Battery sampling device, battery pack and automated guided vehicle

Abstract

The invention discloses a battery sampling device, a battery pack and an automated guided vehicle, and relates to the technical field of batteries. The battery pack comprises a plurality of battery cells, the plurality of battery cells are provided with sampling points, and the battery sampling device comprises a main control circuit; the substrate is provided with a plurality of openings, and the plurality of openings are respectively in one-to-one correspondence with the sampling points; the substrate is electrically connected with sampling points of the battery cell through a nickel-plated steel sheet arranged at the opening, and is provided with a plurality of output loops corresponding to the sampling points so as to output corresponding voltage sampling signals; the multiplexing circuit is used for acquiring a plurality of voltage sampling signals and switching and outputting the voltage sampling signals; the voltage detection circuit is used for receiving the voltage sampling signal and converting and outputting the voltage sampling signal into a voltage detection signal; wherein the multiplexing circuit is used for connecting or disconnecting a path between the output loop and the voltage detection circuit according to a switching control signal output by the main control circuit. The invention aims to improve the detection accuracy of the battery sampling device in the battery pack on each battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery sampling device, a battery pack and an automatic guided transport vehicle. Background Art

[0002] In the prior art, a battery pack usually includes a plurality of battery cells and a battery management system connected in series. The battery management system needs to realize the sampling process by electrically connecting to each battery cell, and the electrical connection between the battery management system and each battery cell is to connect with physical sampling lines corresponding to the number of battery cells to obtain relevant information such as the voltage and internal resistance of the battery cell. However, this connection method will lead to complex physical sampling lines and difficult wiring; wiring harness welding is prone to problems such as cold welding due to operational errors, which will lead to errors in the sampling data obtained by the battery management system, reducing the stability of battery operation. Summary of the invention

[0003] The main purpose of the present invention is to provide a battery sampling device, a battery pack and an automatic guided transport vehicle, aiming to improve the accuracy of the battery sampling device in detecting each battery cell in the battery pack.

[0004] To achieve the above object, the present invention proposes a battery sampling device, which is applied to a battery pack, wherein the battery pack includes a plurality of battery cells, each of which is provided with a sampling point, and the battery sampling device includes:

[0005] Main control circuit;

[0006] A substrate, wherein the substrate is provided with a plurality of openings, and the plurality of openings correspond to the sampling points one by one respectively; the substrate is electrically connected to the sampling points of the battery cell through the nickel-plated steel sheets provided at the openings, and a plurality of output circuits corresponding to the sampling points are provided to output corresponding voltage sampling signals;

[0007] A multiplexing circuit, wherein the input end of the multiplexing circuit is electrically connected to the plurality of output loops respectively, and the controlled end of the multiplexing circuit is electrically connected to the main control circuit; the multiplexing circuit is used to obtain the plurality of voltage sampling signals and switch the outputs;

[0008] A voltage detection circuit, wherein the input end of the voltage detection circuit is electrically connected to the output end of the multiplexing circuit, and the output end of the voltage detection circuit is electrically connected to the main control circuit; the voltage detection circuit is used to receive a voltage sampling signal and convert the output into a voltage detection signal;

[0009] The multiplexing circuit is used to switch on or off the path between the output loop and the voltage detection circuit according to the switching control signal output by the main control circuit.

[0010] In one embodiment, the battery sampling device further includes a signal amplifying circuit, the input end of the signal amplifying circuit is electrically connected to the output end of the multiplexing circuit, and the output end of the signal amplifying circuit is electrically connected to the voltage detection circuit; the signal amplifying circuit is used to amplify the input voltage sampling signal and then output it.

[0011] In one embodiment, the battery sampling device further includes a filter circuit, the input end of the filter circuit is electrically connected to the output end of the signal amplification circuit, and the output end of the filter circuit is electrically connected to the voltage detection circuit; the filter circuit is used to filter the output voltage sampling signal and then output it.

[0012] In one embodiment, the battery sampling device further includes a temperature detection circuit, and an output end of the temperature detection circuit is electrically connected to the main control circuit; the temperature detection circuit is used to detect the operating temperature of the battery cell and output a temperature detection signal.

[0013] In one embodiment, the main control circuit is further configured as:

[0014] Correct the voltage detection result according to the temperature detection signal and the temperature compensation algorithm;

[0015] Among them, the temperature compensation algorithm is: V comp =V raw ×(1+α(T-T0));

[0016] V comp is the voltage value after compensation, V raw is the voltage value before compensation, α is the temperature compensation coefficient, T is the current temperature, and T0 is the calibration temperature.

[0017] In one embodiment, the battery sampling device further includes an optocoupler isolation circuit, and the optocoupler isolation circuit is connected in series between the multiplexing circuit and the voltage detection circuit.

[0018] In one embodiment, the battery sampling device further includes a voltage conversion circuit, the input end of the voltage conversion circuit is electrically connected to the battery cell, and the output end of the voltage conversion circuit is electrically connected to the main control circuit; the voltage conversion circuit is used to convert the input first voltage into a second voltage and output it.

[0019] The present invention also provides a battery pack, comprising the battery sampling device as described in any one of the above items and a plurality of battery cells;

[0020] Wherein, a plurality of the battery cells are provided with sampling points.

[0021] In one embodiment, the battery pack includes N battery cells connected in series, and the number of sampling points is N+1;

[0022] When a sampling point is set at the positive electrode of each of the battery cells, a sampling point is set at the negative electrode of the initial battery cell; when a sampling point is set at the negative electrode of each of the battery cells, a sampling point is set at the positive electrode of the initial battery cell.

[0023] The present invention also provides an automatic guided transport vehicle, characterized in that the automatic guided transport vehicle comprises a battery pack as described in any one of the above items.

[0024] The technical solution of the present invention adopts a substrate with multiple openings, and uses a nickel-plated steel sheet to electrically connect the sampling points of the battery cell one by one through the openings, so as to obtain the voltage signal of the battery cell. Based on each opening on the substrate, a corresponding output circuit is set, the input end of the circuit is each opening, and the output end of the circuit is the input end of the multiplexing circuit. The multiplexing circuit selectively turns on or off the path between the output circuit and the voltage detection circuit by receiving the switching control signal output by the main control circuit, so as to realize the sampling of the voltage of different battery cells. The voltage detection circuit receives the voltage sampling signal output by the multiplexing circuit and converts the output voltage detection signal to the main control circuit, thereby avoiding the processing of the voltage sampling signal by multiple voltage detection circuits, thereby reducing the volume and complexity of the battery sampling device. In addition, by adopting the substrate opening and setting the output path, the method of sequentially connecting the sampling lines is avoided, which effectively improves the accuracy of the battery sampling device in the battery pack to detect each battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of the battery sampling device of the present invention;

[0027] Figure 2 It is a structural schematic diagram of another embodiment of the battery sampling device of the present invention;

[0028] Figure 3 A schematic diagram of a module of another embodiment of a battery sampling device of the present invention;

[0029] Figure 4 It is a structural schematic diagram of another embodiment of the battery sampling device of the present invention;

[0030] Figure 5 This is a schematic structural diagram of another embodiment of the battery sampling device of the present invention.

[0031] A. Substrate; B. Sampling point; 10. Main control circuit; 20. Multiplexing circuit; 30. Voltage detection circuit; 40. Signal amplification circuit; 50. Filter circuit; 60. Temperature detection circuit; 70. Optocoupler isolation circuit; 80. Voltage conversion circuit.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] In the prior art, a battery pack usually includes a plurality of battery cells and a battery management system connected in series. The battery management system needs to realize the sampling process by electrically connecting to each battery cell, and the electrical connection between the battery management system and each battery cell is to connect with physical sampling lines corresponding to the number of battery cells to obtain relevant information such as the voltage and internal resistance of the battery cell. However, this connection method will lead to complex physical sampling lines and difficult wiring; wiring harness welding is prone to problems such as cold welding due to operational errors, which will lead to errors in the sampling data obtained by the battery management system, reducing the stability of battery operation.

[0037] Therefore, reference Figure 1The present invention proposes a battery sampling device, which is applied to a battery pack, wherein the battery pack includes a plurality of battery cells, each of which is provided with a sampling point B. The battery sampling device includes:

[0038] Main control circuit 10;

[0039] A substrate A, wherein the substrate A is provided with a plurality of openings, and the plurality of openings correspond to the sampling points B one by one respectively; the substrate A is electrically connected to the sampling points B of the battery cell through the nickel-plated steel sheets provided at the openings, and a plurality of output circuits corresponding to the sampling points B are provided to output corresponding voltage sampling signals;

[0040] A multiplexing circuit 20, wherein the input end of the multiplexing circuit 20 is electrically connected to the plurality of output loops respectively, and the controlled end of the multiplexing circuit 20 is electrically connected to the main control circuit 10; the multiplexing circuit 20 is used to obtain the plurality of voltage sampling signals and switch the outputs;

[0041] A voltage detection circuit 30, wherein the input end of the voltage detection circuit 30 is electrically connected to the output end of the multiplexing circuit 20, and the output end of the voltage detection circuit 30 is electrically connected to the main control circuit 10; the voltage detection circuit 30 is used to receive a voltage sampling signal and convert the output into a voltage detection signal;

[0042] The multiplexing circuit 20 is used to switch on or off the path between the output loop and the voltage detection circuit 30 according to the switching control signal output by the main control circuit 10 .

[0043] In this embodiment, the main control circuit 10 can be implemented by a main controller, such as FPGA (Field Programmable Gate Array), MCU (Microcontroller Unit), DSP (Digital Signal Process), SOC (System On Chip), etc. In the battery sampling device, the main control circuit 10 is responsible for processing data from various sensors and executing corresponding control algorithms to ensure the safety and efficient operation of the battery pack. Furthermore, in terms of voltage detection, the main control circuit 10 quickly confirms the voltage status of each battery cell in the battery pack by receiving the voltage detection signal output by the voltage detection circuit 30.

[0044] In this embodiment. Substrate A can be implemented by PCB board, insulated metal substrate A or composite material. Among them, PCB board is divided into FR-4PCB board and metal substrate APCB. FR-4PCB board is made of glass fiber reinforced epoxy resin, and has good electrical insulation, mechanical strength and heat resistance; metal substrate APCB has better thermal conductivity. Furthermore, the opening of substrate A needs to be set corresponding to the sampling point B of the battery cell in the battery pack, so that the nickel-plated steel sheet can be accurately welded to each battery cell through the opening on substrate A. Among them, the nickel-plated steel sheet is used to achieve a stable electrical connection between the battery cell sampling point B and the corresponding opening on substrate A. As part of the conductive path, it ensures that the voltage sampling signal collected from each battery cell can be accurately transmitted to the subsequent processing circuit. Nickel is a metal with good conductivity, and the oxide layer formed on its surface is more stable than steel and is not easy to further oxidize. Therefore, nickel plating can improve the conductivity of the steel sheet, greatly improve its antioxidant ability, and extend its service life. For the output circuits set on substrate A, it is necessary to ensure sufficient electrical isolation between each output circuit by using appropriate PCB interlayer insulation materials and maintaining sufficient spacing to avoid signal interference or damage caused by short circuit or leakage. In addition, the output circuit should minimize line length and crossover to reduce the risk of electromagnetic interference and crosstalk.

[0045] In this embodiment, the multiplexing circuit 20 can be implemented by a switch array circuit, an analog switch circuit, etc. Among them, one of the most direct implementation methods of the analog switch circuit is to use an analog switch composed of CMOS or bipolar transistors to switch different input signals. They are usually integrated in IC chips and provide low on-resistance, fast switching time and good linearity. The multiplexing circuit 20 switches the sampling point B output voltage sampling signal of different cells to the voltage detection circuit 30 by receiving the switching control signal output by the main control circuit 10. Further, the switching process will be set according to the arrangement of the cells and the output circuit, specifically the switching conduction time and switching sequence of the multiplexing circuit 20. It can be understood that the battery pack, as the energy supply unit of the automatic guided transport vehicle, needs to sample and process each cell at a higher frequency. This is because during the operation of the automatic guided transport vehicle, the working state of the battery will change rapidly with the driving conditions (such as acceleration, deceleration, uphill, downhill, etc.). A high sampling frequency can ensure that the battery management system (BMS) can monitor these rapidly changing states in real time, so as to adjust the control strategy in time to ensure vehicle performance and safety. Therefore, the switching on time of the multiplexing circuit 20 is usually between tens of nanoseconds and hundreds of nanoseconds. In addition, the multiplexing circuit 20 itself has a certain on-and-off delay, that is, the time required to switch from one channel to another. When the multiplexing circuit 20 switches to a new channel, the output voltage may have a short fluctuation or transient process until it stabilizes. Make sure to give enough stabilization time to avoid collecting unstable voltage values. Therefore, the switching on time of the multiplexing circuit 20 is specifically between tens of nanoseconds and several microseconds to ensure that each channel can be fully sampled without affecting the sampling of other channels. It is understandable that different switching orders will affect the temperature change on the substrate A. When multiple output loops are in the same area and are turned on in sequence, the temperature of the area will rise rapidly in a short time. Therefore, the switching order will be set according to the output loop set on the substrate A. Specifically, the output circuit is divided into multiple groups of output circuit groups, and the first boundary and the second boundary of the substrate A are set, and the output circuits in each output circuit group are adjacent circuits, and the output circuits in the output circuit group close to the first boundary are further set as the first output circuit. After the sampling of the first output circuit of the first group of output circuit groups is completed, the sampling of the first output circuit of the second group of output circuit groups is switched. And so on, until all the cells in the battery pack have been sampled, so as to avoid the temperature of the local area of ​​the substrate A rising too fast. It can be understood that for the output end of each output circuit, and the area where the output circuit is electrically connected to the multiplexing circuit 20, a corresponding heat dissipation structure is provided to avoid its temperature being too high.

[0046] In this embodiment, the voltage detection circuit 30 can be implemented by an operational amplifier buffer circuit, an analog-to-digital conversion circuit, etc. Among them, the voltage detection circuit 30 receives the voltage sampling signal output by the multiplexing circuit 20, and outputs the voltage detection signal to the main control circuit 10 after corresponding processing, so as to avoid the main control circuit 10 being damaged due to the large voltage of the input voltage sampling signal. Further, the voltage detection circuit 30 includes an analog-to-digital conversion circuit, so as to directly output the corresponding digital signal to the main control circuit 10. In order to reduce the influence of noise, before the voltage detection signal is input to the analog-to-digital conversion circuit, it usually undergoes some filtering processing, such as using an RC filter to smooth the signal. By inputting the pre-processed analog voltage signal into the analog-to-digital conversion circuit for analog-to-digital conversion, the continuously changing voltage signal is converted into a series of discrete digital values, which are directly output to the main control circuit 10. The main control circuit 10 determines the working state of the battery cell at this time through the result output by the analog-to-digital conversion circuit. By including the analog-to-digital conversion circuit in the voltage detection circuit 30, the voltage detection can be made more convenient and accurate, and it is convenient to realize the automatic control of the power supply protection circuit. In addition, the voltage signal to be detected can be reduced to a level suitable for the input range of the analog-to-digital conversion circuit through a voltage divider circuit or other means.

[0047] In this embodiment, a substrate A with multiple openings is used, and a nickel-plated steel sheet is used through the openings to be electrically connected to the sampling points B of the battery cells one by one, so as to obtain the voltage signal of the battery cells. A corresponding output circuit is set based on each opening on the substrate A, the input end of the circuit is each opening, and the output end of the circuit is the input end of the multiplexing circuit 20. The multiplexing circuit 20 selectively turns on or off the path between the output circuit and the voltage detection circuit 30 by receiving the switching control signal output by the main control circuit 10, so as to realize the sampling of the voltage of different battery cells. The voltage detection circuit 30 receives the voltage sampling signal output by the multiplexing circuit 20 and converts the output voltage detection signal to the main control circuit 10, thereby avoiding the processing of the voltage sampling signal by multiple voltage detection circuits 30, thereby reducing the volume and complexity of the battery sampling device. In addition, by using the substrate A opening and setting the output path, the method of sequentially connecting the sampling lines is avoided, which effectively improves the accuracy of the battery sampling device in the battery pack to detect each battery cell.

[0048] refer to Figure 1 and Figure 3 In one embodiment of the present invention, the battery sampling device further includes a signal amplifying circuit 40, the input end of the signal amplifying circuit 40 is electrically connected to the output end of the multiplexing circuit 20, and the output end of the signal amplifying circuit 40 is electrically connected to the voltage detection circuit 30; the signal amplifying circuit 40 is used to amplify the input voltage sampling signal and then output it.

[0049] It is understandable that in order to achieve a more accurate estimation of the remaining power of the battery cell, the battery cell voltage needs to be measured with high precision. The signal amplifier circuit 40 can help amplify small voltage changes so that the ADC can capture more detailed information, thereby improving the accuracy of SOC estimation. In addition, when it is necessary to detect very subtle voltage fluctuations to identify potential faults, the signal amplifier circuit 40 can improve the signal quality to ensure that no important changes are missed.

[0050] In the present embodiment, the signal amplification circuit 40 can be implemented by an operational amplifier circuit. Among them, the operational amplifier circuit can be implemented by an inverting amplifier, a non-inverting amplifier, a programmable gain amplifier, etc. Inserting the signal amplification circuit 40 between the multiplexing circuit 20 and the voltage detection circuit 30 can effectively increase the amplitude of the weak voltage sampling signal, thereby improving the accuracy and reliability of subsequent measurements. For low-amplitude voltage signals, proper amplification can significantly improve the signal-to-noise ratio and reduce the impact of noise interference. The signal amplification circuit 40 can also be used to adjust the impedance matching between the input and output to optimize the transmission efficiency. Through linear amplification, small voltage changes that were originally difficult to capture can be made more obvious, which is convenient for more accurate monitoring of the battery cell status.

[0051] refer to Figure 1 and Figure 3 In one embodiment of the present invention, the battery sampling device further includes a filter circuit 50, the input end of the filter circuit 50 is electrically connected to the output end of the signal amplifying circuit 40, and the output end of the filter circuit 50 is electrically connected to the voltage detection circuit 30; the filter circuit 50 is used to filter the output voltage sampling signal and then output it.

[0052] In this embodiment, the filter circuit 50 needs to be used to remove noise and unnecessary frequency components in the voltage sampling signal to ensure the purity of the signal and the accuracy of the measurement. Therefore, the filter circuit 50 can be implemented by a low-pass filter, a band-pass filter, etc., and is electrically connected to the output end of the signal amplifier circuit 40, so that the voltage sampling signal amplified by the signal amplifier circuit 40 is filtered and output. In addition, the filter can help eliminate noise caused by power supply ripple, electromagnetic interference, etc., and improve measurement accuracy. Among them, some types of filters can also play a protective role to prevent excessive transient voltages from damaging the back-end circuit.

[0053] refer to Figure 1 and Figure 3 In one embodiment of the present invention, the battery sampling device further includes a temperature detection circuit 60, and an output end of the temperature detection circuit 60 is electrically connected to the main control circuit 10; the temperature detection circuit 60 is used to detect the operating temperature of the battery cell and output a temperature detection signal.

[0054] In this embodiment, the temperature detection circuit 60 can be implemented by a detection circuit based on a thermistor, such as a resistor divider circuit based on an NTC resistor or an NTC probe, or a resistor divider circuit based on a PTC resistor or a PTC probe. Optionally, the temperature detection circuit 60 can also be implemented by a temperature sensor, such as an infrared temperature sensor, a thermocouple temperature sensor, etc. Among them, there can be multiple temperature detection circuits 60, and multiple temperature detection circuits 60 can be arranged at different positions in the battery pack. The main control circuit 10 can determine multiple temperature values ​​based on multiple temperature detection signals, and through a preset temperature algorithm, such as an average value, a weighted calculation, etc., the accuracy of the temperature detection of the battery cells in the battery pack is improved.

[0055] In a battery sampling device, temperature will affect the accuracy of voltage detection. It is understandable that most sensors have a certain temperature coefficient, that is, the output of the sensor changes with temperature. For example, the resistance of a resistive sensor will change with temperature, resulting in a deviation in the measurement result. In addition, temperature changes will affect the performance of the signal amplification circuit 40, causing the gain of the amplifier to change, thereby affecting the amplification effect of the signal; and causing the offset voltage of the amplifier to change, further affecting the measurement result. Furthermore, temperature changes will affect the performance of the analog-to-digital converter, resulting in a decrease in conversion accuracy. Therefore, the influence of many links will cause the voltage detection signal finally obtained by the main control circuit 10 to have a problem of poor detection accuracy.

[0056] Optionally, the main control circuit 10 is further configured as:

[0057] Correct the voltage detection result according to the temperature detection signal and the temperature compensation algorithm;

[0058] Among them, the temperature compensation algorithm is: V comp =V raw ×(1+α(T-T0));

[0059] V comp is the voltage value after compensation, V raw is the voltage value before compensation, α is the temperature compensation coefficient, T is the current temperature, and T0 is the calibration temperature.

[0060] In this embodiment, the main control circuit 10 is configured to be provided with a temperature compensation algorithm, which reduces the influence of temperature on each detection process through the temperature compensation algorithm, thereby improving the accuracy of voltage detection. Among them, the voltage value before compensation is 3.7V, the current temperature is 40°C, the calibration temperature is 25°C, and the temperature compensation coefficient is 0.01% / °C. For example. The main control circuit 10 calculates the temperature compensation algorithm to obtain a compensated voltage value of 3.70555V. The temperature compensation algorithm can significantly improve the accuracy of voltage detection by correcting the measurement error caused by temperature changes. The specific implementation method includes linear compensation and polynomial compensation. Linear compensation is applicable to situations where the relationship between temperature and measurement error is approximately linear, while polynomial compensation is applicable to nonlinear relationships. By integrating high-precision sensors and microcontrollers and implementing temperature compensation algorithms, the reliability of the battery sampling device can be effectively improved.

[0061] refer to Figure 1 and Figure 4 In one embodiment of the present invention, the battery sampling device further includes an optocoupler isolation circuit 70 , and the optocoupler isolation circuit 70 is connected in series between the multiplexing circuit 20 and the voltage detection circuit 30 .

[0062] In this embodiment, different battery cells may be at different voltage levels, and the main control circuit 10 generally operates within a lower voltage range. The optocoupler isolation circuit 70 can effectively isolate these different voltage domains to prevent high voltage from damaging the low voltage circuit. In addition, in an environment with strong electromagnetic interference, the optocoupler isolation circuit 70 can prevent noise from propagating from one circuit part to another, thereby improving the anti-interference ability of the entire system. By connecting the optocoupler isolation circuit 70 in series between the output end of the multiplexing circuit 20 and the input end of the voltage detection circuit 30, electrical isolation is provided to prevent direct conduction of current between the front and rear stage circuits, thereby improving the anti-interference ability and safety of the system.

[0063] refer to Figure 1 and Figure 5 In this embodiment, the battery sampling device also includes a voltage conversion circuit 80, the input end of the voltage conversion circuit 80 is electrically connected to the battery cell, and the output end of the voltage conversion circuit 80 is electrically connected to the main control circuit 10; the voltage conversion circuit 80 is used to convert the input first voltage into a second voltage and output it.

[0064] In this embodiment, the voltage conversion circuit 80 can be implemented by a boost DC / DC converter, a buck DC / DC converter, a buck-boost DC / DC converter, a BUCK circuit, etc. according to the actual application scenario. Specifically, a buck DC / DC converter is taken as an example. When the buck DC / DC converter is connected to a DC voltage greater than the required voltage, the input DC voltage will be stepped down according to the required preset step-down value. For example, when the DC voltage input to the buck DC / DC converter is 87.6V, and the connected main control circuit 10 requires a DC voltage of 3.3V, the buck DC / DC converter can convert the input 87.6V DC voltage into a DC voltage of 3.3V through the internal circuit and output it. Through the voltage conversion circuit 80, when there is a DC voltage input, the DC voltage can be converted into the DC voltage required by the main control circuit 10 in the battery sampling device according to the actual situation to meet the power supply requirements of the main control circuit 10.

[0065] The present invention further provides a battery pack, comprising the battery sampling device as described in any one of the above items and a plurality of battery cells; wherein the plurality of battery cells are all provided with a sampling point B. It is worth noting that since the battery pack of the present invention is based on the above battery sampling device, the embodiments of the battery pack of the present invention include all technical solutions of all embodiments of the above battery sampling device, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0066] In one embodiment of the present invention, the battery pack includes N battery cells connected in series, and the number of the sampling points B is N+1;

[0067] When a sampling point B is set at the positive electrode of each battery cell, a sampling point B is set at the negative electrode of the initial battery cell; when a sampling point B is set at the negative electrode of each battery cell, a sampling point B is set at the positive electrode of the initial battery cell.

[0068] In this embodiment, the cells in the battery pack are usually implemented by lithium cells, and the voltage of a single lithium cell is 3.6V to 4.2V. Therefore, a single lithium cell cannot reach the power supply voltage of the automatic guided transport vehicle, so the connection method of connecting each cell in series is adopted to achieve the power supply voltage of the battery pack to the power supply voltage of the automatic guided transport vehicle. Further, the battery sampling device needs to perform voltage detection on each cell in the battery pack. It can be understood that on the basis of the series connection of each cell, the sampling points B on the cells need to be uniformly set to their respective positive or negative electrodes, and a sampling point B is set at the negative or positive electrode of the initial cell, so as to form a sampling loop. Among them, the initial cell is the starting point of the series connection, that is, the cell electrically connected to the negative electrode of the battery pack. For example, when the number of cells in the battery pack is 20, 20 sampling points B are set at the positive electrodes of the 20 cells, and a sampling point B is set at the negative electrode of the initial cell.

[0069] The present invention further provides an automated guided transport vehicle, the automated guided transport vehicle comprising any of the above-mentioned battery packs. It is worth noting that since the automated guided transport vehicle of the present invention is based on the above-mentioned battery pack, the embodiments of the automated guided transport vehicle of the present invention include all the technical solutions of all the embodiments of the above-mentioned battery packs, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0070] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A battery sampling device, applied to a battery pack, characterized in that: The battery pack includes a plurality of battery cells, each of which is provided with a sampling point, and the battery sampling device includes: Main control circuit; A substrate, wherein the substrate is provided with a plurality of openings, and the plurality of openings correspond to the sampling points one by one respectively; the substrate is electrically connected to the sampling points of the battery cell through the nickel-plated steel sheets provided at the openings, and a plurality of output circuits corresponding to the sampling points are provided to output corresponding voltage sampling signals; A multiplexing circuit, wherein the input end of the multiplexing circuit is electrically connected to the plurality of output loops respectively, and the controlled end of the multiplexing circuit is electrically connected to the main control circuit; the multiplexing circuit is used to obtain the plurality of voltage sampling signals and switch the outputs; A voltage detection circuit, wherein the input end of the voltage detection circuit is electrically connected to the output end of the multiplexing circuit, and the output end of the voltage detection circuit is electrically connected to the main control circuit; the voltage detection circuit is used to receive a voltage sampling signal and convert the output into a voltage detection signal; The multiplexing circuit is used to switch on or off the path between the output loop and the voltage detection circuit according to the switching control signal output by the main control circuit.

2. The battery sampling device according to claim 1, characterized in that: The battery sampling device also includes a signal amplifying circuit, the input end of the signal amplifying circuit is electrically connected to the output end of the multiplexing circuit, and the output end of the signal amplifying circuit is electrically connected to the voltage detection circuit; the signal amplifying circuit is used to amplify the input voltage sampling signal and then output it.

3. The battery sampling device according to claim 2, characterized in that: The battery sampling device also includes a filter circuit, the input end of the filter circuit is electrically connected to the output end of the signal amplification circuit, and the output end of the filter circuit is electrically connected to the voltage detection circuit; the filter circuit is used to filter the output voltage sampling signal and then output it.

4. The battery sampling device according to claim 3, characterized in that: The battery sampling device further comprises a temperature detection circuit, the output end of which is electrically connected to the main control circuit; the temperature detection circuit is used to detect the operating temperature of the battery cell and output a temperature detection signal.

5. The battery sampling device according to claim 4, characterized in that: The main control circuit is also configured as: Correct the voltage detection result according to the temperature detection signal and the temperature compensation algorithm; Among them, the temperature compensation algorithm is: V comp =V raw ×(1+α(T-T0)); V comp is the voltage value after compensation, V raw is the voltage value before compensation, α is the temperature compensation coefficient, T is the current temperature, and T0 is the calibration temperature.

6. The battery sampling device according to claim 1, characterized in that: The battery sampling device further includes an optocoupler isolation circuit, which is connected in series between the multiplexing circuit and the voltage detection circuit.

7. The battery sampling device according to claim 1, characterized in that: The battery sampling device also includes a voltage conversion circuit, the input end of the voltage conversion circuit is electrically connected to the battery cell, and the output end of the voltage conversion circuit is electrically connected to the main control circuit; the voltage conversion circuit is used to convert the input first voltage into a second voltage and output it.

8. A battery pack, characterized in that: The battery pack comprises the battery sampling device according to any one of claims 1 to 7 and a plurality of battery cells; Wherein, a plurality of the battery cells are provided with sampling points.

9. The battery pack according to claim 8, characterized in that: The battery pack includes N battery cells connected in series, and the number of sampling points is N+1; When a sampling point is set at the positive electrode of each of the battery cells, a sampling point is set at the negative electrode of the initial battery cell; when a sampling point is set at the negative electrode of each of the battery cells, a sampling point is set at the positive electrode of the initial battery cell.

10. An automated guided vehicle, characterized in that: The automated guided transport vehicle comprises the battery pack according to any one of claims 8 to 9.

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