Battery sampling unit and battery sampling system

Abstract

The present application relates to a battery sampling unit and a battery sampling system, wherein the battery sampling unit is electrically connected to a battery pack, the battery pack includes a plurality of battery cells, the battery sampling unit includes a plurality of substrates and a plurality of acquisition chips, the substrates are fixed on the surface of the battery cells; the acquisition chips are fixed on the substrates, and the acquisition chips are electrically connected to the positive electrode, the negative electrode and the battery shell of the battery cells through the substrates to collect the battery information of the battery cells. The present application can make the battery more convenient and more reliable in the process of forming a battery pack, is conducive to the cascade utilization of battery cells, and reduces the time cost of writing battery information.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery sampling unit and a battery sampling system. Background Art

[0002] With the development of new energy technology, the battery voltage of new energy vehicles is getting higher and higher, which means that new energy vehicles need more batteries to be used in series. The current battery production model is that the battery cells produced by the battery factory are given to the battery pack assembly (PACK) factory for assembly. The battery pack assembly factory then connects the AFE chip used for battery status monitoring of the battery management system (BMS) to the battery cell for battery management. In this way, the production date, production batch, battery identification (ID), battery type, battery factory capacity, battery cell internal resistance, rated voltage, number of charge and discharge cycles of the battery cell cannot be directly read by the battery management system. Even if it can be written into the battery management system through software during the battery pack production process, it will consume a lot of production calibration time, resulting in an increase in production costs, and once the battery cell fails later and is replaced separately, the battery data cannot be updated because the replacement station does not have the battery information calibration capability. Furthermore, in the process of battery recycling, since it is usually necessary to remove the battery cell of the battery pack and reuse it, the factory information of the battery cell will be lost in this process, and there is a risk of secondary use. Summary of the invention

[0003] In view of this, the present application proposes a battery sampling unit and a battery sampling system, which can make the battery more convenient and more reliable in the process of forming a battery pack, is conducive to the cascade utilization of battery cells, and reduces the time cost of writing battery information.

[0004] According to one aspect of the present application, a battery sampling unit is provided, wherein the battery sampling unit is electrically connected to a battery pack, wherein the battery pack includes a plurality of battery cells, and the battery sampling unit includes a plurality of substrates and a plurality of acquisition chips, wherein the substrates are fixed on surfaces of the battery cells; the acquisition chips are fixed on the substrates, and the acquisition chips are electrically connected to a positive battery electrode, a negative battery electrode, and a battery casing of the battery cells through the substrates to acquire battery information of the battery cells.

[0005] According to another aspect of the present application, a battery sampling system is provided, which includes a battery pack, a battery management system and the battery sampling unit, wherein the battery sampling unit is electrically connected to the battery pack and the battery management system.

[0006] By fixing the acquisition chip on a substrate, fixing the substrate on the surface of a battery cell, and electrically connecting the acquisition chip to the positive electrode, negative electrode and battery shell of the battery cell through the substrate, the battery information of the battery cell is collected. This application can make the battery more convenient and more reliable in the process of forming a battery pack, which is beneficial to the cascade utilization of battery cells and reduces the time cost of writing battery information. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic diagram showing a related art battery sampling architecture.

[0008] Figure 2 A schematic diagram showing a battery cell of the related art.

[0009] Figure 3 A schematic diagram showing battery cell grouping in the related art.

[0010] Figure 4 A schematic diagram showing an equivalent circuit of a battery cell group in the related art.

[0011] Figure 5 A block diagram of a battery sampling unit according to an embodiment of the present application is shown.

[0012] Figure 6 A connection diagram of a battery sampling unit according to an embodiment of the present application is shown.

[0013] Figure 7 A physical schematic diagram of a battery cell according to an embodiment of the present application is shown.

[0014] Figure 8 A physical schematic diagram of a battery pack according to an embodiment of the present application is shown.

[0015] Fig. 9 A block diagram of the acquisition chip according to an embodiment of the present application is shown.

[0016] Fig.10 A schematic diagram of an acquisition chip according to an embodiment of the present application is shown.

[0017] Fig.11 A schematic diagram showing the high voltage equivalent of a battery pack according to an embodiment of the present application.

[0018] Fig.12 A block diagram showing the communication architecture of a battery sampling unit according to an embodiment of the present application.

[0019] Fig.13 A schematic diagram showing a first communication architecture of a battery sampling unit according to an embodiment of the present application.

[0020] Fig.14 A schematic diagram showing a second communication architecture of a battery sampling unit according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0022] Figure 1 Schematic diagram of a battery sampling architecture of the related art is shown. Figure 1 As shown, in the related art, an AFE chip detects multiple battery cells at the same time. Specifically, an AFE chip is responsible for detecting the voltage, temperature and other information of multiple battery cells. The communication between each AFE chip transmits data through daisy chains and other means. The data between the daisy chains is in series, that is, the information of AFEn must pass through AFEn-1, AFEn-2...AFE1, BMS and other loops before it can flow back to the BMS. Among them, n is the serial number of the AFE chip, and n is a positive integer. When any node in the daisy chain fails or communication interference occurs, the battery cell information detected by this AFE chip and the subsequent AFE chips will be lost. When the BMS loses some battery cell data, the vehicle can only stay in place and cannot drive.

[0023] Figure 2 Schematic diagram of a battery cell of the related art is shown. Figure 2 As shown, the battery cell of the related art includes a battery housing, a positive electrode and a negative electrode. The battery cell is separately provided from the AFE chip connected to the battery cell. Both the positive electrode and the negative electrode are insulated from the battery housing, that is, the resistance between the positive electrode and the battery housing is infinite, and the resistance between the negative electrode and the battery housing is also infinite.

[0024] Figure 3 A schematic diagram showing a battery cell grouping in the related art is shown. Figure 3 As shown, in the related art, each battery cell from battery cell 1 to battery cell n is connected to each other through a copper busbar, and the battery shells of each battery cell are in contact with each other. For example, the positive electrode of battery cell 1 is electrically connected to the negative electrode of battery cell 2 through a copper busbar, and the positive electrode of battery cell 2 is electrically connected to the negative electrode of battery cell 3 through another copper busbar.

[0025] Figure 4 Schematic diagram showing the equivalent circuit of a battery cell group in the related art. Figure 4As shown, multiple battery cells are connected in series. Since the battery shells of the battery cells are all metal shells, the shells of the battery cells are mutually conductive after being grouped, and the battery shells are at the same potential.

[0026] Combination Figure 1-Figure 4 It can be seen that in the related technology, an active front-end chip manages several or more than a dozen battery cells, and then each AFE chip communicates in cascade via a daisy chain. In the battery production process, even if the battery information can be written into the battery management system through software during the battery pack production process, it will consume a lot of production calibration time, resulting in an increase in production costs. Once the battery cells fail later and are replaced individually, the battery data cannot be updated because the replacement station does not have the battery information calibration capability. Furthermore, in the process of battery recycling, since it is usually necessary to remove the battery cells of the battery pack for reuse, the factory information of the battery cells will be lost in this process, and there is a risk of secondary utilization.

[0027] In view of this, the present application provides a battery sampling unit, which is electrically connected to a battery pack, and the battery pack includes a plurality of battery cells. The battery sampling unit includes: a plurality of substrates, which are fixed on the surfaces of the battery cells; a plurality of acquisition chips, which are fixed on the substrates, and the acquisition chips are electrically connected to the battery positive electrode, the battery negative electrode and the battery shell of the battery cell through the substrate to collect battery information of the battery cell.

[0028] In one embodiment, the battery information may include voltage information and temperature information of the battery cell. The voltage information of the battery cell may include the voltage between the positive electrode and the negative electrode of the battery cell, and the temperature information of the battery cell may include the surface temperature of the battery cell. The battery information may also include information such as the production date, production batch, battery identification, battery type, battery factory capacity, battery cell internal resistance, rated voltage, number of charge and discharge cycles of the battery cell. It is understood that the present application does not limit the specific content of the battery information.

[0029] Figure 5 FIG. 1 is a block diagram of a battery sampling unit according to an embodiment of the present application. Figure 5 As shown, the battery sampling unit of the present application includes a plurality of substrates 101 and a plurality of acquisition chips 102 . One acquisition chip 102 can be fixed on each of the substrates 101 , and each of the substrates 101 can be fixed on the surface of a corresponding battery cell 201 .

[0030] Since the battery cells 201 of the present application are all equipped with a collection chip 102, and the battery information of the bound batteries has been stored in the collection chip 102, there is no need to query one by one and transfer the battery information to the grouped BMS when the batteries are used in groups. This can make the batteries more convenient, more reliable and have lower time costs in the application process of the battery pack 200, saving a lot of time and making group use more convenient. When needed, the BMS only needs to send specific instructions to obtain the storage data of the AFE chip of the battery cell 201 with a specified ID, and the technical requirements for the BMS are also lower.

[0031] The battery cell 201 includes a positive electrode, a negative electrode and a battery shell, and a plurality of battery cells 201 can be connected in series. The positive electrode of the current battery cell 201 can be electrically connected to the negative electrode of the next adjacent battery cell 201, and the battery shells of the plurality of battery cells 201 can be in contact with each other and connected to each other in an equipotential manner.

[0032] In one embodiment, the acquisition chip 102 may be an active front-end AFE chip, and the battery cell 201 may be a battery cell. The substrate 101 may be a printed circuit board (PCB), and the printed circuit board may be rigid or flexible. It is understood that the acquisition chip 102 may also be other types of chips, and the present application does not limit the type of the acquisition chip 102.

[0033] Figure 6 The figure shows a connection diagram of the battery sampling unit of the embodiment of the present application. Figure 6 As shown, one AFE chip collects battery information of one battery cell 201, such as the voltage and temperature of the battery cell 201, and multiple battery cells 201V1-Vn are connected in series to form a battery pack 200. For example, the first AFE chip AFE1 can collect the voltage between the positive electrode and the negative electrode of the battery cell 201V1, the second AFE chip AFE2 can collect the voltage between the positive electrode and the negative electrode of the battery cell 201V2, and so on, the nth AFE chip AFEn can collect the voltage between the positive electrode and the negative electrode of the battery cell 201Vn.

[0034] Figure 7 A physical schematic diagram of a battery cell according to an embodiment of the present application is shown. Figure 7As shown, the AFE chip is fixed on the PCB board together with the peripheral electronic components of the chip through processes such as reflow soldering, and then the PCB board can be fixed to the surface of the battery cell 201 by gluing, screwing, laser welding, etc. Three signal lines can also be provided on the PCB board: a positive power line, a negative power line, and a ground line, which are respectively connected to the positive battery electrode, the negative battery electrode, and the battery shell of the battery cell 201. Among them, the positive power line is connected to the positive battery electrode of the battery cell 201, the negative power line is connected to the negative battery electrode of the battery cell 201, and the ground line is connected to the battery shell of the battery cell 201. The AFE chip has pins such as power supply and grounding. The positive power line and the negative power line can be led out from the power pin of the AFE chip, and the ground line can be led out from the ground pin of the AFE chip.

[0035] Figure 8 A physical schematic diagram of a battery pack according to an embodiment of the present application is shown. Figure 8 As shown, the AFE chip and PCB of a single battery cell 201 are fixed to the surface of the single battery cell 201 by gluing, and the multiple battery cells 201 of the battery pack 200 are connected to each other by copper bars. The battery shell of the battery cell 201 can be made of metal and have conductive properties, so that the shells of all battery cells 201 in the battery pack 200 will be in contact with each other, and the battery shells of all battery cells 201 are connected at the same potential. Since the vehicle body is generally used as the grounding point in automobile technology, and the shell of the battery pack 200 will be connected to the battery pack shell, the potential of the shell of the battery pack 200 in this application is also the grounding point.

[0036] Fig. 9 FIG. 1 is a block diagram of a collection chip according to an embodiment of the present application. Fig. 9 As shown, the acquisition chip includes an analog-to-digital conversion module 1021 , a digital module 1022 , a communication processing module 1023 , a transmission module 1024 and a battery information storage module 1025 .

[0037] The analog-to-digital conversion module 1021 is electrically connected to the positive electrode and the negative electrode of the battery cell 201. In some embodiments, a temperature sensor may be provided on the surface of the battery cell 201, and the temperature sensor is used to detect the temperature information of the single battery cell 201. The analog-to-digital conversion module 1021 may also be electrically connected to the temperature sensor.

[0038] The digital module 1022 is electrically connected to the analog-to-digital conversion module 1021, and is used to process the battery information after analog-to-digital conversion. The communication processing module 1023 is electrically connected to the digital module 1022, and is used to convert the battery information processed by the digital module 1022 into a format that meets communication requirements. The transmission module 1024 is electrically connected to the communication processing module 1023, and is used to transmit the battery information that meets the communication requirements.

[0039] The battery information storage module 1025 is used to pre-store the battery information of the battery cell 201 before leaving the factory. Each AFE chip and its necessary electronic components such as resistors and capacitors will finally leave the factory in a state of being connected to the battery cell 201. Before leaving the factory, the production date, production batch, battery ID, battery type, battery factory capacity, battery cell internal resistance, rated voltage, number of charge and discharge cycles, battery factory electrolyte state and other information will be stored in the AFE chip. Since the battery cell 201 and the AFE chip are inseparable after the battery cell 201 leaves the factory, the factory information of the battery cell 201 will be stored in the AFE chip all the time, which is convenient for the subsequent BMS to manage the battery pack. In addition, the AFE chip will continuously update the real-time battery capacity, battery internal resistance, number of charge and discharge cycles, battery SOH, battery SOC, electrolyte state and other parameters of its battery cell 201 during use, so that the AFE chip acts as a close butler for the battery cell 201.

[0040] Fig.10 FIG. 1 is a schematic diagram showing a collection chip according to an embodiment of the present application. Fig.10 As shown, the analog-to-digital conversion module 1021 includes at least two analog-to-digital converters (ADCs), namely a voltage ADC and a temperature ADC. The voltage ADC can receive the voltage information of the battery cell 201Vn, and the temperature ADC can be used to receive the temperature information of the single battery cell 201 collected by the temperature sensor Tn. Since the collected voltage information and temperature information are both analog quantities, the voltage ADC and the temperature ADC process the analog quantities to send the digitized voltage information and temperature information to the digital module 1022 for further processing.

[0041] The digital module 1022 is electrically connected to the battery information storage module 1025, the communication processing module 1023 and at least two of the analog-to-digital converters. The transmission module 1024 includes a sending module and a receiving module, both of which are electrically connected to the communication processing module 1023, and are used for receiving and sending communication signals of the AFE chip.

[0042] The working principle of the acquisition chip 102 is: the voltage ADC acquires the voltage of the battery cell 201 and sends it to the digital module 1022 for processing; the temperature ADC acquires the temperature of the battery cell 201 and sends it to the digital module 1022 for processing; the digital module 1022 processes the voltage information and temperature information of the battery cell 201 through the communication processing module 1023 and then sends it out through the sending module. The receiving module is responsible for receiving the instructions sent by the battery management system 300, and inputs the instructions into the digital module 1022 through the communication processing module 1023, and the digital module 1022 performs corresponding actions according to the corresponding instructions. The battery information storage module 1025 can store basic information such as production date, production batch, battery ID, battery type, battery factory capacity, battery cell internal resistance, rated voltage, battery factory electrolyte state, etc. before the battery leaves the factory, and can also write and update the real-time battery capacity, battery internal resistance, number of charge and discharge cycles, battery SOH, battery SOC, electrolyte state and other parameters of its battery cell 201 in subsequent use.

[0043] Compared with the existing battery data which are all stored in the battery management system 300, and the existing AFE chip which usually monitors multiple battery cells 201 at the same time, the AFE chip cannot be bound to the battery cell 201 and does not have the battery information storage capability. The AFE chip of the present application can store the battery information of the bound battery cell 201. In this way, the AFE chip can be shipped with the battery cell 201, and in the subsequent working process, since the AFE chip and the battery cell 201 are inseparable, the production date, production batch, battery ID, battery type, battery factory capacity, battery cell internal resistance, rated voltage, charge and discharge cycle number and other information of the battery cell 201 can be always bound to the battery cell 201, and in the subsequent use, the real-time battery capacity, battery internal resistance, charge and discharge cycle number, battery SOH, battery SOC and other parameters of the battery cell 201 are also written and updated, which will play an important role in the subsequent BMS battery management, replacement and maintenance of the battery cell 201, and cascade utilization of the battery cell 201.

[0044] Among them, battery SOH represents the current battery's ability to store electrical energy relative to a new battery, and expresses the battery's state from the beginning to the end of its life in percentage form, which is used to quantitatively describe the current battery's performance state. Battery SOC refers to the battery's state of charge, that is, the remaining battery power.

[0045] Since the information of the battery cell 201 stored in the AFE is bound to the battery cell 201, the information of the battery cell 201 is more accurate and targeted during the cascade utilization. According to this feature, during the cascade utilization of the battery, the information such as the battery factory capacity, battery type, battery cell factory internal resistance, production batch, battery factory electrolyte state, etc. stored in the AFE chip and the parameters such as the battery capacity, battery internal resistance, number of charge and discharge cycles, battery SOH, battery SOC, electrolyte state, etc. updated in real time during the later use of the battery cell 201 can be used to select battery cells 201 with similar performance to be regrouped, thereby reducing the difficulty of the cascade utilization of the battery pack 200 and improving the reliability of the cascade utilization of the battery pack 200. If the solution of the present application is not adopted, since the new battery loading application and the old battery cascade utilization are the responsibility of different R&D teams, and the time span between the new and old batteries is very long, it is almost impossible to obtain some basic information and specific battery health status of the old battery during the cascade utilization of the old battery, which creates great technical barriers and safety risks for the cascade utilization of the old battery.

[0046] Fig.11 A schematic diagram showing the high voltage equivalent of a battery pack according to an embodiment of the present application is shown. Fig.11 As shown, the battery cells 201V1-Vn are a high-voltage battery string formed by connecting n battery cells 201 in series. The high-voltage battery string supplies power to the load of the whole vehicle, such as motors, air conditioners and other electrical equipment. K1 and K2 are high-voltage switches of the battery pack. Only when the high-voltage switch is turned on can the electric energy of the high-voltage battery string supply power to the load of the whole vehicle, such as motors, air conditioners and other electrical equipment.

[0047] Rp is the equivalent resistance of the total positive side of the battery pack 200 facing the shell of the battery pack 200, and Rn is the equivalent resistance of the total negative side of the battery pack 200 facing the shell of the battery pack 200. The resistances Rp and Rn are not real specific resistances, but parasitic resistances. When the insulation performance of the battery pack 200 is good, Rp / Rn≥10MΩ, that is, the resistance values ​​of Rp and Rn are both greater than or equal to 10MΩ; when an insulation failure occurs in the battery pack 200, the resistance values ​​of one or both of Rn and Rn will drop rapidly. The resistance values ​​of Rp and Rn only reflect the insulation condition of the battery pack 200 and do not affect the specific implementation of this application.

[0048] When the battery pack 200 is discharging, the current flow path is composed of Vn positive electrode → K1 high voltage switch → Rload load → K2 high voltage switch → V1 negative electrode → V1 positive electrode → V2 negative electrode → ... Vn positive electrode, and this current path is the power circuit of the battery pack 200. It should be noted that, Fig.11 The battery pack 200 may also be a battery pack, and the battery pack may include multiple battery packs 200 .

[0049] In one embodiment, the battery sampling unit is electrically connected to a battery management system 300 , and the battery management system 300 includes at least one communication chip 301 . The communication chip 301 and the plurality of acquisition chips 102 are electrically connected to a power circuit of the battery pack 200 , and the power circuit is a charge and discharge circuit of the battery pack 200 .

[0050] The existing battery management technology is that an active front end (AFE) chip manages several or dozens of battery cells, and then each AFE chip communicates in cascade through a daisy chain, that is, the communication between the chips is in series. Once one of the chips or the daisy chain fails, the communication of this chip and all the subsequent chips will be lost. When more batteries are used in series, it means that the number of AFE chips used for battery status monitoring is also greater, and the probability of communication loss is also higher. Once one or more AFE chips lose communication, it means that several or even hundreds of batteries lose monitoring, the vehicle will inevitably fail and cannot be used normally, and user complaints will increase. Moreover, with the development of new energy technology and electronic control technology, the interference in the high-voltage system of the battery pack will become more and more serious. Severe interference will increase the failure probability of the daisy chain communication of the AFE chip.

[0051] Fig.12 A block diagram showing the communication architecture of the battery sampling unit of an embodiment of the present application is shown. Fig.12 As shown, the battery sampling unit is electrically connected to the battery management system 300. The battery management system 300 is provided with a communication chip 301, which communicates with the multiple acquisition chips 102 of the battery sampling unit.

[0052] In one embodiment, the battery sampling unit further includes a first resonant circuit 103, a first induction circuit 104 and a second resonant circuit 105, wherein the first resonant circuit 103 is electrically connected to one of the acquisition chips 102, the first induction circuit 104 is electrically connected to the first resonant circuit 103, and the second resonant circuit 105 is electrically connected to the first induction circuit 104. In other words, each acquisition chip 102 may be provided with a first resonant circuit 103, a first induction circuit 104 and a second resonant circuit 105.

[0053] The battery pack 200 is electrically connected to the third resonant circuit 210 , and the third resonant circuit 210 is electrically connected to a plurality of the second resonant circuits 105 .

[0054] The battery management system 300 includes a communication chip 301, a fourth resonant circuit 302 and a second sensing circuit 303, wherein the second sensing circuit 303 is electrically connected to the third resonant circuit 210, the fourth resonant circuit 302 is electrically connected to the second sensing circuit 303, and the communication chip 301 is electrically connected to the fourth resonant circuit 302. The communication chip 301 can send instructions to the AFE chip, and can also receive battery information sent by the AFE chip. In other words, the communication between the communication chip 301 and the plurality of acquisition chips 102 can be bidirectional.

[0055] The first resonant circuit, the second resonant circuit, the third resonant circuit and the fourth resonant circuit each include at least one LC series resonant structure, wherein the first resonant circuit and the fourth resonant circuit each include two LC series resonant structures arranged in parallel, and the second resonant circuit and the third resonant circuit each include one LC series resonant structure. Each LC series resonant structure includes an inductor and a capacitor connected in series with each other, and the inductance value and the capacitance value of each LC series resonant structure are adjusted according to the communication frequency of the communication chip.

[0056] Fig.13 A schematic diagram showing a first communication architecture of a battery sampling unit according to an embodiment of the present application is shown. Fig.13 As shown, AFE1-AFEn are connected to battery cells 201V1-Vn respectively, and the battery information such as the voltage and temperature of each battery cell 201 is sent to the battery management system 300BMS for processing through the communication method of the present application. Among them, the first resonant circuit 103, the second resonant circuit 105, the third resonant circuit 210 and the fourth resonant circuit 302 are all LC series resonance. The first resonant circuit 103 includes two LC series resonance structures, the first LC series resonance structure is electrically connected to the sending module of the acquisition chip 102, and the second LC series resonance structure is electrically connected to the receiving module of the acquisition chip 102. The first LC series resonance structure and the second LC series resonance structure are arranged in parallel.

[0057] Taking the acquisition chip 102 as AFE1 as an example, the first LC series resonant structure includes a first inductor L1 and a first capacitor C1, the first end of the first inductor L1 is electrically connected to the receiving module of AFE1, the second end of the first inductor L1 is electrically connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is electrically connected to the first induction circuit 104; the second LC series resonant structure includes a second inductor L2 and a second capacitor C2, the first end of the second inductor L2 is electrically connected to the sending module of AFE1, the second end of the second inductor L2 is electrically connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is electrically connected to the first induction circuit 104. The second end of the first capacitor C1 is electrically connected to the second end of the second capacitor C2.

[0058] The first induction circuit includes a first transformer, the primary side of the first transformer is electrically connected to the first resonant circuit, and the secondary side of the first transformer is electrically connected to the second resonant circuit and the power circuit. The second induction circuit includes a second transformer, the primary side of the second transformer is electrically connected to the third resonant circuit and the power circuit, and the secondary side of the first transformer is electrically connected to the fourth resonant circuit.

[0059] Specifically, the first induction circuit 104 may include a first transformer, the second end of the first capacitor C1 and the second end of the second capacitor C2 are electrically connected to one end of the primary side of the first transformer, and the other end of the primary side of the first transformer is grounded.

[0060] The second resonant circuit 105 includes an LC series resonant structure. Specifically, the second resonant circuit 105 includes a third inductor L3 and a third capacitor C3, a first end of the third inductor L3 is electrically connected to the battery positive electrode or the battery negative electrode of the battery cell 201, a second end of the third inductor L3 is electrically connected to the first end of the third capacitor C3, a second end of the third capacitor C3 is electrically connected to one end of the secondary side of the first transformer, and the other end of the secondary side of the first transformer is grounded.

[0061] See also Fig.13 The battery management system 300 includes a communication chip 301, a fourth resonant circuit 302 and a second induction circuit 303. The fourth resonant circuit 302 includes two LC series resonant structures. The first LC series resonant structure is electrically connected to the transmitting module of the communication chip 301, and the second LC series resonant structure is electrically connected to the receiving module of the communication chip 301. The first LC series resonant structure and the second LC series resonant structure are arranged in parallel.

[0062] For the communication chip 301, the first LC series resonant structure includes a seventh inductor L7 and a seventh capacitor C7, the first end of the seventh inductor L7 is electrically connected to the receiving module of the communication chip 301, the second end of the seventh inductor L7 is electrically connected to the first end of the seventh capacitor C7, and the second end of the seventh capacitor C7 is electrically connected to the second induction circuit 303; the second LC series resonant structure includes an eighth inductor L8 and an eighth capacitor C8, the first end of the eighth inductor L8 is electrically connected to the sending module of the communication chip 301, the second end of the eighth inductor L8 is electrically connected to the first end of the eighth capacitor C8, and the second end of the eighth capacitor C8 is electrically connected to the second induction circuit 303. The second end of the seventh capacitor C7 is electrically connected to the second end of the eighth capacitor C8.

[0063] The second induction circuit 303 may include a second transformer, a second end of the seventh capacitor C7 and a second end of the eighth capacitor C8 are electrically connected to one end of the secondary side of the second transformer, and the other end of the secondary side of the second transformer is electrically connected to the sending module and the receiving module of the communication chip 301.

[0064] The third resonant circuit 210 includes an LC series resonant structure. Specifically, the third resonant circuit 210 includes a ninth inductor L9 and a ninth capacitor C9, a first end of the ninth inductor L9 is electrically connected to one end of the primary side of the second transformer, the other end of the primary side of the second transformer is grounded, a second end of the ninth inductor L9 is electrically connected to a first end of the ninth capacitor C9, and a second end of the ninth capacitor C9 is electrically connected to the positive electrode or the negative electrode of the battery cell 201.

[0065] When the communication chip 301 communicates with the acquisition chip 102, the LC parameters in each resonant circuit can be adjusted according to the communication frequency of the acquisition chip 102, so that the resonance point of each resonant circuit matches the communication frequency. In this way, a bandpass filter with a narrow bandwidth can be formed, and interference signals outside the bandwidth are not easy to interfere with the communication circuit of the present application, so that the communication anti-interference performance of the present application is greatly improved.

[0066] The specific communication process between the communication chip 301 and the acquisition chip 102 is as follows: When the BMS needs to send an instruction to the AFE1 chip, the BMS encodes the instruction containing the ID of the battery cell 201 through the communication processing module 1023 of the BMS communication chip 301, and then sends it to the primary side of the transformer through the C7 / L7 resonant circuit through the sending module of the communication chip 301. Since the transformer has an induction principle, the secondary side of the transformer will sense the voltage of the corresponding instruction code, and the secondary side of the transformer will then send the voltage of the instruction code to the battery power circuit and the battery pack shell (the whole vehicle ground) through the resonant circuit C9 / L9.

[0067] Since an AC signal appears between the battery power circuit and the battery pack shell at this time, that is, the voltage of the changing instruction code, PCB1-PCBn will receive the instruction signal. The resonant circuit C3 / L3 of PCB1 inputs the instruction signal to the primary side of the transformer of PCB1, and then the instruction signal is generated on the secondary side of the transformer by the induction principle of the transformer, and then the resonant circuit C1 / L1 sends it to the receiving module of the AFE1 chip. Since the ID in the instruction signal corresponds to the ID of AFE1, the AFE1 chip will know that the instruction signal is sent to itself, and then the AFE1 chip will execute the corresponding instruction action. Similarly, the instruction signal will also be received by AFEn, but since the ID in the instruction signal does not correspond to AFEn, AFEn knows that the instruction signal is not sent to itself, so it will not execute the corresponding action.

[0068] When AFE1 performs a corresponding voltage detection action such as battery 1 according to the instruction of BMS, AFE1 will send the voltage data of battery 1 and BMS ID to the communication processing module 1023 of AFE1 and send it from the sending module of AFE1 chip, and then send it to the transformer of PCB1 through the resonant circuit C2 / L2. At this time, the original secondary side of the transformer becomes the primary side in the sending state, and then the transformer will sense the corresponding voltage data signal of battery 1 on the secondary side due to the induction principle. The voltage data signal and BMS ID are sent between the battery power circuit and the shell through the resonant circuit C3 / L3. The signal passes through the resonant circuit C9 / L9 and then enters the primary side of the transformer of BMS. Then the secondary side of the transformer will also sense the signal of battery 1 voltage data and BMS ID, and then resonate through C8 / L8 and send it to the receiving module of the communication chip 301. After the data received by the receiving module is processed by the communication processing module 1023, it is known that the ID of the data is consistent with the ID of the BMS communication chip 301, so it will be judged that the data is sent to the BMS and then handed over to the BMS for processing. Since the traditional communication cables are eliminated, the embodiments of the present application can further reduce the cost of the battery system.

[0069] In one embodiment, the communication frequency of the acquisition chip 102 and the communication chip 301 can be 5KHZ. At this time, each resonant circuit can achieve no attenuation at a frequency of 5KHZ, while frequencies greater than and less than 5KHZ will have attenuation. In other words, the resonant circuit of the present application can filter interference greater than or less than the communication frequency of the present application, while the signal within the communication frequency is not attenuated and does not affect the communication, which can greatly improve the communication anti-interference level of the present patent. It is worth noting that the resonant parameters of the present application, such as the inductance value of the inductor and the capacitance value of the capacitor, can be matched accordingly according to the communication frequency.

[0070] Fig.14A schematic diagram showing a second communication architecture of a battery sampling unit according to an embodiment of the present application is shown. Fig.14 As shown, since the cost of the transformer may be relatively high, the withstand voltage of the circuit capacitor can be increased while ensuring high voltage safety, and then Fig.14 The implementation method eliminates the transformer, further reducing the implementation cost.

[0071] Existing daisy chain communication generally relies on capacitors or transformers for isolation. According to the characteristics that capacitors pass high frequencies and block low frequencies, and transformers can transmit variable voltages, it can be known that the filter of existing daisy chain communication is a high-pass filter. Therefore, although the existing daisy chain communication can filter out low-frequency interference, high-frequency noise will still affect the communication reliability of the daisy chain, especially because silicon carbide power tubes are gradually replacing IGBTs, and silicon carbide has a higher operating frequency, which also brings higher high-frequency noise. The existing daisy chain communication method faces greater challenges. The communication method of this application uses LC resonance technology to form a narrow bandwidth bandpass filter, so it has a good filtering effect on low-frequency and high-frequency interference signals that are not within the communication frequency range, and the communication anti-interference performance is stronger.

[0072] In summary, the present application collects battery information of the battery cell by fixing the acquisition chip on a substrate, fixing the substrate on the surface of the battery cell, and electrically connecting the acquisition chip to the positive electrode, negative electrode and battery shell of the battery cell through the substrate. This can make the battery more convenient and more reliable in the process of forming a battery pack, is beneficial to the cascade utilization of battery cells, and reduces the time cost of writing battery information.

[0073] The present application also provides a battery sampling system, the battery sampling system comprising a battery pack, a battery management system and the battery sampling unit, the battery sampling unit being electrically connected to the battery pack and the battery management system. In the above embodiments, the description of each embodiment has its own emphasis, and for parts not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0074] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0075] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application has different focuses on the description of each embodiment, for the parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A battery sampling unit, characterized in that: The battery sampling unit is electrically connected to a battery pack, the battery pack includes a plurality of battery cells, the battery sampling unit includes a plurality of substrates and a plurality of acquisition chips, the substrates are fixed on the surfaces of the battery cells; the acquisition chip is fixed on the substrate, the acquisition chip is electrically connected to the battery positive electrode, the battery negative electrode and the battery shell of the battery cell through the substrate, so as to collect the battery information of the battery cell; Among them, multiple acquisition chips are respectively connected to the battery management system for communication, and multiple acquisition chips communicate with the communication chip of the battery management system through the power circuit and the battery shell, and the power circuit is the charging and discharging circuit of the battery pack.

2. The battery sampling unit according to claim 1, characterized in that: The acquisition chip is an active front-end AFE chip, and the acquisition chip includes a battery information storage module, and the battery information storage module is used to pre-store the battery information of the battery cell before leaving the factory.

3. The battery sampling unit according to claim 1, characterized in that: The multiple battery cells are connected in series, wherein the positive electrode of the current battery cell is electrically connected to the negative electrode of the next adjacent battery cell, and the multiple battery shells of the multiple battery cells are in contact with each other and connected to each other in an equipotential manner.

4. The battery sampling unit according to claim 1, characterized in that: The substrate is a printed circuit board, on which a positive power line, a negative power line and a ground line are provided, wherein the positive power line is connected to the positive electrode of the battery cell, the negative power line is connected to the negative electrode of the battery cell, and the ground line is connected to the battery shell of the battery cell.

5. The battery sampling unit according to claim 2, characterized in that: The battery sampling unit is electrically connected to a battery management system. The battery management system includes at least one communication chip. The communication chip and the plurality of acquisition chips are electrically connected to a power circuit of the battery pack.

6. The battery sampling unit according to claim 5, characterized in that: The acquisition chip also includes an analog-to-digital conversion module, a digital module, a communication processing module and a transmission module, wherein the analog-to-digital conversion module is electrically connected to the positive electrode and the negative electrode of a battery cell; the digital module is electrically connected to the analog-to-digital conversion module, and is used to process the battery information after analog-to-digital conversion; the communication processing module is electrically connected to the digital module, and is used to convert the battery information processed by the digital module into a format that meets communication requirements; the transmission module includes a sending module and a receiving module, and the sending module and the receiving module are both electrically connected to the communication processing module, and are used to transmit battery information that meets communication requirements.

7. The battery sampling unit according to claim 6, characterized in that: The battery sampling unit includes a first resonant circuit, a first induction circuit and a second resonant circuit, the first resonant circuit is electrically connected to one of the acquisition chips, the first induction circuit is electrically connected to the first resonant circuit, and the second resonant circuit is electrically connected to the first induction circuit.

8. The battery sampling unit according to claim 7, characterized in that: The battery pack is electrically connected to a third resonant circuit, the third resonant circuit is electrically connected to multiple second resonant circuits, the battery management system also includes a fourth resonant circuit and a second induction circuit, the second induction circuit is electrically connected to the third resonant circuit, the fourth resonant circuit is electrically connected to the second induction circuit, and the communication chip is electrically connected to the fourth resonant circuit.

9. The battery sampling unit according to claim 8, characterized in that: The first resonant circuit, the second resonant circuit, the third resonant circuit and the fourth resonant circuit each include at least one LC series resonant structure, wherein the first resonant circuit and the fourth resonant circuit each include two LC series resonant structures arranged in parallel, and the second resonant circuit and the third resonant circuit each include one LC series resonant structure.

10. The battery sampling unit according to claim 9, characterized in that: In the two LC series resonant structures of the first resonant circuit, the first LC series resonant structure is electrically connected to the transmitting module of the acquisition chip, the second LC series resonant structure is electrically connected to the receiving module of the acquisition chip, and the first LC series resonant structure and the second LC series resonant structure are arranged in parallel.

11. The battery sampling unit according to claim 10, characterized in that: The first LC series resonant structure includes a first inductor and a first capacitor, wherein the first end of the first inductor is electrically connected to the receiving module of the acquisition chip, the second end of the first inductor is electrically connected to the first end of the first capacitor, and the second end of the first capacitor is electrically connected to the first induction circuit; the second LC series resonant structure includes a second inductor and a second capacitor, wherein the first end of the second inductor is electrically connected to the sending module of the acquisition chip, the second end of the second inductor is electrically connected to the first end of the second capacitor, the second end of the second capacitor is electrically connected to the first induction circuit, and the second end of the first capacitor is electrically connected to the second end of the second capacitor.

12. The battery sampling unit according to claim 11, characterized in that: The first induction circuit includes a first transformer, the primary side of the first transformer is electrically connected to the first resonant circuit, the secondary side of the first transformer is electrically connected to the second resonant circuit and the power loop, wherein the second end of the first capacitor and the second end of the second capacitor are electrically connected to one end of the primary side of the first transformer, and the other end of the primary side of the first transformer is grounded.

13. The battery sampling unit according to claim 12, characterized in that: The second induction circuit includes a second transformer, the primary side of the second transformer is electrically connected to the third resonant circuit and the power loop, and the secondary side of the first transformer is electrically connected to the fourth resonant circuit, wherein the second end of the seventh capacitor and the second end of the eighth capacitor are electrically connected to one end of the secondary side of the second transformer, and the other end of the secondary side of the second transformer is electrically connected to the sending module and the receiving module of the communication chip.

14. The battery sampling unit according to claim 9, characterized in that: The second resonant circuit includes an LC series resonant structure, wherein the second resonant circuit includes a third inductor and a third capacitor, the first end of the third inductor is electrically connected to the positive electrode of the battery or the negative electrode of the battery cell, the second end of the third inductor is electrically connected to the first end of the third capacitor, the second end of the third capacitor is electrically connected to one end of the secondary side of the first transformer, and the other end of the secondary side of the first transformer is grounded.

15. The battery sampling unit according to claim 9, characterized in that: The fourth resonant circuit includes two LC series resonant structures, the first LC series resonant structure is electrically connected to the transmitting module of the communication chip, the second LC series resonant structure is electrically connected to the receiving module of the communication chip, and the first LC series resonant structure and the second LC series resonant structure are arranged in parallel.

16. The battery sampling unit according to claim 15, characterized in that: The first LC series resonant structure includes a seventh inductor and a seventh capacitor, the first end of the seventh inductor is electrically connected to the receiving module of the communication chip, the second end of the seventh inductor is electrically connected to the first end of the seventh capacitor, and the second end of the seventh capacitor is electrically connected to the second induction circuit; the second LC series resonant structure includes an eighth inductor and an eighth capacitor, the first end of the eighth inductor is electrically connected to the sending module of the communication chip, the second end of the eighth inductor is electrically connected to the first end of the eighth capacitor, the second end of the eighth capacitor is electrically connected to the second induction circuit, and the second end of the seventh capacitor is electrically connected to the second end of the eighth capacitor.

17. The battery sampling unit according to claim 13, characterized in that: The third resonant circuit includes an LC series resonant structure, wherein the third resonant circuit includes a ninth inductor and a ninth capacitor, a first end of the ninth inductor is electrically connected to one end of the primary side of the second transformer, the other end of the primary side of the second transformer is grounded, a second end of the ninth inductor is electrically connected to the first end of the ninth capacitor, and a second end of the ninth capacitor is electrically connected to the positive electrode or the negative electrode of the battery cell.

18. The battery sampling unit according to any one of claims 9 to 17, characterized in that: Each LC series resonant structure includes an inductor and a capacitor connected in series with each other, and the inductance value and the capacitance value of the inductor and the capacitance value of each LC series resonant structure are adjusted according to the communication frequency of the communication chip.

19. A battery sampling system, characterized in that: The battery sampling system comprises a battery pack, a battery management system and a battery sampling unit according to any one of claims 1 to 18, wherein the battery sampling unit is electrically connected to the battery pack and the battery management system.

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