Battery voltage detection circuit, battery management system device, and battery device

Abstract

The utility model discloses a battery voltage detection circuit, a battery management system device and battery equipment, and belongs to the technical field of electronics and electrics. In the circuit, a first potential adjusting module is respectively connected with a first input end and an input end of a first voltage follower module, and a second potential adjusting module is respectively connected with a second input end and an input end of a second voltage follower module. The first and second potential adjustment modules are configured to adjust the potential of the voltage provided by the first or second input end to the input end of the first or second voltage follower module to the midpoint potential of the power supply used by the first or second voltage follower module. The first differential input end and the second differential input end of the differential amplifier module are connected with the output end of the first voltage follower module and the output end of the second voltage follower module respectively. The battery voltage detection device can help to reduce the loss of the battery power when the battery voltage detection component works.

Description

Technical Field

[0001] This application relates to electro - electrical technology, and particularly to a battery voltage detection circuit, a battery management system device, and a battery device. Background Art

[0002] A Battery Management System (BMS) device is a device in a battery device (energy storage device) that is responsible for monitoring the battery state and maintaining each battery cell to prevent over - charging and over - discharging of the battery, thereby extending the service life of the battery. As a basic component of the battery management system device, the output voltage detection part of a battery or a battery pack needs to be able to stably and reliably continuously detect the output voltage of the battery or the battery pack for a long period of time, and needs to be able to withstand the high voltage (up to several thousand volts) formed by the series connection of battery elements, and also needs to have as little impact on the battery or the battery pack as possible. However, it is difficult for current battery voltage detection components to meet all of the above requirements at the same time; for example, current battery voltage detection components generally consume the electrical energy stored in the battery continuously with a non - negligible power, which may seriously limit the maximum standby time of the battery device and affect its power storage performance. Summary of the Invention

[0003] This application provides a battery voltage detection circuit, a battery management system device, and a battery device, which can help reduce the power consumption of the battery voltage detection component during operation.

[0004] An embodiment of this application provides a battery voltage detection circuit. The circuit has a first input terminal for connecting the positive electrode of the battery, a second input terminal for connecting the negative electrode of the battery, and a detection signal output terminal. The circuit includes a first potential adjustment module, a first voltage follower module, a second potential adjustment module, a second voltage follower module, and a differential amplifier module; wherein,

[0005] The first potential adjustment module is respectively connected to the first input terminal and the input terminal of the first voltage follower module, and the first potential adjustment module is configured to adjust the potential of the voltage provided from the first input terminal to the input terminal of the first voltage follower module to the mid - point potential of the power supply used by the first voltage follower module;

[0006] The second potential adjustment module is respectively connected to the second input terminal and the input terminal of the second voltage follower module, and the second potential adjustment module is configured to adjust the potential of the voltage provided from the second input terminal to the input terminal of the second voltage follower module to the mid - point potential of the power supply used by the second voltage follower module;

[0007] The first differential input terminal and the second differential input terminal of the differential amplifier module are respectively connected to the output terminal of the first voltage follower module and the output terminal of the second voltage follower module, and the output terminal of the differential amplifier module is connected to the detection signal output terminal.

[0008] In some possible implementation manners, the first potential adjustment module includes a first resistor and a second resistor with equal resistance values. The first end of the first resistor is connected to the positive pole of the power supply used by the first voltage follower module. The second end of the first resistor is respectively connected to the first end of the second resistor, the first input terminal, and the input terminal of the first voltage follower module. The second end of the second resistor is connected to the negative pole of the power supply used by the first voltage follower module;

[0009] The second potential adjustment module includes a third resistor and a fourth resistor with equal resistance values. The first end of the third resistor is connected to the positive pole of the power supply used by the second voltage follower module. The second end of the third resistor is respectively connected to the first end of the fourth resistor, the second input terminal, and the input terminal of the second voltage follower module. The second end of the fourth resistor is connected to the negative pole of the power supply used by the second voltage follower module.

[0010] In some possible implementation manners, the first voltage follower module includes a first operational amplifier and a fifth resistor. The non-inverting input terminal of the first operational amplifier is connected to the input terminal of the first voltage follower module. The inverting input terminal of the first operational amplifier is connected to the first end of the fifth resistor. The second end of the fifth resistor is respectively connected to the output terminal of the first operational amplifier and the output terminal of the first voltage follower module;

[0011] The second voltage follower module includes a second operational amplifier and a sixth resistor. The non-inverting input terminal of the second operational amplifier is connected to the input terminal of the second voltage follower module. The inverting input terminal of the second operational amplifier is connected to the first end of the sixth resistor. The second end of the sixth resistor is respectively connected to the output terminal of the second operational amplifier and the output terminal of the second voltage follower module.

[0012] In some possible implementation manners, the differential amplifier module includes a third operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and a first capacitor. A first differential input terminal of the differential amplifier module is connected to a first end of the seventh resistor. A second end of the seventh resistor is respectively connected to a first end of the eighth resistor and a non-inverting input terminal of the third operational amplifier. A second end of the eighth resistor is connected to a negative electrode of a power supply used by the differential amplifier module. A second differential input terminal of the differential amplifier module is connected to a first end of the ninth resistor. A second end of the ninth resistor is respectively connected to an inverting input terminal of the third operational amplifier, a first end of the tenth resistor, and a first end of the first capacitor. A second end of the tenth resistor is respectively connected to a second end of the first capacitor, an output terminal of the third operational amplifier, and an output terminal of the differential amplifier module. Wherein, a resistance value of the seventh resistor is equal to a resistance value of the ninth resistor, and a resistance value of the eighth resistor is equal to a resistance value of the tenth resistor.

[0013] In some possible implementation manners, both the seventh resistor and the ninth resistor are formed by connecting in series a plurality of resistors with the same resistance value and the same quantity.

[0014] In some possible implementation manners, the battery voltage detection circuit further includes: a first filter module disposed between the first input terminal and the first potential adjustment module, a second filter module disposed between the second input terminal and the second potential adjustment module, and a third filter module disposed between the differential amplifier module and the detection signal output terminal. The first filter module, the second filter module, and the third filter module have the same circuit structure.

[0015] In some possible implementation manners, the battery voltage detection circuit includes three power supply modules respectively used for providing power supplies for the first voltage follower module, the second voltage follower module, and the differential amplifier module. Each power supply module includes an inverter unit, a transformer unit, and a rectifier unit. Two input terminals of the inverter unit are respectively connected to a positive DC power supply terminal and a negative DC power supply terminal of the power supply module. Two output terminals of the inverter unit are respectively connected to two ends of a primary coil of the transformer unit. Two ends of a secondary coil of the transformer unit are respectively connected to two input terminals of the rectifier unit. Two output terminals of the rectifier unit are respectively connected to a positive output terminal and a negative output terminal of the power supply module.

[0016] In some possible implementation manners, the first potential adjustment module and the first voltage follower module are mirror-symmetrical to the second potential adjustment module and the second voltage follower module.

[0017] The embodiment of the present application further provides a battery management system device, and the battery management system device includes at least one battery voltage detection circuit of any one of the above.

[0018] The embodiment of the present application further provides a battery device, and the battery device includes the battery management system device of any one of the above.

[0019] In the battery voltage detection circuit of the embodiment of the present application, two differential voltage acquisition paths are respectively set corresponding to the positive electrode and the negative electrode of the battery - the first potential adjustment module adjusts the potential of the positive electrode of the battery to the mid - point potential of the power supply of the first voltage follower module, so that the first voltage follower module can collect the voltage of the positive electrode of the battery and output it to the first differential input end of the differential amplifier module; the second potential adjustment module adjusts the potential of the negative electrode of the battery to the mid - point potential of the power supply of the second voltage follower module, so that the second voltage follower module can collect the voltage of the negative electrode of the battery and output it to the second differential input end of the differential amplifier module; thus, the differential amplifier module can detect the voltage difference between the positive electrode and the negative electrode of the battery and output it through the detection signal output end. Since the input impedance of the voltage follower is very large, the current passing through the two differential voltage acquisition paths can be limited to almost zero, that is, it can hardly cause loss to the electric energy stored in the battery; at the same time, the potential adjustment enables the voltage follower module to stably and accurately collect the voltages of the positive electrode and the negative electrode of the battery when the battery voltage is very high; thus, the embodiment of the present application can help reduce the loss of battery power caused by the battery voltage detection component during operation, can continuously detect the high output voltage of the battery for a long time, stably and reliably, and hardly has any impact on the battery, which helps to improve the performance and reliability of related products such as battery management system devices and battery devices.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is a structural block diagram of a battery voltage detection circuit in an embodiment of the present application;

[0023] Figure 2 is a circuit structure schematic diagram of a battery voltage detection circuit in an embodiment of the present application;

[0024] Figure 3 It is a schematic circuit diagram of three power supply modules in a battery voltage detection circuit in an embodiment of the present application;

[0025] Figure 4 It is a structural block diagram of a battery management system device in an embodiment of the present application;

[0026] Figure 5 It is a structural block diagram of a battery device in an embodiment of the present application. Specific Embodiments

[0027] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0028] In the present application, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0029] Figure 1 It is a structural block diagram of a battery voltage detection circuit in an embodiment of the present application. Refer to Figure 1 , this battery voltage detection circuit has a first input terminal BAT1 for connecting to the positive electrode of the battery, a second input terminal BAT0 for connecting to the negative electrode of the battery, and a detection signal output terminal OUT; this battery voltage detection circuit includes: a first potential adjustment module 11, a second potential adjustment module 12, a first voltage follower module 13, a second voltage follower module 14, and a differential amplifier module 15.

[0030] The first potential adjustment module 11 is respectively connected to the first input terminal BAT1 and the input terminal of the first voltage follower module 13. The first potential adjustment module 11 is configured to adjust the potential of the voltage provided from the first input terminal BAT1 to the input terminal of the first voltage follower module 13 to the midpoint potential of the power supply used by the first voltage follower module 13; the second potential adjustment module 12 is respectively connected to the second input terminal BAT0 and the input terminal of the second voltage follower module 14. The second potential adjustment module 12 is configured to adjust the potential of the voltage provided from the second input terminal BAT0 to the input terminal of the second voltage follower module 14 to the midpoint potential of the power supply used by the second voltage follower module 14.

[0031] The first differential input terminal and the second differential input terminal of the differential amplifier module 15 are respectively connected to the output terminal of the first voltage follower module 13 and the output terminal of the second voltage follower module 14, and the output terminal of the differential amplifier module 15 is connected to the detection signal output terminal OUT.

[0032] It should be understood that the first voltage follower module 13 and the second voltage follower module 14 are circuit structures that include a voltage follower or have the same function as a voltage follower, and the internal circuit structures of the first voltage follower module 13 and the second voltage follower module 14 may be the same or different; correspondingly, the first potential adjustment module 11 and the second potential adjustment module 12 are circuit structures used to adjust the voltage input to the first voltage follower module 13 or the second voltage follower module 14 to the required potential, and can be implemented by any one or more circuit structures with potential adjustment functions or their combinations; the differential amplifier module 15 is a circuit structure that includes a differential amplifier or has the same function as a differential amplifier, so it can reflect the voltage difference between the two differential input terminals in the output electrical signal. The optional circuit structures of the above modules will be introduced in the form of examples later.

[0033] In the battery voltage detection circuit of the embodiment of the present application, two differential voltage acquisition paths are respectively set corresponding to the positive electrode and the negative electrode of the battery - the first potential adjustment module 11 adjusts the potential of the positive electrode of the battery to the mid - point potential of the power supply of the first voltage follower module 13, so that the first voltage follower module 13 can collect the voltage of the positive electrode of the battery and output it to the first differential input terminal of the differential amplifier module 15; the second potential adjustment module 12 adjusts the potential of the negative electrode of the battery to the mid - point potential of the power supply of the second voltage follower module 14, so that the second voltage follower module 14 can collect the voltage of the negative electrode of the battery and output it to the second differential input terminal of the differential amplifier module 15; thus, the differential amplifier module 15 can detect the voltage difference between the positive electrode and the negative electrode of the battery and output it through the detection signal output terminal.

[0034] It can be seen that because the input impedance of the voltage follower is very large, the above - mentioned circuit can limit the current passing through the two differential voltage acquisition paths to almost zero, that is, it can hardly cause loss to the electrical energy stored in the battery; at the same time, the potential adjustment enables the voltage follower module to stably and accurately collect the voltages of the positive electrode and the negative electrode of the battery when the battery voltage is very high; thus, the embodiment of the present application can help reduce the loss of battery power caused by the battery voltage detection component during operation, can continuously detect the high output voltage of the battery for a long time, stably and reliably, and hardly has any impact on the battery, which helps to improve the performance and reliability of related products such as battery management system devices and battery equipment.

[0035] Figure 2It is a schematic diagram of the circuit structure of a battery voltage detection circuit in an embodiment of the present application.

[0036] Refer to Figure 2 , as an example, the first potential adjustment module 11 includes a first resistor R1 and a second resistor R2 (the resistance values of the first resistor R1 and the second resistor R2 are equal). The first end of the first resistor R1 is connected to the positive electrode VP1 of the power supply used by the first voltage follower module 13. The second end of the first resistor R1 is connected to the first end of the second resistor R2. The second end of the first resistor R1 is connected to the first input terminal BAT1 through the first filter module 16A, and the second end of the first resistor R1 is connected to the input terminal of the first voltage follower module 13. The second end of the second resistor R2 is connected to the negative electrode VP0 of the power supply used by the first voltage follower module 13; the second potential adjustment module 12 includes a third resistor R3 and a fourth resistor R4 (the resistance values of the third resistor R3 and the fourth resistor R4 are equal). The first end of the third resistor R3 is connected to the positive electrode VN1 of the power supply used by the second voltage follower module 14. The second end of the third resistor R3 is connected to the first end of the fourth resistor R4. The second end of the third resistor R3 is connected to the second input terminal BAT0 through the second filter module 16B. The second end of the third resistor R3 is also connected to the input terminal of the second voltage follower module 14. The second end of the fourth resistor R4 is connected to the negative electrode VN0 of the power supply used by the second voltage follower module 14.

[0037] Continue to refer to Figure 2 , as an example, the first voltage follower module 13 includes a first operational amplifier OP1 and a fifth resistor R5. The non-inverting input terminal of the first operational amplifier OP1 is connected to the input terminal of the first voltage follower module 13 (i.e., connected to the second end of the first resistor R1 and the first end of the second resistor R2 respectively). The inverting input terminal of the first operational amplifier OP1 is connected to the first end of the fifth resistor R5. The second end of the fifth resistor R5 is connected to the output terminal of the first operational amplifier OP1 and the output terminal of the first voltage follower module 13 respectively. In addition, the positive power supply terminal of the first operational amplifier OP1 is connected to the positive electrode VP1 of the power supply used by the first voltage follower module 13, and the negative power supply terminal of the first operational amplifier OP1 is connected to the negative electrode VP0 of the power supply used by the first voltage follower module 13. Moreover, the first voltage follower module 13 further includes a second capacitor C2 with both ends connected to the positive electrode VP1 and the negative electrode VP0 of the power supply used by the first voltage follower module 13 respectively (the second capacitor C2 is an optional component). The second capacitor C2 can help filter out the high-frequency noise between the positive electrode VP1 and the negative electrode VP0 of the power supply, and can use the stored electrical energy to help stabilize the DC voltage between the positive electrode VP1 and the negative electrode VP0 of the power supply.

[0038] Continue to refer to Figure 2, as an example, the second voltage follower module 14 includes a second operational amplifier OP2 and a sixth resistor R6. The non-inverting input terminal of the second operational amplifier OP2 is connected to the input terminal of the second voltage follower module 14 (i.e., connected to the second terminal of the third resistor R2 and the first terminal of the fourth resistor R4 respectively). The inverting input terminal of the second operational amplifier OP2 is connected to the first terminal of the sixth resistor R6. The second terminal of the sixth resistor R6 is connected to the output terminal of the second operational amplifier OP2 and the output terminal of the second voltage follower module 14 respectively. In addition, the positive power supply terminal of the second operational amplifier OP2 is connected to the positive electrode VN1 of the power supply used by the second voltage follower module 14, and the negative power supply terminal of the second operational amplifier OP2 is connected to the negative electrode VN0 of the power supply used by the second voltage follower module 14. Moreover, the second voltage follower module 14 further includes a third capacitor C3 whose two ends are respectively connected to the positive electrode VN1 and the negative electrode VN0 of the power supply used by the second voltage follower module 14 (the third capacitor C3 is an optional component). The third capacitor C3 helps filter out high-frequency noise between the positive electrode VN1 and the negative electrode VN0 of the power supply, and can use the stored electrical energy to help stabilize the DC voltage between the positive electrode VN1 and the negative electrode VN0 of the power supply.

[0039] Continue to refer to Figure 2 , as an example, the differential amplifier module 15 includes a third operational amplifier OP3, a seventh resistor R7 (formed by connecting 5 identical resistors in series), an eighth resistor R8, a ninth resistor R9 (formed by connecting 5 identical resistors in series), a tenth resistor R10 and a first capacitor C1. The first differential input terminal of the differential amplifier module 15 (i.e., the end connected to the output terminal of the first voltage follower module 13 and connected to the output terminal of the first operational amplifier OP1) is connected to the first terminal of the seventh resistor R7. The second terminal of the seventh resistor R7 is connected to the first terminal of the eighth resistor R8 and the non-inverting input terminal of the third operational amplifier OP3 respectively. The second terminal of the eighth resistor R8 is connected to the negative electrode VT0 of the power supply used by the differential amplifier module 15. The second differential input terminal of the differential amplifier module 15 (i.e., the end connected to the output terminal of the second voltage follower module 14 and connected to the output terminal of the second operational amplifier OP2) is connected to the first terminal of the ninth resistor R9. The second terminal of the ninth resistor R9 is connected to the inverting input terminal of the third operational amplifier OP3, the first terminal of the tenth resistor R10 and the first terminal of the first capacitor C1 respectively. The second terminal of the tenth resistor R10 is connected to the second terminal of the first capacitor C1, the output terminal of the third operational amplifier OP3 and the output terminal of the differential amplifier module 15 (i.e., the end used to connect to the detection signal output terminal OUT, Figure 2In the example, it is connected to the detection signal output terminal OUT through the third filter module 16C. Among them, the resistance value of the seventh resistor R7 is equal to the resistance value of the ninth resistor R9, and the resistance value of the eighth resistor R8 is equal to the resistance value of the tenth resistor R10. In addition, the positive power supply terminal of the third operational amplifier OP3 is connected to the positive electrode VT1 of the power supply used by the differential amplifier module 15, the negative power supply terminal of the third operational amplifier OP3 is connected to the negative electrode VT0 of the power supply used by the differential amplifier module 15, and the differential amplifier module 15 further includes a fourth capacitor C4 (this fourth capacitor C4 is an optional component) with both ends respectively connected to the positive electrode VT1 and the negative electrode VT0 of the power supply used by the differential amplifier module 15. This fourth capacitor C4 can help filter out high-frequency noise between the positive electrode VT1 and the negative electrode VT0 of the power supply and can use the stored electrical energy to help stabilize the DC voltage between the positive electrode VT1 and the negative electrode VT0 of the power supply.

[0040] Continue to refer to Figure 2 , in some possible implementation manners, the battery voltage detection circuit of the embodiment of the present application further includes: a first filter module 16A spaced between the first input terminal BAT1 and the first potential adjustment module 11, a second filter module 16B spaced between the second input terminal BAT0 and the second potential adjustment module 12, and a third filter module 16C spaced between the differential amplifier module 15 and the detection signal output terminal OUT. These filter modules can play a role in reducing or eliminating noise signals to improve the battery voltage detection accuracy and protecting the connected circuit structure. In some possible implementation manners, the first filter module 16A, the second filter module 16B, and the third filter module 16C have the same circuit structure; for example, Figure 2 in, the first filter module 16A, the second filter module 16B, and the third filter module 16C are all LC filter circuits, and the difference is only in the connected circuit nodes ( Figure 2 in, the first filter module 16A, the second filter module 16B, and the third filter module 16C respectively use the negative electrode VP0, the negative electrode VN0, and the negative electrode VT0 as their respective common terminals.

[0041] By Figure 2As can be seen from the shown circuit structure, the first resistor R1 and the second resistor R2 with the same resistance value can adjust the level at the non-inverting input terminal of the first operational amplifier OP1 to the midpoint potential between the positive pole VP1 and the negative pole VP0. The third resistor R3 and the fourth resistor R4 with the same resistance value can adjust the level at the non-inverting input terminal of the second operational amplifier OP2 to the midpoint potential between the positive pole VN1 and the negative pole VN0. Since the first voltage follower module 13, the second voltage follower module 14, and the differential amplifier module 15 each use a separate power supply, even if the potential at the first input terminal BAT1 is adjusted to the midpoint potential between the positive pole VP1 and the negative pole VP0, and the potential at the second input terminal BAT0 is adjusted to the midpoint potential between the positive pole VN1 and the negative pole VN0, the voltage value of the first input terminal BAT1 relative to the second input terminal BAT0 will not change. After being adjusted to their respective midpoint potentials, the voltage signals of the battery positive and negative poles can be transmitted to the differential amplifier module 15 under the action of the stably operating voltage follower. Since the operational amplifier has a very large input impedance, the current magnitude between the first input terminal BAT1 and the first operational amplifier OP1 is almost zero, and the current magnitude between the second input terminal BAT0 and the second operational amplifier OP2 is almost zero. Therefore Figure 2 the shown circuit structure hardly consumes the electrical energy stored in the battery during normal operation. In the differential amplifier module 15, a differential amplification circuit is formed with the third operational amplifier OP3 as the core. The ratio of differential amplification is equal to the resistance value of the seventh resistor R7 (equal to the resistance value of the ninth resistor R9) divided by the resistance value of the eighth resistor R8. In one example, both the seventh resistor R7 and the ninth resistor R9 are composed of 5 identical 1-megohm resistors connected in series, and the resistance value of the eighth resistor R8 is 5.1 kilohms. Therefore, the ratio of differential amplification is equal to 5000:5.1, approximately equal to 1000:1, that is, the voltage value output at the output terminal of the third operational amplifier OP3 is approximately equal to one-thousandth of the voltage difference between the first input terminal BAT1 and the second input terminal BAT0. In addition, since the first operational amplifier OP1 and the second operational amplifier OP2 both play a role in isolating electrical signals between the input terminal and the output terminal, it is possible to largely avoid risks such as short circuits caused by resistor failure due to excessive voltage, thus improving the safety and reliability of the battery voltage detection component and related products.

[0042] It should also be understood that, in order to improve the accuracy of battery voltage detection, the circuit structure connected to the non-inverting input terminal of the third operational amplifier OP3 can be a mirror image of the circuit structure connected to the inverting input terminal of the third operational amplifier OP3. For example, the first potential adjustment module 11 and the first voltage follower module 13 can be symmetrically mirrored with respect to the second potential adjustment module 12 and the second voltage follower module 14; the first filter module 16A, the first potential adjustment module 11, the first voltage follower module 13, and the seventh resistor R7 can be symmetrically mirrored with respect to the first filter module 16B, the second potential adjustment module 12, the second voltage follower module 14, and the ninth resistor R9. Among them, both the seventh resistor R7 and the ninth resistor R9 are formed by connecting in series a plurality of resistors with the same resistance value and the same number; the resistance value of the eighth resistor R8 is equal to the resistance value of the tenth resistor R10, and the circuit connection lines of the mutually mirrored circuit parts can be arranged in a mutually symmetric manner.

[0043] Figure 3 is a schematic circuit diagram of three power supply modules in a battery voltage detection circuit according to an embodiment of the present application. Refer to Figure 3 , as an example of a power supply implementation method, the above battery voltage detection circuit may include three power supply modules 17, 18, and 19 respectively used to supply power to the first voltage follower module 13, the second voltage follower module 14, and the differential amplifier module 15. Each power supply module includes: an inverter unit UA1 / UA2 / UA3, a transformer unit UB1 / UB2 / UB3, a rectifier unit UC1 / UC2 / UC3, and also includes an input capacitor C11 / C21 / C31, a first output capacitor C21 / C22 / C23, and a second output capacitor C31 / C32 / C33. Refer to Figure 3, in the power supply modules 17 / 18 / 19, two input terminals of the inverter units UA1 / UA2 / UA3 are respectively connected to the positive DC power supply terminal V1 and the negative DC power supply terminal V0 of the power supply module. Two output terminals of the inverter units UA1 / UA2 / UA3 are respectively connected to both ends of the primary coil of the transformer units UB1 / UB2 / UB3. Both ends of the secondary coil of the transformer units UB1 / UB2 / UB3 are respectively connected to two input terminals of the rectifier units UC1 / UC2 / UC3. Two output terminals of the rectifier units UC1 / UC2 / UC3 are respectively connected to the positive output terminals VP1 / VN1 / VT1 and the negative output terminals VP0 / VN0 / VT0 of the power supply module. In this way, each power supply module 17 / 18 / 19 can isolate the circuit structures on both sides from each other through the primary coil and the secondary coil of the transformer by first inverting the DC signal into an AC signal and then rectifying it into a DC signal after passing through the transformer, so that there is no mutual interference between any two of the power signals between the positive DC power supply terminal V1 and the negative DC power supply terminal V0, between the positive output terminal VP1 and the negative output terminal VP1, between the positive output terminal VN1 and the negative output terminal VN1, and between the positive output terminal VT1 and the negative output terminal VT1. Thus, the accuracy of battery voltage detection can be guaranteed to a great extent.

[0044] It should be understood that the transformer units UB1 / UB2 / UB3 can set the turn ratio between the primary coil and the secondary coil according to the voltage value of the required power supply voltage. The input capacitors C11 / C21 / C31 can play the role of filtering high-frequency noise and helping to maintain the voltage stability between the positive DC power supply terminal V1 and the negative DC power supply terminal V0. In addition, the first output capacitors C21 / C22 / C23 and the second output capacitors C31 / C32 / C33 can achieve better effects of filtering noise signals and transmitting voltage signals by using a combination of large-capacity capacitors and small-capacity capacitors.

[0045] Figure 4 is a structural block diagram of a battery management system device in an embodiment of the present application. Refer to Figure 4, the battery management system device (BMS device) 40 includes at least one battery voltage detection circuit 41, which is any one of the above-mentioned battery voltage detection circuits, and further includes a control circuit 42 corresponding to each battery voltage detection circuit 41 and connected thereto (the control circuit 42 and the battery voltage detection circuit 41 can be connected one-to-one, or one-to-many, and this is not limited thereto). In one example, the control circuit 42 includes: a processor and a memory for storing executable instructions of the processor. The processor may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components.

[0046] Figure 5 is a structural block diagram of a battery device in an embodiment of the present application. Refer to Figure 5 , the battery device 50 includes any one of the above-mentioned battery management system devices 51, and a battery 52 connected to the battery management system device 51. The battery 52 refers to any component or structure capable of storing electrical energy, and the battery device 50 can be any type of energy storage device.

[0047] As described above, the embodiments of the present application can help reduce the loss of battery power caused by the battery voltage detection component during operation, can continuously detect the high output voltage of the battery for a long time, stably and reliably, and hardly have any impact on the battery, which helps to improve the performance and reliability of related products such as battery management system devices and battery devices.

[0048] It should be noted that the above are only optional embodiments of the present application, and each of the above implementation manners can be appropriately modified according to actual application requirements. For example, in any of the above circuit structures, any resistor can be implemented by multiple resistors having a series structure and / or a parallel structure, and any capacitor can be implemented by multiple capacitors having a series structure and / or a parallel structure.

[0049] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery voltage detection circuit, characterized in that, The circuit has a first input terminal for connecting to the positive electrode of the battery, a second input terminal for connecting to the negative electrode of the battery, and a detection signal output terminal. The circuit includes a first potential adjustment module, a first voltage follower module, a second potential adjustment module, a second voltage follower module, and a differential amplifier module; wherein, The first potential adjustment module is respectively connected to the first input terminal and the input terminal of the first voltage follower module. The first potential adjustment module is configured to adjust the potential of the voltage provided from the first input terminal to the input terminal of the first voltage follower module to the midpoint potential of the power supply used by the first voltage follower module; The second potential adjustment module is respectively connected to the second input terminal and the input terminal of the second voltage follower module. The second potential adjustment module is configured to adjust the potential of the voltage provided from the second input terminal to the input terminal of the second voltage follower module to the midpoint potential of the power supply used by the second voltage follower module; The first differential input terminal and the second differential input terminal of the differential amplifier module are respectively connected to the output terminal of the first voltage follower module and the output terminal of the second voltage follower module. The output terminal of the differential amplifier module is connected to the detection signal output terminal.

2. The battery voltage detection circuit according to claim 1, wherein, The first potential adjustment module includes a first resistor and a second resistor with equal resistance values. The first end of the first resistor is connected to the positive electrode of the power supply used by the first voltage follower module. The second end of the first resistor is respectively connected to the first end of the second resistor, the first input terminal, and the input terminal of the first voltage follower module. The second end of the second resistor is connected to the negative electrode of the power supply used by the first voltage follower module; The second potential adjustment module includes a third resistor and a fourth resistor with equal resistance values. The first end of the third resistor is connected to the positive electrode of the power supply used by the second voltage follower module. The second end of the third resistor is respectively connected to the first end of the fourth resistor, the second input terminal, and the input terminal of the second voltage follower module. The second end of the fourth resistor is connected to the negative electrode of the power supply used by the second voltage follower module.

3. The battery voltage detection circuit according to claim 1, wherein The first voltage follower module includes a first operational amplifier and a fifth resistor. The non-inverting input terminal of the first operational amplifier is connected to the input terminal of the first voltage follower module. The inverting input terminal of the first operational amplifier is connected to the first end of the fifth resistor. The second end of the fifth resistor is respectively connected to the output terminal of the first operational amplifier and the output terminal of the first voltage follower module; The second voltage follower module includes a second operational amplifier and a sixth resistor. The non-inverting input terminal of the second operational amplifier is connected to the input terminal of the second voltage follower module. The inverting input terminal of the second operational amplifier is connected to the first end of the sixth resistor. The second end of the sixth resistor is respectively connected to the output terminal of the second operational amplifier and the output terminal of the second voltage follower module.

4. The battery voltage detection circuit according to claim 1, wherein The differential amplifier module includes a third operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and a first capacitor. The first differential input terminal of the differential amplifier module is connected to the first end of the seventh resistor. The second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the non-inverting input terminal of the third operational amplifier. The second end of the eighth resistor is connected to the negative electrode of the power supply used by the differential amplifier module. The second differential input terminal of the differential amplifier module is connected to the first end of the ninth resistor. The second end of the ninth resistor is respectively connected to the inverting input terminal of the third operational amplifier, the first end of the tenth resistor, and the first end of the first capacitor. The second end of the tenth resistor is respectively connected to the second end of the first capacitor, the output terminal of the third operational amplifier, and the output terminal of the differential amplifier module. Among them, the resistance value of the seventh resistor is equal to the resistance value of the ninth resistor, and the resistance value of the eighth resistor is equal to the resistance value of the tenth resistor.

5. The battery voltage detection circuit according to claim 4, wherein Both the seventh resistor and the ninth resistor are formed by connecting in series a plurality of resistors with the same resistance value and the same number.

6. The battery voltage detection circuit according to claim 1, characterized in that The battery voltage detection circuit further includes: a first filter module spaced between the first input terminal and the first potential adjustment module, a second filter module spaced between the second input terminal and the second potential adjustment module, and a third filter module spaced between the differential amplifier module and the detection signal output terminal. The first filter module, the second filter module, and the third filter module have the same circuit structure.

7. The battery voltage detection circuit according to any one of claims 1 to 6, characterized in that The battery voltage detection circuit includes three power supply modules respectively used to supply power to the first voltage follower module, the second voltage follower module, and the differential amplifier module. Each power supply module includes an inverter unit, a transformer unit, and a rectifier unit. Among them, the two input terminals of the inverter unit are respectively connected to the positive DC power terminal and the negative DC power terminal of the power supply module. The two output terminals of the inverter unit are respectively connected to the two ends of the primary coil of the transformer unit. The two ends of the secondary coil of the transformer unit are respectively connected to the two input terminals of the rectifier unit. The two output terminals of the rectifier unit are respectively connected to the positive output terminal and the negative output terminal of the power supply module.

8. The battery voltage detection circuit according to any one of claims 1 to 6, characterized in that The first potential adjustment module and the first voltage follower module are mirror-symmetrical to the second potential adjustment module and the second voltage follower module.

9. A battery management system device, characterized in that, The device includes at least one battery voltage detection circuit as described in any one of claims 1 to 7.

10. A battery device, characterized in that, The battery device includes the battery management system device as described in claim 9.

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