Lithium battery pack voltage and temperature sampling circuit, monitoring device and lithium battery pack

Abstract

The utility model provides a lithium battery pack voltage and temperature sampling circuit, a monitoring device and a lithium battery pack, the sampling circuit comprises an acquisition chip, voltage sampling circuits, temperature sampling circuits, a multiplexer I and a multiplexer II, each voltage sampling circuit is connected with an input pin of the acquisition chip, and each temperature sampling circuit is connected with an output pin of the acquisition chip. The acquisition chip is used for transmitting an acquired voltage signal to the acquisition chip; the input end of the multiplexer I and the input end of the multiplexer II are connected with the corresponding temperature sampling circuits respectively, and the output end of the multiplexer I and the output end of the multiplexer II are connected with input pins of the acquisition chip respectively and used for transmitting acquired temperature signals to the acquisition chip. According to the voltage and temperature sampling circuit for the lithium battery pack, the voltage sampling circuit is directly connected with the acquisition chip, the plurality of temperature sampling circuits are connected to the acquisition chip through the two multiplexers, and the voltage sampling circuit and the temperature sampling circuits are integrated together, so that the structure of the whole sampling circuit is simplified.

Description

Technical Field

[0001] The utility model relates to lithium battery management equipment, in particular to a lithium battery pack voltage and temperature sampling circuit, a monitoring device and a lithium battery pack. Background Art

[0002] A large-scale lithium battery energy storage system is a system that uses lithium-ion batteries as energy storage media to store and release electrical energy. It is usually composed of multiple lithium batteries and equipped with components such as a battery management system (BMS) and corresponding power converters. It is widely used in renewable energy grid connection, grid ancillary services, grid transmission and distribution, distributed and microgrids, user-side energy storage and other application scenarios. The voltage and temperature acquisition of lithium batteries is an important part of the battery management system (BMS), which is of great significance for ensuring the safe operation of the battery, optimizing performance and extending service life.

[0003] In large-scale lithium battery energy storage systems, the sampling circuit structure of lithium battery voltage and temperature is often more complicated. This is mainly because large-scale lithium battery energy storage systems usually contain a large number of battery cells or modules, and each cell or module needs to accurately collect voltage and temperature. For example, the Chinese patent with application number CN201320562126.9 discloses a device for measuring voltage and temperature of lithium battery packs. The temperature measurement board includes 16 temperature measurement circuits and a first single-chip microcomputer, and the voltage measurement board includes 16 voltage measurement circuits and a second single-chip microcomputer. The host computer communicates with the single-chip microcomputers of each measurement board through the RS485 interface; the temperature measurement board and the voltage measurement board are independent of each other, and at least two single-chip microcomputers are required, which is not only complex in structure but also costly.

[0004] In order to ensure the safe and stable operation of the system, it is also necessary to consider multiple links such as front-end and back-end isolation, signal transmission, and data processing, which further increases the complexity of the sampling circuit structure; such as the Chinese patent application number CN201410178496.1, which discloses a lithium battery pack temperature and voltage monitoring system; and, since the sampling circuit structure involves multiple components and modules, once a fault occurs, it is necessary to check and locate the problem one by one, and it is also more troublesome to repair it when returning it for repair.

[0005] In order to solve the above problems, it is necessary to design a circuit with simple structure, easy maintenance and low cost. Summary of the invention

[0006] The purpose of the utility model is to address the deficiencies of the prior art and thus provide a lithium battery pack voltage and temperature sampling circuit, a monitoring device and a lithium battery pack. The voltage sampling circuit is directly connected to an acquisition chip, and several temperature sampling circuits are connected to the acquisition chip through two multiplexers. The voltage sampling circuit and the temperature sampling circuit are concentrated together to simplify the entire sampling circuit structure, and the temperature is collected in a multiplexing manner to reduce the design complexity and circuit cost.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the utility model provides a lithium battery pack voltage and temperature sampling circuit, which includes an acquisition chip, a plurality of voltage sampling circuits, a plurality of temperature sampling circuits, a multiplexer I and a multiplexer II, each voltage sampling circuit is respectively connected to the acquisition chip, and is used to transmit the collected voltage signal to the acquisition chip; the input ends of the multiplexer I and the multiplexer II are respectively connected to the corresponding temperature sampling circuits, and the output ends of the multiplexer I and the multiplexer II are respectively connected to the acquisition chip, and are used to transmit the collected temperature signal to the acquisition chip.

[0008] In order to achieve the above objectives, the second aspect of the utility model provides a lithium battery pack monitoring device, which includes a single-chip microcomputer and a sampling circuit connected to the single-chip microcomputer through an optocoupler isolation circuit, and the sampling circuit is the above-mentioned lithium battery pack voltage and temperature sampling circuit.

[0009] In order to achieve the above-mentioned object, the third aspect of the present invention provides a lithium battery pack, which includes the above-mentioned lithium battery pack monitoring device.

[0010] The beneficial effects of the utility model are:

[0011] The utility model proposes a lithium battery pack voltage and temperature sampling circuit, comprising an acquisition chip, a plurality of voltage sampling circuits, a plurality of temperature sampling circuits, a multiplexer I and a multiplexer II. Two multiplexers are used to realize signal transmission of all temperature sampling circuits, and the voltage sampling circuit and the temperature sampling circuit are concentrated together, thereby simplifying the entire sampling circuit structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the voltage and temperature sampling circuit of the lithium battery pack of the utility model;

[0013] Figure 2 It is a circuit schematic diagram of the acquisition chip and voltage sampling circuit of the utility model;

[0014] Figure 3 It is a circuit schematic diagram of the temperature sampling circuit and two multiplexers of the utility model;

[0015] Figure 4 It is a circuit schematic diagram of the connector of the utility model;

[0016] Figure 5 It is a structural schematic diagram of the monitoring device of the utility model;

[0017] Figure 6 The utility model is a circuit principle diagram of an optocoupler isolation circuit. DETAILED DESCRIPTION

[0018] The technical solution of the utility model is further described in detail below through specific implementation methods.

[0019] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances. This is just a way of distinguishing objects with the same attributes when describing the embodiments of this application.

[0020] Example 1

[0021] As attached Figure 1 As shown, this embodiment provides a specific implementation of a lithium battery pack voltage and temperature sampling circuit;

[0022] The lithium battery pack voltage and temperature sampling circuit includes an acquisition chip, a plurality of voltage sampling circuits, a plurality of temperature sampling circuits, a multiplexer I and a multiplexer II, each voltage sampling circuit is respectively connected to an input pin of the acquisition chip, and is used to transmit the collected voltage signal to the acquisition chip;

[0023] The input ends of the multiplexer I and the multiplexer II are respectively connected to the corresponding temperature sampling circuits, and the output ends of the multiplexer I and the multiplexer II are respectively connected to the input pins of the acquisition chip, so as to transmit the collected temperature signals to the acquisition chip.

[0024] It should be noted that the voltage sampling circuit in this embodiment is directly connected to the acquisition chip, and the temperature sampling circuit is connected to the acquisition chip through two multiplexers, which brings the voltage sampling circuit and the temperature sampling circuit together, thereby simplifying the entire sampling circuit structure.

[0025] In some embodiments, as shown in the attached Figure 2As shown, the circuit structure of each voltage sampling circuit is the same, and all include a signal input terminal, a first resistor, a second resistor, a third resistor, a fourth resistor, a MOS tube, a first diode, and a second diode; the drain of the MOS tube is connected to one end of the second resistor, the other end of the second resistor is connected to the positive electrode of the first diode, the negative electrode of the first diode and one end of the third resistor are respectively connected to one end of the first resistor, and the other end of the first resistor is connected to the signal input terminal; the other end of the third resistor is connected to the input pin of the acquisition chip, and the other end of the third resistor is also connected to the adjacent voltage sampling circuit through a capacitor and a second diode; the gate of the MOS tube is connected to another input pin of the acquisition chip through the fourth resistor, and the source of the MOS tube is connected to the adjacent voltage sampling circuit.

[0026] In a specific embodiment, as shown in the attached Figure 2 As shown, the lithium battery pack voltage and temperature sampling circuit includes 16 voltage sampling circuits, and the input terminals BV1_1 to BV1_17 of the 16 voltage sampling circuits are respectively connected to the voltage sampling points of the corresponding single cells in the lithium battery pack (such as BV1_1 is connected to the negative electrode of the lithium battery pack, and BV1_2 to BV1_17 are respectively connected to the positive electrodes of the 16 single cells in the lithium battery pack), and the output terminals of the 16 voltage sampling circuits are respectively connected to the corresponding pins of the acquisition chip U8, thereby realizing 16-channel battery voltage sampling;

[0027] As attached Figure 2 As shown, one of the voltage sampling circuits is taken as an example for explanation. The signal input end of the voltage sampling circuit is BV1_2. The circuit specifically includes a resistor R45, a resistor R52, a resistor R78, a resistor R79, a diode D3, a diode D22, and a MOS tube Q7. The drain of the MOS tube Q7 is connected to one end of the resistor R52, the other end of the resistor R52 is connected to the positive electrode of the diode D3, the negative electrode of the diode D3 and one end of the resistor R78 are respectively connected to one end of the resistor R45, and the other end of the resistor R45 is connected to the signal input end BV1_2; the other end of the resistor R78 is connected to the input pin C1 of the acquisition chip U8, and the other end of the resistor R78 is connected to the resistor R80 in another adjacent voltage sampling circuit through the capacitor C22 and the diode D22; the gate of the MOS tube Q7 is connected to another input pin S2 of the acquisition chip U8 through the resistor R79, and the source of the MOS tube Q7 is connected to the connection point between the resistor R46 and the resistor R80 in another adjacent voltage sampling circuit;

[0028] It can be understood that the voltage sampling circuit corresponding to BV1_2 includes two branches, in which the resistor R45 and the resistor R78 on one branch are used as voltage dividing resistors to transmit the voltage signal to the acquisition chip U8; the resistor R52, the resistor R79, the diode D3 and the MOS tube Q7 on the other branch are used for passive balancing control, and the capacitor and the diode between the two adjacent voltage sampling circuits are used to improve the anti-interference ability so that the voltage sampling circuits do not affect each other;

[0029] It should be noted that the circuit structures and connection methods of other voltage sampling circuits are similar and will not be described in detail here.

[0030] In some embodiments, two adjacent temperature sampling circuits reuse an electrostatic suppressor, such as the attached Figure 3 shown.

[0031] In a specific embodiment, as shown in the attached Figure 3 As shown, the lithium battery pack voltage and temperature sampling circuit includes 16 temperature sampling circuits, and the signal input terminals are AD_F01 to AD_F16 in sequence, and AD_F01 to AD_F16 are used to connect to the signal output terminals of the temperature sensors arranged on the corresponding single cells;

[0032] AD_F01 to AD_F08 are connected to the I / O0 to I / O7 pins of multiplexer Ⅰ (U20), and the I / O pins of U20 are connected to the I / O pins of multiplexer Ⅰ (U20) through resistor R122. Figure 2 The ADC1 pin of the acquisition chip U8 is connected to transmit the temperature signals collected by the 8-way temperature sampling circuit to the acquisition chip U8; the I / O0 to I / O7 pins of the multiplexer Ⅰ (U20) are also connected to VCC1_5V through pull-up resistors R147, R146, R145, R144, R143, R142, R141 and R140 respectively;

[0033] AD_F01 and AD_F02 are respectively connected to the same electrostatic suppressor U11, and AD_F01 and AD_F02 are also respectively connected to the ground terminal AFE1_GND through a capacitor; AD_F03 and AD_F04 are respectively connected to the same electrostatic suppressor U12, and AD_F03 and AD_F04 are also respectively connected to the ground terminal AFE1_GND through a capacitor; AD_F05 and AD_F06 are respectively connected to the same electrostatic suppressor U13, and AD_F05 and AD_F06 are also respectively connected to the ground terminal AFE1_GND through a capacitor; AD_F07 and AD_F08 are respectively connected to the same electrostatic suppressor U15, and AD_F07 and AD_F08 are also respectively connected to the ground terminal AFE1_GND through a capacitor;

[0034] AD_F09 to AD_F16 are connected to the I / O0 to I / O7 pins of multiplexer II (U19). The I / O pins of U19 are connected to the I / O pins of the multiplexer II (U19) through resistor R103. Figure 2 The ADC2 pin of the acquisition chip U8 is connected to transmit the temperature signals collected by the 8-way temperature sampling circuit to the acquisition chip U8; the I / O0 to I / O7 pins of the multiplexer II (U19) are also connected to VCC1_5V through pull-up resistors R139, R138, R137, R136, R135, R123, R113 and R114 respectively;

[0035] AD_F09 and AD_F12 are respectively connected to the same electrostatic suppressor U18, and AD_F09 and AD_F12 are also connected to the ground terminal AFE1_GND through a capacitor; AD_F10 and AD_F11 are respectively connected to the same electrostatic suppressor U17, and AD_F10 and AD_F11 are also connected to the ground terminal AFE1_GND through a capacitor; AD_F13 and AD_F15 are respectively connected to the same electrostatic suppressor U14, and AD_F13 and AD_F15 are also connected to the ground terminal AFE1_GND through a capacitor; AD_F14 and AD_F16 are respectively connected to the same electrostatic suppressor U16, and AD_F14 and AD_F16 are also connected to the ground terminal AFE1_GND through a capacitor.

[0036] In a specific implementation manner, the model of the acquisition chip is ADBMS1818, and the models of the multiplexer I and the multiplexer II are both CD4051BM.

[0037] It should be noted that the model of the acquisition chip and the model of the multiplexer are not limited to the above models. In other embodiments, they may also be other chips that can achieve the above functions.

[0038] It should also be noted that this embodiment uses a multiplexing method to collect the temperature of the single battery, which further reduces the design complexity and circuit cost.

[0039] Example 2

[0040] Based on Example 1, this example provides another specific implementation of a lithium battery pack voltage and temperature sampling circuit.

[0041] In some embodiments, each voltage sampling circuit is also connected to a connector, and the connector is used to connect to a voltage sampling point of a corresponding single lithium battery.

[0042] As attached Figure 4As shown, the model of the connector P2 is IMSA-13065B-2-40Y900. In other embodiments, it may be other models that can achieve the above functions, such as 2024WRS-2*20A-LPSW1BRs.

[0043] It should be noted that Figure 4 BV1_1 to BV1_17 on connector P2 need to be connected to Figure 2 The BV1_1 to BV1_17 of the medium voltage sampling circuit are connected to transmit the output voltage signal of the single battery to the acquisition chip U8 via the connector P2 and the voltage sampling circuit;

[0044] Figure 4 AD_F01 to AD_F16 on connector P2 need to be connected to Figure 3 AD_F01 to AD_F16 are connected to transmit the temperature signal collected by the temperature sensor on the single battery to the collection chip U8 through the connector P2 and the multiplexer.

[0045] Example 3

[0046] Based on the above embodiments, this embodiment provides a specific implementation of a lithium battery pack monitoring device.

[0047] In some embodiments, the lithium battery pack monitoring device includes a single-chip microcomputer and a sampling circuit connected to the single-chip microcomputer via an optocoupler isolation circuit. The sampling circuit is the lithium battery pack voltage and temperature sampling circuit in Embodiment 1 or 2.

[0048] As attached Figure 6 As shown, the optocoupler isolation circuit includes a four-channel digital isolator U10, and the model of the four-channel digital isolator U10 is NSI8241W1-DSWR; INA, INB, INC and OUTD of the four-channel digital isolator U10 are respectively connected to the pins SPI1_SCK, SPI1_CS, SPI1_MOSI and SPI1_MISO of the acquisition chip U8, and IND, OUTA, PUTB and OUTC of the four-channel digital isolator U10 are respectively connected to the pins of the microcontroller.

[0049] It should be noted that the optocoupler isolation circuit is located between the acquisition chip U8 and the single-chip microcomputer, and is used to prevent electrical noise or interference from affecting the monitoring device, thereby improving the overall performance and stability.

[0050] Example 4

[0051] Based on the above embodiment, this embodiment provides another specific implementation of the lithium battery pack monitoring device, as shown in the attached Figure 5 shown.

[0052] In some embodiments, the lithium battery pack monitoring device further comprises a CAN communication circuit connected to the single-chip microcomputer, and the CAN communication circuit is in communication connection with a host computer. Therefore, the lithium battery pack monitoring device can transmit the voltage signal and temperature signal collected by the sampling circuit to the host computer via the CAN communication circuit for remote monitoring and management.

[0053] It can be understood that the specific circuit structure of the CAN communication circuit is a prior art and will not be described in detail here.

[0054] Example 5

[0055] Based on the above embodiments, this embodiment provides a specific implementation of a lithium battery pack.

[0056] In some embodiments, the lithium battery pack includes a lithium battery body and the lithium battery pack monitoring device of embodiment 3 or 4.

[0057] It should be noted that the lithium battery pack adopts a simple sampling circuit to collect the single cell voltage and battery temperature, and uploads the single cell voltage and battery temperature through the CAN communication circuit.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the utility model, which should be included in the scope of the technical solution for protection of the utility model.

Claims

1. A lithium battery pack voltage and temperature sampling circuit, characterized in that: It includes a data acquisition chip, several voltage sampling circuits, several temperature sampling circuits, a multiplexer I and a multiplexer II. Each voltage sampling circuit is respectively connected to the acquisition chip, and is used to transmit the collected voltage signal to the acquisition chip; The input ends of the multiplexer I and the multiplexer II are respectively connected to the corresponding temperature sampling circuits, and the output ends of the multiplexer I and the multiplexer II are respectively connected to the acquisition chip, so as to transmit the collected temperature signal to the acquisition chip.

2. The lithium battery pack voltage and temperature sampling circuit according to claim 1, characterized in that: The circuit structure of each voltage sampling circuit is the same, and includes a signal input terminal, a first resistor, a second resistor, a third resistor, a fourth resistor, a MOS tube, a first diode, and a second diode; The drain of the MOS tube is connected to one end of the second resistor, the other end of the second resistor is connected to the anode of the first diode, the cathode of the first diode and one end of the third resistor are respectively connected to one end of the first resistor, and the other end of the first resistor is connected to the signal input end; The other end of the third resistor is connected to the input pin of the acquisition chip, and the other end of the third resistor is also connected to the adjacent voltage sampling circuit through the capacitor and the second diode; The gate of the MOS tube is connected to another input pin of the acquisition chip through the fourth resistor, and the source of the MOS tube is connected to an adjacent voltage sampling circuit.

3. The lithium battery pack voltage and temperature sampling circuit according to claim 1 or 2, characterized in that: Two adjacent temperature sampling circuits reuse an electrostatic suppressor.

4. The lithium battery pack voltage and temperature sampling circuit according to claim 3, characterized in that: Each voltage sampling circuit is also connected to the connector respectively.

5. The lithium battery pack voltage and temperature sampling circuit according to claim 4, characterized in that: The model of the connector is IMSA-13065B-2-40Y900.

6. The lithium battery pack voltage and temperature sampling circuit according to claim 1, characterized in that: The model of the acquisition chip is ADBMS1818.

7. The lithium battery pack voltage and temperature sampling circuit according to claim 1, characterized in that: The models of the multiplexer I and the multiplexer II are both CD4051BM.

8. A monitoring device, characterized in that: It comprises a single-chip microcomputer and a sampling circuit connected to the single-chip microcomputer through an optical coupling isolation circuit, wherein the sampling circuit is the lithium battery pack voltage and temperature sampling circuit according to any one of claims 1 to 7.

9. The monitoring device according to claim 8, characterized in that: It also includes a CAN communication circuit connected to the single-chip microcomputer, and the CAN communication circuit is communicatively connected to a host computer.

10. A lithium battery pack, characterized in that: Comprising the monitoring device according to claim 8 or 9.

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