Charging protection circuit, new energy automobile, charging protection method, equipment and medium

Abstract

The invention relates to a charging protection circuit, a new energy automobile, a charging protection method, equipment and a medium. The charging protection circuit comprises a bus protection circuit, a battery protection circuit and a battery management system, and the bus protection circuit is arranged on a communication bus of the new energy automobile and connected with the battery management system and a charging interface circuit of the new energy automobile. The battery protection circuit is respectively connected with the battery management system, the charging interface circuit and a power battery of the new energy automobile; the bus protection circuit is used for conducting communication connection between the charging interface circuit and the battery management system in response to a control instruction sent by the battery management system; and the battery protection circuit is used for adjusting the charging current input into the power battery by the charging interface circuit in response to a control instruction sent by the battery management system. According to the invention, the risk of charging system paralysis caused by surge impact can be reduced.

Description

Technical Field

[0001] This application relates to the field of charging technologies, and particularly to a charging protection circuit, a new energy vehicle, a charging protection method, device, and medium. Background Art

[0002] With the development of new energy technologies, new energy vehicles powered by batteries are becoming increasingly popular among users. Currently, when a new energy vehicle is charging, surge impacts may cause components such as power batteries, BMS (Battery Management System), VCU (Vehicle Control Unit), and instrument panels to burn out, resulting in the paralysis of the charging system and triggering charging faults. Summary of the Invention

[0003] Based on the above problems, this application provides a charging protection circuit, a new energy vehicle, a charging protection method, device, and medium, which can protect the internal devices and components of a new energy vehicle from multiple aspects, reduce the risk of charging system paralysis caused by surge impacts, and reduce charging faults.

[0004] In a first aspect, this application provides a charging protection circuit. The charging protection circuit includes a bus protection circuit, a battery protection circuit, and a battery management system. The bus protection circuit is disposed on the communication bus of the new energy vehicle and is respectively connected to the battery management system and the charging interface circuit of the new energy vehicle. The battery protection circuit is respectively connected to the battery management system, the charging interface circuit, and the power battery of the new energy vehicle. The bus protection circuit is configured to conduct the communication connection between the charging interface circuit and the battery management system in response to a control instruction sent by the battery management system. The battery protection circuit is configured to adjust the charging current input from the charging interface circuit to the power battery in response to a control instruction sent by the battery management system.

[0005] In the technical solution of the embodiments of this application, the bus protection circuit can reduce surge impacts under the control of the battery management system, thereby protecting the battery management system. The battery protection circuit can adjust the charging current under the control of the battery management system, thereby reducing surge impacts and protecting the power battery. The embodiments of this application protect the internal devices and components of the new energy vehicle from multiple aspects, reduce the risk of charging system paralysis caused by surge impacts, and reduce charging faults.

[0006] In some embodiments, the bus protection circuit includes a first isolation relay and a second isolation relay; the communication bus includes a high-level communication bus and a low-level communication bus; the first isolation relay is disposed on the high-level communication bus, and a first end of the first isolation relay is connected to the charging interface circuit, and a second end and a control end of the first isolation relay are both connected to the battery management system; the second isolation relay is disposed on the low-level communication bus, and a first end of the second isolation relay is connected to the charging interface circuit, and a second end and a control end of the second isolation relay are both connected to the battery management system; the first isolation relay is configured to close in response to a control instruction sent by the battery management system, so that the battery management system is communicatively connected to the charging interface circuit through the high-level communication bus; the second isolation relay is configured to close in response to a control instruction sent by the battery management system, so that the battery management system is communicatively connected to the charging interface circuit through the low-level communication bus. In the technical solution of the embodiment of the present application, the first isolation relay and the second isolation relay can be used to achieve isolation between the charging interface circuit and the battery management system, reduce the risk of surge impact being transmitted to the battery management system through the CAN communication bus and damaging the battery management system, and greatly improve the charging safety.

[0007] In some embodiments, the battery protection circuit includes a main negative circuit and at least two main positive circuits; the main negative circuit is respectively connected to the charging interface circuit and the negative electrode of the power battery, and each main positive circuit is respectively connected to the charging interface circuit, the positive electrode of the power battery and the battery management system; the main negative circuit is configured to conduct the connection between the charging interface circuit and the negative electrode of the power battery; each main positive circuit is configured to conduct the connection between the charging interface circuit and the positive electrode of the power battery in response to a control instruction sent by the battery management system; wherein, different main positive circuits conduct different magnitudes of corresponding charging currents. In the technical solution of the embodiment of the present application, by adjusting the charging current through at least two main positive circuits, the charging current can be increased in a gradient manner, which can not only reduce the risk of surge impact damaging the power battery, but also quickly increase the charging current, improve the charging speed and charging efficiency.

[0008] In some embodiments, the main positive circuit includes a resistor, a protection relay, and a switching tube; the first end of the resistor is connected to the charging interface circuit, the second end of the resistor is connected to the first end of the protection relay, the second end of the protection relay is connected to the positive electrode of the power battery, the control end of the protection relay is connected to the first end of the switching tube, and the second end and the control end of the switching tube are both connected to the battery management system; the switching tube is configured to conduct in response to a control instruction sent by the battery management system and transmit the control signal of the battery management system to the protection relay; the protection relay is configured to conduct the connection between the charging interface circuit and the positive electrode of the power battery when closed according to the control signal. In the technical solution of the embodiments of the present application, the battery management system realizes the on-off control of the main positive circuit by controlling the protection relay and the switching tube, so as to conduct multiple main positive circuits step by step and achieve a gradient increase in the charging current. This can not only smoothly increase the charging current and reduce the risk of surge impact damaging the power battery, but also improve the charging speed and charging efficiency.

[0009] In some embodiments, the resistance values of the resistors in different main positive circuits are different, and the protection relay corresponding to the resistor with the largest resistance value is a normally closed relay, and the protection relays corresponding to other resistors are normally open relays. In the technical solution of the embodiments of the present application, the protection relay corresponding to the resistor with the largest resistance value is a normally closed relay, so that when the charging device is connected to the charging interface circuit, small-current charging of the power battery can be realized without other controls, improving the charging speed.

[0010] In some embodiments, the charging protection circuit further includes a diode, the first end of the diode is connected to the communication bus between the charging interface circuit and the bus protection circuit, and the second end of the diode is grounded. In the technical solution of the embodiments of the present application, a highly sensitive diode is connected to prevent surges during charging, and a convenient disassembly and replacement structure is designed so that the diode can be conveniently replaced after being damaged by a surge, thereby improving the surge protection during charging and synchronously reducing the maintenance cost.

[0011] In a second aspect, the present application further provides a new energy vehicle, which includes a charging interface circuit, a power battery, and the charging protection circuit as described in any one of the first aspect.

[0012] In the technical solution of the embodiments of the present application, the charging protection circuit protects the internal devices and components of the new energy vehicle from multiple aspects, reduces the risk of the charging system being paralyzed due to surge impact, and reduces charging failures.

[0013] In some embodiments, the new energy vehicle further includes a vehicle controller and a communication bus, and the charging protection circuit includes a bus protection circuit provided on the communication bus; the bus protection circuit is configured to respond to a control instruction sent by the battery management system and conduct the communication connection between the charging interface circuit and the vehicle controller. In the technical solution of the embodiment of the present application, the bus protection circuit can also protect the vehicle controller, reduce the risk of surge impact damaging the vehicle controller, reduce charging faults, and improve charging safety.

[0014] In some embodiments, the charging interface circuit includes a fast charging interface, a power distribution unit, a slow charging interface, and an on-vehicle charger; the power distribution unit is respectively connected to the fast charging interface, the bus protection circuit, and the battery protection circuit of the charging protection circuit; the on-vehicle charger is respectively connected to the slow charging interface and the power distribution unit. In the technical solution of the embodiment of the present application, the power distribution is responsible for converting external alternating current into direct current required by the power battery to achieve charging of the power battery; the power distribution unit is responsible for connecting the power battery and the charging device to ensure the efficiency and safety of the charging process.

[0015] In a third aspect, the present application also provides a charging protection method, which is applied to the battery management system in the charging protection circuit. The charging protection circuit further includes a bus protection circuit and a battery protection circuit. The method includes: obtaining the charging current input from the charging interface circuit to the power battery; controlling the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current; and controlling the battery protection circuit to adjust the charging current.

[0016] In the technical solution of the embodiment of the present application, the battery management system can control the on-off of the bus protection circuit, thereby reducing surge impact and protecting the battery management system. The battery management system can also control the battery protection circuit to adjust the charging current, thereby reducing surge impact and protecting the power battery. The embodiment of the present application protects the internal devices and components of the new energy vehicle from multiple aspects, reduces the risk of the charging system paralysis caused by surge impact, and reduces charging faults.

[0017] In some embodiments, controlling the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current includes: determining a first fluctuation amount of the charging current within a first preset time period; and controlling the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system when the first fluctuation amount is within a preset fluctuation range. In the technical solution of the embodiment of the present application, the surge can be accurately detected through the fluctuation amount, thereby improving the control accuracy of the bus protection circuit and the safety of the battery management system.

[0018] In some embodiments, controlling the battery protection circuit to adjust the charging current includes: controlling the main positive circuit in the battery protection circuit to conduct one by one in ascending order of current to adjust the charging current. In the technical solution of the embodiments of the present application, the gradient charging scheme gradually increases the charging current to the standard charging current, and transitions from the pre-charge state to the standard charging state relatively smoothly, significantly reducing the impact loss of current mutation on the power battery, and can effectively extend the cycle life of the power battery.

[0019] In some embodiments, controlling the main positive circuit in the battery protection circuit to conduct includes: determining the second fluctuation amount of the charging current within the second preset duration; controlling the main positive circuit to conduct when the second fluctuation amount is within the preset fluctuation range. In the technical solution of the embodiments of the present application, the surge can be accurately detected through the fluctuation amount, thereby improving the control accuracy of the battery protection circuit and the safety of the power battery.

[0020] In some embodiments, the method further includes: controlling each main positive circuit to cut off the electrical connection between the charging interface circuit and the power battery when the second fluctuation amount exceeds the preset fluctuation range. In the technical solution of the embodiments of the present application, when it is detected that the charging current fluctuates greatly, the charging path is cut off in time, which can reduce the risk of surge impact damaging the power battery, thereby effectively protecting the power battery and improving the safety of the power battery and the whole vehicle.

[0021] Fourthly, the present application also provides an electronic device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method according to any one of the third aspects is implemented.

[0022] Fifthly, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method according to any one of the third aspects is implemented.

[0023] Sixthly, the present application also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the method according to any one of the third aspects is implemented. Description of the Drawings

[0024] By reading the detailed description of the following alternative embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the alternative embodiments and are not considered as limiting the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0025] Figure 1 is one of the structural schematic diagrams of the charging protection circuit according to an embodiment of the present application;

[0026] Figure 2 It is the second schematic structural diagram of the charging protection circuit according to an embodiment of the present application;

[0027] Figure 3 It is the third schematic structural diagram of the charging protection circuit according to an embodiment of the present application;

[0028] Figure 4 It is the fourth schematic structural diagram of the charging protection circuit according to an embodiment of the present application;

[0029] Figure 5 It is the fifth schematic structural diagram of the charging protection circuit according to an embodiment of the present application;

[0030] Figure 6 It is the first schematic structural diagram of a new energy vehicle according to an embodiment of the present application;

[0031] Figure 7 It is the second schematic structural diagram of a new energy vehicle according to an embodiment of the present application;

[0032] Figure 8 It is the schematic flow diagram of a charging protection method according to an embodiment of the present application;

[0033] Figure 9 It is the schematic flow diagram of the steps of a control bus protection circuit according to an embodiment of the present application;

[0034] Figure 10 It is the schematic diagram of a voltage - current curve according to an embodiment of the present application;

[0035] Figure 11 It is the schematic flow diagram of the steps for turning on the main positive circuit according to an embodiment of the present application;

[0036] Figure 12 It is the internal structural diagram of an electronic device according to an embodiment of the present application.

[0037] Explanation of reference numerals:

[0038] 10. Charging protection circuit; 11. Bus protection circuit; 12. Battery protection circuit;

[0039] 13. Battery management system; 21. Communication bus; 22. Charging interface circuit;

[0040] 23. Power battery; KT1. First isolation relay; KT2. Second isolation relay;

[0041] 121. Main negative circuit; 122. Main positive circuit; R, R0, R1, R2, Rn, Resistors;

[0042] K, K1, K2, Kn, Protection relays; K’, K1’, K2’, Kn’, Switch tubes;

[0043] D, D1, D2, diodes; 221, fast charging interface; 222, power distribution unit;

[0044] 223, slow charging interface; 224, on - vehicle charger. Specific embodiments

[0045] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above - mentioned drawings are intended to cover non - exclusive inclusion.

[0047] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary - secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise specifically defined.

[0048] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0049] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0050] In the description of the embodiments of this application, the term "a plurality of" refers to two or more (including two). Similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0051] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0052] With the development of new energy technology, new energy vehicles driven by batteries are becoming more and more popular among users. At present, when a new energy vehicle is charging, a surge impact may be transmitted to the power battery, resulting in the power battery being burned out. It may also be transmitted to the BMS, VCU or instrument through the CAN (Controller Area Network) communication bus. If the current of the surge impact exceeds the current allowed by the BMS and VCU, it will cause the BMS, VCU or instrument to be burned out. The burnout of the power battery, BMS, VCU or instrument will cause the charging system to fail and trigger a charging fault.

[0053] In view of the above problems, the embodiments of the present application provide a charging protection circuit. The charging protection circuit includes a bus protection circuit, a battery protection circuit and a battery management system. During the charging process of a new energy vehicle, the bus protection circuit can reduce the surge impact under the control of the battery management system, thereby protecting the battery management system. The battery protection circuit can adjust the charging current under the control of the battery management system, thereby reducing the surge impact and protecting the power battery. Through the technical solution of the embodiments of the present application, the internal devices and components of the new energy vehicle can be protected from multiple aspects, the risk of the charging system being paralyzed due to the surge impact can be reduced, and the charging fault can be reduced.

[0054] According to some embodiments of the present application, refer to Figure 1 , a charging protection circuit is provided. The charging protection circuit 10 includes a bus protection circuit 11, a battery protection circuit 12 and a battery management system 13. The bus protection circuit 11 is disposed on the communication bus 21 of the new energy vehicle and is respectively connected to the battery management system 13 and the charging interface circuit 22 of the new energy vehicle. The battery protection circuit 12 is respectively connected to the battery management system 13, the charging interface circuit 22 and the power battery 23 of the new energy vehicle; the bus protection circuit 11 is configured to conduct the communication connection between the charging interface circuit 22 and the battery management system 13 under the control of the battery management system 13; the battery protection circuit 12 is configured to adjust the charging current input from the charging interface circuit 22 to the power battery 23 under the control of the battery management system 13. It should be noted that the double-arrow connection lines in the figure are communication paths, and the solid lines are conduction paths.

[0055] In the embodiment of the present application, the charging protection circuit 10 includes a bus protection circuit 11, a battery protection circuit 12, and a battery management system 13. The bus protection circuit 11 is disposed on the CAN communication bus 21, and the bus protection circuit 11 is communicatively connected to the battery management system 13 and the charging interface circuit 22 of the new energy vehicle respectively. The battery protection circuit 12 is communicatively connected to the battery management system 13, and the battery protection circuit 12 is electrically connected to the charging interface circuit 22 and the power battery 23 of the new energy vehicle respectively.

[0056] The battery management system 13 can control the on / off of the bus protection circuit 11. Exemplarily, when the new energy vehicle is charging, the charging device is connected to the charging interface circuit 22 of the new energy vehicle. The battery management system 13 first controls the bus protection circuit 11 to disconnect the communication connection between the charging interface circuit 22 and the battery management system 13, so that the surge impact generated by the connection between the charging device and the charging interface circuit 22 will not be transmitted to the battery management system 13 through the CAN communication bus 21, thereby preventing the surge impact from damaging the battery management system 13. Then, the battery management system 13 detects the charging current input by the charging interface circuit 22. If the charging current is within the preset current range, indicating that there is no surge impact, the battery management system 13 controls the bus protection circuit 11 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13, and the battery management system 13 establishes a communication connection with the charging device through the charging interface circuit 22, that is, the battery management system 13 "shakes hands" with the charging device. Subsequently, the battery management system 13 communicates with the charging device to achieve the charging of the new energy vehicle.

[0057] It should be noted that there are various sensors and signal acquisition circuits in the new energy vehicle. Some sensors and signal acquisition circuits can acquire the charging current input by the charging interface circuit 22. The battery management system 13 can obtain the charging current from these sensors and signal acquisition circuits and detect the magnitude of the charging current.

[0058] The battery management system 13 can also control the on / off state of the battery protection circuit 12. Exemplarily, when a new energy vehicle is being charged, the charging device is connected to the charging interface circuit 22 of the new energy vehicle. The battery management system 13 first controls the battery protection circuit 12 to disconnect the electrical connection between the charging interface circuit 22 and the power battery 23, preventing the surge impact generated by the connection between the charging device and the charging interface circuit 22 from being transmitted to the power battery 23 and causing damage to the power battery 23. After that, the battery management system 13 detects the charging current input by the charging interface circuit 22. If the charging current is within the preset current range, indicating no surge impact, the battery management system 13 controls the battery protection circuit 12 to conduct the connection between the charging interface circuit 22 and the power battery 23, enabling the charging device to charge the power battery 23 through the charging interface circuit 22.

[0059] In some embodiments, the battery management system 13 can also control the circuit impedance adjusted by the battery protection circuit 12, so that the battery protection circuit 12 can adjust the magnitude of the charging current input from the charging interface circuit 22 to the power battery 23. For example, in the initial stage of charging, the battery management system 13 controls the battery protection circuit 12 to adjust the circuit impedance to the maximum, reducing the charging current and the risk of surge impact damaging the power battery 23. In the middle stage of charging, the battery management system 13 controls the battery protection circuit 12 to reduce the circuit impedance, thereby increasing the charging current and improving the charging speed and charging efficiency.

[0060] In the above embodiments, the charging protection circuit includes a bus protection circuit, a battery protection circuit, and a battery management system. The bus protection circuit responds to the control instruction sent by the battery management system and conducts the communication connection between the charging interface circuit and the battery management system; the battery protection circuit responds to the control instruction sent by the battery management system and adjusts the charging current input from the charging interface circuit to the power battery. In the technical solution of the embodiments of the present application, the bus protection circuit can reduce surge impact under the control of the battery management system, thereby protecting the battery management system. The battery protection circuit can adjust the charging current under the control of the battery management system, thereby reducing surge impact and protecting the power battery. The embodiments of the present application protect the internal devices and components of the new energy vehicle in multiple aspects, reduce the risk of the charging system being paralyzed due to surge impact, and reduce charging failures.

[0061] According to some embodiments of the present application, with reference to Figure 2, the bus protection circuit 11 includes a first isolation relay KT1 and a second isolation relay KT2; the communication bus 21 includes a high-level communication bus CAN_H and a low-level communication bus CAN_L; the first isolation relay KT1 is arranged on the high-level communication bus CAN_H, and the first end of the first isolation relay KT1 is connected to the charging interface circuit 22, and the second end and the control end of the first isolation relay KT1 are both connected to the battery management system 13; the second isolation relay KT2 is arranged on the low-level communication bus CAN_L, and the first end of the second isolation relay KT2 is connected to the charging interface circuit 22, and the second end and the control end of the second isolation relay KT2 are both connected to the battery management system 13; the first isolation relay KT1 is used to close under the control of the battery management system 13, so that the battery management system 13 is communicatively connected to the charging interface circuit 22 through the high-level communication bus CAN_H; the second isolation relay KT2 is used to close under the control of the battery management system 13, so that the battery management system 13 is communicatively connected to the charging interface circuit 22 through the low-level communication bus CAN_L. It should be noted that in the figure, the double-arrow connection line is the communication path, the solid line is the conduction path, and the dotted line is the control path.

[0062] In the embodiment of the present application, the bus protection circuit 11 includes a first isolation relay KT1 and a second isolation relay KT2, and the communication bus 21 includes a high-level communication bus CAN_H and a low-level communication bus CAN_L.

[0063] The first isolation relay KT1 is arranged on the high-level communication bus CAN_H, and the first end of the first isolation relay KT1 is communicatively connected to the charging interface circuit 22, the second end is communicatively connected to the battery management system 13, and the control end is also communicatively connected to the battery management system 13. Before charging, the battery management system 13 controls the first isolation relay KT1 to disconnect the communication connection between the charging interface circuit 22 and the battery management system 13. After the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the battery management system 13 detects the magnitude of the charging current. If the charging current is within the preset current range, indicating that there is no surge impact, the battery management system 13 controls the first isolation relay KT1 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13, so that the battery management system 13 can establish a communication connection with the charging device through the charging interface circuit 22.

[0064] The second isolation relay KT2 is arranged on the low-level communication bus CAN_L. The first end of the second isolation relay KT2 is communicatively connected to the charging interface circuit 22, the second end is communicatively connected to the battery management system 13, and the control end is also communicatively connected to the battery management system 13. Before charging, the battery management system 13 controls the second isolation relay KT2 to disconnect the communication connection between the charging interface circuit 22 and the battery management system 13. After the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the battery management system 13 detects the magnitude of the charging current. If the charging current is within the preset current range, indicating no surge impact, the battery management system 13 controls the second isolation relay KT2 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13, so that the battery management system 13 can establish a communication connection with the charging device through the charging interface circuit 22.

[0065] In some embodiments, after the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the battery management system 13 detects the magnitude of the charging current and determines the first fluctuation amount of the charging current within the first preset time period; when the first fluctuation amount is within the preset fluctuation range, it controls the first isolation relay KT1 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13 on the high-level communication bus CAN_H; and controls the second isolation relay KT2 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13 on the low-level communication bus CAN_L.

[0066] In some embodiments, the structures of the first isolation relay KT1 and the second isolation relay KT2 may be the same. For example, both the first isolation relay KT1 and the second isolation relay KT2 include two contacts and a coil. The two contacts are respectively connected to the charging interface circuit 22 and the battery management system 13, and the coil is connected to the battery management system 13. The battery management system 13 energizes the coil to drive the two contacts to contact, realizing the connection between the charging interface circuit 22 and the battery management system 13.

[0067] It should be noted that the structures of the first isolation relay KT1 and the second isolation relay KT2 are not limited to the above examples. In actual applications, other structures may also be adopted. Moreover, other types of switches or switching tubes may be used to replace the first isolation relay KT1 and the second isolation relay KT2. The embodiments of the present application do not make any limitations in this regard and can be set according to actual situations.

[0068] In the above embodiments, the bus protection circuit includes a first isolation relay and a second isolation relay; the first isolation relay is configured to close in response to a control instruction sent by the battery management system, so that the battery management system is communicatively connected to the charging interface circuit through the high-level communication bus; the second isolation relay is configured to close in response to a control instruction sent by the battery management system, so that the battery management system is communicatively connected to the charging interface circuit through the low-level communication bus. In the technical solution of the embodiment of the present application, the first isolation relay and the second isolation relay can be used to achieve isolation between the charging interface circuit and the battery management system, reduce the risk of surge impact being transmitted to the battery management system through the CAN communication bus and damaging the battery management system, and greatly improve the charging safety.

[0069] According to some embodiments of the present application, referring to Figure 3 , the battery protection circuit 12 includes a main negative circuit 121 and at least two main positive circuits 122; the main negative circuit 121 is respectively connected to the negative electrode of the charging interface circuit 22 and the power battery 23, and each main positive circuit 122 is respectively connected to the positive electrode of the charging interface circuit 22, the power battery 23, and the battery management system 13; the main negative circuit 121 is configured to conduct the connection between the charging interface circuit 22 and the negative electrode of the power battery 23; each main positive circuit 122 is configured to conduct the connection between the charging interface circuit 22 and the positive electrode of the power battery 23 under the control of the battery management system 13; wherein, different main positive circuits 122 conduct different magnitudes of corresponding charging currents. It should be noted that the double-arrowed connection lines in the figure are communication paths, the solid lines are conduction paths, and the dashed lines are control paths.

[0070] In the embodiment of the present application, the battery protection circuit 12 includes a main negative circuit 121 and at least two main positive circuits 122. Among them, the main negative circuit 121 is responsible for connecting the charging interface circuit 22 to the negative electrode of the power battery 23, and the main positive circuit 122 is responsible for connecting the charging interface circuit 22 to the positive electrode of the power battery 23.

[0071] Before charging, the main negative circuit 121 disconnects the connection between the charging interface circuit 22 and the negative electrode of the power battery 23, and each main positive circuit 122 disconnects the connection between the charging interface circuit 22 and the positive electrode of the power battery 23. After the charging device is connected to the charging interface circuit 22, the main negative circuit 121 conducts the connection between the charging interface circuit 22 and the negative electrode of the power battery 23, and the battery management system 13 controls one or more main positive circuits 122 to conduct the connection between the charging interface circuit 22 and the positive electrode of the power battery 23.

[0072] In some embodiments, the circuit impedances of different main positive circuits 122 are different. The battery management system 13 controls the conduction of different main positive circuits 122, and can adjust the magnitude of the charging current. Taking the battery protection circuit 12 including three main positive circuits 122 as an example, in the initial stage of charging, the battery management system 13 controls the main positive circuit 122 with the largest circuit impedance to conduct, and the charging current is the smallest, reducing the risk of surge impact damage to the power battery 23. After that, the battery management system 13 controls the main positive circuit 122 with the intermediate circuit impedance to conduct, increasing the charging current; if the charging current is normal, the battery management system 13 can control the main positive circuit 122 with the smallest circuit impedance to conduct, further increasing the charging current and improving the charging speed and charging efficiency.

[0073] In some embodiments, the circuit impedances of at least two main positive circuits 122 are the same. The battery management system 13 controls different numbers of main positive circuits 122 to conduct, and can adjust the magnitude of the charging current. Taking the battery protection circuit 12 including three main positive circuits 122 as an example, among the three main positive circuits 122, one main positive circuit 122 has the largest circuit impedance, and the other two main positive circuits 122 have smaller and the same circuit impedances. In the initial stage of charging, the battery management system 13 controls the main positive circuit 122 with the largest circuit impedance to conduct, and the charging current is the smallest, reducing the risk of surge impact damage to the power battery 23; after that, the battery management system 13 controls one of the main positive circuits 122 with smaller circuit impedance to conduct, increasing the charging current; if the charging current is normal, the battery management system 13 can control the two main positive circuits 122 with smaller circuit impedance to conduct simultaneously, further increasing the charging current and improving the charging speed and charging efficiency.

[0074] It should be noted that the circuit impedance of the main positive circuit 122 is not limited to the above examples, and the control of the main positive circuit 122 by the battery management system 13 is not limited to the above manner either.

[0075] In some embodiments, the battery protection circuit 12 includes a main negative circuit 121 and two main positive circuits 122. This solution has a low implementation difficulty, and moreover, the number of judgment times of the sampled current is reduced, which can effectively reduce the cost.

[0076] In some embodiments, the conduction and cutoff of the main negative circuit 121 can be implemented in various ways. For example, the conduction and cutoff of the main negative circuit 121 are similar to those of the main positive circuit 122, and are both controlled by the battery management system 13. Alternatively, the conduction and cutoff of the main negative circuit 121 are controlled by a control device or the charging interface circuit 22. When the charging device is not connected to the charging interface circuit 22, the control device or the charging interface circuit 22 controls the main negative circuit 121 to cutoff; when the charging device is connected to the charging interface circuit 22, the control device or the charging interface circuit 22 controls the main negative circuit 121 to conduct.

[0077] In some embodiments, the main negative circuit 121 may include a main negative relay. The first end of the main negative relay is connected to the charging interface circuit 22, the second end of the main negative relay is connected to the negative electrode of the power battery 23, and the control end of the main negative relay may be connected to any one of the battery management system 13, the control device, and the charging interface circuit 22. Alternatively, the main negative relay is a normally closed relay. After the charging device is connected to the charging interface circuit 22, it can be directly connected to the negative electrode of the power battery 23.

[0078] In the above embodiments, the battery protection circuit includes a main negative circuit and at least two main positive circuits; the main negative circuit conducts the connection between the charging interface circuit and the negative electrode of the power battery; each main positive circuit responds to the control instruction sent by the battery management system and conducts the connection between the charging interface circuit and the positive electrode of the power battery. In the technical solution of the embodiments of the present application, by adjusting the charging current through at least two main positive circuits, the charging current can increase in a gradient manner, which can not only reduce the risk of surge impact damaging the power battery, but also rapidly increase the charging current, improving the charging speed and charging efficiency.

[0079] According to some embodiments of the present application, referring to Figure 4 , the main positive circuit 122 includes a resistor R, a protection relay K, and a switching tube K'; the first end of the resistor R is connected to the charging interface circuit 22, the second end of the resistor R is connected to the first end of the protection relay K, the second end of the protection relay K is connected to the positive electrode of the power battery 23, the control end of the protection relay K is connected to the first end of the switching tube K', and the second end and the control end of the switching tube K' are both connected to the battery management system 13; the switching tube K' is used to conduct under the control of the battery management system 13 and transmit the control signal of the battery management system to the protection relay; the protection relay K is used to conduct the connection between the charging interface circuit 22 and the positive electrode of the power battery 23 when it is closed according to the control signal. It should be noted that the double-arrow connection lines in the figure are communication paths, the solid lines are conduction paths, and the dashed lines are control paths.

[0080] In the embodiments of the present application, each main positive circuit 122 includes a resistor R, a protection relay K, and a switching tube K'. The two ends of the resistor R are respectively connected to the charging interface circuit 22 and the first end of the protection relay K, the second end of the protection relay K is connected to the positive electrode of the power battery 23; the control end of the protection relay K is connected to the first end of the switching tube K', and the second end and the control end of the switching tube K' are both connected to the battery management system 13.

[0081] The process in which the battery management system 13 controls the main positive circuit 122 to conduct the connection between the charging interface circuit 22 and the positive electrode of the power battery 23 may include: The battery management system 13 controls the switching transistor K' in the main positive circuit 122 to conduct. After that, a control signal is input to the protection relay K through the switching transistor K'. The coil of the protection relay K drives the contact to close according to the control signal, so that the second end of the resistor R is electrically connected to the positive electrode of the power battery 23. In this way, the charging interface circuit 22 can input the charging current to the positive electrode of the power battery 23 through the resistor R and the protection relay K.

[0082] Taking the battery protection circuit 12 including n main positive circuits 122 as an example, in the n main positive circuits 122, the resistor R0 > resistor R1... > resistor Rn. The process in which the battery management system 13 controls the battery protection circuit 12 to adjust the charging current may include: The battery management system 13 controls the switching transistor K0' to conduct and other switching transistors to turn off. In this way, the battery management system 13 can transmit the control signal to the protection relay K0 through the switching transistor K0'. The protection relay K0 closes, and the charging interface circuit 22 inputs the charging current to the positive electrode of the power battery 23 through the resistor R0 and the protection relay K0. After that, the battery management system 13 controls the switching transistor K1' to conduct and other switching transistors to turn off. In this way, the battery management system 13 transmits the control signal to the protection relay K1 through the switching transistor K1'. The protection relay K1 closes, and the charging interface circuit 22 can input the charging current to the positive electrode of the power battery 23 through the resistor R1 and the protection relay K1. And so on. Since in the n main positive circuits 122, the resistor R0 > resistor R1... > resistor Rn, when the multiple main positive circuits 122 are conducted in sequence, the charging current gradually increases.

[0083] In some embodiments, after the previous main positive circuit 122 is conducted, the battery management system 13 detects the magnitude of the charging current and determines the second fluctuation amount of the charging current within the second preset time period; when the second fluctuation amount is within the preset fluctuation range, it controls the next main positive circuit 122 to conduct. For example, the protection relay K0 is closed under normal conditions, and the protection relays K1... Kn are turned off under normal conditions. After the charging device is connected to the charging interface circuit 22, the charging device is connected to the positive electrode of the power battery 23 through the charging interface circuit 22, the resistor R0, and the protection relay K0. The battery management system 13 detects Figure 4Determine the magnitude of the charging current at point A0 in [system name], and determine the first fluctuation amount of the charging current within the first preset time period; when the first fluctuation amount is within the preset fluctuation range, control the first isolation relay KT1 and the second isolation relay KT2 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13; and, control the protection relay K0 to turn off, the protection relay K1 to turn on, and the protection relays K2... Kn to turn off, that is, control the branch where the protection relay K1 is located to conduct the connection between the charging device and the power battery 23. After that, the battery management system 13 detects Figure 4 Determine the magnitude of the charging current at point A in [system name], and determine the second fluctuation amount of the charging current within the second preset time period; when the second fluctuation amount is within the preset fluctuation range, control the protection relay K2 to turn on and the other protection relays to turn off, that is, control the branch where the protection relay K2 is located to conduct the connection between the charging device and the power battery 23.

[0084] It should be noted that in the embodiments of the present application, the signal acquisition circuit can be used to acquire Figure 4 the current values of the charging currents at points A0 and A in [system name], and transmit the current values to the battery management system 13. The signal acquisition circuit can adopt a CSC (Cell Supervisory Controller, battery monitoring unit). The CSC has a data acquisition function and is responsible for monitoring a certain number of battery cells or modules and acquiring data such as cell voltage, current, and module temperature. Among them, the CSC can be integrally set with the battery management system 13 or separately set. According to the fact that the duration of a surge is generally in the millisecond (ms) level, the current sampling step can be set to the second level (s), for example, 3 to 5 s, that is, the next-level circuit can be turned on when the current is stable for 3 to 5 s.

[0085] It can be understood that when turning on the current-level main positive circuit 122, synchronously turning off the previous-level main positive circuit 122 can reduce the electric energy consumed by the resistor.

[0086] In some embodiments, the switching tube can adopt a MOS (Metal-Oxide-Semiconductor) tube.

[0087] In the above embodiments, the main positive circuit includes a resistor, a protection relay, and a switching transistor; the switching transistor conducts in response to a control instruction sent by the battery management system, and transmits the control signal of the battery management system to the protection relay; when the protection relay closes according to the control signal, the connection between the charging interface circuit and the positive electrode of the power battery is conducted. In the technical solution of the embodiments of the present application, the battery management system controls the on-off of the main positive circuit by controlling the protection relay and the switching transistor, so as to conduct multiple main positive circuits step by step, realizing the gradient increase of the charging current. This can not only smoothly increase the charging current and reduce the risk of surge impact damaging the power battery, but also improve the charging speed and charging efficiency.

[0088] According to some embodiments of the present application, the resistance values of the resistors in different main positive circuits 122 are different. The protection relay corresponding to the resistor with the largest resistance value is a normally closed relay, and the protection relays corresponding to other resistors are normally open relays.

[0089] In the embodiments of the present application, the resistance values of the resistors in different main positive circuits 122 are different. Taking the battery protection circuit 12 including n main positive circuits 122 as an example, the resistance values of the resistors in the n main positive circuits 122 are R0 > R1 > R2... > Rn. The protection relay K0 corresponding to the resistor R0 with the largest resistance value is a normally closed relay, and the protection relays K1, K2... Kn corresponding to the other resistors R1, R2... Rn are normally open relays.

[0090] After the charging device is connected to the charging interface circuit 22, the charging interface circuit 22 is connected to the negative electrode of the power battery 23 through the main negative circuit 121; since the protection relay K0 is a normally closed relay, the charging interface circuit 22 is connected to the positive electrode of the power battery 23 through the resistor R0 and the protection relay K0, and the charging device can directly charge the power battery 23.

[0091] It should be noted that the resistance value of the resistor R0 should be large enough so that the charging current input from the charging interface circuit 22 to the power battery 23 is small enough, thereby reducing the risk of surge transmission to the power battery 23.

[0092] In some embodiments, since the protection relay K0 corresponding to the resistor R0 is a normally closed relay, considering the protection of each circuit and the power battery 23, the current I0 flowing through the resistor R0 should satisfy formula (1):

[0093] I0 = U / R0 ≤ Ic ------------------------------------- (1)

[0094] Formula (1) can be transformed to obtain formula (2):

[0095] R0≥U / Ic-----------------------------------------(2)

[0096] Wherein, U is the DC bus voltage, and Ic is the pre-charge current allowed for the power battery 23.

[0097] The above formula indicates that the current I0 of the resistor R0 should not exceed the pre-charge current Ic of the power battery 23. At this time, the resistor R0 branch can replace the pre-charge circuit to complete the pre-charge requirement of the power battery 23 while protecting the circuit.

[0098] If it is necessary to strengthen the circuit protection in the initial stage of charging, the current I0 should be much lower than the pre-charge current Ic. At this time, the current I0 flowing through the resistor R0 is very small, and the protection effect is strengthened. If it takes a long pre-charge time to rely on the resistor R0 for pre-charging, the branch where the resistor R1 is located can be used as the pre-charge branch, and the resistor R1 should satisfy formula (3):

[0099] R1≥U / Ic--------------------------------------(3)

[0100] Wherein, U is the DC bus voltage, and Ic is the pre-charge current allowed for the power battery 23.

[0101] For other resistors R2~Rn, the resistance values can be reasonably selected according to the actual maximum charging power requirement. The main logic is to make the charging current increase in an exponential-like form, that is, the growth rate gradually increases. In addition, the branch where the resistor Rn is located can be used as the main charging circuit. Considering that the power loss of the resistor Rn should not be too high, the resistor Rn should be small enough or completely replaced by a wire (0Ω).

[0102] In the above embodiments, the resistance values of the resistors in different main positive circuits are different. The protection relay corresponding to the resistor with the largest resistance value is a normally closed relay, and the protection relays corresponding to other resistors are normally open relays. In the technical solution of the embodiment of the present application, the protection relay corresponding to the resistor with the largest resistance value is a normally closed relay. In this way, when the charging device is connected to the charging interface circuit, small-current charging of the power battery can be realized without other controls, improving the charging speed.

[0103] According to some embodiments of the present application, the charging protection circuit 10 further includes a diode D. The first end of the diode D is connected to the communication bus between the charging interface circuit 22 and the bus protection circuit 11, and the second end of the diode D is grounded. It should be noted that the double-arrow connection line in the figure is the communication path, the solid line is the conduction path, and the dotted line is the control path.

[0104] In the embodiment of the present application, with reference to Figure 5, the charging protection circuit 10 includes a diode D1 and a diode D2. The first end of the diode D1 is connected to the high-level communication bus CAN_H between the charging interface circuit 22 and the bus protection circuit 11, and the second end is grounded. The first end of the diode D2 is connected to the low-level communication bus CAN_L between the charging interface circuit 22 and the bus protection circuit 11, and the second end is grounded.

[0105] In some embodiments, the diode D can be a TVS (Transient Voltage Suppressor) tube. This TVS tube should be more sensitive than the on-board TVS tubes of the battery management system 13 or other boards (such as VCU), that is, the voltage triggering protection is lower than that of the on-board TVS tubes, and the response time is shorter. And this combination of TVS diodes should be installed independently and have the characteristic of being easily replaceable.

[0106] During the charging process, when a charging device inputs a surge through the charging interface circuit 22 and the surge flows into the communication bus 21, the surge is discharged through the diodes D1 and D2, avoiding damage to boards such as the battery management system 13. When the diode D is damaged by the surge, the diode can be easily replaced to restore the charging circuit, reducing the corresponding maintenance cost.

[0107] In the above embodiments, the charging protection circuit further includes a diode. In the technical solution of the embodiments of the present application, a high-sensitivity diode is connected, preventing surges during the charging process, and by designing a convenient disassembly and replacement structure, the diode can be easily replaced after being damaged by a surge impact, thereby improving the surge protection during the charging process and synchronously reducing the maintenance cost.

[0108] According to some embodiments of the present application, referring to Figure 1 , a new energy vehicle is provided. The new energy vehicle includes a charging interface circuit 22, a power battery 23, and the charging protection circuit 10 in the above embodiments; the charging protection circuit 10 is used to protect the power battery 23 and the battery management system 13 in the charging protection circuit 10 when the charging interface circuit 22 is connected to a charging device.

[0109] In the embodiments of the present application, the new energy vehicle includes a charging interface circuit 22, a power battery 23, and the charging protection circuit 10 in the above embodiments. The charging protection circuit 10 is respectively connected to the charging interface circuit 22 and the power battery 23.

[0110] The charging protection circuit 10 includes a bus protection circuit 11, a battery protection circuit 12, and a battery management system 13. Before charging, the battery management system 13 controls the bus protection circuit 11 to disconnect the communication connection between the charging interface circuit 22 and the battery management system 13. During charging, when the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the communication connection between the charging interface circuit 22 and the battery management system 13 is disconnected, which can prevent surge impact from being transmitted to the battery management system 13 through the CAN communication bus and cause damage to the battery management system 13. After that, the battery management system 13 detects the charging current input by the charging interface circuit 22. If the charging current is within the preset current range, indicating no surge impact, the battery management system 13 controls the bus protection circuit 11 to conduct the communication connection between the charging interface circuit 22 and the battery management system 13, and the battery management system 13 establishes a communication connection with the charging device through the charging interface circuit 22, that is, the battery management system 13 "shakes hands" with the charging device. Subsequently, the battery management system 13 communicates with the charging device to achieve the charging of the new energy vehicle.

[0111] Before charging, the battery management system 13 controls the battery protection circuit 12 to disconnect the electrical connection between the charging interface circuit 22 and the power battery 23. During charging, when the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the connection between the charging interface circuit 22 and the power battery 23 is disconnected, which can prevent surge impact from being transmitted to the power battery 23 and cause damage to the power battery 23. After that, the battery management system 13 detects the charging current input by the charging interface circuit 22. If the charging current is within the preset current range, indicating no surge impact, the battery management system 13 controls the battery protection circuit 12 to conduct the connection between the charging interface circuit 22 and the power battery 23, so that the charging device charges the power battery 23 through the charging interface circuit 22.

[0112] In some embodiments, the battery management system 13 can also control the battery protection circuit 12 to adjust the circuit impedance, so as to adjust the magnitude of the charging current input by the charging interface circuit 22 to the power battery 23 by the battery protection circuit 12. For example, in the initial stage of charging, the charging current is small, which can filter out surge impact; after that, the charging current is gradually increased to improve the charging speed.

[0113] In the above embodiments, the new energy vehicle includes a charging interface circuit, a power battery, and a charging protection circuit; the charging protection circuit protects the power battery and the battery management system in the charging protection circuit when the charging interface circuit is connected to the charging device. In the technical solution of the embodiment of the present application, the charging protection circuit protects the internal devices and components of the new energy vehicle from multiple aspects, reduces the risk of the charging system being paralyzed caused by surge impact, and reduces charging failures.

[0114] According to some embodiments of the present application, with reference to Figure 6 The new energy vehicle further includes a vehicle controller 24 and a communication bus 21. The charging protection circuit 10 includes a bus protection circuit 11 disposed on the communication bus 21; the bus protection circuit 11 is configured to conduct a communication connection between the charging interface circuit 22 and the vehicle controller 24 under the control of the battery management system 13.

[0115] In the embodiments of the present application, the new energy vehicle further includes a vehicle controller 24 and a communication bus 21. The vehicle controller 24 is connected to the communication bus 21. The charging protection circuit 10 includes a bus protection circuit 11 disposed on the communication bus 21. Among them, the vehicle controller 24 is the core control unit of the new energy vehicle control system.

[0116] Before charging, the battery management system 13 first controls the bus protection circuit 11 to disconnect the communication connection between the charging interface circuit 22 and the vehicle controller 24. During charging, when the charging device is connected to the charging interface circuit 22 of the new energy vehicle, the communication connection between the charging interface circuit 22 and the vehicle controller 24 is disconnected, and a surge impact can be transmitted to the vehicle controller 24 through the communication bus 21, causing damage to the vehicle controller 24. Then, the battery management system 13 detects the charging current input by the charging interface circuit 22. If the charging current is within a preset current range, indicating no surge impact, the battery management system 13 controls the bus protection circuit 11 to conduct the communication connection between the charging interface circuit 22 and the vehicle controller 24, and the vehicle controller 24 establishes a communication connection with the charging device through the charging interface circuit 22.

[0117] In the above embodiments, the new energy vehicle further includes a vehicle controller and a communication bus. The bus protection circuit responds to a control instruction sent by the battery management system to conduct a communication connection between the charging interface circuit and the vehicle controller. In the technical solution of the embodiments of the present application, the bus protection circuit can also protect the vehicle controller, reduce the risk of surge impact damaging the vehicle controller, reduce charging failures, and improve charging safety.

[0118] According to some embodiments of the present application, with reference to Figure 7 The charging interface circuit 22 includes a fast charging interface 221, a power distribution unit (PDU) 222, a slow charging interface 223, and an on-board charger (OBC) 224; the power distribution unit 222 is respectively connected to the fast charging interface 221, the bus protection circuit 11, and the battery protection circuit 12 of the charging protection circuit 10; the on-board charger 224 is respectively connected to the slow charging interface 223 and the power distribution unit 222.

[0119] In the embodiments of the present application, the charging interface circuit 22 includes a fast charging interface 221, a power distribution unit 222, a slow charging interface 223, and an on-vehicle charger 224. Among them, the on-vehicle charger 224 is responsible for converting external alternating current into direct current required by the power battery, realizing the charging of the power battery 23. The power distribution unit 222 is responsible for connecting the power battery 23 and the charging device (such as a DC charging pile) to ensure the efficiency and safety of the charging process.

[0120] The fast charging interface 221 is connected to the bus protection circuit 11 and the battery protection circuit 12 through the power distribution unit 222. When the charging device is connected to the fast charging interface 221, the power distribution unit 222 can connect the charging device to the bus protection circuit 11, and then connect the charging device to the battery management system 13 and the vehicle controller 24; the power distribution unit 222 can also connect the charging device to the battery protection circuit 12, and then connect the charging device to the power battery 23.

[0121] The slow charging interface 223 is connected to the power distribution unit 222 through the on-vehicle charger 224, and the slow charging interface 223 is also connected to the bus protection circuit 11. When the charging device is connected to the slow charging interface 223, the charging device can be connected to the bus protection circuit 11, and then communicate with the battery management system 13 and the vehicle controller 24; the charging device can also be connected to the on-vehicle charger 224 through the slow charging interface 223, convert the alternating current input by the charging device into direct current through the on-vehicle charger 224, and then transmit the direct current to the power battery 23 through the power distribution unit 222 and the battery protection circuit 12 to charge the power battery 23.

[0122] In the above embodiments, the charging interface circuit includes a fast charging interface, a power distribution unit, a slow charging interface, and an on-vehicle charger; in the technical solution of the embodiments of the present application, the power distribution is responsible for converting external alternating current into direct current required by the power battery to realize the charging of the power battery; the power distribution unit is responsible for connecting the power battery and the charging device to ensure the efficiency and safety of the charging process.

[0123] According to some embodiments of the present application, with reference to Figure 8 , a charging protection method is provided. Taking the battery management system in the charging protection circuit in the above embodiments as an example for illustration, the charging protection circuit further includes a bus protection circuit and a battery protection circuit. The method may include the following steps:

[0124] Step 301, obtain the charging current input from the charging interface circuit to the power battery.

[0125] After the charging device is connected to the charging interface circuit, a charging current is input through the charging interface circuit. The battery management system can detect the magnitude of the charging current transmitted from the charging interface circuit to the power battery.

[0126] Step 302: Control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current.

[0127] If the charging current is within a preset current range, the battery management system controls the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system, enabling the battery management system to "shake hands" with the charging device and establish a communication connection.

[0128] Step 303: Control the battery protection circuit to adjust the charging current.

[0129] If the charging current is within a preset current range, the battery management system also controls the battery protection circuit to conduct the connection between the charging interface circuit and the power battery, enabling the charging device to charge the power battery.

[0130] During the charging process, the battery management system controls the battery protection circuit to adjust the circuit impedance, thereby adjusting the charging current, making the charging current smaller in the initial stage of charging, filtering out surge impacts, and reducing the risk of surge impacts damaging the power battery. Subsequently, the charging current is increased to improve the charging speed and charging efficiency.

[0131] In the above embodiments, the charging current input from the charging interface circuit to the power battery is obtained; the bus protection circuit is controlled to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current; and the battery protection circuit is controlled to adjust the charging current. In the technical solution of the embodiments of the present application, the battery management system can control the on-off of the bus protection circuit, thereby reducing surge impacts and protecting the battery management system. The battery management system can also control the battery protection circuit to adjust the charging current, thereby reducing surge impacts and protecting the power battery. The embodiments of the present application protect the internal devices and components of new energy vehicles in multiple aspects, reduce the risk of the charging system being paralyzed due to surge impacts, and reduce charging failures.

[0132] According to some embodiments of the present application, referring to Figure 9 , in the above embodiments, "controlling the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current" may include the following steps:

[0133] Step 401: Determine the first fluctuation amount of the charging current within the first preset duration.

[0134] In practical applications, the method of determining whether there is a surge may not only be detecting the magnitude of the charging current but also detecting the fluctuation of the charging current. The battery management system can obtain the charging current multiple times within the first preset duration and calculate the difference between the maximum value and the minimum value of the charging current to obtain the first fluctuation amount.

[0135] Step 402, when the first fluctuation amount is within the preset fluctuation range, control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system.

[0136] If the first fluctuation amount is within the preset fluctuation range, it indicates that the charging current fluctuation is small and there is no surge impact. Then the battery management system controls the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system, enabling the battery management system to "shake hands" with the charging device through the charging interface circuit.

[0137] In the above embodiment, determine the first fluctuation amount of the charging current within the first preset duration; when the first fluctuation amount is within the preset fluctuation range, control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system. In the technical solution of the embodiment of the present application, the surge can be accurately detected through the fluctuation amount, thereby improving the control accuracy of the bus protection circuit and the safety of the battery management system.

[0138] According to some embodiments of the present application, "controlling the battery protection circuit to adjust the charging current" in the above embodiment may include: controlling the main positive circuits in the battery protection circuit to conduct one by one in ascending order of current to adjust the charging current.

[0139] The battery protection circuit includes multiple main positive circuits, and different main positive circuits being conducted results in different magnitudes of the charging current. After the battery management system determines that the first fluctuation amount is within the preset fluctuation range, it controls the main positive circuits to conduct one by one. Moreover, the battery management system controls the main positive circuit with a larger circuit impedance to conduct first and the main positive circuit with a smaller circuit impedance to conduct later.

[0140] Take Figure 7 as an example, resistance R0 > resistance R1... > resistance Rn, and the protection relay K0 is a normally closed relay. After the charging device is connected to the fast charging interface, the charging current flows through resistance R0. Since resistance R0 is large, the charging current is small, which can effectively filter out surges. Then, the battery management system controls the protection relay K1 to close in ascending order of current, and all other protection relays are turned off. Under the same charging voltage, compared with the charging current flowing through resistance R0, the charging current flowing through resistance R1 increases. Then, the battery management system controls the protection relay K2 to close, and all other protection relays are turned off. Under the same charging voltage, compared with the charging current flowing through resistance R1, the charging current flowing through resistance R2 further increases.

[0141] During this regulation process, the battery management system can determine whether there is a next-level main positive circuit that is not conducting; if there is a next-level main positive circuit that is not conducting, it controls the next-level main positive circuit to conduct until there is no non-conducting next-level main positive circuit. For example, after the battery management system controls the protection relay Kn to close and all other protection relays are turned off, and it is determined that there is no non-conducting next-level main positive circuit, it remains in this state.

[0142] As Figure 10 shown, the curve marked with squares represents the charging voltage-current (U-I) curve of the traditional charging scheme, which is divided into four stages, details are as follows.

[0143] Stage I: When the cell voltage is less than 2.5V, pre-charging is required first, and the current at this time is 1 / 10 of the set current.

[0144] Stage II: After the pre-charging is completed, that is, when the cell voltage rises to 2.5V, it switches to the constant current high-power standard charging state;

[0145] Stage III: When the cell voltage rises to 4.2V, it changes to constant voltage charging. At this time, the charging current gradually decreases. When the current drops to 1 / 10 of the set current, it enters the next stage;

[0146] Stage IV: At this time, it is the trickle floating charge mode, or the charging ends.

[0147] In the traditional charging scheme, from the pre-charging state to the standard charging state, the current mutation amplitude is large, the impact loss on the power battery is large, and over time, the life loss of the power battery is large.

[0148] The curve without marks represents the voltage-current curve of the charging scheme of this application. In the embodiment of this application, the pre-charging circuit is cancelled, and the function of the pre-charging circuit can be realized by the branch where the resistor R0 is located or the branch where the resistor R1 is located. It should be noted that the charging current passing through the branches where the resistor R0 and the resistor R1 are located does not exceed the pre-charging current allowed by the power battery. After the pre-charging is completed, a gradient current release is performed.

[0149] After charging enters the maximum power charging circuit, the subsequent charging stage can be completed by the branch where the resistor Rn is located.

[0150] In the above embodiment, in the order of increasing current, the main positive circuits in the battery protection circuit are controlled to conduct one by one to regulate the charging current. In the technical solution of the embodiment of this application, the gradient charging scheme gradually increases the charging current to the standard charging current, and transitions from the pre-charging state to the standard charging state relatively smoothly, significantly reducing the impact loss of the current mutation on the power battery and effectively extending the cycle life of the power battery.

[0151] According to some embodiments of this application, with reference toFigure 11 In the above embodiments, "controlling the main positive circuit in the battery protection circuit to conduct" may include the following steps:

[0152] Step 501: Determine the second fluctuation amount of the charging current within a second preset duration.

[0153] The battery management system obtains the charging current multiple times within the second preset duration, calculates the difference between the maximum value and the minimum value of the charging current, and obtains the second fluctuation amount.

[0154] Step 502: Control the main positive circuit to conduct when the second fluctuation amount is within a preset fluctuation range.

[0155] If the second fluctuation amount is within the preset fluctuation range, it indicates that the charging current fluctuates less and there is no surge impact. Then the battery management system controls the main positive circuit to conduct the connection between the charging interface circuit and the positive electrode of the power battery.

[0156] For example, after the charging device is connected to the charging interface circuit, it charges the power battery through the branch where the resistor R0 is located. The battery management system determines the first fluctuation amount of the charging current within a first preset duration. If the first fluctuation amount is within the preset fluctuation range, the battery management system controls the bus protection circuit to conduct the connection between the charging interface circuit and the battery management system, enabling the battery management system to "shake hands" with the charging device. And the battery management system controls the protection relay K1 to close, and all other protection relays are turned off. After that, the battery management system determines the second fluctuation amount of the charging current within a second preset duration. If the second fluctuation amount is within the preset fluctuation range, the battery management system controls the protection relay K2 to close, and all other protection relays are turned off. Then, the battery management system determines the second fluctuation amount of the charging current within the second preset duration again. If the second fluctuation amount is within the preset fluctuation range, the battery management system controls the protection relay K3 to close, and all other protection relays are turned off.

[0157] It should be noted that the second preset duration and the first preset duration may be the same or different.

[0158] In the above embodiments, the second fluctuation amount of the charging current within the second preset duration is determined. When the second fluctuation amount is within the preset fluctuation range, the main positive circuit is controlled to conduct. In the technical solution of the embodiments of the present application, the surge can be accurately detected through the fluctuation amount, thereby improving the control accuracy of the battery protection circuit and the safety of the power battery.

[0159] According to some embodiments of the present application, the method may further include: when the second fluctuation amount exceeds the preset fluctuation range, controlling each main positive circuit to cut off the electrical connection between the charging interface circuit and the power battery.

[0160] If the second fluctuation momentum exceeds the preset fluctuation range, indicating that a surge may occur, the battery management system controls the protective relays in each main positive circuit to turn off, cutting off the electrical connection between the charging interface circuit and the power battery, and pausing the charging. At the same time, the battery management system can report charging anomalies or charging faults to the vehicle controller.

[0161] After the battery management system controls the protective relays in each main positive circuit to turn off, it can restart the charging. For example, after a third preset duration, it controls the protective relay K0 to close, restoring the small-current charging of the branch where the resistor R0 is located. Then, in the order of increasing current, it controls multiple main positive circuits to conduct gradually again, and enables the charging device to charge the power battery again.

[0162] In the above embodiments, when the second fluctuation momentum exceeds the preset fluctuation range, the electrical connection between the charging interface circuit and the power battery is cut off for each main positive circuit. In the technical solution of the embodiments of the present application, when it is detected that the charging current fluctuates greatly, the charging path is cut off in time, which can reduce the risk of surge impact damaging the power battery, thereby effectively protecting the power battery and improving the safety of the power battery and the vehicle.

[0163] According to some embodiments of the present application, a charging protection method is provided. Taking the example of the battery management system applied to the charging protection circuit, the method may include the following steps:

[0164] Step 1, obtain the charging current input from the charging interface circuit to the power battery.

[0165] Step 2, determine the first fluctuation momentum of the charging current within the first preset duration.

[0166] Step 3, when the first fluctuation momentum is within the preset fluctuation range, control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system.

[0167] Step 4, determine the second fluctuation momentum of the charging current within the second preset duration.

[0168] Step 5, when the second fluctuation momentum is within the preset fluctuation range, control the main positive circuit to conduct.

[0169] Step 6, when the second fluctuation momentum exceeds the preset fluctuation range, control each main positive circuit to cut off the electrical connection between the charging interface circuit and the power battery.

[0170] In the technical solution of the embodiment of the present application, the battery management system can control the on / off of the bus protection circuit, thereby reducing surge impact and protecting the battery management system. The battery management system can also control the battery protection circuit to adjust the charging current, thereby reducing surge impact and protecting the power battery. The embodiment of the present application protects the internal devices and components of new energy vehicles in multiple aspects, reduces the risk of the charging system paralysis caused by surge impact, and reduces charging failures.

[0171] It should be understood that although the steps in the above flowchart are shown sequentially according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the above flowchart may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps in other steps.

[0172] According to some embodiments of the present application, an electronic device is provided. The electronic device may be the battery management system in the above embodiment, and its internal structure diagram may be as Figure 12 shown. The electronic device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through the system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store charging protection data. The input / output interface of the electronic device is used to exchange information between the processor and external devices. The communication interface of the electronic device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a charging protection method is implemented.

[0173] Those skilled in the art can understand that Figure 12 the structure shown in

[0174] According to some embodiments of the present application, there is also provided a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, and the above instructions can be executed by a processor of an electronic device to complete the above method. For example, the non-transitory computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0175] According to some embodiments of the present application, there is also provided a computer program product. When the computer program is executed by a processor, the above method can be implemented. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, part or all of the above method can be implemented in accordance with the process or function described in the embodiments of the present application.

[0176] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0177] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0178] The above-described embodiments merely represent several implementation manners of the present application, facilitating the specific and detailed understanding of the technical solution of the present application. However, it should not be construed as a limitation on the protection scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning, or limited experiments based on the technical solution provided by the present application are all within the protection scope of the appended claims of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the content of the appended claims, and the specification and drawings can be used to explain the content of the claims.

Claims

1. A charging protection circuit, characterized in that, The charging protection circuit includes a bus protection circuit, a battery protection circuit, and a battery management system. The bus protection circuit is arranged on the communication bus of the new energy vehicle and is respectively connected to the battery management system and the charging interface circuit of the new energy vehicle. The battery protection circuit is respectively connected to the battery management system, the charging interface circuit, and the power battery of the new energy vehicle; The bus protection circuit is used to conduct the communication connection between the charging interface circuit and the battery management system in response to the control instruction sent by the battery management system; The battery protection circuit is used to adjust the charging current input from the charging interface circuit to the power battery in response to the control instruction sent by the battery management system.

2. The charging protection circuit according to claim 1, wherein The bus protection circuit includes a first isolation relay and a second isolation relay; the communication bus includes a high-level communication bus and a low-level communication bus; The first isolation relay is arranged on the high-level communication bus, and the first end of the first isolation relay is connected to the charging interface circuit, and the second end and the control end of the first isolation relay are both connected to the battery management system; The second isolation relay is arranged on the low-level communication bus, and the first end of the second isolation relay is connected to the charging interface circuit, and the second end and the control end of the second isolation relay are both connected to the battery management system; The first isolation relay is used to close in response to the control instruction sent by the battery management system, so that the battery management system communicates with the charging interface circuit through the high-level communication bus; The second isolation relay is used to close in response to the control instruction sent by the battery management system, so that the battery management system communicates with the charging interface circuit through the low-level communication bus.

3. The charging protection circuit according to claim 1, characterized in that, The battery protection circuit includes a main negative circuit and at least two main positive circuits; the main negative circuit is respectively connected to the charging interface circuit and the negative electrode of the power battery, and each main positive circuit is respectively connected to the charging interface circuit, the positive electrode of the power battery, and the battery management system; The main negative circuit is used to conduct the connection between the charging interface circuit and the negative electrode of the power battery; Each main positive circuit is used to conduct the connection between the charging interface circuit and the positive electrode of the power battery in response to the control instruction sent by the battery management system; among them, the magnitudes of the corresponding charging currents conducted by different main positive circuits are different.

4. The charging protection circuit according to claim 3, wherein The main positive circuit includes a resistor, a protection relay, and a switching tube; The first end of the resistor is connected to the charging interface circuit, the second end of the resistor is connected to the first end of the protection relay, the second end of the protection relay is connected to the positive electrode of the power battery, the control end of the protection relay is connected to the first end of the switching tube, and the second end and the control end of the switching tube are both connected to the battery management system; The switching tube is used to conduct in response to the control instruction sent by the battery management system and transmit the control signal of the battery management system to the protection relay; The protection relay is used to conduct the connection between the charging interface circuit and the positive pole of the power battery when it is closed according to the control signal.

5. The charging protection circuit according to claim 4, wherein The resistance values of the resistors in different main positive circuits are different. The protection relay corresponding to the resistor with the largest resistance value is a normally closed relay, and the protection relays corresponding to other resistors are normally open relays.

6. The charging protection circuit according to any one of claims 1-5, characterized in that, The charging protection circuit further includes a diode. The first end of the diode is connected to the communication bus between the charging interface circuit and the bus protection circuit, and the second end of the diode is grounded.

7. A new energy vehicle, characterized in that, The new energy vehicle includes a charging interface circuit, a power battery, and the charging protection circuit according to any one of claims 1-6.

8. The new energy vehicle according to claim 7, characterized in that, The new energy vehicle further includes a vehicle controller and a communication bus. The charging protection circuit includes a bus protection circuit provided on the communication bus; The bus protection circuit is used to conduct the communication connection between the charging interface circuit and the vehicle controller in response to the control instruction sent by the battery management system.

9. The new energy vehicle according to claim 8, characterized in that, The charging interface circuit includes a fast charging interface, a power distribution unit, a slow charging interface, and an on-vehicle charger; The power distribution unit is respectively connected to the fast charging interface, the bus protection circuit, and the battery protection circuit of the charging protection circuit; The on-vehicle charger is respectively connected to the slow charging interface and the power distribution unit.

10. A charging protection method, characterized in that, Applied to the battery management system in the charging protection circuit, the charging protection circuit further includes a bus protection circuit and a battery protection circuit. The method includes: Obtain the charging current input from the charging interface circuit to the power battery; Control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current; and Control the battery protection circuit to adjust the charging current.

11. The method according to claim 10, characterized in that, The controlling the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system according to the charging current includes: Determine the first fluctuation amount of the charging current within a first preset time period; When the first fluctuation amount is within the preset fluctuation range, control the bus protection circuit to conduct the communication connection between the charging interface circuit and the battery management system.

12. The method according to claim 10, wherein The controlling the battery protection circuit to adjust the charging current includes: Sequentially control the main positive circuits in the battery protection circuit to conduct from small to large current to adjust the charging current.

13. The method according to claim 12, characterized in that, The controlling the main positive circuit in the battery protection circuit to conduct includes: Determine the second fluctuation amount of the charging current within a second preset time period; When the second fluctuation amount is within the preset fluctuation range, control the main positive circuit to conduct.

14. The method according to claim 13, wherein The method further includes: When the second fluctuation amount exceeds the preset fluctuation range, control each of the main positive circuits to cut off the electrical connection between the charging interface circuit and the power battery.

15. An electronic device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 10 to 14.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method according to any one of claims 10 to 14.

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