Power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy complementing method

Abstract

The invention relates to a power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy complementing method, which is characterized in that an all-in-one controller is additionally arranged on a connecting circuit of a power battery, a power battery BMS (Battery Management System), a lithium battery and a lithium battery BMS, and the all-in-one controller is provided with a backup power supply and a DC / DC (Direct Current / Direct Current) converter for charging the lithium battery; low-voltage electricity is supplied to the power battery safety monitoring system through the lithium battery, power is supplied to a non-power battery through the DC / DC converter, and therefore the problems that due to the fact that the DC / DC converter is small in power and often needs to operate excessively, the fault rate is high, and monitoring cannot be achieved are solved; meanwhile, on the whole connecting circuit, the backup power supply of the all-in-one controller and the DC / DC converter used for charging the lithium battery are combined, low-power-consumption, high-stability and safe timing awakening power supply is achieved, energy supplementation is conducted on the lithium battery, and the whole circuit structure and the control method are simple and compact and high in safety and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle batteries, and more specifically to an all-in-one low-voltage power supply and lithium battery energy replenishment method for power battery safety monitoring. Background Art

[0002] The research on power battery safety monitoring and low-voltage lithium battery energy replenishment control technology is one of the key areas in electric vehicles and renewable energy systems. It is an important technology that is essential to improving the safety, efficiency and reliability of battery systems.

[0003] In terms of power battery safety monitoring, the existing power battery safety monitoring is usually a 24-hour monitoring system, which uses a specially customized 300W DC / DC converter to draw power from the power battery and provide low-voltage power to the battery monitoring system. This low-voltage power supply method requires additional customized equipment, which increases the cost of the entire vehicle. At the same time, a special control strategy is required to follow up the communication with the device. The customized 300W DC / DC converter has a small power and often needs to operate in excess, resulting in a high failure rate and inability to monitor. At the same time, the failure of the equipment also causes the vehicle to be unable to charge, causing complaints from users.

[0004] In the case of low-voltage lithium batteries, commercial vehicles on the market mainly use lead-acid batteries as starting batteries, but due to environmental protection and short life issues, they need to be replaced many times during the vehicle's service life. The development of lithium-ion starting battery replenishment can effectively solve such problems. At present, the domestic intelligent charging related to lithium batteries is not mature. In the industry, the lithium battery charging strategy is mainly to recharge the lithium battery through the power battery, and the starting battery is recharged with a preset charging time or a preset starting battery target charging amount as the charging target. This charging strategy will cause the starting battery to need to be frequently recharged when the vehicle components are aging, affecting the power supply performance of the electric vehicle; in addition, it is necessary to additionally design the transformer charging and corresponding control circuit to electrically connect the power battery and the lithium battery, and the normal circuit structure is complicated and cumbersome.

[0005] To this end, the applicant provides an all-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring, aiming to improve the safety, efficiency and reliability of the battery system. Based on the all-in-one integrated control technology, it focuses on the safety monitoring of the power battery after the vehicle is powered off and maintains the service life of the low-voltage lithium battery, ensures the safety monitoring of the power battery after the vehicle is powered off, fills the gap in domestic lithium battery energy replenishment, and improves the safety and reliability of the product. Summary of the invention

[0006] The object of the present invention is to provide an all-in-one low-voltage power supply and lithium battery energy replenishment method for power battery safety monitoring to solve the above-mentioned problems.

[0007] The present invention adopts the following technical solution: A power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method, an all-in-one controller is added to the connection circuit of the power battery, the power battery BMS, the lithium battery and the lithium battery BMS, and the all-in-one controller is provided with a backup power supply and a DC / DC converter for charging the lithium battery, which comprises the following steps: Step 1: When the vehicle is powered on, the safety monitoring system and all-in-one controller of the power battery BMS are powered by the low voltage of the lithium battery.

[0008] Step 2: After the vehicle is powered off, the backup power supply of the all-in-one controller wakes up the all-in-one controller and the power battery BMS at the set time to complete self-test; if the power battery BMS self-test is abnormal, the fault is reported to the vehicle T-box; if the power battery BMS self-test is normal, the all-in-one controller wakes up the lithium battery BMS to complete self-test; if the lithium battery BMS self-test is normal, the backup power supply stops the low-voltage power supply, and the lithium battery provides low-voltage power to the all-in-one controller and the power battery BMS, so that the power battery BMS can operate the power battery safety monitoring system; if the lithium battery BMS detects the lithium battery SOC low-voltage setting value during self-test, the lithium battery recharge strategy is entered, and the power battery recharges the lithium battery through the DC / DC converter of the all-in-one controller.

[0009] Step three, after the vehicle is powered off, the lithium battery BMS low power mode always monitors the SOC status of the lithium battery. When the SOC status of the lithium battery is lower than the set value, the backup power supply of the all-in-one controller is awakened through the CAN line, and the backup power supply wakes up the all-in-one controller and the power battery BMS to complete self-test. If the power battery BMS self-test is normal, the all-in-one controller wakes up the lithium battery BMS to complete self-test. If there is no abnormality in the lithium battery BMS self-test, the lithium battery recharge strategy is entered, and the power battery recharges the lithium battery through the DC / DC converter of the all-in-one controller.

[0010] Furthermore, the all-in-one controller includes an all-in-one PDU control board, a DC / DC converter, a backup power supply and a relay switch K1. The power battery is connected to the high voltage of the DC / DC converter through the relay switch K1. The lithium battery is provided with an electronic switch K2 for controlling the input and output of the lithium battery.

[0011] Furthermore, the lithium battery charging strategy of step 2 and step 3 includes the following steps: S1, the lithium battery BMS performs a self-test, and the self-test is normal but the lithium battery SOC is lower than the set value.

[0012] S2, the relay switch K1 of the all-in-one PDU control board is closed, and the power battery supplies high voltage power to the DC / DC converter.

[0013] S3, the all-in-one controller interacts with the lithium battery BMS through the CAN line, and collects the output voltage of the DC / DC converter and the current total voltage of the lithium battery through the voltage sampling circuits of the two. When the deviation of the two voltages is less than the set value, the lithium battery BMS closes the electronic switch K2 and enters step S4; if the deviation of the two voltages is greater than or equal to the set value, the fault is reported to the vehicle T-box.

[0014] S4, the DC / DC converter starts working, and then the output current of the DC / DC converter and the input current of the lithium battery are collected through the current sampling circuits of the two. When the deviation of the two currents is less than the set value, the DC / DC converter keeps working, continuously charging the lithium battery, and enters step S5; if the deviation of the two currents is greater than or equal to the set value, the abnormal conversion efficiency fault is reported to the vehicle T-box, the relay switch K1 and / or the electronic switch K2 are disconnected, the DC / DC converter stops working, and charging stops.

[0015] S5. During the charging process, the all-in-one controller interacts with the power battery BMS through the CAN line to constantly detect the conversion efficiency of the DC / DC converter's output power and the power battery's input power. If the conversion efficiency is lower than the set value N times within the set time period T, charging will be stopped again, and the abnormal conversion efficiency fault will be reported to the vehicle T-box; otherwise, charging will continue until the lithium battery is charged to the set SOC value, completing the recharging of the lithium battery. In this step, the setting that the conversion efficiency is lower than the set value N times within the set time period T can effectively avoid false alarms caused by voltage circuit fluctuations and improve the operating stability of the charging system. In addition, the monitoring of the conversion efficiency during the charging process can not only ensure the charging safety of the lithium battery, but also monitor the quality of the DC / DC converter of the all-in-one controller.

[0016] Preferably, in step S5, charging is performed according to the required voltage and current of the lithium battery BMS and a curve combined with maximum power point tracking.

[0017] Furthermore, an emergency switch is provided on the operating console of the cab, and the emergency switch is electrically connected to the backup power supply of the all-in-one controller for waking up the backup power supply operation.

[0018] Furthermore, it also includes step 4. When the whole vehicle is powered on again, if it is found that the lithium battery is faulty or out of power, the driver can manually press the emergency switch to wake up the backup power supply of the all-in-one control, and the backup power supply then provides low-voltage power to the all-in-one controller and the power battery BMS. The power battery BMS performs a self-check. If there is no abnormality in the self-check, the all-in-one controller wakes up the lithium battery BMS through the CAN line and requires the electronic switch K2 to be disconnected. Then the all-in-one controller controls the relay K1 to close and provide high voltage power to the DC / DC converter, and the all-in-one controller sends a command to let the DC / DC converter output low-voltage power to the electrical equipment of the whole vehicle, ensuring that the whole vehicle can be started and driven to the repair shop for maintenance.

[0019] Furthermore, the backup power supply is a backup DC / DC converter, which is connected to the high voltage of the power battery to obtain power, and is connected to the low voltage of the all-in-one controller and the power battery BMS to supply power.

[0020] From the above description of the structure of the present invention, it can be seen that compared with the prior art, the present invention has the following advantages: 1. The low-voltage electricity of the safety monitoring system of the power battery BMS of the present invention is provided by a lithium battery, rather than the power battery itself through a DC / DC converter, thereby avoiding the problem that the DC / DC converter often needs to operate in excess due to its low power, resulting in a high failure rate and inability to monitor; at the same time, in the entire connection circuit, the backup power supply of the all-in-one controller and the DC / DC converter used to charge the lithium battery are combined to achieve low power consumption, high stability and safe timed wake-up, as well as energy replenishment for the lithium battery. The entire circuit structure and control method are simple and compact, with high safety and reliability.

[0021] 2. In the lithium battery energy replenishment strategy of the present invention, before charging, the voltage difference between the DC / DC converter and the lithium battery is checked to improve the safety of charging. During the charging process, the current difference between the DC / DC converter and the lithium battery is checked, and the conversion power of the DC / DC converter and the power battery is checked, thereby reducing energy loss and further improving the safety and reliability of charging. At the same time, the quality of the DC / DC converter can be monitored through the conversion efficiency.

[0022] 3. The present invention is also provided with an emergency switch, which can wake up the backup power supply when the lithium battery is out of power or fails. The backup power supply wakes up the all-in-one controller and the power battery BMS. The all-in-one controller message requires disconnecting the electronic switch of the lithium battery, and the DC / DC converter of the all-in-one controller takes power from the power battery to supply the low-voltage electrical equipment of the whole vehicle, ensuring that the whole vehicle can be started in an emergency and driven to the repair shop for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a circuit diagram of the all-in-one low-voltage power supply and lithium battery energy replenishment of the present invention.

[0024] Figure 2 This is a low-voltage power supply block diagram of the present invention under vehicle power-on and power-off conditions.

[0025] Figure 3-1 It is the upper part of the flow chart of the lithium battery energy replenishment strategy of the present invention.

[0026] Figure 3-2 This is the lower part of the flow chart of the lithium battery energy replenishment strategy of the present invention.

[0027] Among them, the numbers in the figure are: power battery 11, power battery BMS 12, lithium battery 21, lithium battery BMS 22, all-in-one controller 30, all-in-one PDU control board 31, DC / DC converter 32, backup power supply 33, emergency switch 40. DETAILED DESCRIPTION

[0028] The specific implementation of the embodiment of the present invention is described below with reference to the accompanying drawings.

[0029] Reference Figure 1 A power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method, the circuit structure of which includes a power battery 11, a power battery BMS 12, a lithium battery 21, a lithium battery BMS 22, an all-in-one controller 30 and an emergency switch 40. The all-in-one controller 30 includes an all-in-one PDU control board 31, a DC / DC converter 32, a backup power supply 33 and a relay switch K1.

[0030] Reference Figure 1 The lithium battery 21 is provided with an electronic switch K2 for controlling the input and output of the lithium battery 21. The lithium battery 21 is respectively connected to the power battery BMS12 and the all-in-one controller 30 at a low voltage for power supply.

[0031] The power battery 11 is electrically connected to the DC / DC converter 32 at high voltage via the relay switch K1 for power supply, and the DC / DC converter 32 is electrically connected to the lithium battery 21 at low voltage for charging via the electronic switch K2.

[0032] The backup power supply 33 is respectively connected to the all-in-one controller 30 and the power battery BMS12 at a low voltage for supplying power. In this embodiment, the backup voltage is preferably a backup DC / DC converter. The backup DC / DC converter is connected to the high voltage of the power battery 11 for supplying power, and is connected to the low voltage of the all-in-one controller 30 and the power battery BMS12 for supplying power.

[0033] The all-in-one PDU control board 31 is connected to the relay switch K1 through a control line to control the opening and closing of the relay switch K1. The lithium battery BMS22 is connected to the electronic switch K2 through a control line to control the opening and closing of the electronic switch K2. The power battery BMS12, the all-in-one controller 30 and the lithium battery BMS22 are connected through a CAN line communication.

[0034] The emergency switch 40 is arranged on the operating console of the cab, and is electrically connected to the backup power supply 33 of the all-in-one controller 30 through a hard-wired control line, and is used to wake up the backup power supply 33. In addition to charging the lithium battery 21, the DC / DC converter 32 is also electrically connected to the low-voltage electrical equipment of the vehicle, and can supply power to it.

[0035] Reference Figure 1 to Figure 3-2 The present invention provides a method for safely monitoring a power battery 11 and replenishing energy for a lithium battery 21 with an all-in-one low-voltage power supply. The method is based on the above-mentioned connection circuit. An all-in-one controller 30 is added to the connection circuit of the power battery 11, the power battery BMS 12, the lithium battery 21 and the lithium battery BMS 22. The all-in-one controller 30 is provided with a backup power supply 33 and a DC / DC converter 32 for charging the lithium battery 21. The method for safely monitoring a power battery 11 and replenishing energy for a lithium battery 21 includes the following steps: Step 1, refer to Figure 2 When the vehicle is powered on, the safety monitoring system of the power battery BMS12 and the all-in-one controller 30 are powered by the low voltage of the lithium battery 21, so that the power battery BMS12 can operate the battery safety monitoring system normally and monitor the power battery 11 safely.

[0036] Step 2, refer to Figure 2 and Figure 3-1 , Figure 3-2 When the whole vehicle is powered off, the backup power supply 33 of the all-in-one controller 30 wakes up the all-in-one controller 30 and the power battery BMS12 at the set time to complete self-test; if the self-test of the power battery BMS12 is abnormal, the fault is reported to the whole vehicle T-box, and if the self-test of the power battery BMS12 is normal, the all-in-one controller 30 wakes up the lithium battery BMS22 to complete self-test; if the self-test of the lithium battery BMS22 is normal, the backup power supply 33 stops the low-voltage power supply, and the lithium battery 21 provides low-voltage power to the all-in-one controller 30 and the power battery BMS12, so that the power battery BMS12 can run the power battery 11 safety monitoring system operation; if the lithium battery BMS22 detects the low-voltage setting value of the lithium battery 21 SOC during self-test, the lithium battery 21 power replenishment strategy is entered, and the power battery 11 replenishes the lithium battery 21 through the DC / DC converter 32 of the all-in-one controller 30.

[0037] Step 3, refer to Figure 3-1 and Figure 3-2After the vehicle is powered off, the lithium battery BMS22 monitors the SOC status of the lithium battery 21 in low power consumption mode at all times. When the SOC status of the lithium battery 21 is lower than the set value, the backup power supply 33 of the all-in-one controller 30 is awakened through the CAN line, and the backup power supply 33 wakes up the all-in-one controller 30 and the power battery BMS12 to complete self-test. If the self-test of the power battery BMS12 is normal, the all-in-one controller 30 wakes up the lithium battery BMS22 to complete self-test. If there is no abnormality in the self-test of the lithium battery BMS22, the lithium battery 21 recharge strategy is entered, and the power battery 11 recharges the lithium battery 21 through the DC / DC converter 32 of the all-in-one controller 30.

[0038] Step 4: When the vehicle is powered on again, if the lithium battery 21 is found to be faulty or out of power, the driver can manually press the emergency switch 40 to wake up the backup power supply 33 of the all-in-one control. The backup power supply 33 then provides low-voltage power to the all-in-one controller 30 and the power battery BMS12. The power battery BMS12 performs self-inspection of SOC status, temperature, single cell voltage, total voltage and other data. If the self-inspection is abnormal, the fault is reported to the vehicle T-box; if there is no abnormality in the self-inspection, the all-in-one controller 30 wakes up the lithium battery BMS22 through the CAN line and requires the electronic switch K2 to be disconnected. Then the all-in-one controller 30 controls the relay K1 to close and provide high voltage power to the DC / DC converter 32, and the all-in-one controller 30 sends a command to let the DC / DC converter 32 output low-voltage power to the electrical equipment of the vehicle to ensure that the vehicle can be started and driven to the repair shop for maintenance.

[0039] Reference Figure 3-1 and Figure 3-2 In step 2 and step 3 of the present invention, the lithium battery 21 power replenishment strategy includes the following steps: S1. The lithium battery BMS22 performs a self-test. The self-test is normal but the lithium battery 21 SOC is lower than the set value.

[0040] S2. The relay switch K1 of the all-in-one PDU control board 31 is closed, and the power battery 11 supplies high voltage power to the DC / DC converter 32 .

[0041] S3, the all-in-one controller 30 interacts with the lithium battery BMS22 through the CAN line, and the output voltage of the DC / DC converter 32 and the current total voltage of the lithium battery 21 are respectively collected through the voltage sampling circuits of the two. When the deviation of the two voltages is less than the set value, the lithium battery BMS22 closes the electronic switch K2 and enters step S4; if the deviation of the two voltages is greater than or equal to the set value, the fault is reported to the vehicle T-box.

[0042] S4, the DC / DC converter 32 starts working, and then the output current of the DC / DC converter 32 and the input current of the lithium battery 21 are respectively collected through the current sampling circuits of the two. When the deviation of the two currents is less than the set value, the DC / DC converter 32 keeps working, continuously charges the lithium battery 21, and enters step S5; if the deviation of the two currents is greater than or equal to the set value, the abnormal conversion efficiency fault is reported to the vehicle T-box, the relay switch K1 and / or the electronic switch K2 are disconnected, the DC / DC converter 32 is stopped, and the charging is stopped.

[0043] S5. Charging is performed according to the required voltage and current of the lithium battery BMS22 and the curve combined with the maximum power point tracking. During the charging process, the all-in-one controller 30 interacts with the power battery BMS12 through the CAN line to constantly detect the conversion efficiency of the output power of the DC / DC converter 32 and the input power of the power battery 11. If the conversion efficiency is lower than the set value N times within the set time period T, charging is stopped again, and the abnormal conversion efficiency fault is reported to the vehicle T-box; otherwise, charging continues until the set SOC value of the lithium battery 21 is charged to complete the charging of the lithium battery 21. In this step, the setting that the conversion efficiency is lower than the set value N times within the set time period T can effectively avoid the false alarm caused by voltage circuit fluctuations and improve the operating stability of the charging system. In addition, the monitoring of the conversion efficiency during the charging process can not only ensure the charging safety of the lithium battery 21, but also monitor the quality of the DC / DC converter 32 of the all-in-one controller 30.

[0044] Below, refer to Figure 1 As shown in FIG3 , the present invention takes step 2 as an example and provides working condition 1 as a further analysis: After the vehicle detects the external power-off state, the backup power supply 33 of the all-in-one controller 30 will regularly wake up the all-in-one controller 30 and the power battery BMS12 1 hour, 4 hours, 8 hours after power-off, and every 8 hours thereafter. The power battery BMS12 first self-checks the SOC status, temperature, single cell voltage, total voltage and other data of the power battery 11, and reports the information to the vehicle T-box as a record. If the power battery BMS12 self-checks abnormally, the fault will be reported to the vehicle T-box at the same time. If the power battery BMS12 self-checks normally, the all-in-one controller 30 wakes up the lithium battery BMS22 through the CAN line message communication, and the lithium battery BMS22 self-checks the SOC status, temperature, single cell voltage, total voltage and other data of the lithium battery 21. If the lithium battery BMS22 self-checks normally, the backup power supply 33 stops the low-voltage power supply and enters the sleep state. The lithium battery 21 provides a low-voltage power supply for the all-in-one controller 30 and the power battery BMS12 , so that the power battery BMS12 can operate the power battery 11 safety monitoring system to monitor the power battery 11 .

[0045] If the lithium battery BMS 22 self-checks and finds that the SOC of the lithium battery 21 is lower than the set value, but other parameters are normal, the power replenishment strategy is entered. The specific steps and processes of the power replenishment strategy are shown in the above-mentioned lithium battery 21 power replenishment strategy S1 to S5. No further details are given here.

[0046] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method, characterized in that: An all-in-one controller is added to the connection circuit of the power battery, the power battery BMS, the lithium battery and the lithium battery BMS. The all-in-one controller is provided with a backup power supply and a DC / DC converter for charging the lithium battery, which includes the following steps: Step 1: When the vehicle is powered on, the safety monitoring system and all-in-one controller of the power battery BMS are powered by the low voltage of the lithium battery; Step 2: After the vehicle is powered off, the backup power supply of the all-in-one controller wakes up the all-in-one controller and the power battery BMS at the set time to complete self-test; if the power battery BMS self-test is abnormal, the fault is reported to the vehicle T-box; if the power battery BMS self-test is normal, the all-in-one controller wakes up the lithium battery BMS to complete self-test; if the lithium battery BMS self-test is normal, the backup power supply stops the low-voltage power supply, and the lithium battery provides low-voltage power to the all-in-one controller and the power battery BMS, so that the power battery BMS can operate the power battery safety monitoring system; if the lithium battery BMS detects the low-voltage setting value of the lithium battery SOC during self-test, the lithium battery recharge strategy is entered, and the power battery recharges the lithium battery through the DC / DC converter of the all-in-one controller; In the step three, after the whole vehicle is powered off, the lithium battery BMS low power consumption mode constantly monitors the SOC status of the lithium battery. When the SOC status of the lithium battery is lower than the set value, the backup power supply of the all-in-one controller is awakened through the CAN line, and the backup power supply wakes up the all-in-one controller and the power battery BMS to complete self-test. If the power battery BMS self-test is normal, the all-in-one controller wakes up the lithium battery BMS to complete self-test. If there is no abnormality in the lithium battery BMS self-test, the lithium battery recharge strategy is entered, and the power battery recharges the lithium battery through the DC / DC converter of the all-in-one controller.

2. According to claim 1, a power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method is characterized by: The all-in-one controller includes an all-in-one PDU control board, a DC / DC converter, a backup power supply and a relay switch K1. The power battery is connected to the high voltage of the DC / DC converter through the relay switch K1. The lithium battery is provided with an electronic switch K2 for controlling the input and output of the lithium battery.

3. According to claim 2, a power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method is characterized in that: The lithium battery charging strategy of step 2 and step 3 includes the following steps: S1, the lithium battery BMS performs self-test, the self-test is normal but the lithium battery SOC is lower than the set value; S2, the relay switch K1 of the all-in-one PDU control board is closed, and the power battery supplies high voltage power to the DC / DC converter; S3, the all-in-one controller interacts with the lithium battery BMS through the CAN line, and the output voltage of the DC / DC converter and the current total voltage of the lithium battery are respectively collected through the voltage sampling circuits of the two. When the deviation of the two voltages is less than the set value, the lithium battery BMS closes the electronic switch K2 and enters step S4; if the deviation of the two voltages is greater than or equal to the set value, the fault is reported to the vehicle T-box; S4, the DC / DC converter starts working, and then the output current of the DC / DC converter and the input current of the lithium battery are respectively collected through the current sampling circuits of the two. When the deviation of the two currents is less than the set value, the DC / DC converter keeps working, continuously charging the lithium battery, and enters step S5; if the deviation of the two currents is greater than or equal to the set value, the abnormal conversion efficiency fault is reported to the vehicle T-box, the relay switch K1 and / or the electronic switch K2 are disconnected, the DC / DC converter stops working, and charging stops; S5. During the charging process, the all-in-one controller interacts with the power battery BMS through the CAN line to constantly detect the conversion efficiency between the output power of the DC / DC converter and the input power of the power battery. If the conversion efficiency is lower than the set value N times within the set time period, charging will be stopped again and the abnormal conversion efficiency fault will be reported to the vehicle T-box; otherwise, charging will continue until the set SOC value of the lithium battery is reached to complete the charging of the lithium battery.

4. According to claim 3, a power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method is characterized in that: In step S5, charging is performed according to the voltage and current required by the lithium battery BMS and in combination with the maximum power point tracking curve.

5. According to claim 1, a power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method is characterized by: An emergency switch is provided on the operating console of the cab, and the emergency switch is electrically connected to the backup power supply of the all-in-one controller for waking up the backup power supply operation.

6. The method of claim 5 for all-in-one low-voltage power supply and lithium battery energy replenishment for power battery safety monitoring, characterized in that: It also includes step 4. When the whole vehicle is powered on again, if the lithium battery is found to be faulty or out of power, the driver can manually press the emergency switch to wake up the backup power supply of the all-in-one control. The backup power supply then provides low-voltage power to the all-in-one controller and the power battery BMS. The power battery BMS performs a self-test. If there is no abnormality in the self-test, the all-in-one controller wakes up the lithium battery BMS through the CAN line and requires the electronic switch K2 to be disconnected. Then the all-in-one controller controls the relay K1 to close and provide high voltage power to the DC / DC converter. The all-in-one controller sends a command to let the DC / DC converter output low-voltage power to the electrical equipment of the whole vehicle to ensure that the whole vehicle can be started and driven to the repair shop for maintenance.

7. A power battery safety monitoring all-in-one low-voltage power supply and lithium battery energy replenishment method according to claim 1 or 2, characterized in that: The backup power supply is a backup DC / DC converter, which is connected to the high voltage of the power battery to draw power, and is connected to the low voltage of the all-in-one controller and the power battery BMS to supply power.

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