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] Embodiments of this application relate to the field of batteries, and more particularly to a battery impedance detection device. [Background technology]

[0002] As charging speed and battery energy density increase, the safety risks of batteries continuously rise. In particular, with ternary lithium batteries, the initial oxygen generated during temperature rise is highly likely to cause an explosion, which poses a serious threat to the safety of users' personal and property. Therefore, prior detection and prevention by technical means before spontaneous combustion of batteries is 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. It contains a wealth of basic electrochemical and physical process information about the battery and can be used to detect exceptions in batteries such as short circuits, lithium metal deposition, overheating, and expansion. It is an effective method for proactively detecting and preventing battery failures.

[0004] However, EIS detection is a static detection method, meaning that detection can only be performed if there is no interfering current in the battery. Therefore, a method is needed to perform EIS detection in scenarios where load interference is present in the battery. [Overview of the Initiative]

[0005] This application provides a battery impedance detection device for performing EIS detection in scenarios where load interference exists in the battery.

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

[0007] According to the method described above, by using the first and second code conversions, the interference signal spectrum can be removed from the test frequency for EIS detection, and EIS detection can be performed when the battery is charged or when the battery is under load and discharged. In addition, the method described above has strong interference immunity 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 in order to obtain an excitation signal.

[0009] The first code conversion is performed in the manner described above to acquire the excitation signal. This solution is simple and easy to implement. In addition, the excitation signal may be acquired in a different manner, which is not limited in this application. The frequency domain waveform of the excitation signal acquired 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 an excitation signal to acquire an analog signal, and a current generator configured to generate an excitation current based on the analog signal and apply the excitation current to a battery.

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

[0012] In possible designs, 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 aforementioned design, the current signal may be acquired in multiple 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 a 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 each pre-configured code is a sequence of all values ​​equal to 1.

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

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

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

[0020] According to a second aspect, the present application provides a battery impedance detection device. The device is A processor configured to apply an excitation signal to a battery, wherein the first signal is the original signal used to generate the excitation signal; and a sampler coupled to the battery and configured to sample the battery voltage after the excitation signal has been applied to the battery, in order to obtain a sampled voltage signal, wherein the processor is further configured to perform a second coding on the sampled voltage signal based on a preset code to obtain a first voltage signal, perform a second coding on the battery current signal based on a preset code to obtain a first current signal, and determine the 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 preset code by the first signal in order to obtain the excitation signal, when performing a first coding transformation on the first signal based on a preset code in order to obtain the excitation signal.

[0022] In a possible design, the processor is configured to perform a 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.

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

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

[0025] In a possible design, the product of the preset code and the preset code is all a sequence of 1.

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

[0027] In a possible design, the preset code is a periodic sequence, and the sampler is further configured to sample the voltage of the battery to obtain an interference voltage signal before the first processing module applies an 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 an aperiodic sequence. In this case, the periodicity of the preset code need not be determined.

[0029] According to a third aspect, the present application provides an electronic system. The system includes 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 comprising: applying an excitation signal to a battery, the first signal being the original signal used to generate the excitation signal; sampling the battery voltage by using a sampler after the excitation signal has been applied to the battery, in order to obtain a sampled voltage signal; performing a second coding on the sampled voltage signal based on a preset code, in order to obtain a first voltage signal; performing a second coding on the current signal of the battery based on a preset code, in order to obtain a first current signal; and determining the impedance corresponding to the battery based on the first voltage signal and the first current signal.

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

[0032] In a possible design, when the 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 possible designs, the battery current is sampled using a sampler to obtain a current signal, or the current signal is determined by calculations based on the excitation signal.

[0034] In a possible design, to obtain a first voltage signal, a second coding transformation is performed on a sampled voltage signal based on a preset code; to obtain a first current signal, a second coding transformation is performed on a battery current signal based on a preset code; in this case, to obtain the first voltage signal, the sampled voltage signal is multiplied by the preset code; and to obtain the first current signal, the current signal is multiplied by the preset code.

[0035] In a possible design, the product of each pre-configured code is a sequence of all values ​​equal to 1.

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

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

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

[0039] According to a fifth aspect, the present application further provides an apparatus that can perform a method design according to a fourth aspect. The apparatus may be a chip or circuit, or a device including a chip or circuit, that can perform the functions corresponding to the aforementioned method.

[0040] In one possible embodiment, the device includes a memory configured to store computer executable program code and a processor, the processor being coupled to the memory. The program code stored in the memory includes instructions. When the processor executes an instruction, the device or the device on which the device is installed is enabled to perform any one of the aforementioned possible designs.

[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 input / output pins.

[0042] In possible designs, the device includes corresponding functional units separately configured to implement the steps in the method described above. This functionality may be performed by hardware or by running corresponding software in hardware. The hardware or software includes one or more units corresponding to the aforementioned functionality.

[0043] According to the 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 the device, a method in any one of the possible designs of the fourth aspect is performed.

[0044] According to the seventh aspect, the present application provides a computer program product. The computer program product includes a computer program, and when the computer program is run on a device, a method in any one of the possible designs of the fourth aspect is performed. [Brief explanation of the drawing]

[0045] [Figure 1] This is a schematic diagram of EIS detection according to this application. [Figure 2] This is a schematic diagram of the VCCS circuit according to this application. [Figure 3] This is a schematic diagram illustrating the failure of EIS detection when the battery is online, according to this application. [Figure 4] This is a schematic diagram of the structure of the terminal device according to this application. [Figure 5] This is a schematic diagram of the battery impedance detection device according to this application. [Figure 6] This is a schematic diagram of the components included in the first processing module 501 according to this application. [Figure 7] This is a schematic diagram of the time-domain and frequency-domain waveforms of the pre-set code according to this application. [Figure 8] This is a schematic diagram of the signal passing through the module when the battery impedance is detected, according to this application. [Figure 9] This is a schematic diagram of the time-domain and frequency-domain waveforms of the excitation signal according to this application. [Figure 10] This is a schematic diagram of the components included in the second processing module 503 according to this application. [Figure 11] This is a schematic diagram of the time-domain and frequency-domain waveforms of the first voltage signal according to this application. [Figure 12] This is a schematic diagram of the time-domain and frequency-domain waveforms of the first current signal according to this application. [Modes for carrying out the invention]

[0046] The technical solutions of the embodiments of this application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of this application. It will be clear that the embodiments described are only a part of, and not all, of, the embodiments of this application. In the specification, claims, and accompanying drawings of this application, “First,” “Second,” corresponding term numbers, etc., are intended to distinguish similar subjects and do not necessarily indicate a particular order or sequence. It should be understood that the terms used in this way are interchangeable in appropriate contexts and are merely a distinguishing method used when subjects having the same attributes are described in the embodiments of this application. Furthermore, the terms “include,” “have,” and any other variations mean to cover non-exclusive inclusion, so that a process, method, system, product, or device including a set of units may include other units that are not explicitly enumerated or specific to such a process, method, system, product, or device, but are not necessarily limited to those units.

[0047] In the description of this application, unless otherwise specified, " / " means "or". For example, A / B may indicate A or B. In this application, "and / or" only describes a relational relationship to describe related subjects and indicates that three relationships may exist. For example, A and / or B may indicate the following three cases: that only A exists, that both A and B exist, and that 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 of the following items" or similar expressions means any combination of singular items or any combination of multiple items. For example, at least one 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 this application, EIS detection is briefly described below.

[0049] As shown in Figure 1, the excitation signal S(n), for example, S(n) = A*sin(2πf0n / f s In the case of ), the analog excitation signal S(t) corresponding to S(n) is generated via a digital-to-analog conversion first 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 the multiplication symbol.

[0050] Next, S(t) is input to a current generator, such as a voltage-controlled current source (VCCS). The current generator produces an excitation current I(t) corresponding to S(t) and applies the excitation current I(t) to the battery. As shown in Figure 1, I(t) is applied to the positive electrode of the battery. Alternatively, the excitation current I(t) may be applied to the negative electrode of the battery. Here, only the example where the excitation current I(t) is applied to the positive electrode of the battery is used for explanation. For example, the VCCS circuit includes an operational amplifier and a power MOS transistor, as shown in Figure 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, the sampler detects the voltage V(t) across the battery terminals 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 the sampler, or by obtaining a constant after performing a Fourier transform on the current value obtained by pre-sampling, for example.

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

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 method described above, sinusoidal excitation signals having test frequencies f0, f1, ..., and fm are continuously applied, and the acquired Z(ω0), Z(ω1), ..., and Z(ω m Determine the respective values ​​and form the EIS impedance spectrum, where m is a positive integer.

[0055] Note that in Figure 1, the excitation signal is explained using a sinusoidal excitation signal as an example. However, the excitation signal may also be a square wave signal, a triangular wave signal, or other types of signals.

[0056] However, the aforementioned EIS detection is a static detection method and cannot be performed in scenarios where load interference is present in the battery; in other words, dynamic detection cannot be performed when the battery is in an online operating state. Being in an online operating state can include being in a charged state or a load-discharged state. As shown in Figure 3, when the battery is operating online, an interference current I_noise(t) is generated during charging or discharging, so if EIS detection is still being performed, the voltage Vsn(t) across the battery is the voltage corresponding to the excitation response which includes both current I(t) and current I_noise(t), and an accurate result of the battery impedance 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 charged or discharged state, EIS detection methods cannot meet the requirements. For example, to ensure battery safety, EIS detection may need to be performed when the battery is online, such as for batteries in new energy vehicles, numerous batteries in solar power plants, and batteries in terminal devices such as mobile phones, watches, or tablet computers. However, EIS detection methods cannot meet the aforementioned requirements.

[0058] Embodiments of this 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. Below, to illustrate a specific application scenario of this embodiment of the application, we will use the terminal device shown in Figure 4 as an example.

[0059] Figure 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, internal memory 121, a universal serial bus (USB) interface 130, a charge 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, and the like. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, a barometric 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 structures shown in this embodiment of the present invention are not intended to impose any particular limitations on terminal devices. In some other embodiments of this application, terminal devices may include more or fewer components than those shown in the figures, or some components may be combined, or some components may be separated, or different component arrangements may be used. The components shown in the figures 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, memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). 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 unit and command center of a terminal device. The controller can generate operation control signals based on instruction operation codes and time-series signals to complete the control of instruction reading and instruction execution.

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

[0064] In some embodiments, the processor 110 may include one or more interfaces. The interfaces 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.

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

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

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

[0068] The internal memory 121 may be configured to store computer executable program code. Executable program code includes instructions. The processor 110 executes 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 the operating system, applications required by at least one function (e.g., audio playback function or image playback function), etc. The data storage area may store data (such as audio data and phonebook) created during use of the terminal device, etc. In addition, the internal memory 121 may include high-speed random access memory, or non-volatile memory, such as at least one magnetic disk storage device, flash memory, or universal flash storage (UFS).

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

[0070] As shown in Figure 5, this application provides a battery impedance spectrum detection device for performing EIS detection in a scenario where load interference is present in 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 within 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 several modules. The sampler 502 may be a hardware accelerator within the processor 110 or an independent hardware component. Alternatively, the sampler 502 may be located inside the battery 142. This is not limited to the embodiments. For example, the first processing module 501 and the second processing module 503 are two functional modules within the processor 110 shown in Figure 4, or the first processing module 501 and the second processing module 502 are respectively located within two processors 110. 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 to the present application. For example, the first processing module 501 and the second processing module 503 may be hardware-accelerated logic circuits within the processor 110. Alternatively, the first processing module 501 and the second processing module 503 may be software modules executed by the processor 110.

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

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

[0073] The following describes each component of the aforementioned apparatus. 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 any particular limitation on the first processing module 501. In some other embodiments of this application, the first processing module 501 may include more or fewer components than those shown in the figure, or it may combine some components, or divide some components, or it may have a different component arrangement.

[0074] As shown in Figure 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 in 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) in order to obtain the excitation signal.

[0076] For example, the first signal, as the original signal, may be a single-frequency signal or a multi-frequency signal, and is used to generate the 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 to the present application. In the following, for illustrative purposes, only an example where the first signal is a sine wave signal will be used. For example, the first signal is s(n) = A * sin(2πf0n / f s ) where f0 is the test frequency and fs is the sampling rate. f0 = 125 Hz, f s If we set the frequency to 32 kHz, the first signal will be s(n) = A*sin(2πn / 256).

[0077] For example, the pre-set code C(n) is a sequence containing +1 and -1. For example, the pre-set code may be a periodic sequence containing +1 and -1, or a non-periodic sequence containing +1 and -1. For example, the pre-set code may be a random sequence containing +1 and -1. It will be understood that the pre-set codes in this application are different from general binary codes. In this application, high electrical levels are represented as 1 and low electrical levels are represented as -1, resulting in a sequence containing +1 and -1. In addition, the product of pre-set codes is a sequence where all are 1.

[0078] For example, the pre-configured code C(n) may be generated by a code generator. The output terminal of the code generator is connected separately to the first processing module 501 and the second processing module 503.

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

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[0080] Here,

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

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

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

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

[0085] The current generator 603 is configured to generate an excitation current Ic(t) based on an analog signal Sc(t) and to 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 current. This is not limited to this embodiment.

[0087] The following describes the signals that pass through the modules in the first processing module 501 when the battery impedance is detected, with reference to Figure 8.

[0088] For example, the first signal is s(n) = A * sin(2πf0n / f s ) and the pre-configured code is given by equation (1). The first code conversion module 601 obtains the excitation signal Sc(n) by multiplying s(n) by C(n). As shown in Figure 8, the excitation signal output by the first code conversion module 601 is Sc(n), and Sc(n) is a digital signal.

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[0089] f0 = 125 Hz, f s It is assumed that the frequency is 32 kHz, P=2048, and N=8192.

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[0090] As shown in Figure 9, the upper part of Figure 9 is the time-domain waveform Sc(n) of the excitation signal given by equation (2), and the lower part of Figure 9 is the frequency-domain waveform Sc(ω) of the excitation signal given by equation (2). From Sc(n), we can see that Sc(n) is no longer a perfect sinusoidal waveform, and from Sc(ω), we can see that the two harmonics of Sc(ω) (x=109.315, x=140.625) are located separately on either side of the fundamental frequency of s(n) (x=125) (i.e., the test frequency).

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

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[0092] The current generator 603 is assumed to be VCCS. As shown in Figure 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 the battery, for example, to the positive electrode of the battery.

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[0093] Here, α is a constant coefficient.

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

[0095] For example, as shown in Figure 8, after the excitation signal Ic(t) is applied to the battery, the sampler 502 samples the battery voltage Vcn(t), performs an analog-to-digital conversion on Vcn(t), and obtains the 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 Figure 8, the current signal obtained by sampling the battery current by the sampler 502 is Ic(n).

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

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

[0099] Figure 10 is a schematic diagram of the components included in the second processing module 503. It will be understood that the structure shown in Figure 10 does not constitute any particular limitation to the second processing module 503. In some other embodiments of this 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 divided, or different component arrangements may be used.

[0100] As shown in Figure 10, the second processing module 503 includes a second code conversion module 1001, a Fourier transform module 1002, and a computation 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 computation module 1003 may be hardware or software.

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

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

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

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

[0105] The following describes the signals that pass through the modules in the second processing module 503 when the battery impedance is detected, with reference to Figure 8.

[0106] The second code conversion module 1001 multiplies the sampled voltage signal Vcn(n) acquired by the sampler 502 by the preset code C(n) corresponding to Equation (1) to obtain the first voltage signal Vn(n), and multiplies the current signal Ic(n) by the preset code C(n) corresponding to Equation (1) to obtain the 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] Hereinafter, as an example, Vcn(n)=μ*(Ic(n)+I_noise(n)) is used. 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. Assuming that the frequency of the interference current I_noise(t) is the test frequency f0, that is, 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 in, for example, a charging circuit or a load discharge circuit. The following estimation is performed.

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[0108] Here

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

[0110] Assuming that f0 = 125 Hz, f s = 32 kHz, P = 2048, and N = 8192 are substituted into Equations (5) and (6), the following is obtained.

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[0111] As shown in Figure 11, the upper part of Figure 11 is the time-domain waveform Vn(n) of the first voltage signal given by equation (7), and the lower part of Figure 11 is the frequency-domain waveform Vn(ω) of the first voltage signal given by 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 Figure 12, the upper part of Figure 12 is the time-domain waveform I(n) of the first current signal shown in equation (8), and the lower part of Figure 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 transforms on the first voltage signal Vn(n) and the first current signal I(n) separately, obtaining the voltage Fourier transform result V(k) and the current Fourier transform result I(k). As shown in Figure 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), and here

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[0115] The calculation module 1003 is configured to determine the impedance Z(ω0) 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 as follows:

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[0117] Assuming f0=125 Hz, N=8192, and fs=32 kHz, the following is obtained:

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[0118] The process described above may also be called the detection phase, and it should be noted that the detection phase is used to detect the impedance of the battery. Below, we will describe the method for determining the periodicity of the preset code. The method for determining the periodicity of the preset code may also be called the 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 the input to the detection phase. In addition, when the preset code is a non-periodic sequence, the process for determining the periodicity of the preset code does not need to be performed, that is, the following process does not need to be performed.

[0119] The following describes the method for determining the periodicity of the pre-set code. To determine how to determine the appropriate periodicity of the pre-set code when load interference is present, in order to apply and measure the next excitation signal when no excitation signal is applied to the battery, the following solutions are employed.

[0120] The sampler 502 is further configured to sample the battery voltage to obtain an interference voltage signal before the first processing module 501 applies an excitation signal to the battery, i.e., when no excitation signal is applied to the battery.

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

[0122] The second processing module 503 is further configured to determine the 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 an interference voltage signal in order to obtain a Fourier transform result corresponding to the interference voltage signal, and 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,

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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:

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[0126] According to the process described above, the period length of the pre-configured code is determined to be P, and here

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

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[0128] The EIS detection solution provided in the embodiments of this application features strong interference prevention and high accuracy. This is because, firstly, a first coding transformation is performed on a first signal based on a preset code to acquire an excitation signal, the excitation signal is applied to the battery, and then a second coding transformation is performed separately on the sampled voltage and current signals 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 coding transformation is performed (the first coding transformation is not performed), and the spectrum of the interference current is spread more widely to other frequencies. Therefore, the interference signal spectrum is removed at the test frequency of the EIS detection.

[0129] Those skilled in the art will notice, in combination with the examples described in the embodiments disclosed herein, that the units and algorithmic steps can be implemented by electronic hardware or by a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software will depend on the specific application and the design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but it is not expected that such implementations would exceed 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 performing the aforementioned solutions and including the corresponding functions, for example, a processor, for example, the processor 110 in Figure 4.

[0131] Those skilled in the art will clearly understand that, for the sake of brevity, the specific operating processes of the aforementioned systems, apparatus, and units should be referred to the corresponding processes in the aforementioned method embodiments, and that further details will not be provided here.

[0132] In some embodiments provided in this application, it should be understood that the disclosed systems, apparatus, and methods may be implemented in other ways. For example, the embodiments of the apparatus described are merely examples. For example, the division into units is merely a logical functional division, and other divisions may be used in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or omitted. In addition, the mutual coupling, direct coupling, or communication connection shown or discussed may be implemented through some interfaces. Indirect coupling or communication connection between apparatus or units may be implemented in an electrical, mechanical, or other form.

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

[0134] In addition, the functional units in the embodiments of this application may be integrated into a single processing unit, each unit may exist physically independently, or two or more units may be integrated into a single unit.

[0135] When a function is implemented in the form of a software function 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 Figure 4. Based on this understanding, the technical solution of this application may be implemented as essential in the form of a software product, a portion of which may contribute to the prior art, or a portion of the technical solution may be implemented. A computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, server, or network device) to perform all or part of the steps of the method described in the embodiments of this application. The aforementioned storage medium includes any medium capable of storing program code, such as flash memory, removable hard disk, read-only memory ROM, random access memory RAM, disk, or optical disk. [Explanation of symbols]

[0136] 1 Antenna 2 antennas 110 processors 120 External memory interface 121 Internal Memory 130 USB Interfaces 140 Charging Management Module 141 Power Management Module 142 Batteries 150 Mobile Communication Modules 160 Wireless Communication Modules 170 Audio Modules 170A speaker 170B receiver 170C Microphone 170D headset jack 180 Sensor Modules 180A pressure sensor 180B Gyroscope Sensor 180°C barometric pressure sensor 180D Magnetic Sensor 180E Accelerometer 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 buttons 191 Motor 192 Indicators 193 Camera 194 displays 195 SIM card interface 501 First processing module 502 Sanpla 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 Computation Module

Claims

1. A method for detecting battery impedance, wherein the method is The steps include: obtaining an excitation signal by performing a first code conversion on a first signal based on a preset code using a first processing module, and applying the excitation signal to a battery, wherein the first signal is the original signal used to generate the excitation signal; To obtain a sampled voltage signal, the steps include: sampling the voltage of the battery by a sampler after the excitation signal has been applied to the battery; Steps include: obtaining a first voltage signal by performing a second code conversion on the sampled voltage signal by multiplying the preset code by the sampled voltage signal using a second processing module; obtaining a first current signal by performing the second code conversion on the battery current signal by multiplying the preset code by the battery current signal; and determining the impedance corresponding to the battery based on the first voltage signal and the first current signal. Methods that include...

2. The method according to claim 1, wherein the step of performing a first code transformation on a first signal based on a preset code in order to obtain an excitation signal includes the step of multiplying the first signal by the preset code in order to obtain the excitation signal.

3. The step of applying the excitation signal to the battery is, A step of performing a digital-to-analog conversion on the excitation signal in order to acquire an analog signal, A step of generating an excitation current based on the analog signal and applying the excitation current to the battery. The method according to claim 1 or 2, including the method described in claim 1 or 2.

4. The method further includes the step of acquiring the current signal, or The method according to claim 1 or 2, wherein the current signal is determined by a calculation based on the excitation signal.

5. The method according to claim 1 or 2, wherein the product of the preset code and the preset code is a sequence of all 1s.

6. The method according to claim 5, wherein the preset code is a sequence including +1 and -1.

7. The preset code is a periodic sequence, and the sampler is further configured to sample the voltage of the battery in order to obtain an interference voltage signal before the first processing module applies the excitation signal to the battery. The method according to claim 1 or 2, wherein the second processing module is further configured to determine the periodicity of the preset code based on the interference voltage signal.

8. A battery impedance detection device, wherein the device is A processor configured to perform a first code conversion on a first signal based on a preset code in order to acquire an excitation signal, and to apply the excitation signal to a battery, wherein the first signal is the original signal used to generate the excitation signal, and the processor A sampler coupled to the battery and configured to sample the battery voltage after the excitation signal is applied to the battery in order to obtain a sampled voltage signal, The device further comprises a processor which performs a second coding transformation on the sampled voltage signal by multiplying the sampled voltage signal by a preset code in order to obtain a first voltage signal, performs the second coding transformation on the battery current signal by multiplying the battery current signal by a preset code in order to obtain a first current signal, and determines the impedance corresponding to the battery based on the first voltage signal and the first current signal.

9. The apparatus according to claim 8, wherein the processor is configured to multiply the first signal by the preset code in order to obtain the excitation signal when performing the first code conversion on the first signal based on the preset code in order to obtain the excitation signal.

10. The apparatus according to claim 8 or 9, wherein the processor is configured to perform a 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.

11. The sampler is further configured to sample the current of the battery in order to acquire the current signal, or The apparatus according to claim 8 or 9, wherein the current signal is determined by a calculation based on the excitation signal.

12. The apparatus according to claim 8 or 9, wherein the product of the preset code and the preset code is a sequence of all 1s.

13. The apparatus according to claim 12, wherein the preset code is a sequence including +1 and -1.

14. The preset code is a periodic sequence, and the sampler is further configured to sample the voltage of the battery in order to obtain an interference voltage signal before the processor applies the excitation signal to the battery. The apparatus according to claim 8 or 9, wherein the processor is further configured to determine the periodicity of the preset code based on the sampled interference voltage signal.

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