Voltage sampling circuit, electronic device, battery pack and energy storage device

Abstract

The application provides a voltage sampling circuit, an electronic device, a battery pack and an energy storage device. In the voltage sampling circuit, a voltage sampling end is used for being connected to a sampling point, and a first end of a first voltage dividing unit is connected to the voltage sampling end. A second end of the first voltage dividing unit is connected to a first end of a bias unit, a second end of the bias unit is connected to a reference voltage source, a second voltage dividing unit is further connected between the first end of the bias unit and a reference ground, and the first end of the bias unit is further connected to a voltage input end of an isolation operational amplifier chip. The isolation operational amplifier chip is used for outputting the voltage of the voltage input end after isolation. The voltage sampling circuit provided by the application can widen the voltage sampling range when the isolation operational amplifier chip is used for voltage sampling through simple circuit design, and realize the function of negative voltage sampling based on the isolation operational amplifier chip.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a voltage sampling circuit, electronic device, battery pack, and energy storage device. Background Technology

[0002] In the field of energy storage, when the controller and the high-voltage bus are not grounded together, it is necessary to isolate and feed back the signal collected at the high-voltage end to the controller in order to achieve high-low voltage isolation. Isolated voltage sampling can be achieved using linear optocouplers, isolated operational amplifiers, magnetic isolation, and other solutions. Among these, the isolated operational amplifier solution has the advantages of high linearity and high immunity to common-mode transient interference, and is widely used in the energy storage field.

[0003] Meanwhile, pluggable ports in related equipment, such as energy storage battery output ports and photovoltaic interfaces, need to have reverse connection protection to prevent incorrect installation and damage to user property and personal safety. Therefore, the sampling circuit is required to have negative voltage sampling functionality to identify reverse connection states. However, in related technologies, some isolated operational amplifier chips have an input voltage range of 0.1V to 2V, and neither their input nor output sides support negative voltage sampling functionality. Utility Model Content

[0004] In view of this, this application provides a voltage sampling circuit, electronic device, battery pack and energy storage device, which can broaden the voltage acquisition range when using isolated operational amplifier chips for voltage sampling through simple circuit design, and realize negative voltage sampling function based on isolated operational amplifier chips, thereby effectively reducing the cost of sampling circuit.

[0005] This application provides a voltage sampling circuit, including a voltage sampling terminal, a first voltage divider unit, a second voltage divider unit, a bias unit, and an isolation operational amplifier chip. The voltage sampling terminal is connected to the point to be sampled. The first terminal of the first voltage divider unit is connected to the voltage sampling terminal. The second terminal of the first voltage divider unit is connected to the first terminal of the bias unit, which is also connected to a reference voltage source. The second voltage divider unit is further connected between the first terminal of the bias unit and a reference ground. The first terminal of the bias unit is also connected to the voltage input terminal of the isolation operational amplifier chip, which isolates the voltage at the voltage input terminal before outputting it.

[0006] In one embodiment, the first voltage divider unit includes at least two first voltage divider resistors connected in series.

[0007] In one embodiment, the second voltage divider unit includes at least one second voltage divider resistor, with a first terminal of each second voltage divider resistor connected to a first terminal of the bias unit and a second terminal of each second voltage divider resistor connected to a reference ground.

[0008] In one embodiment, the voltage sampling circuit further includes a filtering unit connected in parallel with the second voltage divider unit.

[0009] In one embodiment, the voltage sampling circuit further includes a unidirectional conduction unit, the positive terminal of which is connected to the voltage input terminal of the isolation operational amplifier chip and the first terminal of the bias unit, and the negative terminal of which is connected to the second terminal of the bias unit.

[0010] In one embodiment, the voltage sampling circuit further includes a voltage regulator unit, and the second end of the bias unit is also connected to the power input terminal of the isolation operational amplifier chip; the first end of the voltage regulator unit is connected to the power input terminal of the isolation operational amplifier chip, and the second end of the voltage regulator unit is connected to a reference ground.

[0011] In one embodiment, the voltage regulator unit includes two capacitors connected in parallel, with the first terminals of both capacitors connected to the power input terminal and the second terminals of both capacitors connected to a reference ground.

[0012] A second aspect of this application provides an electronic device including a positive terminal of a DC interface, a negative terminal of a DC interface, and a voltage sampling circuit as described in any of the preceding claims. The voltage sampling terminal of the voltage sampling circuit is connected to the positive terminal of the DC interface.

[0013] A third aspect of this application provides a battery pack including at least one energy storage battery, a positive DC bus, a negative DC bus, and a voltage sampling circuit as described in any of the preceding claims. The positive terminal of the energy storage battery is connected to the positive DC bus, and the negative terminal of the energy storage battery is connected to the negative DC bus. The voltage sampling terminal of the voltage sampling circuit is connected to the positive DC bus.

[0014] A fourth aspect of this application provides an energy storage device, including the battery pack described above.

[0015] The voltage sampling circuit provided in this application adds a bias unit to the voltage input terminal of the isolated operational amplifier chip. One end of the bias unit is connected to the voltage input terminal of the isolated operational amplifier chip and the midpoint between the first voltage divider unit and the second voltage divider unit, and the other end is connected to a reference voltage source. This superimposes a DC voltage bias onto the voltage input terminal of the isolated operational amplifier chip, so that the input voltage of the voltage input terminal of the isolated operational amplifier chip and the voltage sampling value of the voltage sampling terminal remain linearly correlated. When the sampling voltage value of the voltage sampling terminal is negative within a preset range, the voltage at the voltage input terminal can still be positive. This expands the voltage acquisition range when using the isolated operational amplifier chip for voltage sampling and realizes the negative voltage sampling function based on the isolated operational amplifier chip. Compared with the related technology that directly uses the isolated operational amplifier chip with negative voltage sampling function for sampling, it can effectively reduce the cost of the sampling circuit. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation on the scope of protection of this application. In the various drawings, similar components are numbered similarly.

[0017] Figure 1 A circuit block diagram of a voltage sampling circuit provided in one embodiment of this application.

[0018] Figure 2 for Figure 1 A schematic diagram of the voltage curve between the voltage sample value at the voltage sampling terminal and the input voltage at the voltage input terminal.

[0019] Figure 3 A circuit block diagram of a voltage sampling circuit provided in another embodiment of this application.

[0020] Figure 4 A circuit diagram of a voltage sampling circuit provided in one embodiment of this application.

[0021] Figure 5 This is a block diagram of an electronic device provided in an embodiment of this application.

[0022] Figure 6 This is a block diagram of a battery pack provided in one embodiment of this application.

[0023] Figure 7 A block diagram of an energy storage device provided in an embodiment of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0029] In the field of energy storage, when the controller and the high-voltage bus are not grounded together, it is necessary to isolate and feed back the signal collected at the high-voltage end to the controller in order to achieve high-low voltage isolation. Isolated voltage sampling can be achieved using linear optocouplers, isolated operational amplifiers, magnetic isolation, and other solutions. Among these, the isolated operational amplifier solution has the advantages of high linearity and high immunity to common-mode transient interference, and is widely used in the energy storage field.

[0030] Meanwhile, pluggable ports in related equipment, such as energy storage battery output ports and photovoltaic interfaces, need to have reverse connection protection to prevent incorrect installation and damage to user property and personal safety. Therefore, the sampling circuit is required to have negative voltage sampling functionality to identify reverse connection states. However, in related technologies, some isolated operational amplifier chips have an input voltage range of 0.1V to 2V, and neither their input nor output sides support negative voltage sampling functionality.

[0031] Based on this, this application provides a voltage sampling circuit, a battery pack, and an energy storage device, which can broaden the voltage acquisition range of the isolated operational amplifier chip and realize the negative voltage sampling function of the isolated operational amplifier chip through simple circuit design.

[0032] Next, the voltage sampling circuit provided in this application will be described with reference to the accompanying drawings. This voltage sampling circuit is suitable for various electronic devices that require negative voltage sampling through an isolation operational amplifier chip.

[0033] Please see Figure 1 , Figure 1This is a circuit block diagram of a voltage sampling circuit 10 provided in an embodiment of this application. The voltage sampling circuit 10 includes a voltage sampling terminal V_sap, a first voltage divider unit 110, a second voltage divider unit 120, a bias unit 130, and an isolation operational amplifier chip 140. The voltage sampling terminal V_sap is connected to the point to be sampled. The first terminal of the first voltage divider unit 110 is connected to the voltage sampling terminal V_sap, and the second terminal of the first voltage divider unit 110 is connected to the first terminal of the bias unit 130. The second terminal of the bias unit 130 is connected to a reference voltage source 20. The second voltage divider unit 120 is also connected between the first terminal of the bias unit 130 and the reference ground GND. The first terminal of the bias unit 130 is also connected to the voltage input terminal V_in of the isolation operational amplifier chip 140. The isolation operational amplifier chip 140 isolates the input voltage at the voltage input terminal V_in and outputs it through the voltage output terminal V_out.

[0034] Taking the sampling point connected to the sampling terminal V_sap as the positive output terminal of the battery pack as an example, when the external power supply is correctly connected to the battery pack, the sampling terminal V_sap can detect positive voltage. When the external power supply is reversed to the battery pack, that is, the negative output terminal of the external power supply is connected to the positive output terminal of the battery pack, the sampling terminal V_sap can detect negative voltage.

[0035] The first voltage divider unit 110 and the second voltage divider unit 120 divide the voltage sampled at the voltage sampling terminal V_sap to reduce the amplitude of the input voltage at the voltage input terminal V_in of the isolation operational amplifier chip 140. It can be understood that in some embodiments, the voltage sampled value at the voltage sampling terminal V_sap is much larger than the upper limit of the input voltage at the voltage input terminal V_in of the isolation operational amplifier chip 140. For example, when the sampling point is the positive output terminal of the battery pack, the voltage sampled at the voltage sampling terminal V_sap can be as high as 1000V, while the input voltage range of the voltage input terminal V_in of the isolation operational amplifier chip 140 is 0.1V to 2V, which is much smaller than the voltage sampled at the voltage sampling terminal V_sap. Therefore, in the voltage sampling circuit 10 provided in this application, the input voltage collected by the voltage sampling terminal V_sap is divided by setting the first voltage divider unit 110 and the second voltage divider unit 120, so that the amplitude of the input voltage received by the voltage input terminal V_in of the isolation operational amplifier chip 140 is within the input voltage range of the voltage input terminal V_in, thereby protecting the isolation operational amplifier chip 140. The first voltage divider unit 110 and the second voltage divider unit 120 may include at least one of electronic devices such as resistors, capacitors, diodes, operational amplifiers, Zener diodes, and inductors. This application does not impose specific limitations on the specific circuit structure of the first voltage divider unit 110 and the second voltage divider unit 120 or the electrical parameters of its electronic components.

[0036] The bias unit 130 is used to superimpose a DC voltage bias onto the voltage input terminal V_in of the isolated operational amplifier chip 140, so that the input voltage received at the voltage input terminal V_in is linearly related to the voltage sample value at the voltage sampling terminal V_sap. Simultaneously, it allows the voltage to be adjusted to a positive voltage within the input voltage range even when the input voltage at the voltage sampling terminal V_sap is negative. The bias unit 130 may include at least one of the following electronic devices: resistor, capacitor, diode, operational amplifier, Zener diode, and inductor. This application does not impose specific limitations on the specific circuit structure of the bias unit 130 or the electrical parameters of its electronic components.

[0037] The isolation operational amplifier chip 140 is used to achieve electrical isolation between the voltage input terminal V_in and the voltage output terminal V_out, thereby improving the accuracy and safety of signal sampling. The isolation operational amplifier chip 140 also includes a power input terminal VDD1. The power input terminal VDD1 is used to connect a power supply to maintain the normal operation of the isolation operational amplifier chip 140. For example, the power input terminal VDD1 can be connected to a reference voltage source 20. In other embodiments, the power input terminal VDD1 can also be connected to other voltage sources.

[0038] Please refer to it again. Figure 1 The following content will be based on Figure 1 This will illustrate the working principle of the voltage sampling circuit 10 provided in this application.

[0039] First, based on Kirchhoff's voltage laws (KCV), in the voltage sampling circuit 10, the input voltage received by the voltage input terminal V_in of the isolation operational amplifier chip 140 conforms to the following formula (1):

[0040]

[0041] Wherein, Vsap represents the voltage sample value acquired by the voltage sampling terminal V_sap; Vin represents the input voltage received by the voltage input terminal V_in; R1 represents the equivalent resistance of the first voltage divider unit 110; V1 represents the voltage of the reference ground GND; R2 represents the equivalent resistance of the second voltage divider unit 120; V2 represents the voltage of the reference voltage source 20; and R3 represents the equivalent resistance of the bias unit 130.

[0042] After processing the above formula (1), the formula (2) for calculating the input voltage received at the voltage input terminal V_in can be obtained:

[0043]

[0044] As can be seen from formula (2), the input voltage Vin received by the voltage input terminal V_in is linearly related to the voltage sampling value Vsap collected by the voltage sampling terminal V_sap.

[0045] make

[0046] Then, according to the above formula (2), we can obtain Figure 2 The diagram shows the curve between the input voltage Vin and the voltage sample value Vsap.

[0047] Obviously, when the voltage sampled value acquired by the voltage sampling terminal V_sap is within the range of -a / b to 0, the input voltage received by the voltage input terminal V_in of the isolation operational amplifier chip 140 is still positive. In other words, in the circuit design of the voltage sampling circuit 10 provided in this application, by setting the bias unit 130, even if the voltage sampling terminal V_sap of the voltage sampling circuit 10 acquires a negative voltage, the input voltage received by the voltage input terminal V_in can still be positive. Thus, the voltage output terminal V_out of the isolation operational amplifier chip 140 can output the isolated input voltage received by the voltage input terminal V_in, achieving negative voltage sampling, and then realizing reverse connection detection based on the negative voltage sampling result.

[0048] It is understood that this application does not impose any restrictions on the specific values ​​of the equivalent resistance R1 of the first voltage divider unit 110, the equivalent resistance R2 of the second voltage divider unit 120, the equivalent resistance R3 of the bias unit 130, the voltage V1 of the reference ground GND, and the voltage V2 of the reference voltage source 20. Accordingly, the lower limit value -a / b of the negative voltage sampling of the voltage sampling circuit 10 can be adjusted based on the above formula according to the electrical parameters of each device in the voltage sampling circuit 10. This application does not impose any restrictions on the specific value of the lower limit value -a / b of the negative voltage sampling.

[0049] In summary, the voltage sampling circuit 10 provided in this application adds a bias unit 130 to the voltage input terminal V_in of the isolated operational amplifier chip 140. One end of the bias unit 130 is connected to the voltage input terminal V_in of the isolated operational amplifier chip 140 and the midpoint between the first voltage divider unit 110 and the second voltage divider unit 120, and the other end is connected to the reference voltage source 20. This superimposes a DC voltage bias onto the voltage input terminal V_in of the isolated operational amplifier chip 140, so that the input voltage of the voltage input terminal V_in of the isolated operational amplifier chip 140 and the voltage sampling value of the voltage sampling terminal V_sap remain linearly correlated. When the sampling voltage value of the voltage sampling terminal V_sap is negative within a preset range, the voltage of the voltage input terminal V_in can still be positive. This expands the voltage acquisition range when using the isolated operational amplifier chip 140 for voltage sampling and realizes the negative voltage sampling function based on the isolated operational amplifier chip 140. Compared with the related technology of directly using the isolated operational amplifier chip with negative voltage sampling function for sampling, the cost of the sampling circuit can be effectively reduced.

[0050] Please continue reading. Figure 3In some embodiments, the voltage sampling circuit 10 further includes a filtering unit 150. The filtering unit 150 is connected in parallel with the second voltage divider unit 120. The filtering unit 150 is used to filter the input voltage at the voltage input terminal V_in to reduce interference at the voltage input terminal V_in and improve the accuracy of signal sampling. The filtering unit 150 may include at least one of a capacitor, an inductor, and a filtering element. This application does not impose specific limitations on the electronic devices and their electrical parameters in the filtering unit 150.

[0051] In some embodiments, the voltage sampling circuit 10 further includes a unidirectional conduction unit 160. The positive terminal of the unidirectional conduction unit 160 is connected to the voltage input terminal V_in of the isolation operational amplifier chip 140 and the first terminal of the bias unit 130, and the negative terminal of the unidirectional conduction unit 160 is connected to the second terminal of the bias unit 130; that is, the unidirectional conduction unit 160 and the bias unit 130 are connected in parallel. The unidirectional conduction unit 160 is used to form a discharge circuit at the voltage input terminal V_in, reducing the probability of damage to the voltage input terminal V_in due to overvoltage. The unidirectional conduction unit 160 may include at least one of a diode and other voltage regulating components. This application does not specifically limit the specific circuit structure of the unidirectional conduction unit 160 or the electrical parameters of its electronic components.

[0052] In some embodiments, the voltage sampling circuit 10 further includes a voltage regulator unit 170. The second terminal of the bias unit 130 is also connected to the power input terminal VDD1 of the isolation operational amplifier chip 140, the first terminal of the voltage regulator unit 170 is connected to the power input terminal VDD1 of the isolation operational amplifier chip 140, and the second terminal of the voltage regulator unit 170 is connected to the reference ground GND. The voltage regulator unit 170 is used to stabilize the power supply voltage at the power input terminal VDD1 to improve the power supply voltage quality and protect the power input terminal VDD1. The voltage regulator unit 170 may include at least one of capacitors, resistors, diodes, and other voltage regulating components. This application does not specifically limit the specific circuit structure of the voltage regulator unit 170 or the electrical parameters of its electronic components.

[0053] In some embodiments, the voltage sampling circuit 10 further includes a signal amplification unit 180. The input terminal of the signal amplification unit 180 is connected to the output terminal V_out of the isolation operational amplifier chip 140 to amplify the voltage signal output from the output terminal V_out and output it through the output terminal OUT. Thus, the amplification by the signal amplification unit 180 facilitates subsequent calculations on the voltage signal sampled by the voltage sampling circuit 10. The signal amplification unit 180 may include at least one of operational amplifiers, resistors, capacitors, and other electronic components. This application does not limit the specific circuit structure of the signal amplification unit 180. Furthermore, it should be noted that the amplification factor of the signal amplification unit 180 can be reasonably set according to actual conditions, for example, according to the control circuit controlling the voltage sampling circuit 10.

[0054] In summary, based on Figure 3 The circuit design of the voltage sampling circuit 10 shown can further improve the voltage sampling accuracy and working stability of the voltage sampling circuit 10.

[0055] In some embodiments, based on Figure 1 or Figure 3 The circuit design shown converts the voltage sample value Vsap, ranging from -200V to 1000V, acquired at the voltage sampling terminal V_sap into an input voltage within the range of 0V-2V at the voltage input terminal V_in. For example, when the input voltage at the voltage input terminal V_in is 0.072V, based on... Figure 2 The voltage curve shown confirms that the voltage sample value acquired at the voltage sampling terminal V_sap is approximately -100 volts; when the input voltage at the voltage input terminal V_in is 2.755V, based on Figure 2 The voltage curve shown confirms that the voltage sample value collected by the voltage sampling terminal V_sap exceeds 1000 volts.

[0056] Thus, when the output terminal V_out of the isolation operational amplifier chip 140 outputs the isolated voltage input terminal V_in, or when the signal amplification unit 180 outputs the isolated and amplified voltage input terminal V_in, both can be based on... Figure 2 The voltage curve shown allows for easy calculation of the voltage sampling value Vsap based on the input voltage Vin, thus enabling a wider range of voltage sampling while also achieving negative voltage sampling based on the isolated operational amplifier chip 140.

[0057] Please continue reading. Figure 4 , Figure 4 This is a circuit diagram of a voltage sampling circuit 10 provided in one embodiment of this application.

[0058] The first voltage divider unit 110 includes at least two first voltage divider resistors connected in series. This application does not limit the number of first voltage divider resistors included in the first voltage divider unit 110. For example, the first voltage divider unit 110 includes first voltage divider resistors R11 to R18 connected in series. The first end of the series circuit formed by the series connection of first voltage divider resistors R11 to R18 serves as the first end of the first voltage divider unit 110, used to connect to the voltage sampling terminal V_sap, and the second end of the series circuit serves as the second end of the first voltage divider unit 110, used to connect to the first end of the bias unit 130. The first end of the series circuit can be one end of the first voltage divider resistor R11, and the second end of the series circuit can be one end of the first voltage divider resistor R18.

[0059] The bias unit 130 includes at least one bias resistor. For example, the bias unit 130 may include a bias resistor R31. The first terminal of the bias resistor R31 serves as the first terminal of the bias unit 130 and is used to connect to the second terminal of the first voltage divider unit 110. The second terminal of the bias resistor R31 serves as the second terminal of the bias unit 130 and is used to connect to the reference voltage source 20, such as voltage source VD1. It is understood that this application does not limit the number of bias resistors included in the bias unit 130. In other embodiments, the bias unit 130 may include multiple bias resistors, and the multiple bias resistors may be connected in parallel, in series, in series then in parallel, or in parallel then in series, etc. This application does not limit the number and connection method of the bias resistors in the bias unit 130.

[0060] The second voltage divider unit 120 includes at least one second voltage divider resistor. The first terminal of each second voltage divider resistor is connected to the first terminal of the bias unit 130, and the second terminal of each second voltage divider resistor is connected to the reference ground (GND). For example, the second voltage divider unit 120 includes second voltage divider resistors R21 and R22 connected in parallel. The first terminals of the second voltage divider resistors R21 and R22 are connected to the first terminal of the bias resistor R31, and the second terminals of the second voltage divider resistors R21 and R22 are connected to the reference ground (GND).

[0061] The isolated operational amplifier chip 140 includes a voltage input terminal V_in, a power input terminal VDD1, a shutdown control terminal SHTDN, a ground terminal gnd1, a power input terminal VDD2, and a ground terminal gnd2. Furthermore, the output terminal V_out of the isolated operational amplifier chip 140 includes a non-inverting output terminal V_outp and an inverting output terminal V_outn. The voltage input terminal V_in is connected to the first end of the bias resistor R31 to receive the voltage sample value acquired by the voltage sampling terminal V_sap, which is then adjusted by the first voltage divider unit 110, the second voltage divider unit 120, and the bias unit 130 to obtain the input voltage. The power input terminal VDD1 is connected to the reference voltage source 20, i.e., connected to the voltage source VD1, to receive the voltage output from the voltage source VD1 to power the input side of the isolated operational amplifier chip 140. The shutdown control terminal SHTDN, the ground terminal gnd1, and the ground terminal gnd2 are all connected to the reference ground HV_GND. When the shutdown control terminal SHTDN is pulled low, such as to ground, the isolation operational amplifier chip 140 can operate normally. When the shutdown control terminal SHTDN is pulled high, the isolation operational amplifier chip 140 enters a low-power state and disables the non-inverting output terminal V_outp and the inverting output terminal V_outn. The power input terminal VDD2 is connected to the voltage source VD2 to receive the voltage output from the voltage source VD2 to power the output side of the isolation operational amplifier chip 140. The non-inverting output terminal V_outp and the inverting output terminal V_outn are used to jointly output a differential voltage signal.

[0062] The filter unit 150 includes a filter capacitor C1. The first terminal of the filter capacitor C1 is connected to the first terminal of the bias resistor R31, and the second terminal of the filter capacitor C1 is connected to the reference ground HV_GND.

[0063] The unidirectional conduction unit 160 includes a diode D1. The anode of diode D1 serves as the positive terminal of the unidirectional conduction unit 160 and is connected to the voltage input terminal V_in. The cathode of diode D1 serves as the negative terminal of the unidirectional conduction unit 160 and is connected to the power input terminal VDD1.

[0064] The voltage regulator unit 170 includes two capacitors connected in parallel, such as capacitor C2 and capacitor C3. The first terminals of both capacitors C2 and C3 are connected to the power input terminal VDD1, and the second terminals of both capacitors C2 and C3 are connected to the reference ground HV_GND. Thus, capacitors C2 and C3 can regulate the voltage at the power input terminal VDD1 on the input side of the isolation operational amplifier chip 140.

[0065] Accordingly, the voltage sampling circuit 10 also includes a voltage regulator unit 190. The first terminal of the voltage regulator unit 190 is connected to the power input terminal VDD2 of the isolated operational amplifier chip 140, and the second terminal of the voltage regulator unit 190 is connected to the reference ground LV_GND. The voltage regulator unit 190 is used to regulate the voltage at the power input terminal VDD2 on the output side of the isolated operational amplifier chip 140. In one embodiment, the voltage regulator unit 190 includes capacitors C4 and C5. The first terminals of both capacitors C4 and C5 are connected to the power input terminal VDD2, and the second terminals of both capacitors C4 and C5 are connected to the reference ground LV_GND.

[0066] In this embodiment, the signal amplification unit 180 includes a signal amplifier 181, a current limiting subunit 182, a bias subunit 183, a negative feedback subunit 184, and a voltage regulation subunit 185. The signal amplifier 181 includes a non-inverting input terminal in+, an inverting input terminal in-, an output terminal out, a power supply terminal VCC, and a ground terminal GND. The power supply terminal VCC is connected to a voltage source VD3 to receive the voltage output from the voltage source VD3 to power the signal amplifier 181. The ground terminal GND is connected to the reference ground LV_GND to provide grounding for the signal amplifier 181. The non-inverting input terminal in+ and the inverting input terminal in- are connected to the non-inverting output terminal V_outp and the inverting output terminal V_outn of the isolation operational amplifier chip 140 through the current limiting subunit 182. The current limiting subunit 182 limits the current flowing to the non-inverting input terminal in and the inverting input terminal in- to protect the non-inverting input terminal in+ and the inverting input terminal in-. The non-inverting input terminal in+ is also grounded through bias subunit 183. Bias subunit 183 is used to superimpose a bias voltage onto the non-inverting input terminal in+, stabilize the voltage at in+, and filter out some interference signals. The output terminal out is also connected to the inverting input terminal in- through negative feedback subunit 184, so that a portion of the output signal from out is fed back to in- through negative feedback subunit 184, thereby improving the stability and accuracy of the signal amplifier 181 and reducing distortion. The power supply terminal VCC is grounded through voltage regulator subunit 185, which is used to stabilize the voltage at the power supply terminal VCC.

[0067] In one embodiment, the current limiting subunit 182 includes resistors R81 and R82. The non-inverting input terminal in+ and the inverting input terminal in- are connected to the corresponding non-inverting output terminal V_outp and inverting output terminal V_outn, respectively, via resistors R81 and R82.

[0068] In one embodiment, the bias subunit 183 includes a capacitor C6 and a resistor R83. The first terminal of the capacitor C6 and the first terminal of the resistor R83 are both connected to the non-inverting input terminal in+, and the second terminal of the capacitor C6 and the second terminal of the resistor R83 are both connected to the reference ground LV_GND.

[0069] In one embodiment, the negative feedback subunit 184 includes a capacitor C7 and a resistor R84. The first ends of both capacitor C7 and resistor R84 are connected to the output terminal out, and the second ends of both capacitor C7 and resistor R84 are connected to the inverting input terminal in-.

[0070] In one embodiment, the voltage regulator subunit 185 includes at least one voltage regulator capacitor. For example, the voltage regulator subunit 185 may include capacitor C8, and the power supply terminal VCC is also grounded through capacitor C8.

[0071] Understandably, the output terminal OUT of operational amplifier 181 can be used as... Figure 4 The voltage sampling circuit 10 shown outputs an amplified input voltage at its output terminal OUT. Thus, the controller of the voltage sampling circuit 10 can calculate the voltage sample value Vsap acquired by the voltage sampling terminal V_sap based on the voltage signal output from the output terminal OUT, according to the amplification factor of the signal amplification unit 180 and the linear relationship described in formula (1) above.

[0072] In some embodiments, the voltage output by voltage source VD1 may be, for example, 5V, and the voltage output by voltage sources VD2 and VD3 may be, for example, 3.3V. This application does not limit the specific values ​​of the voltages output by voltage sources VD1, VD2, and VD3.

[0073] In summary, based on Figure 4 The voltage sampling circuit 10 shown can broaden the voltage acquisition range when using the isolated operational amplifier chip 140 for voltage sampling through simple circuit design, and realize the negative voltage sampling function based on the isolated operational amplifier chip 140, thereby effectively reducing the cost of the sampling circuit.

[0074] Please continue reading. Figure 5 An embodiment of this application also provides an electronic device 100. The electronic device 100 includes a DC interface positive terminal INT+, a DC interface negative terminal INT-, and a voltage sampling circuit 10 as described in any of the preceding claims. The voltage sampling terminal V_sap of the voltage sampling circuit 10 is connected to the DC interface positive terminal.

[0075] The DC interface positive terminal INT+ and DC interface negative terminal INT- can be interfaces used to connect the electronic device 100 to external electronic devices. Alternatively, the DC interface positive terminal INT+ and DC interface negative terminal INT- can be integrated inside the electronic device 100 to provide electrical connections between different components within the electronic device 100. This application does not limit the location of the DC interface positive terminal INT+ and DC interface negative terminal INT- in the electronic device 100.

[0076] Please see Figure 6An embodiment of this application also provides a battery pack 200, including at least one energy storage battery 201, a positive DC bus BUS+, a negative DC bus BUS-, and a voltage sampling circuit 10 as described in any of the preceding claims. The positive terminal P+ of the energy storage battery 201 is connected to the positive DC bus BUS+, the negative terminal P- of the energy storage battery 201 is connected to the negative DC bus BUS-, and the voltage sampling terminal V_sap of the voltage sampling circuit 10 is connected to the positive DC bus BUS+.

[0077] Please see Figure 7 An embodiment of this application also provides an energy storage device 300, including the battery pack 200 as described above.

[0078] It is understandable that energy storage devices can be devices with pure energy storage functions, or electronic devices with energy storage functions, such as air conditioners, refrigerators, and self-moving devices with battery packs.

[0079] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0080] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A voltage sampling circuit, characterized in that, The voltage sampling circuit includes a voltage sampling terminal, a first voltage divider unit, a second voltage divider unit, a bias unit, and an isolation operational amplifier chip. The voltage sampling terminal is connected to the point to be sampled. The first terminal of the first voltage divider unit is connected to the voltage sampling terminal. The second terminal of the first voltage divider unit is connected to the first terminal of the bias unit. The second terminal of the bias unit is connected to a reference voltage source. The second voltage divider unit is also connected between the first terminal of the bias unit and a reference ground. The first terminal of the bias unit is also connected to the voltage input terminal of the isolation operational amplifier chip. The isolation operational amplifier chip is used to isolate the voltage at the voltage input terminal before outputting it.

2. The voltage sampling circuit according to claim 1, characterized in that, The first voltage divider unit includes at least two first voltage divider resistors connected in series.

3. The voltage sampling circuit according to claim 1, characterized in that, The second voltage divider unit includes at least one second voltage divider resistor, the first end of each second voltage divider resistor is connected to the first end of the bias unit, and the second end of each second voltage divider resistor is connected to the reference ground.

4. The voltage sampling circuit according to claim 1, characterized in that, The voltage sampling circuit further includes a filtering unit, which is connected in parallel with the second voltage divider unit.

5. The voltage sampling circuit according to claim 1, characterized in that, The voltage sampling circuit further includes a unidirectional conduction unit, the positive terminal of which is connected to the voltage input terminal of the isolation operational amplifier chip and the first terminal of the bias unit, and the negative terminal of which is connected to the second terminal of the bias unit.

6. The voltage sampling circuit according to claim 1, characterized in that, The voltage sampling circuit further includes a voltage regulator unit, and the second end of the bias unit is also connected to the power input terminal of the isolated operational amplifier chip; the first end of the voltage regulator unit is connected to the power input terminal of the isolated operational amplifier chip, and the second end of the voltage regulator unit is connected to the reference ground.

7. The voltage sampling circuit according to claim 6, characterized in that, The voltage regulator unit includes two capacitors connected in parallel. The first end of each capacitor is connected to the power input terminal, and the second end of each capacitor is connected to the reference ground.

8. An electronic device, characterized in that, The electronic device includes a positive DC interface, a negative DC interface, and a voltage sampling circuit as described in any one of claims 1 to 7, wherein the voltage sampling terminal of the voltage sampling circuit is connected to the positive DC interface.

9. A battery pack, characterized in that, It includes at least one energy storage battery, a positive DC bus, a negative DC bus, and a voltage sampling circuit as described in any one of claims 1 to 7, wherein the positive terminal of the energy storage battery is connected to the positive DC bus, the negative terminal of the energy storage battery is connected to the negative DC bus, and the voltage sampling terminal of the voltage sampling circuit is connected to the positive DC bus.

10. An energy storage device, characterized in that, The energy storage device includes the battery pack as described in claim 9.

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