All-in-one low-voltage power supply and energy compensation circuit for power battery safety monitoring

Abstract

The utility model relates to an all-in-one low voltage power supply and energy supplement circuit for power battery safety monitoring, comprising a power battery, a power battery BMS, a lithium battery, a lithium battery BMS and an all-in-one controller, the all-in-one controller comprises an all-in-one PDU control board, a DC / DC converter, a backup power supply and a relay switch K1, a backup power supply wakes up an all-in-one controller and a power battery BMS for self-inspection, then a lithium battery supplies power to a safety monitoring system of the power battery BMS, a non-power battery supplies power through a DC / DC converter, and the problems that the DC / DC converter is high in failure rate and cannot be monitored due to small power and excessive operation are solved; besides, by means of the backup power supply and the DC / DC converter used for charging the lithium battery, low-power-consumption and high-stability timing wake-up power supply is achieved, energy supplementation is conducted on the lithium battery, the circuit structure is simple and compact, and safety and reliability are high.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicle batteries, and more specifically to an all-in-one low-voltage power supply and energy replenishment circuit 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] Existing power battery safety monitoring systems typically utilize a 24 / 7 monitoring system, utilizing a custom 300W DC / DC converter to draw power from the power battery and provide a low-voltage power supply to the battery monitoring system. This low-voltage power supply requires additional custom equipment, increasing vehicle costs and requiring specialized control strategies to monitor and communicate with the equipment. Due to its low power, the custom 300W DC / DC converter often operates beyond its capacity, resulting in a high failure rate and inability to monitor. Furthermore, equipment failures can prevent charging, leading to user complaints.

[0004] In the case of low-voltage lithium batteries, commercial vehicles on the market mainly use lead-acid batteries as starting batteries. However, due to environmental protection and short life issues, they need to be replaced many times during the life cycle of the vehicle. The development of lithium-ion starting battery recharge can effectively solve such problems. At present, domestic intelligent recharge related to lithium batteries is not mature. In the industry, the lithium battery recharge strategy mainly uses the power battery to recharge the lithium battery, and recharges the starting battery with a preset recharge time or a preset starting battery target recharge amount as the recharge target. This recharge strategy will cause the starting battery to need frequent recharge when the vehicle components are aging, affecting the power supply performance of the electric vehicle. In addition, it is necessary to additionally design a transformer charging and corresponding control circuit to electrically connect the power battery and the lithium battery. 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, ensuring the safety monitoring of the power battery after the vehicle is powered off, and filling the domestic lithium battery energy replenishment gap, thereby improving the safety and reliability of the product. Utility Model Content

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

[0007] The utility model adopts the following technical solutions:

[0008] A multi-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring includes a power battery, a power battery BMS, a lithium battery and a lithium battery BMS, and also includes an multi-in-one controller. The multi-in-one controller includes an multi-in-one PDU control board, a DC / DC converter, a backup power supply and a relay switch K1. The lithium battery is provided with an electronic switch K2 for controlling the input and output of the lithium battery. The lithium battery is respectively connected to the power battery BMS and the multi-in-one controller at low voltage for power supply; the power battery is connected to the DC / DC converter at high voltage for power supply through the relay switch K1, the DC / DC converter is charged by the electronic switch K2, the backup power supply is respectively connected to the multi-in-one controller and the power battery BMS at low voltage for power supply, the multi-in-one PDU control board is connected to the relay switch K1 via a control line, the lithium battery BMS is connected to the electronic switch K2 via a control line, and the power battery BMS, the multi-in-one controller and the lithium battery BMS are connected via a CAN line for communication.

[0009] 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.

[0010] Furthermore, it also includes an emergency switch, which is electrically connected to the backup power supply, and the DC / DC converter is electrically connected to the low-voltage electrical equipment of the entire vehicle for power supply.

[0011] From the above description of the structure of the utility model, it can be seen that compared with the prior art, the utility model has the following advantages:

[0012] 1. The circuit structure of the utility model includes a power battery, a power battery BMS, a lithium battery, a lithium battery BMS and an all-in-one controller. The power battery BMS and the all-in-one controller are awakened by a backup power supply for self-test, and then the all-in-one controller awakens the lithium battery BMS for self-test. At the same time, the lithium battery is used to power the safety monitoring system of the power battery BMS, rather than the power battery itself being powered by a DC / DC converter. This avoids 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. In addition, the backup power supply of the all-in-one controller and the DC / DC converter used to charge the lithium battery can also achieve low power consumption, high stability and safe timed wake-up power supply, as well as energy replenishment for the lithium battery. The entire circuit structure is simple and compact, with high safety and reliability.

[0013] 2. The utility model is also equipped 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 sends a message requesting to disconnect the electronic switch of the lithium battery, and the DC / DC converter of the all-in-one controller draws power from the power battery to supply the low-voltage electrical equipment of the entire vehicle, ensuring that the entire vehicle can be started in an emergency and driven to a repair shop for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit diagram of the utility model's all-in-one low-voltage power supply and lithium battery energy replenishment circuit.

[0015] Figure 2 This is a low-voltage power supply block diagram of the utility model under the power-on and power-off conditions of the entire vehicle.

[0016] Figure 3-1 This is the upper part of the flow chart of the battery recharging strategy of the present invention.

[0017] Figure 3-2 This is the lower part of the flow chart of the lithium battery energy replenishment strategy of the present invention.

[0018] 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

[0019] The specific implementation of the embodiment of the present utility model is described below with reference to the accompanying drawings.

[0020] Reference Figure 1 An all-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring 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.

[0021] 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.

[0022] The power battery 11 is connected to the DC / DC converter 32 via a relay switch K1 for high voltage power supply, and the DC / DC converter 32 is connected to the lithium battery 21 via an electronic switch K2 for low voltage power supply.

[0023] The backup power supply 33 is respectively connected to the all-in-one controller 30 and the power battery BMS12 at low voltage for power supply. 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 power supply, and is connected to the low voltage of the all-in-one controller 30 and the power battery BMS12 for power supply.

[0024] The all-in-one PDU control board 31 is connected to the relay switch K1 via a control line to control its opening and closing. The lithium battery BMS 22 is connected to the electronic switch K2 via a control line to control its opening and closing. The power battery BMS 12, all-in-one controller 30, and lithium battery BMS 22 are connected via a CAN bus.

[0025] An emergency switch 40 is located on the cab's operating console and is electrically connected to the backup power supply 33 of the all-in-one controller 30 via a hard-wired control line, enabling the backup power supply 33 to be activated. In addition to charging the lithium battery 21, the DC / DC converter 32 also provides low-voltage electrical connection to the vehicle's low-voltage electrical equipment, providing power to these devices.

[0026] Reference Figure 1 to Figure 3-1 and Figure 3-2 The utility model discloses an all-in-one low-voltage power supply and lithium battery energy replenishment method for safety monitoring of the power battery 11. 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 includes the following steps:

[0027] 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 safety of the power battery 11.

[0028] Step 2, refer to Figure 2 and Figure 3-1 and Figure 3-2When the 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 power battery BMS12 self-test is abnormal, the fault is reported to the vehicle T-box. If the power battery BMS12 self-test is normal, the all-in-one controller 30 wakes up the lithium battery BMS22 to complete self-test; if the lithium battery BMS22 self-test 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 lithium battery 21 SOC low-voltage set value during self-test, 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.

[0029] Step 3, refer to Figure 3-1 and Figure 3-2 After the vehicle is powered off, the lithium battery BMS22 monitors the SOC status of the lithium battery 21 in low-power 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-testing. 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-testing. If the self-test of the lithium battery BMS22 is normal, 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.

[0030] 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-tests on the SOC status, temperature, single cell voltage, total voltage and other data. If the self-test is abnormal, the fault is reported to the vehicle T-box; if there is no abnormality in the self-test, 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.

[0031] Reference Figure 3-1 and Figure 3-2 In step 2 and step 3 of the present invention, the lithium battery 21 charging strategy includes the following steps:

[0032] S1. The lithium battery BMS22 performs a self-test. The self-test is normal, but the SOC of the lithium battery 21 is lower than the set value.

[0033] 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 .

[0034] S3, the all-in-one controller 30 interacts with the lithium battery BMS22 through the CAN line. Through the voltage sampling circuits of the two, the output voltage of the DC / DC converter 32 and the current total voltage of the lithium battery 21 are respectively collected. When the deviation between 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 between the two voltages is greater than or equal to the set value, the fault is reported to the vehicle T-box.

[0035] 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 charging 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 stops working, and charging stops.

[0036] S5. Charging is carried out 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, and constantly detects 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, and the recharging of the lithium battery 21 is completed. 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 operational 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.

[0037] Below, refer to Figure 1 to Figure 3-1 and Figure 3-2 , this utility model takes step 2 as an example and provides working condition 1 as further analysis:

[0038] After the vehicle passes the external power-off detection, the backup power supply 33 of the all-in-one controller 30 will periodically 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 performs a self-test of 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-test is abnormal, the fault will be reported to the vehicle T-box at the same time. If the power battery BMS12 self-test is normal, the all-in-one controller 30 will wake up the lithium battery BMS22 through CAN line message communication. The lithium battery BMS22 will self-test the SOC status, temperature, single cell voltage, total voltage, and other data of the lithium battery 21. If the lithium battery BMS22 self-tests normally, the backup power supply 33 will stop the low-voltage power supply and enter the sleep state. The lithium battery 21 provides a low-voltage power supply to the all-in-one controller 30 and the power battery BMS 12 , so that the power battery BMS 12 can run the power battery 11 safety monitoring system to monitor the power battery 11 .

[0039] 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 activated. 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.

[0040] The above is only a specific implementation method of the present invention, but the design concept of the present invention is not limited to this. 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. An all-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring, comprising a power battery, a power battery BMS, a lithium battery, and a lithium battery BMS, characterized in that: It also includes an all-in-one controller, which includes an all-in-one PDU control board, a DC / DC converter, a backup power supply and a relay switch K1. The lithium battery is provided with an electronic switch K2 for controlling the input and output of the lithium battery. The lithium battery is respectively connected to the power battery BMS and the all-in-one controller at low voltage for power supply; the power battery is connected to the DC / DC converter at high voltage for power supply through the relay switch K1, and the DC / DC converter is charged by the electronic switch K2 at low voltage. The backup power supply is respectively connected to the all-in-one controller and the power battery BMS at low voltage for power supply, the all-in-one PDU control board is connected to the relay switch K1 through a control line, and the lithium battery BMS is connected to the electronic switch K2 through a control line. The power battery BMS, the all-in-one controller and the lithium battery BMS are connected through a CAN line for communication.

2. The all-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring according to claim 1, 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.

3. The all-in-one low-voltage power supply and energy replenishment circuit for power battery safety monitoring according to claim 1, characterized in that: It also includes an emergency switch, which is electrically connected to the backup power supply, and the DC / DC converter is electrically connected to the low-voltage electrical equipment of the entire vehicle for power supply.

Images