Battery management circuit and battery management system

Abstract

The invention relates to the technical field of battery management, in particular to a battery management circuit and a battery management system, and aims to reduce the calculation amount of a controller on a digital signal obtained by analog-to-digital conversion, further reduce the calculation load of the controller and improve the signal processing efficiency. The battery management circuit comprises an analog operation circuit and an analog conversion circuit; the analog operation circuit is used for determining state parameters of the battery based on the battery sampling signal; the analog-to-digital conversion circuit is coupled to the analog operation circuit and is used for converting the state parameters into digital signals and outputting the digital signals. The battery management system comprises a battery, a controller and the battery management circuit, wherein the battery management circuit is coupled between the battery and the controller. The battery management circuit is configured to determine state parameters of the battery based on a battery sampling signal of the battery and output a digital signal obtained by converting the state parameters to the controller, so that the controller evaluates the working state of the battery based on the digital signal.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and more particularly to a battery management circuit and a battery management system. Background Technology

[0002] A battery management system (BMS) is an electronic system that monitors and manages rechargeable batteries (such as lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, etc.).

[0003] In related technologies, the Battery Management System (BMS) collects battery voltage and current signals through a battery management chip. After performing digital calculations on these signals, it transmits them to a microcontroller unit (MCU). The MCU then calculates battery state parameters, such as state of energy (SOE) and state of charge (SOC), based on these digital signals. This enables the assessment and monitoring of the battery's state.

[0004] However, since the MCU processes all the digital signals, the MCU chip has a large computational load, which can easily lead to delays in the calculated battery state parameters, affecting the stability and reliability of the battery management system. Summary of the Invention

[0005] The purpose of this application is to provide a battery management circuit and a battery management system, which aim to reduce the computational load of digital signals and improve signal processing efficiency.

[0006] In a first aspect, a battery management circuit is provided, comprising: an analog computing circuit and an analog-to-digital converter (ADC). The analog computing circuit is used to determine the battery's state parameters based on battery sampling signals. The ADC is coupled to the analog computing circuit and is used to convert the state parameters into digital signals for output.

[0007] The technical solution provided in this application adds an analog computing circuit before the analog-to-digital conversion circuit. The analog computing circuit pre-calculates the battery sampling signal to determine the battery's state parameters, realizing the preprocessing of the state parameters. This allows the analog-to-digital conversion circuit to directly convert the battery's state parameters into digital signals, reducing the computational workload of the subsequent controller in processing the digital signals, improving signal processing efficiency, and thus improving the real-time performance of the state parameters, effectively ensuring the stability and reliability of the battery management system.

[0008] In one implementation, the battery sampling signal includes at least one of the following: a current sampling signal and a voltage sampling signal. The state parameters include at least one of the following: change in state of energy (SGE), change in state of charge (SBC), and battery power. Wherein, battery power represents the product of the current sampling signal and the voltage sampling signal, the change in SGE represents the integral of the battery power, and the change in SBC represents the integral of the current sampling signal. Pre-calculating the battery's SGE, SBC, and power allows the subsequent controller to directly calculate the battery's SGE and SBC based on the digital signals of the SGE and SBC, and directly obtain the battery power, simplifying the controller's signal processing flow and improving signal processing efficiency.

[0009] In some embodiments, the analog-to-digital conversion circuit is an analog-to-digital converter (ADC). ADCs offer high accuracy and programmability, strong anti-interference capabilities, and can ensure the stability and reliability of the battery management circuit.

[0010] In one embodiment, the battery management circuit provided in this application further includes a signal sampling circuit. The signal sampling circuit is coupled to the analog computing circuit and is used to acquire battery sampling signals. By accurately and efficiently acquiring the battery sampling signals through the signal sampling circuit, the accuracy of the battery sampling signals is improved, thereby enhancing the reliability of the battery management circuit.

[0011] In one embodiment, the battery management circuit provided in this application further includes a multiplexer. The multiplexer is coupled between the signal sampling circuit and the analog processing circuit, and is used to switch the battery sampling signal input to the analog processing circuit. The multiplexer enables flexible signal switching, saves hardware resources, reduces circuit costs, improves circuit integration, and makes signal acquisition and processing more flexible.

[0012] In one embodiment, the battery management circuit provided in this application further includes a filtering circuit. The filtering circuit is coupled to the analog-to-digital converter circuit and is used to filter the digital signal. By extracting the effective components from the digital signal and suppressing noise and interference, the quality of the digital signal can be improved, thereby enhancing the stability and reliability of the battery management circuit.

[0013] In one implementation, the filtering circuit is a digital filter. Digital filters offer high stability and accuracy, strong anti-interference capabilities, and further improve the stability and reliability of the battery management circuit.

[0014] In one embodiment, the analog computing circuit includes a first current-to-voltage converter and a first integrator analog computing circuit. The first current-to-voltage converter converts a current sampling signal into a voltage signal. The first integrator analog computing circuit is coupled to the first current-to-voltage converter and integrates the voltage signal to output the change in state of charge. By using the first current-to-voltage converter and the first integrator analog computing circuit to calculate the change in state of charge in hardware, the risk of digital signal overflow is avoided, the accuracy and reliability of the calculation results are improved, the complexity of the algorithm calculation is simplified, and the signal processing effect is improved.

[0015] In one embodiment, a first current-to-voltage converter includes an operational amplifier and a feedback circuit. A first terminal of the operational amplifier is used to input a current sampling signal, a second terminal of the operational amplifier is coupled to ground, and a third terminal of the operational amplifier is used to output a voltage signal. A first terminal of the feedback circuit is coupled to the first terminal of the operational amplifier, a second terminal of the feedback circuit is coupled to the third terminal of the operational amplifier, and the third terminal of the feedback circuit is coupled to ground. The current-to-voltage conversion process is achieved through the operational amplifier and the feedback circuit, resulting in low input impedance and improved conversion accuracy. Furthermore, by adjusting the conversion gain through the feedback circuit, a wider conversion range is achieved.

[0016] In one implementation, the first integral analog operation circuit is an integrator. The integrator enables continuous, high-precision time integration, offering strong real-time performance and low computational delay, thus improving signal processing efficiency.

[0017] In one embodiment, the analog computing circuit further includes a second current-to-voltage converter and a first multiplication analog circuit. The second current-to-voltage converter converts the current sampling signal into a voltage signal. The first multiplication analog circuit is coupled to the second current-to-voltage converter and is used to calculate the battery power based on the voltage signal and the voltage sampling signal. Converting the current sampling signal into a voltage signal and then calculating the battery power based on the voltage signal and the voltage sampling signal allows for the processing of a wider range of signals. Compared to calculations based on sampled digital signals, this method offers faster response and lower power consumption.

[0018] In one implementation, the multiplication operation analog circuit is a multiplier. The multiplier enables real-time calculation of instantaneous power, offering faster response and lower signal delay compared to calculating power after sampling voltage and current, thus improving the reliability of the battery management circuit and the signal processing performance.

[0019] In one embodiment, the analog computing circuit further includes a third current-to-voltage converter, a second multiplication analog circuit, and a second integration analog circuit. The third current-to-voltage converter converts the current sampling signal into a voltage signal. The second multiplication analog circuit, coupled to the second current-to-voltage converter, calculates the battery power based on the voltage signal and the voltage sampling signal. The second integration analog circuit, coupled to the second multiplication analog circuit, integrates the power and outputs the change in state of energy.

[0020] In one implementation, the second integral analog operation circuit is an integrator.

[0021] Secondly, a battery management system is also provided, comprising a battery, a controller, and a battery management circuit in any of the real-time modes described in the first aspect. The battery management circuit is coupled between the battery and the controller. The battery management circuit is configured to: determine the battery's state parameters based on battery sampling signals, and output a digital signal obtained from the state parameter conversion to the controller, so that the controller can evaluate the battery's operating state based on the digital signal. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a battery management system provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of a battery management circuit provided in an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of another battery management circuit provided in an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of the structure of a first current-voltage converter provided in an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the structure of an integrator provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the structure of a multiplier provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of an analog computing circuit provided in an embodiment of this application.

[0030] Figure label:

[0031] 100. Battery;

[0032] 200. Battery management circuit;

[0033] 20. Analog computing circuit; 21. Analog-to-digital converter circuit; 22. Signal sampling circuit; 23. Multiplexer; 24. Filtering circuit; 25. Register; 26. Serial peripheral interface;

[0034] A1, First operational amplifier; A2, Second operational amplifier; A3, Third operational amplifier; A4, Fourth operational amplifier; A5, Fifth operational amplifier; A6, Sixth operational amplifier;

[0035] R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor; R14, fourteenth resistor; R15, fifteenth resistor; R16, sixteenth resistor; R17, seventeenth resistor;

[0036] T1, the first transistor; T2, the second transistor; T3, the third transistor;

[0037] C1, the first capacitor; C2, the second capacitor;

[0038] 1. First current-to-voltage converter; 2. Second integrator; 3. Multiplier; 4. Second integrator; 5. Switching circuit;

[0039] K1, first switch; K2, second switch; K3, third switch; K4, fourth switch;

[0040] 300. Controller. Detailed Implementation

[0041] In the embodiments of this application, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of that feature.

[0042] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. "A and / or B" includes three combinations: A only, B only, and a combination of A and B.

[0043] In describing some embodiments, the terms "coupled" and "connected," and their derivative expressions, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. Similarly, the term "coupled" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0044] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner. In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0045] This application provides a battery management system, which is an electronic system for monitoring and managing rechargeable batteries (such as lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, etc.).

[0046] For example, a Battery Management System (BMS) can monitor the voltage, current, and temperature of individual cells or battery packs in real time to avoid problems such as overcharging, over-discharging, overheating, low temperature, and insufficient power. For instance, the BMS calculates the battery's State of Charge (SOC) to monitor remaining battery power, calculates the battery's State of Health (SOH) to assess the degree of aging and remaining lifespan, and calculates the battery's State of Power (SOP) to predict the battery's instantaneous available power.

[0047] For example, a battery management system includes a battery, sensor circuitry, an analog-to-digital converter (ADC) circuit, a communication interface, and a controller. For instance, such as... Figure 1 As shown, the battery management system includes a battery 100, a battery management circuit 200, and a controller 300. The battery management circuit 200 is coupled between the battery 100 and the controller 300. The battery management circuit 200 is configured to: determine the state parameters of the battery 100 based on the battery sampling signal of the battery 100, and output the digital signal obtained by converting the state parameters to the controller 300, so that the controller 300 can evaluate the operating state of the battery 100 based on the digital signal.

[0048] Optionally, the sensor circuit includes a voltage sensor, a current sensor, a temperature sensor, etc., which are used to detect the battery's voltage, current, and temperature, respectively.

[0049] The ADC circuit is used to convert analog signals such as battery voltage, current and temperature into digital signals, and transmit them to the MCU through the communication interface, so that the MCU can analyze and process the digital signals.

[0050] In related technologies, the hardware circuits of battery management circuits (such as sensors, ADC circuits, and filter circuits) mainly sample, filter, and reduce noise of detected voltage and current signals. They do not directly perform calculations or analysis on the signals. Signal processing is primarily handled by the internal digital core unit (such as a central processing unit, CPU) or an external MCU, for example, calculating state parameters such as SOC, SOE, SOH, and battery power. The computational load on the digital core and MCU is significant, which can easily lead to delays in the calculated battery state parameters, affecting the stability and reliability of the battery management system.

[0051] Based on this, this application provides a battery management circuit that can reduce the computational burden on the MCU. For example, please refer to... Figure 2 , Figure 2 This is a schematic diagram of a battery management circuit provided in an embodiment of this application. The battery management circuit includes an analog computing circuit 20 and an analog-to-digital converter circuit 21, wherein the analog-to-digital converter circuit 21 is coupled to the analog computing circuit 20.

[0052] The analog computing circuit 20 is used to determine the state parameters of the battery based on the battery sampling signal, and the analog-to-digital conversion circuit 21 is used to convert the state parameters into digital signals for output.

[0053] Optionally, the battery sampling signals include current sampling signals and voltage sampling signals. State parameters include change in state of energy (ΔSOE), change in state of charge (ΔSOC), and battery power.

[0054] Here, battery power represents the product of the current sampling signal and the voltage sampling signal, the change in energy state represents the integral of battery power, and the change in state of charge represents the integral of the current sampling signal. Specifically, power represents the rate of energy transfer, ΔSOE represents the change in the total energy stored in the battery, therefore, the ratio of the energy change ΔSOE to time Δt can be used to obtain power, that is, ΔSOE represents the integral of power over Δt. ΔSOC is determined by the ratio of the integral of the voltage sampling signal to the battery's rated capacity, expressed by the formula:

[0055]

[0056] In the formula, Q represents the rated capacity of the battery, and I(t) represents the integral of the voltage sampling signal. Therefore, ΔSOC can characterize the integral of the current sampling signal.

[0057] The analog computing circuit 20 calculates parameters such as ΔSOE and ΔSOC, enabling the controller to directly calculate SOC and SOE based on these parameters, thus reducing the controller's computational load.

[0058] In some embodiments, the analog-to-digital conversion circuit is an analog-to-digital converter.

[0059] For example, the analog-to-digital converter acquires the instantaneous value of the analog signal at fixed time intervals, maps the sampled instantaneous value to a finite number of discrete levels to obtain the quantized value, and finally converts the quantized value into a binary digital signal for output.

[0060] In some embodiments, such as Figure 3 As shown, the battery management circuit provided in this embodiment further includes a signal sampling circuit 22, a multiplexer 23, and a filter circuit 24. The multiplexer 23 is coupled to the signal sampling circuit 22, the analog processing circuit 20 is coupled to the multiplexer 23, and the filter circuit 24 is coupled to the analog-to-digital converter circuit 21 for filtering digital signals.

[0061] The signal sampling circuit 22 is used to acquire the battery sampling signal.

[0062] Optionally, the signal sampling circuit 22 includes a voltage sampling circuit, a current sampling circuit, a temperature sampling circuit (such as a thermistor temperature sampling circuit), a protection circuit, etc.

[0063] Multiplexer 23 is used to switch the battery sampling signal input to analog processing circuit 20. Specifically, multiplexer 23 switches different battery sampling signals, enabling a single analog-to-digital converter circuit 21 to acquire multiple signals (such as the voltage and temperature of multiple batteries) in a time-division multiplexing manner, thereby reducing costs and improving system integration.

[0064] The filter circuit 24 is used to filter digital signals. Specifically, the filter circuit 24 performs noise reduction, smoothing, or feature extraction on the digital signals acquired by the analog-to-digital converter circuit 21, thereby improving measurement accuracy and system reliability.

[0065] For example, the filter circuit 24 is a digital filter.

[0066] Optionally, digital filters include finite impulse response (FIR) filters, infinite impulse response (IIR) filters, etc.

[0067] In some embodiments, the battery management circuit provided in this application also includes a register 25, a serial peripheral interface (SPI) 26, an equalization circuit, a memory protection and transaction (MPT) module, a power supply circuit, a clock circuit, etc.

[0068] Register 25 stores the filtered signal from filter circuit 24 and transmits the filtered signal to controller 300 via SPI. The equalization circuit balances the voltage of each individual cell in battery 100. For example, the equalization circuit is also coupled to multiplexer 23, which switches which cells need equalization. The clock circuit generates a clock signal for calibration, etc. MPT stores parameters in the power-off state. The power supply circuit receives external power and outputs a stable voltage to the battery management circuit through a linear regulator.

[0069] In some embodiments, the analog computing circuit includes a first current-to-voltage converter and a first integrator analog computing circuit, the first integrator analog computing circuit being coupled to the first current-to-voltage converter.

[0070] The first current-to-voltage converter is used to convert the current sampling signal into a voltage signal.

[0071] The first integrator analog circuit is used to integrate the voltage signal and output the change in state of charge.

[0072] For example, such as Figure 4As shown, the first current-to-voltage converter includes a first operational amplifier A1 and a first feedback circuit. The first terminal of the first operational amplifier A1 is used to input a current sampling signal, the second terminal of the first operational amplifier A1 is coupled to a ground terminal, and the third terminal of the first operational amplifier A1 is used to output a voltage signal. The first terminal of the first feedback circuit is coupled to the first terminal of the first operational amplifier A1, the second terminal of the first feedback circuit is coupled to the third terminal of the first operational amplifier A1, and the third terminal of the first feedback circuit is coupled to a ground terminal.

[0073] For example, the first feedback circuit includes a first resistor R1, a second resistor R2, and a third resistor R3. The first end of the first resistor R1 serves as the first end of the first feedback circuit, the first end of the second resistor R2 is coupled to the second end of the first resistor R1, and the second end of the second resistor R2 serves as the second end of the first feedback circuit. The first end of the third resistor R3 is coupled to the second end of the first resistor R1, and the second end of the third resistor R3 serves as the third end of the first feedback circuit.

[0074] For example, the first integral analog operation circuit is an integrator.

[0075] For example, such as Figure 5 As shown, the integrator includes a second operational amplifier A2 and a second feedback circuit. The first terminal of the second operational amplifier A2 serves as the input terminal, the second terminal of the second operational amplifier A2 is coupled to ground, and the third terminal of the second operational amplifier A2 serves as the output terminal. The first and second terminals of the second feedback circuit are respectively coupled to the first and second terminals of the second operational amplifier A2. Specifically, the second feedback circuit includes a fourth resistor R4 and a first capacitor C1. The first and second terminals of the fourth resistor R4 serve as the first and second terminals of the second feedback circuit, respectively, and the first capacitor C1 is connected in parallel with the fourth resistor R4. The integrator also includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a second capacitor C2. The first terminals of the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 are respectively coupled to the second, first, and third terminals of the integrator, and the second terminals of the fifth resistor R5 and the seventh resistor R7 are coupled to ground. The first terminal of the second capacitor C2 is coupled to the first terminal of the integrator, and the second terminal of the second capacitor C2 is coupled to ground. Among them, the sixth resistor R6 is used to match the impedance of the input terminal, the fifth resistor is used to limit the low-frequency gain of the integrator, the seventh resistor R7 is used to provide a discharge path for current limiting protection, and the second capacitor C2 is used for high-frequency noise filtering or phase compensation.

[0076] In some embodiments, the analog operation circuit further includes a second current-to-voltage converter and a first multiplication operation analog circuit, the first multiplication operation analog circuit being coupled to the second current-to-voltage converter.

[0077] The second current-to-voltage converter is used to convert the current sampling signal into a voltage signal.

[0078] The first multiplication operation analog circuit is used to calculate battery power based on voltage signals and voltage sampling signals.

[0079] For example, the first multiplication operation analog circuit is a multiplier. The multiplier includes a first logarithmic amplifier, a second logarithmic amplifier, an adder, and an exponential amplifier. The first terminal of the first logarithmic amplifier is used to input a voltage sampling signal, and the second terminal of the first logarithmic amplifier is coupled to ground. The first terminal of the second logarithmic amplifier is coupled to a second current-to-voltage converter, and the second terminal of the second logarithmic amplifier is coupled to ground. The first terminal of the adder is coupled to the third terminal of both the first and second logarithmic amplifiers, and the second terminal of the adder is coupled to ground. The first terminal of the exponential amplifier is coupled to the third terminal of the adder, the second terminal of the exponential amplifier is coupled to ground, and the third terminal of the exponential amplifier outputs battery power.

[0080] The system consists of a first logarithmic amplifier that performs a logarithmic transformation on the voltage sample signal, and a second logarithmic amplifier that performs a logarithmic transformation on the voltage signal. An adder sums the logarithmically transformed voltage sample signal and the voltage signal. An exponential amplifier performs an exponential transformation on the summed logarithmic signal, outputting the product of the voltage sample signal and the voltage signal, which represents the battery power.

[0081] For example, such as Figure 6 As shown, the first logarithmic amplifier includes a third operational amplifier A3, a first transistor T1, an eighth resistor R8, and a ninth resistor R9. It utilizes the logarithmic relationship between the collector current and emitter-base voltage of the transistor to perform a logarithmic transformation. The first terminal of the third operational amplifier A3 is coupled to the first terminal of the first logarithmic amplifier, the second terminal of the third operational amplifier A3 is coupled to the second terminal of the first logarithmic amplifier, and the third terminal of the third operational amplifier A3 is coupled to the third terminal of the first logarithmic amplifier. The base of the first transistor T1 is coupled to ground or a fixed bias voltage, the collector of the first transistor T1 is coupled to the first terminal of the third operational amplifier A3, and the emitter of the first transistor T1 is coupled to the second terminal of the third operational amplifier A3. The eighth resistor R8 and the ninth resistor R9 are coupled to the first and second terminals of the third operational amplifier A3, respectively. The eighth resistor R8 is used to limit the input, and the ninth resistor R9 is used to balance the impedance and adjust the offset of the logarithmic transformation.

[0082] The second logarithmic amplifier includes a fourth operational amplifier A4, a second transistor T2, a tenth resistor R10, and an eleventh resistor R11. The first terminal of the fourth operational amplifier A4 is coupled to the first terminal of the second logarithmic amplifier, the second terminal of the fourth operational amplifier A4 is coupled to the second terminal of the second logarithmic amplifier, and the third terminal of the fourth operational amplifier A4 is coupled to the third terminal of the second logarithmic amplifier. The base of the second transistor T2 is coupled to ground or a fixed bias voltage, the collector of the second transistor T2 is coupled to the first terminal of the fourth operational amplifier A4, and the emitter of the second transistor T2 is coupled to the second terminal of the fourth operational amplifier A4. The tenth resistor R10 and the eleventh resistor R11 are coupled to the first and second terminals of the fourth operational amplifier A4, respectively.

[0083] The adder includes a fifth operational amplifier A5, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifteenth resistor R15. The first terminals of the twelfth and thirteenth resistors R12 and R13 are coupled to the third terminals of the first and second logarithmic amplifiers, respectively. The second terminals of the twelfth and thirteenth resistors R13 are coupled to the first terminal of the fifth operational amplifier A5. The first terminal of the fourteenth resistor R14 is coupled to the second terminal of the fifth operational amplifier A5, serving as the second terminal of the adder. The third terminal of the fifth operational amplifier A5 serves as the third terminal of the adder. The first and second terminals of the fifteenth resistor R15 are coupled to the first and third terminals of the fifth operational amplifier A5, respectively. The twelfth and thirteenth resistors R12 and R13 are used for signal isolation and to match the output impedances of the first and second logarithmic amplifiers. The fourteenth resistor R14 is used to eliminate the DC offset voltage caused by the input bias current, ensuring the accuracy and stability of the adder. The fifteenth resistor R15 is used to adjust the gain of the adder.

[0084] The exponential amplifier includes a sixth operational amplifier A6, a third transistor T3, a sixteenth resistor R16, and a seventeenth resistor R17. The base of the third transistor T3 is coupled to ground or a fixed bias voltage. The collector of the third transistor T3 serves as the first terminal of the exponential amplifier, and its emitter is coupled to the first terminal of the sixth operational amplifier A6. The first terminal of the seventeenth resistor R17 is coupled to the second terminal of the sixth operational amplifier A6, serving as the second terminal of the exponential amplifier. The third terminal of the sixth operational amplifier A6 serves as the third terminal of the exponential amplifier. The first and second terminals of the sixteenth resistor R16 are coupled to the first and third terminals of the sixth operational amplifier A6, respectively. The seventeenth resistor R17 is used for impedance matching, and the sixteenth resistor R16 is used to convert the current of the third transistor T3 into a voltage.

[0085] In some embodiments, the analog operation circuit further includes a third current-to-voltage converter, a second multiplication operation analog circuit, and a second integration operation analog circuit, wherein the second multiplication operation analog circuit is coupled to the second current-to-voltage converter, and the second integration operation analog circuit is coupled to the second multiplication operation analog circuit.

[0086] The third current-to-voltage converter is used to convert the current sampling signal into a voltage signal.

[0087] The second multiplication operation analog circuit is used to calculate battery power based on voltage signals and voltage sampling signals.

[0088] The second integrator analog circuit is used to integrate the power and output the change in energy state.

[0089] For example, the second integral analog operation circuit is an integrator.

[0090] In some embodiments, the first current-to-voltage converter, the second current-to-voltage converter, and the third current-to-voltage converter are the same current-to-voltage converter. The first integrator analog circuit and the second integrator analog circuit are the same integrator.

[0091] For example, such as Figure 7 As shown, the analog operation circuit 20 includes a first current-to-voltage converter 1, a first integrator 2, a multiplier 3, a second integrator 4, and a switching circuit 5. The first current-to-voltage converter 1 converts the current signal into a voltage signal. The first integrator 2 integrates the voltage signal to obtain ΔSOC. The multiplier 3 calculates the power signal based on the voltage signal. The second integrator 4 integrates the power signal to obtain ΔSOE. The switching circuit 5 transmits the current signal, voltage sampling signal (voitage), ΔSOE, power, ΔSOC, and battery temperature (temp) to the analog-to-digital converter 21, enabling switching between current, votage, ΔSOE, power, and ΔSOC. Specifically, when the second switch K2 is closed and the other switches are off, the analog operation circuit 20 outputs ΔSOC; when the first switch K1 and the fourth switch K4 are closed and the other switches are off, the analog operation circuit 20 outputs power; and when the first switch K1 and the third switch K3 are closed and the other switches are off, the analog operation circuit 20 outputs ΔSOE.

[0092] In the description of the embodiments of this application, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0093] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery management circuit, characterized in that, include: Analog computing circuitry is used to determine the state parameters of the battery based on battery sampling signals; An analog-to-digital converter circuit, coupled to the analog arithmetic circuit, is used to convert the state parameters into digital signals for output.

2. The circuit according to claim 1, characterized in that, The battery sampling signal includes at least one of the following: current sampling signal and voltage sampling signal; the state parameters include at least one of the following: energy state change, charge state change, and battery power; Wherein, the battery power represents the product of the current sampling signal and the voltage sampling signal, the energy state change represents the integral of the battery power, and the state of charge change represents the integral of the current sampling signal.

3. The circuit according to claim 1, characterized in that, The analog-to-digital conversion circuit is an analog-to-digital converter.

4. The circuit according to claim 1, characterized in that, The battery management circuit also includes: A signal sampling circuit, coupled to the analog computing circuit, is used to acquire the battery sampling signal.

5. The circuit according to claim 4, characterized in that, The battery management circuit also includes: A multiplexer, coupled between the signal sampling circuit and the analog computing circuit, is used to switch the battery sampling signal input to the analog computing circuit.

6. The circuit according to claim 1, characterized in that, The battery management circuit also includes: A filtering circuit, coupled to the analog-to-digital converter circuit, is used to filter the digital signal.

7. The circuit according to claim 6, characterized in that, The filtering circuit is a digital filter.

8. The circuit according to claim 2, characterized in that, The analog computing circuit includes: A first current-to-voltage converter is used to convert the current sampling signal into a voltage signal; A first integrator analog circuit, coupled to the first current-to-voltage converter, is used to integrate the voltage signal and output the change in state of charge.

9. The circuit according to claim 8, characterized in that, The first current-to-voltage converter includes: An operational amplifier, wherein a first terminal of the operational amplifier is used to input the current sampling signal, a second terminal of the operational amplifier is coupled to a ground terminal, and a third terminal of the operational amplifier is used to output the voltage signal; A feedback circuit, wherein the first terminal of the feedback circuit is coupled to the first terminal of the operational amplifier, the second terminal of the feedback circuit is coupled to the third terminal of the operational amplifier, and the third terminal of the feedback circuit is coupled to the ground terminal.

10. The circuit according to claim 8, characterized in that, The first integral analog operation circuit is an integrator.

11. The circuit according to claim 2, characterized in that, The analog computing circuit further includes: A second current-to-voltage converter is used to convert the current sampling signal into a voltage signal; A first multiplication operation analog circuit, coupled to the second current-voltage converter, is used to calculate the battery power based on the voltage signal and the voltage sampling signal.

12. The circuit according to claim 11, characterized in that, The multiplication operation simulation circuit is a multiplier.

13. The circuit according to claim 2, characterized in that, The analog computing circuit further includes: A third current-to-voltage converter is used to convert the current sampling signal into a voltage signal; A second multiplication operation analog circuit, coupled to the second current-voltage converter, is used to calculate the battery power based on the voltage signal and the voltage sampling signal; The second integral analog operation circuit, coupled to the second multiplication analog operation circuit, is used to integrate the battery power and output the energy state change.

14. The circuit according to claim 13, characterized in that, The second integral analog operation circuit is an integrator.

15. A battery management system, characterized in that, The battery management system includes: a battery, a controller, and a battery management circuit as described in any one of claims 1-14; the battery management circuit is coupled between the battery and the controller, and the battery management circuit is configured to: determine the state parameters of the battery based on the battery sampling signal of the battery, and output a digital signal obtained by converting the state parameters to the controller, so that the controller evaluates the working state of the battery based on the digital signal.

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