In addition to the multiplication method, other methods may alternatively be used in the second code conversion. This is not limited in the present application.

[0103] The Fourier transform module 1002 is configured to perform a Fourier transform on the first voltage signal V(n) to obtain a voltage Fourier transform result V(k) and to perform a Fourier transform on the first current signal I(n) to obtain a current Fourier transform result I(k).

[0104] The computation module 1003 is configured to determine an impedance corresponding to the battery based on the voltage Fourier transform result V(k) and the current Fourier transform result I(k).

[0105] In the following, with reference to FIG. 8, the signals passing through the modules in the second processing module 503 when the impedance of the battery is detected will be described.

[0106] The second code conversion module 1001 multiplies the sampled voltage signal Vcn(n) obtained by the sampler 502 by a preset code C(n) corresponding to equation (1) to obtain a first voltage signal Vn(n), and multiplies the current signal Ic(n) by a preset code C(n) corresponding to equation (1) to obtain a first current signal I(n). As shown in FIG. 8, the second code conversion module 1001 outputs the first voltage signal Vn(n) and the first current signal I(n).

[0107] In the following, Vcn(n)=μ*(Ic(n)+I_noise(n)) is used as an example. I_noise(n) is a digital signal corresponding to the interference current I_noise(t), and μ is a constant related to the impedance of the battery. If the frequency of the interference current I_noise(t) is the test frequency f0, i.e., I_noise(t)=B*cos(2πnf0t), then I_noise(n)=B*cos(2πnf0n). It should be understood that the interference current I_noise(t) is caused by the load when the battery has a load, for example in a charging circuit or a load discharging circuit. The following estimation is made:

number

[0108] Where:

number

[0109] Here, C(n)*C(n)=1.

[0110] In equations (5) and (6), f0 = 125 Hz, f s Assuming that = 32 kHz, P = 2048, and N = 8192 are substituted, we obtain:

number

[0111] As shown in Fig. 11, the upper part of Fig. 11 is the time domain waveform Vn(n) of the first voltage signal shown in equation (7), and the lower part of Fig. 11 is the frequency domain waveform Vn(ω) of the first voltage signal shown in equation (7). Therefore, the amplitude corresponding to the test frequency f0 is independent of I_noise(n). The fundamental frequency of Vn(ω) is the same as the test frequency f0.

[0112] As shown in Fig. 12, the upper part of Fig. 12 is the time domain waveform I(n) of the first current signal shown in equation (8), and the lower part of Fig. 12 is the frequency domain waveform I(ω) of the first current signal shown in equation (8). The fundamental frequency of I(ω) is the same as the test frequency f0.

[0113] The Fourier transform module 1002 performs Fourier transform on the first voltage signal Vn(n) and the first current signal I(n) separately to obtain a voltage Fourier transform result V(k) and a current Fourier transform result I(k). As shown in FIG. 8, the Fourier transform module 1002 outputs the voltage Fourier transform result V(k) and the current Fourier transform result I(k).

[0114] For example, an N-point FFT is performed on Vn(n) to obtain V(k), where

number

number

[0115] The computation module 1003 is configured to determine an impedance Z(ω 0 ) corresponding to the battery based on the voltage Fourier transform result V(k) and the current Fourier transform result I(k).

[0116] For example, the impedance Z(ω0) of the battery at the test frequency f0 is:

number

[0117] Assuming f0=125 Hz, N=8192, and fs=32 kHz, we obtain:

number

[0118] It should be noted that the above process may be called a detection phase, and the detection phase is used to detect the impedance of the battery. In the following, a manner of determining the periodicity of the preset code is described. The manner of determining the periodicity of the preset code may be called an observation phase. The observation phase is used to detect the frequency of the interference current and determine the periodicity of the preset code, and the preset code is used as an input of the detection phase. In addition, when the preset code is a non-periodic sequence, the process of determining the periodicity of the preset code may not be performed, i.e., the following process does not need to be performed.

[0119] The following describes a method for determining the periodicity of the preset code. When no excitation signal is applied to the battery, the following solution is carried out to determine how to determine the appropriate periodicity of the preset code when load interference exists, in order to apply and measure the next excitation signal.

[0120] The sampler 502 is further configured to sample the voltage of the battery to obtain an interference voltage signal before the first processing module 501 applies the excitation signal to the battery, i.e. when the excitation signal is not applied to the battery.

[0121] For example, when no excitation signal is applied to the battery, the sampler 502 samples the voltage of the battery to obtain an interference voltage signal V'n(t).

[0122] The second processing module 503 is further configured to determine a periodicity of the preset code based on the sampled interference voltage signal.

[0123] For example, the Fourier transform module 1002 is configured to perform a Fourier transform on the interference voltage signal to obtain a Fourier transform result corresponding to the interference voltage signal, where the Fourier transform result corresponding to the interference voltage signal includes N frequency domain values, where N is the number of sampling points.

[0124] The calculation module 1003 is

number

number

number

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[0125] For example, the Fourier transform module 802 performs an N-point FFT on V'n(t) to obtain N frequency domain values, and the specific results are as follows:

number

number

number

number

number

number

number

[0126] According to the above process, the period length of the preset code is determined to be P, where

number

[0127] For example, f0=125 Hz, fs=32 kHz, N=8192,

number

number

[0128] The EIS detection solution provided in the embodiment of the present application has the characteristics of strong anti-interference and high accuracy. The reason is that a first code conversion is first performed on the first signal based on a preset code to obtain an excitation signal, the excitation signal is applied to the battery, and then a second code conversion is separately performed on the sampled voltage signal and current signal of the battery based on the preset code, so that the fundamental frequency of the first voltage signal is the same as the fundamental frequency of the first signal (i.e., the test frequency), and the fundamental frequency of the first current signal is the same as the fundamental frequency of the first signal (i.e., the test frequency). However, for the interference current and the corresponding voltage signal, only the second code conversion is performed (no first code conversion is performed), and the spectrum of the interference current is spread to many other frequencies. Therefore, the interference signal spectrum is eliminated at the test frequency of EIS detection.

[0129] Those skilled in the art will notice that the units and algorithm steps can be implemented by electronic hardware or by a combination of computer software and electronic hardware in combination with the examples described in the embodiments disclosed herein. Whether the functions are implemented by hardware or software depends on the specific application and the design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but this implementation is naturally not considered to go beyond the scope of this application.

[0130] According to a fifth aspect, the present application further provides an apparatus, which may be a chip or circuit capable of implementing the above-mentioned solution, including corresponding functionality, for example including a processor, for example the processor 110 of FIG.

[0131] Those skilled in the art may clearly understand that for the sake of convenient description, for the specific operation processes of the above-mentioned systems, apparatuses, and units, please refer to the corresponding processes in the above-mentioned method embodiments, and the details will not be described again here.

[0132] In some embodiments provided in the present application, it should be understood that the disclosed system, device, and method may be realized in other manners. For example, the described device embodiment is only an example. For example, the division into units is only a logical functional division, and may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. Indirect couplings or communication connections between devices or units may be implemented in electrical, mechanical, or other forms.

[0133] The units described as separate parts may or may not be physically separate, and the parts presented as units may or may not be physical units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments.

[0134] In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit.

[0135] When the function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium, for example, the internal memory 121 shown in FIG. 4. Based on this understanding, the technical solution of the present application may be implemented as an essential part, a part contributing to the prior art may be implemented, or a part of the technical solution may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to perform all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes any medium capable of storing program code, such as a flash memory, a removable hard disk, a read-only memory ROM, a random access memory RAM, a disk, or an optical disk. [Explanation of symbols]

[0136] 1 Antenna 2 Antennas 110 Processor 120 External Memory Interface 121 Internal Memory 130 USB interface 140 Charging Management Module 141 Power Management Module 142 Batteries 150 Mobile communication module 160 Wireless communication module 170 Audio Module 170A Speaker 170B Receiver 170C Microphone 170D Headset Jack 180 Sensor Module 180A PRESSURE SENSOR 180B Gyroscope Sensor 180C Barometric Pressure Sensor 180D Magnetic Sensor 180E Acceleration Sensor 180F Distance Sensor 180G Optical Proximity Sensor 180H Fingerprint Sensor 180J Temperature Sensor 180K touch sensor 180L Ambient Light Sensor 180M Bone Conduction Sensor 190 Button 191 Motor 192 Indicator 193 Camera 194 Display 195 SIM card interface 501 First Processing Module 502 Sampler 503 Second Processing Module 601 First Code Conversion Module 602 Digital-to-Analog Converter 603 Current Generator 802 Fourier Transform Module 1001 Second code conversion module 1002 Fourier Transform Module 1003 Calculation Module

Claims

1. 1. A battery impedance detection apparatus, comprising: a first processing module configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal, and apply the excitation signal to a battery, the first signal being an original signal used to generate the excitation signal; a sampler coupled to the battery and configured to sample a voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal; a second processing module configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, perform the second code conversion on the battery current signal based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal; An apparatus comprising:

2. The apparatus of claim 1 , wherein the first processing module comprises a first code conversion module configured to multiply the first signal by the preset code to obtain the excitation signal.

3. The first processing module includes: a digital-to-analog converter DAC configured to perform a digital-to-analog conversion on the excitation signal to obtain an analog signal; a current generator configured to generate an excitation current based on the analog signal and apply the excitation current to the battery; 3. The apparatus according to claim 1 or 2, comprising:

4. The sampler is further configured to sample a current of the battery to obtain the current signal; or 4. Apparatus according to claim 1, wherein the current signal is determined by calculation based on the excitation signal.

5. The second processing module includes:

5. The apparatus of claim 1, further comprising a second code conversion module configured to multiply the sampled voltage signal by the preset code to obtain the first voltage signal and to multiply the current signal by the preset code to obtain the first current signal.

6. The apparatus of claim 1 , wherein a product of the preset code and the preset code is a sequence of all ones.

7. The apparatus of claim 6 , wherein the preset code is a sequence including +1 and −1.

8. the preset code is a periodic sequence, and the sampler is further configured to sample the voltage of the battery cell to obtain an interference voltage signal before the first processing module applies the excitation signal to the battery cell; The apparatus of claim 1 , wherein the second processing module is further configured to determine a periodicity of the pre-set code based on the sampled interference voltage signal.

9. 1. A battery impedance detection apparatus, comprising: a processor configured to perform a first code conversion on a first signal based on a preset code to obtain an excitation signal, and apply the excitation signal to a battery, the first signal being an original signal used to generate the excitation signal; a sampler coupled to the battery and configured to sample a voltage of the battery after the excitation signal is applied to the battery to obtain a sampled voltage signal; wherein the processor is further configured to perform a second code conversion on the sampled voltage signal based on the preset code to obtain a first voltage signal, perform the second code conversion on the battery current signal based on the preset code to obtain a first current signal, and determine an impedance corresponding to the battery based on the first voltage signal and the first current signal.

10. 10. The apparatus of claim 9, wherein the processor is configured to multiply the first signal by the preset code to obtain the excitation signal when performing the first code conversion on the first signal based on the preset code to obtain the excitation signal.

11. 11. The apparatus of claim 9 or 10, wherein the processor is configured to perform digital-to-analog conversion on the excitation signal to obtain an analog signal when the excitation signal is applied to the battery, generate an excitation current based on the analog signal, and apply the excitation current to the battery.

12. The sampler is further configured to sample a current of the battery to obtain the current signal; or 12. Apparatus according to any one of claims 9 to 11, wherein the current signal is determined by calculation based on the excitation signal.

13. 13. The apparatus of claim 9, wherein the processor is further configured to: multiply the sampled voltage signal by the preset code to obtain the first voltage signal; and multiply the sampled voltage signal by the preset code to obtain the first voltage signal; and multiply the current signal by the preset code to obtain the first current signal when performing the second code conversion on the battery current signal based on the preset code to obtain the first voltage signal.

14. 14. The apparatus of claim 9, wherein a product of the preset code and the preset code is a sequence of all ones.

15. The apparatus of claim 14, wherein the preset code is a sequence including +1 and -1.

16. the preset code is a periodic sequence, and the sampler is further configured to sample the voltage of the battery cell to obtain an interference voltage signal before the first processing module applies the excitation signal to the battery cell; 16. The apparatus of claim 9, wherein the processor is further configured to determine a periodicity of the pre-set code based on the sampled interference voltage signal.

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