Battery management system and automobile

Abstract

The application provides a battery management system and a vehicle. The battery management system comprises a current detection circuit, an overcurrent comparison circuit, a differential signal generation circuit, a differential signal conversion circuit and a controller. The current detection circuit is used for detecting the current of the battery. The overcurrent comparison circuit is used for receiving the current and comparing the current with a reference current to output a comparison signal. The differential signal generation circuit is used for receiving the comparison signal and generating a corresponding differential signal according to the comparison signal. The differential signal conversion circuit is used for receiving the differential signal and converting the differential signal into a single-ended output signal. The controller is used for receiving the single-ended output signal and issuing a corresponding operation instruction according to the single-ended output signal, so that the battery is in a safe state. The application transmits the overcurrent warning signal by using the differential signal, avoids the interference of the external electromagnetic environment during signal transmission, can respond to the overcurrent warning signal in time, and is safe and reliable.

Description

Technical Field

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

[0002] New energy vehicles have become an important part of the automotive industry, and the safety performance of the batteries used inside them requires special attention. Monitoring the charging and discharging current of the battery, especially under overcurrent conditions, is particularly important. In related technologies, battery management systems either lack a separate overcurrent alarm signal or transmit a single-ended signal, making them susceptible to interference from external signals during transmission, thus failing to properly handle overcurrent scenarios. Summary of the Invention

[0003] This application provides a battery management system and an automobile that can respond promptly to overcurrent warning signals.

[0004] This application provides a battery management system, connected to a battery, including:

[0005] A current detection circuit is connected to the battery and is used to detect the current of the battery;

[0006] An overcurrent comparison circuit is connected to the current detection circuit and is used to receive the current, compare it with a reference current, and output a comparison signal.

[0007] A differential signal generation circuit is connected to the overcurrent comparator circuit and is used to receive the comparison signal and generate a corresponding differential signal based on the comparison signal.

[0008] A differential signal conversion circuit, connected to the differential signal generation circuit, is used to receive the differential signal and convert the differential signal into a single-ended output signal; and

[0009] The controller is connected to the differential signal conversion circuit and the battery. The controller is used to receive the single-ended output signal and issue corresponding operation instructions according to the single-ended output signal to keep the battery in a safe state.

[0010] Optionally, the differential signal generation circuit includes a first enable terminal, a second enable terminal, and a plurality of switching transistors connected to the first enable terminal and the second enable terminal. The first enable terminal and the second enable terminal are connected to the output terminal of the overcurrent comparator circuit. The differential signal generation circuit receives the comparison signal through the first enable terminal and the second enable terminal, and enables and controls some of the switching transistors among the plurality of switching transistors to conduct according to the comparison signal, thereby generating the corresponding differential signal.

[0011] Optionally, the differential signal generation circuit further includes a power supply terminal and a ground terminal; the plurality of switching transistors include a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor, wherein the first terminal of the first switching transistor is connected to the first enable terminal, the second terminal of the first switching transistor is connected to the power supply terminal, and the third terminal of the first switching transistor is connected to the first differential output terminal of the differential signal generation circuit; the first terminal of the second switching transistor is connected to the first enable terminal, the second terminal of the second switching transistor is connected to the ground terminal, and the third terminal of the second switching transistor is connected to the second differential output terminal of the differential signal generation circuit; the first terminal of the fourth switching transistor is connected to the second enable terminal, the second terminal of the fourth switching transistor is connected to the ground terminal, and the third terminal of the fourth switching transistor is connected to the first differential output terminal of the differential signal generation circuit;

[0012] The overcurrent comparator circuit is used to output a high level at its output terminal when it determines that the current is higher than the reference current, thereby enabling the third and fourth switching transistors to conduct, so that the first differential output terminal and the second output terminal of the differential signal generation circuit output a first differential signal; the overcurrent comparator circuit is used to output a low level at its output terminal when it determines that the current is lower than the reference current, thereby enabling the first and second switching transistors to conduct, so that the first differential output terminal and the second output terminal of the differential signal generation circuit output a second differential signal.

[0013] Optionally, the current detection circuit includes a first detection terminal, a second detection terminal, and a signal amplifier; the signal amplifier is connected to the first detection terminal and the second detection terminal; the battery is connected to the first detection terminal and the second detection terminal; the current detection circuit further includes a detection resistor connected between the first detection terminal and the second detection terminal.

[0014] Optionally, the current detection circuit further includes a first current-limiting resistor connected to the first detection terminal and the inverting input terminal of the signal amplifier.

[0015] Optionally, the current detection circuit further includes a second current-limiting resistor connected to the second detection terminal and the non-inverting input terminal of the signal amplifier.

[0016] Optionally, the current detection circuit further includes a first pull-down resistor connected between the non-inverting input terminal of the signal amplifier and the ground terminal.

[0017] Optionally, the current detection circuit further includes a first feedback resistor connected between the inverting input terminal and the output terminal of the signal amplifier.

[0018] Optionally, the overcurrent comparison circuit includes a reference terminal and a comparator connected to the reference terminal; the non-inverting input terminal of the comparator is connected to the output terminal of the current detection circuit, and the inverting input terminal of the comparator is connected to the reference terminal.

[0019] The overcurrent comparator circuit further includes a third current-limiting resistor and a second pull-down resistor. The third current-limiting resistor is connected between the reference terminal and the inverting input terminal of the comparator, and the second pull-down resistor is connected between the inverting input terminal of the comparator and the ground terminal.

[0020] Optionally, the differential signal conversion circuit includes a first differential input terminal, a second differential input terminal, and a differential amplifier; the differential amplifier is connected to the first differential input terminal and the second differential input terminal; the first differential input terminal is connected to the first differential output terminal of the differential signal generation circuit, and the second differential input terminal is connected to the second differential output terminal of the differential signal generation circuit.

[0021] Optionally, the differential signal conversion circuit further includes a fourth current-limiting resistor connected between the first differential input terminal and the inverting input terminal of the differential amplifier.

[0022] Optionally, the differential signal conversion circuit further includes a fifth current-limiting resistor connected between the second differential input terminal and the non-inverting input terminal of the differential amplifier.

[0023] Optionally, the current detection circuit further includes a third pull-down resistor connected between the non-inverting input terminal and the ground terminal of the differential amplifier.

[0024] Optionally, the current detection circuit further includes a second feedback resistor connected between the inverting input terminal and the output terminal of the differential amplifier.

[0025] Optionally, the differential signal conversion circuit and the controller are integrated on the same circuit board.

[0026] Optionally, the current detection circuit and the overcurrent comparison circuit are integrated on the same circuit board.

[0027] Optionally, the current detection circuit, the overcurrent comparison circuit, and the differential signal generation circuit are integrated on the same circuit board.

[0028] Optionally, the battery management system further includes a pulse width modulation generator connected between the overcurrent detection circuit and the differential signal generation circuit.

[0029] This application also provides a car, including:

[0030] Batteries; and

[0031] The battery management system as described in any of the above embodiments is connected to the battery and is used to control the charging and discharging of the battery.

[0032] The battery management system of this application embodiment is connected to a battery and includes a current detection circuit, an overcurrent comparison circuit, a differential signal generation circuit, a differential signal conversion circuit, and a controller. The current detection circuit is connected to the battery and is used to detect the battery current. The overcurrent comparison circuit is connected to the current detection circuit and is used to receive the current, compare it with a reference current, and output a comparison signal. The differential signal generation circuit is connected to the overcurrent comparison circuit and is used to receive the comparison signal and generate a corresponding differential signal based on the comparison signal. The differential signal conversion circuit is connected to the differential signal generation circuit and is used to receive the differential signal and convert the differential signal into a single-ended output signal. The controller is connected to the differential signal conversion circuit and the battery. The controller receives the single-ended output signal and issues corresponding operation commands based on the single-ended output signal to ensure the battery is in a safe state. This configuration generates a corresponding overcurrent warning differential signal through a differential signal generation circuit. The differential signal conversion circuit then converts the overcurrent warning differential signal into an overcurrent warning single-ended output signal. The controller then issues corresponding operation commands based on the overcurrent warning single-ended output signal to keep the battery in a safe state. By using differential signals to transmit overcurrent warning signals, interference from the external electromagnetic environment is avoided during signal transmission, ensuring timely response to overcurrent warning signals and making the process safe and reliable.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0035] Figure 1 The diagram shown is a schematic block diagram of one embodiment of the battery management system of this application.

[0036] Figure 2 As shown Figure 1 The circuit diagram shown is an embodiment of the differential signal generation circuit of the battery management system.

[0037] Figure 3 As shown Figure 1 The circuit diagram shown is an embodiment of the current detection circuit and overcurrent comparison circuit of the battery management system.

[0038] Figure 4 As shown Figure 1 The circuit diagram shown is an embodiment of the differential signal conversion circuit of the battery management system. Detailed Implementation

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0040] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper," etc., are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," etc., mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected," "linked," etc., are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0041] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0042] This application provides a battery management system connected to a battery, including a current detection circuit, an overcurrent comparison circuit, a differential signal generation circuit, a differential signal conversion circuit, and a controller. The current detection circuit is connected to the battery and is used to detect the battery's current. The overcurrent comparison circuit is connected to the current detection circuit and is used to receive the current, compare it with a reference current, and output a comparison signal. The differential signal generation circuit is connected to the overcurrent comparison circuit and is used to receive the comparison signal and generate a corresponding differential signal based on the comparison signal. The differential signal conversion circuit is connected to the differential signal generation circuit and is used to receive the differential signal and convert it into a single-ended output signal. The controller is connected to the differential signal conversion circuit and the battery. The controller receives the single-ended output signal and issues corresponding operation commands based on the single-ended output signal to ensure the battery is in a safe state. This configuration generates a corresponding overcurrent warning differential signal through a differential signal generation circuit. The differential signal conversion circuit then converts the overcurrent warning differential signal into an overcurrent warning single-ended output signal. The controller then issues corresponding operation commands based on the overcurrent warning single-ended output signal to keep the battery in a safe state. By using differential signals to transmit overcurrent warning signals, interference from the external electromagnetic environment is avoided during signal transmission, ensuring timely response to overcurrent warning signals and making the process safe and reliable.

[0043] New energy vehicles have become an important part of the automotive industry, and the safety performance of the batteries used inside them requires special attention. Monitoring the charging and discharging current of the battery, especially under overcurrent conditions, is particularly important. In related technologies, battery management systems often lack a separate overcurrent alarm signal, or the transmitted overcurrent alarm signal is a single-ended signal. Furthermore, when the transmission wiring distance is long or the external electromagnetic environment is poor, it is easily affected by interference. Severe interference can cause the high and low levels of the single-ended signal to become disordered, resulting in a failure to respond to the overcurrent alarm signal in a timely manner, and consequently, an inability to properly handle overcurrent scenarios.

[0044] Therefore, this application provides a battery management system and a vehicle that avoids interference.

[0045] Figure 1 The diagram shown is a schematic block diagram of an embodiment of the battery management system 1 of this application. The battery management system 1 is connected to the battery 2 and is used to control the charging and discharging of the battery 2, as well as to collect and calculate key parameters of the battery 2 such as voltage, temperature, SOC (State of Charge, the usable state of the remaining charge in the battery, generally expressed as a percentage), and SOH (State of Health, the percentage of the battery's full charge capacity relative to its rated capacity; 100% for a new battery and 0% for a completely scrapped battery). This ensures that the performance of the battery 2 can be fully utilized and guarantees safe use. In this embodiment, the battery 2 can be a lithium battery.

[0046] exist Figure 1 In the illustrated embodiment, the battery management system 1 includes a current detection circuit 11, an overcurrent comparison circuit 12, a differential signal generation circuit 13, a differential signal conversion circuit 14, and a controller 15. The current detection circuit 11 is connected to the battery 2 and is used to detect the current of the battery 2. The overcurrent comparison circuit 12 is connected to the current detection circuit 11 and is used to receive the current and compare it with a reference current to determine whether the received current is higher than the reference current, thus outputting a comparison signal. In this embodiment, when the received current is determined to be higher than the reference current, the output comparison signal is high, indicating that the current of the battery 2 has exceeded the reference current; this result is an overcurrent warning signal. When the received current is determined to be lower than the reference current, the output comparison signal is low, indicating that the current of the battery 2 has not exceeded the reference current; this result is a normal current signal. The differential signal generation circuit 13 is connected to the overcurrent comparison circuit 12 and is used to receive the comparison signal and generate a corresponding differential signal based on the comparison signal. In this embodiment, when the differential signal generation circuit 13 outputs an overcurrent warning signal, the corresponding overcurrent warning differential signal is enabled using the overcurrent warning signal. This overcurrent warning differential signal can maintain a constant level difference even under external common-mode interference, avoiding external interference and improving transmission stability. When the differential signal generation circuit 13 outputs a normal current signal, the corresponding normal current differential signal is enabled using the normal current signal. The differential signal conversion circuit 14 is connected to the differential signal generation circuit 13 and is used to receive differential signals and convert them into single-ended output signals. In this embodiment, when the differential signal conversion circuit 14 receives an overcurrent warning differential signal, it converts the overcurrent warning differential signal into an overcurrent warning single-ended output signal for transmission to the controller 15. When the differential signal conversion circuit 14 receives a normal current differential signal, it converts the current differential signal into a normal current single-ended output signal for transmission to the controller 15. The controller 15 is connected to the differential signal conversion circuit 14 and the battery 2. The controller 15 receives single-ended output signals and issues corresponding operation commands based on the single-ended output signals to keep the battery 2 in a safe state. In this embodiment, when the controller 15 receives an overcurrent warning single-ended output signal, it issues corresponding operation commands based on the overcurrent warning single-ended output signal to keep the battery 2 in a safe state. When the controller 15 receives a normal current single-ended output signal, it maintains its original operation based on the normal current single-ended output signal to ensure that the battery 2 is always in a safe state.

[0047] In the above scheme, the differential signal generation circuit 13 generates a corresponding overcurrent warning differential signal, the differential signal conversion circuit 14 converts the overcurrent warning differential signal into an overcurrent warning single-ended output signal, and the controller 15 issues a corresponding operation command based on the overcurrent warning single-ended output signal to keep the battery 2 in a safe state. In this way, the overcurrent warning signal is transmitted by differential signal, avoiding interference from the external electromagnetic environment during signal transmission, and can respond to the overcurrent warning signal in a timely manner, which is safe and reliable.

[0048] Figure 2 As shown Figure 1 The circuit diagram shows one embodiment of the differential signal generation circuit 13 of the battery management system 1. (In conjunction with...) Figure 1 and Figure 2 As shown, the differential signal generation circuit 13 includes a first enable terminal EN1, a second enable terminal EN2, and multiple switching transistors 131 connected to the first enable terminal EN1 and the second enable terminal EN2. The first enable terminal EN1 and the second enable terminal EN2 are connected to the output terminal of the overcurrent comparator circuit 12. The differential signal generation circuit 13 receives the comparison signal through the first enable terminal EN1 and the second enable terminal EN2, and controls some of the switching transistors 131 to turn on according to the comparison signal, generating a corresponding differential signal. With this configuration, the differential signal generation circuit 13 enables the generation of a corresponding overcurrent warning differential signal from the overcurrent warning signal output by the overcurrent comparator circuit 12. By using differential signals to transmit the overcurrent warning signal, interference from the external electromagnetic environment is avoided during signal transmission, and the overcurrent warning signal can be responded to in a timely manner, ensuring safety and reliability.

[0049] exist Figure 2 In the illustrated embodiment, the differential signal generation circuit 13 further includes a power supply terminal VCC and a ground terminal GND. The plurality of switching transistors 131 include a first switching transistor Q2, a second switching transistor Q3, a third switching transistor Q1, and a fourth switching transistor Q4. In this embodiment, the first switching transistors Q2, Q3, Q1, and Q4 are all MOSFETs. The first terminal of the first switching transistor Q2 is connected to the first enable terminal EN1, the second terminal of the first switching transistor Q2 is connected to the power supply terminal VCC, and the third terminal of the first switching transistor Q2 is connected to the first differential output terminal VIN1+ of the differential signal generation circuit 13. In this embodiment, the first switching transistor Q2 is a PMOS transistor. The gate of the first switching transistor Q2 is connected to the first enable terminal EN1, the source of the first switching transistor Q2 is connected to the power supply terminal VCC, and the drain of the first switching transistor Q2 is connected to the first differential output terminal VIN1+ of the differential signal generation circuit 13.

[0050] The first terminal of the second switch Q3 is connected to the first enable terminal EN1, the second terminal of the second switch Q3 is connected to the ground terminal GND, and the third terminal of the second switch Q3 is connected to the second differential output terminal VIN1- of the differential signal generation circuit. In this embodiment, the second switch Q3 is an NMOS transistor. The gate of the second switch Q3 is connected to the first enable terminal EN1, the source of the second switch Q3 is connected to the ground terminal GND, and the drain of the second switch Q3 is connected to the second differential output terminal VIN1- of the differential signal generation circuit 13.

[0051] The first terminal of the third switch Q1 is connected to the second enable terminal EN2, the second terminal of the third switch Q1 is connected to the power supply terminal VCC, and the third terminal of the third switch Q1 is connected to the second differential output terminal VIN1- of the differential signal generation circuit. In this embodiment, the third switch Q1 is a PMOS transistor. The gate of the third switch Q1 is connected to the second enable terminal EN2, the source of the third switch Q1 is connected to the power supply terminal VCC, and the drain of the third switch Q1 is connected to the second differential output terminal VIN1- of the differential signal generation circuit 13.

[0052] The first terminal of the fourth switch Q4 is connected to the second enable terminal EN2, the second terminal of the fourth switch Q4 is connected to the ground terminal GND, and the third terminal of the fourth switch Q4 is connected to the first differential output terminal VIN1+ of the differential signal generation circuit. In this embodiment, the fourth switch Q4 is an NMOS transistor. The gate of the fourth switch Q4 is connected to the second enable terminal EN2, the source of the fourth switch Q4 is connected to the ground terminal GND, and the drain of the fourth switch Q4 is connected to the first differential output terminal VIN1+ of the differential signal generation circuit 13.

[0053] Overcurrent comparator circuit 12 is used to, when determining that the current is higher than the reference current, output terminal OC (e.g., Figure 3The output of the differential signal generation circuit 13 is high, enabling the third switch Q1 and the fourth switch Q4 to conduct, thereby causing the first differential output terminal VIN1+ and the second differential output terminal VIN1- of the differential signal generation circuit 13 to output the first differential signal. The overcurrent comparator circuit 12, when determining that the current is lower than the reference current, outputs a low level through its output terminal OC, enabling the first switch Q2 and the second switch Q3 to conduct, thereby causing the first differential output terminal VIN1+ and the second differential output terminal VIN- of the differential signal generation circuit 13 to output the second differential signal. With this configuration, the first enable terminal EN1 and the second enable terminal EN2 are controlled by the comparison signal output from the output terminal OC of the overcurrent comparator circuit 12. The effect is that when the comparison signal is high, the third switch Q1 and the fourth switch Q4 are turned on, while the first switch Q2 and the second switch Q3 are not turned on. When the comparison signal is low, the third switch Q1 and the fourth switch Q4 are de-conducted, while the first switch Q2 and the second switch Q3 are turned on. This enables the differential signal generation circuit 13 to output two different differential signals (first differential signal and second differential signal) between its first differential output terminal VIN1+ and its second output terminal VIN-. This differential signal generation circuit 13 uses the first differential output terminal VIN1+ and the second output terminal VIN- to output differential signals. Under external interference, the values ​​of the first differential signal and the second differential signal are not significantly different, demonstrating good anti-interference performance. Figure 2 In the embodiment shown, the differential signal generation circuit 13 further includes a resistor R0 connected between the first differential output terminal VIN1+ and the second output terminal VIN- of the differential signal generation circuit 13. The resistor R0 is used for differential mode signal matching to eliminate differential mode interference and ensure stability.

[0054] Figure 3 As shown Figure 1 The circuit diagram shows an embodiment of the current detection circuit 11 and overcurrent comparison circuit 12 of the battery management system 1. (In conjunction with...) Figures 1 to 3 As shown, the current detection circuit 11 includes a first detection terminal 111, a second detection terminal 112, and a signal amplifier 113. The signal amplifier 113 is connected to the first detection terminal 111 and the second detection terminal 112. The battery 2 is connected to the first detection terminal 111 and the second detection terminal 112. The battery 2 is connected to the signal amplifier 113 through the first detection terminal 111 and the second detection terminal 112. The current detection circuit 11 also includes a detection resistor Rx, connected between the first detection terminal 111 and the second detection terminal 112. The current detection circuit 11 detects the current of the battery 2 through the detection resistor Rx. The signal amplifier 113 amplifies the current detected by the detection resistor Rx and outputs it to the overcurrent comparator circuit 12.

[0055] exist Figure 3In the illustrated embodiment, the current detection circuit 11 further includes a first current-limiting resistor R1, connected to the first detection terminal 111 and the inverting input terminal of the signal amplifier 113. The first current-limiting resistor R1 is used to limit the current between the first detection terminal 111 and the inverting input terminal of the signal amplifier 113 to prevent excessive current from burning out the series-connected signal amplifier 113. Figure 1 In the illustrated embodiment, the current detection circuit 11 further includes a second current-limiting resistor R2, connected to the second detection terminal 112 and the non-inverting input terminal of the signal amplifier 113. The second current-limiting resistor R2 is used to limit the current between the second detection terminal 112 and the non-inverting input terminal of the signal amplifier 113 to prevent excessive current from burning out the connected signal amplifier 113.

[0056] exist Figure 3 In the illustrated embodiment, the current detection circuit 11 further includes a first pull-down resistor R3 connected between the non-inverting input terminal of the signal amplifier 113 and the ground terminal. The first pull-down resistor R3 can provide a loop for the bias current of the signal amplifier 113, improving stability. Figure 3 In the illustrated embodiment, the current detection circuit 11 further includes a first feedback resistor R4, connected between the inverting input and output of the signal amplifier 113. The first feedback resistor R4 is used to provide feedback current.

[0057] exist Figure 3 In the illustrated embodiment, the overcurrent comparator circuit 12 includes a reference terminal VREF and a comparator 121 connected to the reference terminal VREF. The non-inverting input of the comparator 121 is connected to the output of the current detection circuit 11, and the inverting input of the comparator 121 is connected to the reference terminal VREF. Figure 3 In the illustrated embodiment, the overcurrent comparator circuit 12 further includes a third current-limiting resistor R5 and a second pull-down resistor R6. The third current-limiting resistor R5 is connected between the reference terminal VREF and the inverting input terminal of comparator 121, and the second pull-down resistor R6 is connected between the inverting input terminal of comparator 121 and the ground terminal GND. In this embodiment, the non-inverting input terminal of comparator 121 receives the current output from the current detection circuit 11, and the inverting input terminal of comparator 121 receives an external reference current through the reference terminal VREF. Comparator 121 compares the magnitude of this current with the reference current. When the current is greater than the reference current, the output is high; when the current is less than the reference current, the output is low. During this process, the third current-limiting resistor R5 limits the current between the reference terminal VREF and the inverting input terminal of comparator 121 to prevent excessive current from burning out the series-connected comparator 121. The second pull-down resistor R6 provides a loop for the bias current of comparator 121, improving stability.

[0058] In some embodiments, the battery management system 1 further includes a pulse width modulation generator (not shown) connected between the overcurrent detection circuit 12 and the differential signal generation circuit 13. This configuration allows for the output of a pulse width modulation signal with adjustable frequency or duty cycle. Specifically, a pulse width modulation generator is added after the output terminal OC of the overcurrent detection circuit 12, and the comparison signal output from the output terminal OC of the overcurrent detection circuit 12 is used as an enable signal to control the pulse width modulation generator. This scheme is relatively simple.

[0059] Figure 4 As shown Figure 1 The circuit diagram shows one embodiment of the differential signal conversion circuit 14 of the battery management system 1. (In conjunction with...) Figures 1 to 4 As shown, the differential signal conversion circuit 14 includes a first differential input terminal VIN2+, a second differential input terminal VIN2-, and a differential amplifier 141. The differential amplifier 141 is connected to the first differential input terminal VIN2+ and the second differential input terminal VIN2-. The first differential input terminal VIN2+ is connected to the first differential output terminal VIN1+ of the differential signal generation circuit 13, and the second differential input terminal VIN2- is connected to the second differential output terminal VIN1- of the differential signal generation circuit 13. The first differential output terminal VIN1+ of the differential signal generation circuit 13 is connected to the inverting input terminal of the differential amplifier 141 through the first differential input terminal VIN2+, so as to input the first differential signal to the inverting input terminal of the differential amplifier 141 through the first differential input terminal VIN2+. The differential signal generation circuit 13 is connected to the non-inverting input of the differential amplifier 141 via the second differential input terminal VIN2-, so as to input the second differential signal to the non-inverting input of the differential amplifier 141 through the second differential input terminal VIN2-. The differential amplifier 141 is used to convert the first differential signal and the second differential signal into a single-ended output signal. In this embodiment, the differential amplifier 141 can be a subtractor.

[0060] exist Figure 4 In the illustrated embodiment, the differential signal conversion circuit 14 further includes a fourth current-limiting resistor R7, connected between the first differential input terminal VIN2+ and the inverting input terminal of the differential amplifier 141. The fourth current-limiting resistor R7 is used to limit the current between the first differential input terminal VIN2+ and the inverting input terminal of the differential amplifier 141 to prevent excessive current from burning out the series-connected differential amplifier 141. Figure 4 In the illustrated embodiment, the differential signal conversion circuit 14 further includes a fifth current-limiting resistor R8, connected between the second differential input terminal VIN2- and the non-inverting input terminal of the differential amplifier 141. The fifth current-limiting resistor R8 is used to limit the current between the second differential input terminal VIN2- and the non-inverting input terminal of the differential amplifier 141 to prevent excessive current from burning out the differential amplifier 141 connected in series.

[0061] exist Figure 4 In the illustrated embodiment, the current detection circuit 11 further includes a third pull-down resistor R9, connected between the non-inverting input terminal of the differential amplifier 141 and the ground terminal GND. The third pull-down resistor R9 provides a loop for the bias current of the differential amplifier 141, improving stability. Figure 4 In the illustrated embodiment, the current detection circuit 11 further includes a second feedback resistor R10, connected between the inverting input terminal and the output terminal VOUT of the differential amplifier 141. The second feedback resistor R10 is used to provide feedback current.

[0062] In some embodiments, the differential signal conversion circuit 14 and the controller 15 are integrated on the same circuit board. This configuration results in high integration and a small size. In some embodiments, the current detection circuit 11 and the overcurrent comparison circuit 12 are integrated on the same circuit board. For example, they can also be integrated on the same chip, such as the ADBMS2950. This configuration results in high integration and a small size. In some embodiments, the current detection circuit 11, the overcurrent comparison circuit 12, and the differential signal generation circuit 13 are integrated on the same circuit board. This configuration results in high integration and a small size. In this embodiment, the differential signal conversion circuit 14 and the controller 15 are integrated on the same circuit board. The current detection circuit 11, the overcurrent comparison circuit 12, and the differential signal generation circuit 13 are integrated on the same circuit board. These two circuit boards are separated, and the high and low voltages are isolated by the separate board configuration, eliminating the need for isolation circuits and simplifying the layout for easy maintenance. In other embodiments, the current detection circuit 11, the overcurrent comparison circuit 12, the differential signal generation circuit 13, the differential signal conversion circuit 14, and the controller 15 are integrated on the same circuit board. In this circuit board, since the controller 15 and the differential signal conversion circuit 14 are low-voltage modules, and the current detection circuit 11, the overcurrent comparison circuit 12 and the differential signal generation circuit 13 are high-voltage modules, an isolation circuit needs to be set between the high-voltage module and the low-voltage module.

[0063] This application also provides a vehicle, including battery 2 and the aforementioned Figures 1 to 4 The battery management system 1 shown in the embodiment is connected to the battery 2 and is used to control the charging and discharging of the battery 2. The vehicle is equipped with... Figures 1 to 4 The battery management system 1 shown in the embodiment generates a corresponding overcurrent warning differential signal through the differential signal generation circuit 13, converts the overcurrent warning differential signal into an overcurrent warning single-ended output signal through the differential signal conversion circuit 14, and issues a corresponding operation command through the controller 15 based on the overcurrent warning single-ended output signal to keep the battery 2 in a safe state. In this way, the overcurrent warning signal is transmitted by differential signal, avoiding interference from the external electromagnetic environment during signal transmission, and can respond to the overcurrent warning signal in a timely manner, which is safe and reliable.

[0064] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0065] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery management system connected with a battery, characterized by, The application relates to a battery protection circuit, comprising: a current detection circuit connected with the battery and used for detecting the current of the battery; an overcurrent comparison circuit connected with the current detection circuit and used for receiving the current and comparing the current with a reference current to output a comparison signal; a differential signal generation circuit connected with the overcurrent comparison circuit and used for receiving the comparison signal and generating a corresponding differential signal according to the comparison signal; a differential signal conversion circuit connected with the differential signal generation circuit and used for receiving the differential signal and converting the differential signal into a single-ended output signal; and a controller connected with the differential signal conversion circuit and the battery, the controller being used for receiving the single-ended output signal and issuing a corresponding operation instruction according to the single-ended output signal to make the battery in a safe state. The differential signal generation circuit comprises a first enable terminal, a second enable terminal and a plurality of switch tubes connected with the first enable terminal and the second enable terminal, the first enable terminal and the second enable terminal being connected with the output terminal of the overcurrent comparison circuit; the differential signal generation circuit receives the comparison signal through the first enable terminal and the second enable terminal and enables control of the switch tubes in the plurality of switch tubes to be turned on according to the comparison signal, thereby generating the corresponding differential signal. The plurality of switch tubes comprise a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; when the overcurrent comparison circuit judges that the current is higher than the reference current, the overcurrent comparison circuit outputs a high level through the output terminal to enable control of the third switch tube and the fourth switch tube to be turned on, thereby making the first differential output terminal and the second output terminal of the differential signal generation circuit output a first differential signal; when the overcurrent comparison circuit judges that the current is lower than the reference current, the overcurrent comparison circuit outputs a low level through the output terminal to enable control of the first switch tube and the second switch tube to be turned on, thereby making the first differential output terminal and the second output terminal of the differential signal generation circuit output a second differential signal.

2. The battery management system of claim 1, wherein, The differential signal generation circuit further comprises a power terminal and a grounding terminal; the first end of the first switch tube is connected with the first enable terminal, the second end of the first switch tube is connected with the power terminal, and the third end of the first switch tube is connected with the first differential output terminal of the differential signal generation circuit; the first end of the second switch tube is connected with the first enable terminal, the second end of the second switch tube is connected with the grounding terminal, and the third end of the second switch tube is connected with the second differential output terminal of the differential signal generation circuit; the first end of the third switch tube is connected with the second enable terminal, the second end of the third switch tube is connected with the power terminal, and the third end of the third switch tube is connected with the second differential output terminal of the differential signal generation circuit; the first end of the fourth switch tube is connected with the second enable terminal, the second end of the fourth switch tube is connected with the grounding terminal, and the third end of the fourth switch tube is connected with the first differential output terminal of the differential signal generation circuit.

3. The battery management system of claim 1, wherein, The current detection circuit comprises a first detection terminal, a second detection terminal and a signal amplifier; the signal amplifier is connected with the first detection terminal and the second detection terminal; the battery is connected with the first detection terminal and the second detection terminal; The current detection circuit further comprises a detection resistor connected between the first detection terminal and the second detection terminal; and / or The current detection circuit further comprises a first current-limiting resistor connected between the first detection terminal and the inverting input terminal of the signal amplifier; and / or The current detection circuit further comprises a second current-limiting resistor connected between the second detection terminal and the non-inverting input terminal of the signal amplifier; and / or The current detection circuit further comprises a first pull-down resistor connected between the non-inverting input terminal of the signal amplifier and the ground terminal; and / or The current detection circuit further comprises a first feedback resistor connected between the inverting input terminal and the output terminal of the signal amplifier.

4. The battery management system of claim 1, wherein, The overcurrent comparison circuit comprises a reference terminal and a comparator connected with the reference terminal; The non-inverting input terminal of the comparator is connected with the output terminal of the current detection circuit, and the inverting input terminal of the comparator is connected with the reference terminal; and / or The overcurrent comparison circuit further comprises a third current-limiting resistor and a second pull-down resistor, the third current-limiting resistor is connected between the reference terminal and the inverting input terminal of the comparator, and the second pull-down resistor is connected between the inverting input terminal of the comparator and the ground terminal.

5. The battery management system of claim 1, wherein, The differential signal conversion circuit comprises a first differential input terminal, a second differential input terminal and a differential amplifier; the differential amplifier is connected with the first differential input terminal and the second differential input terminal; the first differential input terminal is connected with the first differential output terminal of the differential signal generation circuit, and the second differential input terminal is connected with the second differential output terminal of the differential signal generation circuit; The differential signal conversion circuit further comprises a fourth current-limiting resistor connected between the first differential input terminal and the inverting input terminal of the differential amplifier; and / or The differential signal conversion circuit further comprises a fifth current-limiting resistor connected between the second differential input terminal and the non-inverting input terminal of the differential amplifier; and / or The current detection circuit further comprises a third pull-down resistor connected between the non-inverting input terminal of the differential amplifier and the ground terminal; and / or The current detection circuit further comprises a second feedback resistor connected between the inverting input terminal and the output terminal of the differential amplifier.

6. The battery management system of claim 1, wherein, The differential signal conversion circuit and the controller are integrated on the same circuit board; and / or The current detection circuit and the overcurrent comparison circuit are integrated on the same circuit board.

7. The battery management system of claim 1, wherein, The current detection circuit, the overcurrent comparison circuit and the differential signal generation circuit are integrated on the same circuit board.

8. The battery management system of claim 1, wherein, The battery management system further comprises a pulse width modulation generator connected between the overcurrent detection circuit and the differential signal generation circuit.

9. An automobile characterized by comprising: comprises: a battery; and The battery management system according to any one of claims 1 to 8, connected with the battery and used for controlling the charging and discharging of the battery.

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