BMS (Battery Management System) special for lithium carbon fluoride primary battery

Abstract

The invention provides a special BMS (Battery Management System) management system for a lithium fluorocarbon primary battery, which comprises a BMU main control board and 60 LMU control boards, the BMU main control board and the LMU control boards are arranged in a plastic shell on the side wall of the battery, and the LMU control boards are dispersed on the two sides of the battery, are connected with each string of battery cells of each branch by using acquisition cables, and are connected with a temperature monitoring sensor at the same time; the BMU main control board is arranged in the plastic shell right in front of the battery, the plastic shell is provided with an output plug-in, the output plug-in is welded and fixed with a PCB (printed circuit board) of the BMU main control board, power is supplied to an external load through the plug-in, the BMU main control board is connected with a communication line and transmits data to an upper computer regularly, and the BMU main control board is connected with the LMU control board through a daisy chain communication interface; the system has the advantages of ultra-low power consumption, high power output, high real-time performance, stable topological structure and the like, and meets the performance requirements.

Description

Technical Field

[0001] The invention relates to a battery management system, in particular to a BMS management system dedicated to lithium carbon fluoride primary batteries. Background Art

[0002] Compared with traditional secondary batteries, lithium carbon fluoride primary batteries have the advantages of long storage life, wide operating temperature range and high energy density. At the same time, due to the high energy density, there is also a greater risk of battery loss of control, so higher requirements are placed on the performance of the BMS system. Lithium carbon fluoride battery packs are usually composed of multiple single soft-pack batteries connected in parallel to form a single small module, and then the small modules are connected in series according to certain voltage requirements to form a branch module, and finally multiple branch modules are connected in parallel to form an overall battery.

[0003] In order to adapt to the overall structure and usage requirements of lithium carbon fluoride primary batteries, the battery management system adopts a bus-type multi-daisy chain interface master-slave control topology of multiple LMUs (Load Management Units) + one BMU (Battery Management Unit), such as Figure 1 shown.

[0004] It also has the following dedicated functions:

[0005] (1) One-way capacity prediction (SOC): Carbon fluoride batteries are different from ordinary rechargeable ternary and lithium iron phosphate batteries. They have high energy density, but can only be discharged once in their life cycle. Therefore, it is necessary to monitor the battery capacity online in real time with the lowest power consumption during the discharge process of the carbon fluoride battery, and report the remaining capacity of the battery system in real time based on the battery-specific discharge curve database.

[0006] (2) Overcurrent, excessive pressure difference, and temperature protection: When the battery system has overcurrent, excessive pressure difference, and excessive temperature, it can automatically cut off the battery charging and discharging circuit and notify the management system to send out an alarm signal.

[0007] (3) Within the full discharge range of the battery pack, the management system can realize self-powering of the battery. The voltage, temperature and other information are collected and reported without being affected by the battery supply voltage.

[0008] (5) Self-test alarm: Automatically detect whether the battery function is normal, and judge the battery effectiveness in time. If it is found that a battery in the system is invalid or about to fail or the inconsistency with other batteries increases, the management system will be notified to send out an alarm signal. At the same time, it has the function of external port output voltage monitoring. The three-channel voltage-stabilized output of the battery has a self-test function, which can effectively judge whether the output state is consistent with the set state. When an abnormality occurs, the circuit is cut off in time and an alarm message is issued.

[0009] (6) Communication function: Use CAN bus to communicate with the host computer management system.

[0010] (7) Parameter setting: Various parameters of system operation can be set through the host computer software, such as battery capacity, alarm conditions, battery VC0 database and other parameter tables.

[0011] (8) High current regulated output: The output voltage of ordinary lithium-ion batteries gradually decreases as the battery power decreases. The battery output channel 1 in the present invention is a direct output of the battery cell, and channels 2-4 are equipped with a 40A high current DCDC regulated circuit, which can achieve stable output while maintaining the input voltage within the range of 9-40V. Figure 1 shown.

[0012] At present, all lithium battery BMS systems use daisy chain series or LMU parallel connection on both sides of the same CAN bus to report the battery information of each string. Both of these structures have the disadvantages of main link communication failure and inability to report all or most of the battery information. Combined with the series and parallel structure of primary batteries, there is a risk of battery information being out of control. Summary of the invention

[0013] The technical problem to be solved by the present invention is to provide a BMS management system dedicated to lithium carbon fluoride primary batteries.

[0014] In order to solve the above technical problems, the technical solution of the present invention is:

[0015] A BMS management system dedicated to lithium fluoride carbon primary batteries comprises a BMU main control board and 60 LMU control boards (collection slave boards), wherein the BMU main control board and the LMU control board are placed in a plastic shell on the side wall of the battery, wherein each LMU control board is dispersed on both sides of the battery, and is connected to each string of battery cells of each branch by using a collection cable, and is connected to a temperature monitoring sensor at the same time; the BMU main control board is placed in a plastic shell in front of the battery, and the plastic shell is provided with an output plug-in, and the output plug-in is welded and fixed to a PCB circuit board of the BMU main control board, and supplies power to an external load through the plug-in, connects a communication line, and transmits data to an upper computer at a regular time; the BMU main control board is connected to the LMU control board through a daisy chain communication interface, summarizes the collected voltage and temperature information, determines whether the alarm condition is met, and calculates the SOC power information through software.

[0016] Preferably, in the above-mentioned BMS management system dedicated to lithium fluoride primary batteries, the LMU control board uses the LTC6811 chip produced by American Lingte Company as the AFE acquisition chip, which is used to collect basic information data such as battery voltage and temperature. Since this chip is a universal voltage acquisition chip, it is mainly used for the measurement of ternary lithium batteries and lithium iron phosphate batteries. Its minimum operating voltage is 11V, and the primary battery has about 20% of the remaining power that cannot be discharged at 11V voltage. For this reason, the chip is provided with a separate boost DCDC power supply control circuit that can start or stop following the change of the total battery voltage.

[0017] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the boost DCDC power supply control circuit:

[0018] The third foot of the electronic switch U3 is connected to the highest input voltage of the battery;

[0019] The fourth foot of the electronic switch U3 is connected to the first foot of U4 after being connected in parallel by NTC1 and NTC2;

[0020] The inverting input terminal of comparator U5 is connected to the highest input voltage of the battery through voltage divider resistors RS1 0 (150K) and RS8 (30K) and filter capacitor CS1 0;

[0021] The non-inverting input terminal of the comparator U5 is connected to the reference voltage positive 5V through the voltage dividing resistors RS1 2 and RS1 3 and the filter capacitor CS9;

[0022] The output end of the comparator U5 is connected to the DCDC control chip U4 through the resistor R7 (1K);

[0023] The voltage divider circuit composed of the cathode of the DCDC circuit output diode D1 and the feedback resistor R1 (10k), feedback resistor R2 (10k), and feedback resistor R3 (1k) is connected to the 8th pin of the U4 chip;

[0024] The cathode of the DCDC circuit output diode D1 is connected to the anode of the isolation diode D3;

[0025] The cathode of the DCDC circuit isolation diode D5 is connected to the cathode of the isolation diode D3, and is connected to the first pin of the power input terminal of the acquisition chip LTC6811.

[0026] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the U6 chip in the boost DCDC power supply control circuit is input by the highest output voltage of the battery pack, and its output setting voltage is 5V.

[0027] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the voltage division ratio of RS10 and RS8 in the boost DCDC power supply control circuit is 3 / 18, and when the battery voltage input is 18V, the voltage division value is 3V.

[0028] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the voltage dividing ratio of the voltage dividing resistor RS12 and the voltage dividing resistor RS13 in the boost DCDC power supply control circuit is 3 / 5, and when the battery voltage input is 5V, the voltage dividing value is 3V.

[0029] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, when the battery voltage in the boost DCDC power supply control circuit is lower than 18V, the comparator U5 outputs a high level and turns off the U4 enable signal.

[0030] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the cathodes of the isolation diode D3 and the isolation diode D5 in the boost DCDC power supply control circuit are connected in parallel and connected to the AFE chip power supply to provide two voltage inputs.

[0031] Preferably, in the above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, two self-recovery fuses NTC1 and NTC2 in the boost DCDC power supply control circuit are connected in parallel to provide a 0.2A overcurrent protection function to the DCDC circuit.

[0032] The above-mentioned BMS management system dedicated to lithium carbon fluoride primary batteries, the boost DCDC power supply control circuit can normally collect and report data when the LTC6811 chip (analog front-end acquisition chip) is powered by a power supply lower than its own rated voltage range.

[0033] Since the voltage operating range of the LMU analog front-end acquisition chip LTC6811 is 11-55V, it cannot meet the use range of the primary battery discharge voltage of 5-36V. Therefore, a self-starting boost DCDC power supply control circuit is used in the circuit to enable it to normally collect and report data when powered by a power supply lower than its own rated voltage range. The boost circuit is automatically turned on or off according to the charge state of the battery pack and the lower limit of the power supply voltage required for the acquisition chip to power the battery, which satisfies the data acquisition of the full power supply voltage range of the battery pack and ensures low power consumption loss of the battery pack.

[0034] Preferably, in the above-mentioned BMS management system dedicated to lithium fluoride primary batteries, the LMU control board adopts an ultra-low leakage photorelay chip TLP3407, and dynamically connects and statically cuts off the battery pack acquisition circuit through software control, so that the leakage current generated by the battery cell through the LMU analog front-end chip in the cut-off state is ≤1nA. In the dynamic measurement state, the photorelay switch is turned on, the battery is directly connected to the analog front-end chip, and the battery voltage can be read normally; when entering the static mode, the photorelay cuts off the connection between the battery and the acquisition chip to reduce the battery self-consumption.

[0035] The above-mentioned BMS management system dedicated to lithium fluoride primary batteries, the BMU main control board is expanded by an ultra-low power MCU with a six-channel daisy chain interface control circuit, each channel is connected to 10 LMU acquisition circuit boards, and each LMU collects 10 battery voltages. The system can collect voltage information of up to 600 battery cells and 240 temperature collection points, realizing centralized collection and monitoring of voltages of all branch modules of the battery. At the same time, it has 6-channel Hall sensor input, 4 channels with gain amplifier circuit, and 2 channels of direct input for current detection and capacity calculation. In addition, it also has 6-channel magnetic latching relay control output.

[0036] Preferably, the above-mentioned BMS management system dedicated to lithium fluoride primary batteries adopts a short-time dynamic activation reporting mode plus a long-time static sleep low-power working mode, and an automatic dynamic and static combined switching control strategy, with a switching cycle of 120:1, to reduce the power consumption generated by the BMS system; the short-time dynamic activation reporting mode refers to the MCU on the BMS board entering a high-power activation mode, and quickly collects the voltage and temperature information of each battery string to determine whether an abnormal alarm state occurs, and quickly reports the collected information to the host computer through the RS422 interface; the long-time static sleep low-power working mode refers to shutting down all peripherals in the BMS system and retaining only the micro-power sleep wake-up circuit of the MCU.

[0037] In sleep mode, the total power consumption of the system can be reduced to 1mA, and the power consumption is only 30mW. Conventional BMS systems are generally in a continuous wake-up state or a continuous sleep state according to the working conditions. This design of automatic wake-up and battery status detection at a fixed time is the first application in the BMS system.

[0038] Preferably, the above-mentioned lithium fluoride carbon primary battery dedicated BMS management system adopts a time-sharing voltage acquisition strategy as the software control algorithm, and the overall electronic control system adopts a multi-channel LMU+BMU topology. The main control unit optimizes the sampling time and adopts a short-time dynamic activation reporting mode to extend the static sleep low-power mode. The dynamic and static combined control strategy reduces the power consumption generated during the entire life cycle; the BMS management system sleep cycle is set to a switching cycle with a sleep-activation ratio of 120:1. When in sleep, it retains extremely low power consumption and enters the sleep state. The peripheral interface circuit is cut off by an electronic switch, and only the main processing functions of the CPU and the CAN bus communication function are retained. The working current can be as low as 5mA, and the power consumption is only 200mW. The cumulative consumption in 5 years is about 9kwH, accounting for about 3% of the total energy.

[0039] When the battery system enters the activation state, the BMU and LMU immediately switch to a high-power, long-term operating state, activate the magnetic latching relay through a pulse voltage, and then output it to each port through a regulated voltage.

[0040] Beneficial effects:

[0041] The BMS management system dedicated to lithium fluoride carbon primary batteries has extremely low power consumption in sleep state, which is about 0.2W, and in active state, which is about 0.64W. The sleep mode and active mode can be automatically switched according to the working state of the battery; the LMU acquisition board can realize battery voltage acquisition through the LTC6811 voltage acquisition chip within the voltage range of 5-40V battery self-power supply; the voltage acquisition circuit has an extremely low leakage current of about 1nA, which can meet the long-term standby sleep state of the primary battery with minimal power loss, so that the battery system can work in a long-term standby duty state.

[0042] The series-parallel structure designed for the lithium fluorinated carbon primary battery dedicated BMS management system does not have the concept of a main link. When a link communication fails, only a small part of the link information will be lost, and most of the battery information can be collected, so that the risk of battery system information loss is within a controllable range, and the protection judgment logic of the BMS is not affected, thereby improving the reliability and stability of the system. At the same time, due to the use of a parallel collection method, the collection speed is much better than the above two structures, which improves the real-time performance of the BMS system.

[0043] The BMS management system dedicated to lithium carbon fluoride primary batteries has the advantages of ultra-low power consumption, high power output, high real-time performance, stable topology structure, etc., meets its performance requirements, and solves the technical problems of monitoring and reporting battery parameters during the long-term low-power standby of carbon fluoride primary batteries in years, protecting the normal output of the battery and handling battery abnormalities. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1It is a block diagram of a BMS management system dedicated to lithium carbon fluoride primary batteries in the background technology;

[0045] Figure 2 This is the schematic diagram of the BMS management system for lithium carbon fluoride primary batteries;

[0046] Figure 3 This is the schematic diagram of the LMU circuit;

[0047] Figure 4 It is the LMU boost circuit;

[0048] Figure 5 This is the schematic diagram of the BMU Hall acquisition circuit;

[0049] Figure 6 This is the schematic diagram of the BMU magnetic latching relay drive circuit;

[0050] Figure 7 Expand the daisy chain circuit schematic for the BMU;

[0051] Figure 8 This is the minimum system circuit diagram of MCU;

[0052] Fig. 9 This is the schematic diagram of the output status detection and RS-422 interface circuit. DETAILED DESCRIPTION

[0053] The dedicated BMS management system for lithium carbon fluoride primary batteries of the present invention is described in detail below in conjunction with the embodiments and drawings.

[0054] Example 1

[0055] like Figure 2-9 As shown, the BMS management system dedicated to lithium fluoride carbon primary batteries includes a BMU main control board and 60 LMU control boards (acquisition slave boards), wherein the BMU main control board and the LMU control board are placed in a plastic shell on the side wall of the battery, wherein each LMU control board is scattered on both sides of the battery, and is connected to each string of cells in each branch using an acquisition cable, and is connected to a temperature monitoring sensor at the same time; the BMU main control board is placed in a plastic shell directly in front of the battery, and the plastic shell has an output plug-in, and the output plug-in is welded and fixed to the PCB circuit board of the BMU main control board, and power is supplied to the external load through the plug-in, and the communication line is connected, and data is transmitted to the upper computer at a regular time. The BMU main control board is connected to the LMU control board through a daisy chain communication interface, and the collected voltage and temperature information is summarized, and it is determined whether the alarm condition is met and the SOC power information is calculated by software.

[0056] The LMU control board (such as Figure 3As shown in the figure, the LTC6811 chip produced by the American Lingte Company is used as the AFE acquisition chip to collect basic information data such as battery voltage and temperature. Since this chip is a universal voltage acquisition chip, it is mainly used for measuring ternary lithium batteries and lithium iron phosphate batteries. Its minimum operating voltage is 11V. When the primary battery is at 11V, about 20% of the remaining power cannot be discharged. For this reason, the chip is provided with a separate boost DCDC power supply control circuit that can start or stop following the change of the total battery voltage. In the boost DCDC power supply control circuit:

[0057] The third foot of the electronic switch U3 is connected to the highest input voltage of the battery;

[0058] The fourth foot of the electronic switch U3 is connected to the first foot of U4 after being connected in parallel by NTC1 and NTC2;

[0059] The inverting input terminal of comparator U5 is connected to the highest input voltage of the battery through voltage divider resistors RS1 0 (150K) and RS8 (30K) and filter capacitor CS1 0;

[0060] The non-inverting input terminal of the comparator U5 is connected to the reference voltage positive 5V through the voltage dividing resistors RS1 2 and RS1 3 and the filter capacitor CS9;

[0061] The output end of the comparator U5 is connected to the DCDC control chip U4 through the resistor R7 (1K);

[0062] The voltage divider circuit composed of the cathode of the DCDC circuit output diode D1 and the feedback resistor R1 (10k), feedback resistor R2 (10k), and feedback resistor R3 (1k) is connected to the 8th pin of the U4 chip;

[0063] The cathode of the DCDC circuit output diode D1 is connected to the anode of the isolation diode D3;

[0064] The cathode of the DCDC circuit isolation diode D5 is connected to the cathode of the isolation diode D3, and is connected to the first pin of the power input terminal of the acquisition chip LTC6811;

[0065] The U6 chip is input by the highest output voltage of the battery pack, and its output setting voltage is 5V;

[0066] The two resettable fuses NTC1 and NTC2 are connected in parallel to provide 0.2A overcurrent protection for the DCDC circuit.

[0067] The voltage division ratio of RS10 and RS8 in the boost DCDC power supply control circuit is 3 / 18. When the battery voltage input is 18V, the voltage division value is 3V. The voltage division ratio of the voltage division resistor RS12 and the voltage division resistor RS13 in the boost DCDC power supply control circuit is 3 / 5. When the battery voltage input is 5V, the voltage division value is 3V. When the battery voltage in the boost DCDC power supply control circuit is lower than 18V, the comparator U5 outputs a high level and turns off the U4 enable signal. The cathodes of the isolation diodes D3 and D5 in the boost DCDC power supply control circuit are connected in parallel and connected to the AFE chip power supply to provide two voltage inputs.

[0068] The specific principle of the boost DCDC power supply control circuit is as follows: when the total battery voltage is lower than 18V, the MCU controls the undervoltage function to enable the photoelectric switch U3 to open, and the boost circuit automatically starts to generate a 20V voltage output according to the battery voltage through the NTC protection thermistor. Through the logical "or" relationship of the two diodes D5 and D3, two independent parallel power supplies are formed with the total battery voltage to supply power to the LTC6811, so that the acquisition circuit can work normally under the total battery voltage of 18V-5V. Figure 4 As shown in the figure, LM5155 is a DCDC boost chip produced by ADI. Its output voltage is designed to be 20V through peripheral circuits. Its enable end is controlled by the low-power comparator TLV3691IDCKR. The comparator U5's same-direction input end is generated by the reference voltage U6 through a resistor to generate a fixed 3V reference, and the reverse input end is input by the total battery voltage through a voltage divider circuit. When the battery voltage is lower than 18V, the voltage at the reverse input end of the comparator is lower than 3V and the output is high. At this time, the DCDC boost circuit works and the output is fixed at 20V. Through the isolation diode D3, it replaces the battery pack to supply power to the AFE chip. When the total voltage is higher than 18V, the comparator U5 reverse input voltage is higher than the same-direction input voltage, and the comparator outputs a low level to the enable control pin of the U4 chip, and the DCDC circuit output is turned off. The battery voltage directly supplies power to the AFE chip through the diode D5.

[0069] The above-mentioned BMS management system dedicated to lithium fluoride carbon primary batteries, the boost DCDC power control circuit can normally collect and report data when the LTC6811 chip (analog front-end acquisition chip) is powered by a power supply lower than its own rated voltage range. Since the voltage operating range of the LMU analog front-end acquisition chip LTC6811 is 11-55V, it cannot meet the use range of the primary battery discharge voltage of 5-36V. Therefore, the self-starting boost DCDC power control circuit in the circuit enables it to collect and report data normally when powered by a power supply lower than its own rated voltage range, and automatically turns on or off the boost circuit according to the battery pack's state of charge and the lower limit of the power supply voltage required for the acquisition chip, which satisfies the data collection of the full power supply voltage range of the battery pack and ensures the low power consumption loss of the battery pack.

[0070] The LMU control board adopts the ultra-low leakage photorelay chip TLP3407, and dynamically connects and statically cuts off the battery pack acquisition circuit through software control, so that the leakage current generated by the battery cell through the LMU analog front-end chip in the cut-off state is ≤1nA. In the dynamic measurement state, the photorelay switch is turned on, and the battery is directly connected to the analog front-end chip, so the battery voltage can be read normally; when entering the static mode, the photorelay cuts off the connection between the battery and the acquisition chip to reduce battery self-consumption.

[0071] The BMU main control board is equipped with an ultra-low power MCU that expands a six-channel daisy-chain interface control circuit. Each channel is connected to 10 LMU acquisition circuit boards, and each LMU collects 10 battery voltages. The system can collect voltage information of up to 600 battery cells and 240 temperature acquisition points, realizing centralized acquisition and monitoring of voltages of all branch modules of the battery. It also has 6-channel Hall sensor inputs, 4 channels with gain amplifier circuits, and 2 channels of direct input for current detection and capacity calculation. In addition, it also has 6-channel magnetic latching relay control outputs. The schematic diagram is as follows Figure 5-8 shown.

[0072] The BMS management system dedicated to lithium fluoride carbon primary batteries adopts a short-time dynamic activation reporting mode plus a long-time static sleep low-power working mode, an automatic dynamic and static combined switching control strategy, and a switching cycle of 120:1, which reduces the power consumption generated by the BMS system; the short-time dynamic activation reporting mode means that the MCU on the BMS board enters a high-power activation mode, and quickly collects the voltage and temperature information of each battery string to determine whether an abnormal alarm state occurs, and quickly reports the collected information to the host computer through the RS422 interface; the long-time static sleep low-power working mode means turning off all peripherals in the BMS system and retaining only the micro-power sleep wake-up circuit of the MCU, such as Fig. 9As shown. In sleep mode, the total system power consumption can be reduced to 1mA, and the power consumption is only 30mW. Conventional BMS systems are generally in a continuous wake-up state or a continuous sleep state following the working conditions. This design of timing automatic wake-up to detect battery status is the first application in the BMS system.

[0073] The BMS management system for lithium fluoride carbon primary batteries adopts a time-sharing voltage acquisition strategy as the software control algorithm. The overall electric control system adopts a multi-channel LMU+BMU topology. The main control unit optimizes the sampling time and adopts a short-time dynamic activation reporting mode to increase the static sleep low-power mode. The dynamic and static combined control strategy reduces the power consumption generated throughout the life cycle; the BMS management system sleep cycle is set to a switching cycle with a sleep activation ratio of 120:1. When in sleep, it retains extremely low power consumption and enters the sleep state. The peripheral interface circuit is cut off by an electronic switch, and only the main processing functions of the CPU and the CAN bus communication function are retained. The working current can be as low as 5mA, and the power consumption is only 200mW. The cumulative consumption in 5 years is about 9kwH, accounting for about 3% of the total energy. When the battery system enters the activation state, the BMU and LMU immediately switch to a high-power long-term operation state, activate the magnetic latching relay through a pulse voltage, and then output to each port through voltage regulation.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. The improvements and modifications such as structural modifications made by technicians in this technical field based on this are deemed to be within the scope of protection of the present invention.

Claims

1. A BMS management system dedicated to lithium carbon fluoride primary batteries, characterized by: It includes a BMU main control board and 60 LMU control boards, which are placed in a plastic shell on the side wall of the battery, wherein each LMU control board is scattered on both sides of the battery, and is connected to each string of cells in each branch using a collection cable, and is also connected to a temperature monitoring sensor; the BMU main control board is placed in a plastic shell directly in front of the battery, and the plastic shell has an output plug-in, which is welded and fixed to the PCB circuit board of the BMU main control board, supplies power to the external load through the plug-in, connects the communication line, and transmits data to the upper computer at a regular interval, and the BMU main control board is connected to the LMU control board via a daisy chain communication interface.

2. The BMS management system for lithium carbon fluoride primary batteries according to claim 1, characterized in that: The LMU control board adopts the LTC6811 chip produced by American Lingte Company as the AFE acquisition chip, and the chip is provided with a separate boost DCDC power supply control circuit which can start or stop following the change of the total battery voltage.

3. The BMS management system for lithium carbon fluoride primary batteries according to claim 2, characterized in that: In the boost DCDC power supply control circuit: The third foot of the electronic switch U3 is connected to the highest input voltage of the battery; The fourth foot of the electronic switch U3 is connected to the first foot of U4 after being connected in parallel by NTC1 and NTC2; The inverting input terminal of comparator U5 is connected to the highest input voltage of the battery through voltage divider resistors RS1 0 and RS8 and filter capacitor CS1 0; The non-inverting input terminal of the comparator U5 is connected to the reference voltage positive 5V through the voltage dividing resistors RS12 and RS13 and the filter capacitor CS9; The output end of the comparator U5 is connected to the DCDC control chip U4 through the resistor R7; The voltage divider circuit composed of the cathode of the DCDC circuit output diode D1 and the feedback resistors R1, R2 and R3 is connected to the 8th pin of the U4 chip; The cathode of the DCDC circuit output diode D1 is connected to the anode of the isolation diode D3; The cathode of the DCDC circuit isolation diode D5 is connected to the cathode of the isolation diode D3, and is connected to the first pin of the power input terminal of the acquisition chip LTC6811.

4. The BMS management system for lithium carbon fluoride primary batteries according to claim 3, characterized in that: The U6 chip in the boost DCDC power supply control circuit is input by the highest output voltage of the battery pack, and its output setting voltage is 5V.

5. The BMS management system for lithium carbon fluoride primary batteries according to claim 3, characterized in that: The voltage division ratio of RS10 and RS8 in the boost DCDC power supply control circuit is 3 / 18. When the battery voltage input is 18V, the voltage division value is 3V; the voltage division ratio of the voltage division resistor RS12 and the voltage division resistor RS13 in the boost DCDC power supply control circuit is 3 / 5. When the battery voltage input is 5V, the voltage division value is 3V; when the battery voltage in the boost DCDC power supply control circuit is lower than 18V, the comparator U5 outputs a high level and turns off the U4 enable signal; the cathodes of the isolation diode D3 and the isolation diode D5 in the boost DCDC power supply control circuit are connected in parallel and connected to the AFE chip power supply to provide two voltage inputs.

6. The BMS management system for lithium carbon fluoride primary batteries according to claim 3, characterized in that: In the boost DCDC power supply control circuit, two self-recovery fuses, NTC′1 and NTC2, are connected in parallel to provide a 0.2A overcurrent protection function for the DCDC circuit.

7. The BMS management system for lithium carbon fluoride primary batteries according to claim 1, characterized in that: The LMU control board adopts the ultra-low leakage photorelay chip TLP3407, and dynamically connects and statically cuts off the battery pack acquisition circuit through software control, so that the leakage current generated by the battery cell through the LMU analog front-end chip in the cut-off state is ≤1nA. In the dynamic measurement state, the photorelay switch is turned on, and the battery is directly connected to the analog front-end chip, so the battery voltage can be read normally; when entering the static mode, the photorelay cuts off the connection between the battery and the acquisition chip to reduce battery self-consumption.

8. The BMS management system for lithium carbon fluoride primary batteries according to claim 7, characterized in that: A short-time dynamic activation reporting mode plus a long-time static sleep low-power working mode is adopted, and a control strategy of automatic dynamic and static combined switching is adopted, and the switching cycle is 120:1, so as to reduce the power consumption generated by the BMS system; the short-time dynamic activation reporting mode refers to the MCU on the BMS board entering a high-power activation mode, and judging whether an abnormal alarm state occurs by quickly collecting the voltage and temperature information of each battery string, and quickly reporting the collected information to the host computer through the RS422 interface; the long-time static sleep low-power working mode refers to shutting down all peripherals in the BMS system and retaining only the micro-power sleep wake-up circuit of the MCU.

9. The BMS management system for lithium carbon fluoride primary batteries according to claim 7 or 8, characterized in that: The software control algorithm adopted is the time-sharing voltage acquisition strategy. The overall electronic control system adopts a multi-channel LMU+BMU topology. The main control unit optimizes the sampling time and adopts a short-time dynamic activation reporting mode to extend the static sleep low-power mode. The dynamic and static combined control strategy reduces the power consumption generated during the entire life cycle. The sleep cycle of the BMS management system is set to a switching cycle with a sleep-to-activation ratio of 120:

1. When in sleep mode, it retains extremely low power consumption and enters the sleep state. The peripheral interface circuit is cut off by an electronic switch, leaving only the main processing functions of the CPU and the CAN bus communication functions.

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