Charging and discharging circuit and vehicle

Abstract

The utility model provides a kind of charge-discharge circuit and vehicle, belong to electronic circuit technical field.Charge-discharge circuit includes: main circuit, including battery module;Charging sub-circuit, with main circuit forms charging loop, charging sub-circuit includes the fast charging positive relay of series connection, charging electrical connector and fast charging negative relay;And discharging sub-circuit, with main circuit forms discharge loop, discharging sub-circuit includes the main positive relay of series connection, discharge electrical connector and main negative relay;Wherein, when the charging current of main circuit is greater than or equal to threshold current, fast charging positive relay, fast charging negative relay, main positive relay and main negative relay are closed, and charging loop and discharge loop simultaneously charge battery module.By the charge-discharge circuit provided by the utility model, the safety problem and cost rising problem caused by excessive charging current can be solved.

Description

Technical Field

[0001] This utility model belongs to the field of electronic circuit technology, and specifically relates to a charging and discharging circuit and a vehicle. Background Technology

[0002] Battery packs typically have high-voltage charging connectors and high-voltage discharging connectors. During charging, the Battery Management System (BMS) controls the opening and closing of switches in the high-voltage charging circuit, thereby connecting or disconnecting the high-voltage charging circuit from the high-voltage charging connector to initiate or stop charging. During discharging, the BMS controls the opening and closing of switches in the high-voltage discharging circuit, thereby connecting or disconnecting the high-voltage discharging circuit from the high-voltage discharging connector to initiate or stop discharging.

[0003] When charging battery packs, the charging current increases as the demand for shorter charging times grows. When the charging current is too high, the current-carrying capacity of the high-voltage charging connector cannot meet the requirements, leading to issues with safe fast charging. In such cases, it is necessary to increase the cross-sectional area of ​​the copper busbar in the charging interface, add connectors, or implement water cooling, resulting in increased costs. Utility Model Content

[0004] The purpose of this invention is to provide a charging and discharging circuit and vehicle that can solve the problems of excessive charging current leading to failure to meet safe fast charging requirements, as well as the problem of increased costs.

[0005] To achieve the above objectives, this utility model provides a charging and discharging circuit, comprising at least:

[0006] The main circuit includes the battery module;

[0007] A charging sub-circuit, forming a charging loop with the main circuit, includes a fast-charging positive relay, a charging connector, and a fast-charging negative relay. The fast-charging positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the charging connector, and the fast-charging negative connector is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the charging connector.

[0008] The discharge circuit forms a discharge loop with the main circuit. The discharge circuit includes a main positive relay, a discharge connector, and a main negative relay. The main positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the discharge connector. The main negative relay is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the discharge connector.

[0009] Specifically, when the charging current of the main circuit is greater than or equal to the threshold current, the fast charging positive relay, the fast charging negative relay, the main positive relay, and the main negative relay are closed, and the charging circuit and the discharging circuit simultaneously charge the battery module.

[0010] In one embodiment of the present invention, the main circuit further includes a current detection device, which includes a current sensor and / or a shunt, and the current sensor and / or the shunt is connected in series to the battery module.

[0011] In one embodiment of this utility model, the main circuit further includes a smart fuse, which is connected in series with the battery module and is controlled by the battery management system.

[0012] In one embodiment of the present invention, the charging electronic circuit further includes a first fuse, which is connected in series between the fast charging positive relay and the positive input / output terminal of the main circuit. The first fuse is a thermal fuse.

[0013] In one embodiment of the present invention, the discharge circuit further includes a second fuse, which is connected in series between the main positive relay and the positive input / output terminal of the main circuit. The second fuse is a thermal fuse.

[0014] In one embodiment of this utility model, the discharge circuit further includes a pre-charge circuit, and the pre-charge circuit includes:

[0015] A pre-charge relay, one end of which is electrically connected to one end of the main positive relay, and

[0016] A pre-charge resistor, one end of which is electrically connected to the other end of the pre-charge relay, and the other end of which is electrically connected to the other end of the main positive relay.

[0017] In one embodiment of this utility model, when the charging current of the main circuit is greater than or equal to the threshold current, and the rated current of the discharge connector and the rated current of the charging connector satisfy: 0.4Id≤Ia=Ib≤0.7Id and Ia+Ib≥0.8Ic, the fast charging positive relay, the fast charging negative relay, the main positive relay and the main negative relay are closed, and the charging circuit and the discharging circuit charge the battery module simultaneously.

[0018] Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

[0019] In one embodiment of this utility model, when the charging current of the main circuit is less than the threshold current, and the rated current of the discharge connector and the rated current of the discharge connector satisfy: Ia < 0.4Id, 0.4Id ≤ Ib ≤ 0.7Id and Ib ≥ 0.7Ic, the fast charging positive relay and the fast charging negative relay are closed, and the main positive relay and the main negative relay are open, and the charging circuit charges the battery module;

[0020] Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

[0021] In one embodiment of this utility model, when the charging current of the main circuit is less than the threshold current, and the rated current of the discharge connector and the rated current of the discharge connector satisfy: 0.4Id≤Ia=Ib≤0.7Id and Ia+Ib≥0.8Ic, the fast charging positive relay, the fast charging negative relay, the main positive relay and the main negative relay are closed, and the charging circuit and the discharging circuit charge the battery module simultaneously; or the fast charging positive relay and the fast charging negative relay are closed, and the main positive relay and the main negative relay are open, and the charging circuit charges the battery module.

[0022] Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

[0023] This utility model also provides a vehicle, including the charging and discharging circuit described in any of the above claims.

[0024] In summary, this utility model provides a charging and discharging circuit and vehicle. A battery module is installed in the main circuit, a fast-charging positive relay, a charging connector, and a fast-charging negative relay are installed in the charging sub-circuit, and a main positive relay, a discharging connector, and a main negative relay are installed in the discharging circuit. When the battery module is charging, the battery management system controls the states of the fast-charging positive relay, fast-charging negative relay, main positive relay, and main negative relay according to the charging current of the main circuit. The charging circuit composed of the charging sub-circuit and the main circuit charges the battery module, or simultaneously uses the charging circuit composed of the charging sub-circuit and the main circuit, as well as the discharging circuit composed of the discharging current and the main circuit, to charge the battery module. On the one hand, this avoids the impact of large currents on the charging connector and electrical components within the charging sub-circuit, ensuring the safety of high-current charging. On the other hand, when the current is too high, the discharging circuit diverts the charging current of the main circuit, satisfying the charging needs of the battery module while avoiding the need to use higher-specification charging connectors or add copper busbars or water-cooling structures to the charging connectors, thus avoiding increased charging costs. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a circuit diagram of the charging and discharging circuit in one embodiment of this application.

[0027] Figure 2 In one embodiment of this application, when charging and discharging circuits are used to charge the battery module, Figure 1 Equivalent circuit diagram of the charging and discharging circuit.

[0028] Figure 3 In one embodiment of this application, when a charging circuit is used to charge the battery module, Figure 1 Equivalent circuit diagram of the charging and discharging circuit.

[0029] Figure 4 In one embodiment of this application, when the battery module discharges through the discharge circuit, Figure 1 Equivalent circuit diagram of the charging and discharging circuit.

[0030] Label Explanation:

[0031] 11. Main circuit; 12. Charging circuit; 13. Discharging circuit; 101. Fast charging positive relay; 102. Fast charging negative relay; 103. Battery module; 104. Main positive relay; 105. Main negative relay; 106. Current sensor; 107. Smart fuse; 108. Shunt; 109. Second fuse; 110. First fuse; 111. Pre-charge relay; 112. Pre-charge resistor; 201. Charging connector; 202. Discharging connector; R1. First pre-charge resistor; R2. Second pre-charge resistor. Detailed Implementation

[0032] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0034] In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," and "right," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] New energy vehicles offer excellent energy conservation and emission reduction benefits, and are highly intelligent, making them popular with consumers. Since electric vehicles use battery packs as their power source, they produce no exhaust fumes like those generated by internal combustion engines, resulting in virtually "zero pollution" and contributing significantly to environmental protection and air cleanliness.

[0036] Please combine Figure 1As shown, a charging circuit and a discharging circuit are provided within the battery pack. A charging connector 201 and a discharging connector 202 are provided on the surface of the battery pack. During charging, the battery management unit controls the switch in the charging circuit to close, making the charging circuit conductive and connecting it to the charging connector 201 to charge the battery module 103 in the charging circuit. During discharging, the battery management unit controls the switch in the discharging circuit to close, making the discharging circuit conductive and connecting it to the discharging connector 202 to discharge the battery module 103 in the discharging circuit. The charging connector 201 and discharging connector 202 are high-voltage connectors and are key components of the vehicle's high-voltage system. The main structure of the high-voltage connector includes a contactor, insulator, plastic housing, and accessories. With the development of new energy vehicle technology and fast charging technology, the fast charging current is increasing, posing a significant challenge to the selection and cost of high-voltage connectors.

[0037] This application provides a charging and discharging circuit that, without increasing the cost of high-voltage connectors, adjusts the charging and discharging mode of the circuit according to the magnitude of the charging current to meet the charging requirements under high current.

[0038] Please see Figure 1 As shown, the charging and discharging circuit provided in this application includes a main circuit 11, and a charging sub-circuit 12 and a discharging circuit 13 connected to the main circuit 11. The charging sub-circuit 12 and the main circuit 11 form a charging circuit, and the discharging circuit 13 and the main circuit 11 form a discharging circuit. A battery module 103 is provided in the main circuit 11. A fast-charging positive relay 101, a charging connector 201, and a fast-charging negative relay 102 are connected in series in the charging sub-circuit 12. A main positive relay 104, a discharging connector 202, and a main negative relay 105 are connected in series in the discharging circuit 13. The fast-charging positive relay 101 is connected in series between the positive input / output terminal of the main circuit 11 and the charging connector 201, and the fast-charging negative relay 102 is connected in series between the negative input / output terminal of the main circuit 11 and the charging connector 201. The main positive relay 104 is connected in series between the positive input / output terminal of the main circuit 11 and the discharge connector 202, and the main negative relay 105 is connected in series between the negative input / output terminal of the main circuit 11 and the discharge connector 202.

[0039] Please see Figure 1As shown in this application, the opening and closing of the fast-charging positive relay 101 and the fast-charging negative relay 102, controlled by the battery management system, can control whether the charging sub-circuit 12 is connected to the main circuit 11. Similarly, the opening and closing of the main positive relay 104 and the main negative relay 105, controlled by the battery management system, can control whether the discharging circuit 13 is connected to the main circuit 11. When the charging current of the main circuit is greater than or equal to the threshold current, the fast-charging positive relay 101 and the fast-charging negative relay 102 are closed simultaneously with the main positive relay 104 and the main negative relay 105, thus using the discharging circuit for charging. At this time, the charging current is simultaneously input into the charging connector 201 and the discharging connector 202, using both the charging and discharging circuits to charge the battery module 103 simultaneously.

[0040] It is important to note that the input terminal of each relay in the charging and discharging circuit is electrically connected to the battery management system, which controls the opening and closing of each relay.

[0041] For details, please refer to Figure 1 As shown, in one embodiment of this utility model, the battery module 103 can be any suitable automotive battery. In some embodiments, the battery module 103 is, for example, a lithium iron phosphate battery, which has good stability, can be cycled multiple times, and has good safety. In other embodiments, the battery module 103 can be a ternary lithium battery, which has high battery density and a relatively long driving range. This application does not limit the type and specifications of the battery module 103, as long as it meets the requirements of the vehicle. In this application, the battery module 103 has two output terminals, namely the positive terminal and the negative terminal of the battery module 103. The rated voltage, rated current, and capacity of the battery module 103 can be set according to the needs of the vehicle.

[0042] Please see Figure 1As shown, in one embodiment of this utility model, a current detection device and a current protection device are also provided in the main circuit 11. The current detection device includes a current sensor 106 and / or a shunt 108 connected in series with the battery module 103, and the current protection device includes a smart fuse 107 connected in series with the battery module 103. The current sensor 106 is connected in series with the positive terminal of the battery module 103, and the smart fuse 107 and the shunt 108 are connected in series with the negative terminal of the battery module 103. Specifically, one end of the current sensor 106 is electrically connected to the positive terminal of the battery module 103, and the other end is the positive input / output terminal of the main circuit 11, that is, the other end of the current sensor 106 is the common terminal of the main circuit 11, the charging electronic circuit 12 with the fast charging positive relay 101, and the discharging electronic circuit 13 with the main positive relay 104. One end of the smart fuse 107 is electrically connected to the negative terminal of the battery module 103, and the other end of the smart fuse 107 is electrically connected to one end of the shunt 108. The other end of the shunt 108 is the negative input / output terminal of the main circuit 11, that is, the other end of the shunt 108 is the common terminal of the main circuit 11, the charging electronic circuit 12 with the fast charging negative relay 102, and the discharging electronic circuit 13 with the main negative relay 105.

[0043] Please see Figure 1 As shown, in one embodiment of this utility model, a current sensor 106 and a shunt 108 are connected in series in the main circuit 11 to the battery module 103. The current sensor 106 can be a Hall current sensor, and the shunt 108 can be a Shunt shunt. Both sensors can detect the current in the main circuit 11, i.e., the charging current or discharging current of the main circuit, based on different detection methods, realizing a redundant design for current monitoring and improving the safety level of the system. The current sensor 106 can realize real-time dynamic monitoring of the current and rapid safety response, such as triggering millisecond-level overcurrent protection. The shunt 108 can realize high-precision metering and fault redundancy backup, such as realizing long-term power statistics and fault verification. Using both the current sensor 106 and the shunt 108 simultaneously ensures the safety, accuracy, and reliability of the charging and discharging process, ensuring that the battery module 103 does not exceed safety boundaries during charging and discharging, while accurately managing power and health status. In other embodiments, only the current sensor 106 or only the shunt 108 may be used.

[0044] Please see Figure 1As shown, in one embodiment of this utility model, a smart fuse 107 connected in series with the battery module 103 is provided in the main circuit 11. The smart fuse 107 is controlled by the battery management system and can be triggered to cut off the high-voltage circuit based on the signal emitted by the battery management system through the airbag, achieving redundant high-voltage protection with the thermal fuse in the sub-circuit. Furthermore, since the smart fuse 107 is controlled by the battery management system, unlike the thermal fuse which can only melt when the current is too high to protect the circuit, the smart fuse 107 can also dynamically adjust the protection threshold based on the real-time data of cell voltage, current, and temperature collected by the battery management system. During discharge, it can also adapt to the maximum allowable current according to the load requirements. This prevents the circuit from being damaged by abnormally high current and avoids false triggering of protection under normal operating conditions due to fixed thresholds, improving the flexibility of circuit operation. On the other hand, the smart fuse 107 can also report its own operating status to the battery management system and, combined with other data collected by the battery management system, quickly locate the fault.

[0045] Please see Figure 1 As shown, in one embodiment of this utility model, the charging sub-circuit 12 includes a charging connector 201, a fast-charging positive relay 101, a first fuse 110, and a fast-charging negative relay 102. The fast-charging positive relay 101 is connected in series between the positive input / output terminal of the main circuit 11 and the positive voltage terminal of the charging connector 201. The fast-charging negative relay 102 is connected in series between the negative input / output terminal of the main circuit 11 and the negative voltage terminal of the charging connector 201. The first fuse 110 is connected in series between the fast-charging positive relay 101 and the positive input / output terminal of the main circuit 11. Specifically, one end of the fast-charging positive relay 101 is electrically connected to the positive voltage terminal of the charging connector 201, and the other end of the fast-charging positive relay 101 is electrically connected to one end of the first fuse 110. The other end of the first fuse 110 is electrically connected to the positive input / output terminal of the main circuit 11. One end of the fast-charging negative relay 102 is electrically connected to the negative voltage terminal of the charging connector 201, and the other end of the fast-charging negative relay 102 is electrically connected to the negative input / output terminal of the main circuit 11. The charging sub-circuit 12 and the main circuit 11 form a charging loop, that is, the charging connector 201, the fast-charging positive relay 101, the first fuse 110, the current sensor 106, the battery module 103, the smart fuse 107, the shunt 108 and the fast-charging negative relay 102 form a charging loop.

[0046] Please see Figure 1As shown, in one embodiment of this utility model, the discharge circuit 13 includes a discharge connector 202, a main positive relay 104, a second fuse 109, and a main negative relay 105. The main positive relay 104 is connected in series between the positive input / output terminal of the main circuit 11 and the positive voltage terminal of the discharge connector 202; the main negative relay 105 is connected in series between the negative input / output terminal of the main circuit 11 and the negative voltage terminal of the discharge connector 202; and the second fuse 109 is connected in series between the main positive relay 104 and the positive input / output terminal of the main circuit 11. Specifically, one end of the main positive relay 104 is electrically connected to the positive voltage terminal of the discharge connector 202, and the other end of the main positive relay 104 is electrically connected to one end of the second fuse 109. The other end of the second fuse 109 is electrically connected to the positive input / output terminal of the main circuit 11. One end of the main negative relay 105 is electrically connected to the negative voltage terminal of the discharge connector 202, and the other end of the main negative relay 105 is electrically connected to the negative input / output terminal of the main circuit 11. The discharge circuit 13 and the main circuit 11 form a discharge circuit, that is, the discharge connector 202, the main positive relay 104, the second fuse 109, the current sensor 106, the battery module 103, the smart fuse 107, the shunt 108 and the main negative relay 105 form a discharge circuit.

[0047] Please see Figure 1 As shown, in one embodiment of this utility model, the first fuse 110 in the charging sub-circuit 12 and the second fuse 109 in the discharging circuit 13 are both thermal fuses. When the current value in the charging sub-circuit 12 and the discharging circuit 13 exceeds the threshold of the thermal fuse in the circuit, the thermal fuse will melt due to overheating, thereby cutting off the circuit and preventing excessive current from damaging the battery cell and other electrical components.

[0048] Please see Figure 1 As shown, in one embodiment of this utility model, a pre-charging circuit is further provided in the discharge circuit 13, and the pre-charging circuit includes a pre-charging relay 111 and a pre-charging resistor 112. The series circuit formed by the pre-charging relay 111 and the pre-charging resistor 112 is connected in parallel to the main positive relay 104. Specifically, one end of the pre-charging relay 111 is electrically connected to one end of the main positive relay 104, and the other end of the pre-charging relay 111 is electrically connected to one end of the pre-charging resistor 112, and the other end of the pre-charging resistor 112 is electrically connected to the other end of the main positive relay 104. This application does not limit the number and type of pre-charging resistors 112, and they can be set according to requirements. In this embodiment, the pre-charging resistors 112 include, for example, a first pre-charging resistor R1 and a second pre-charging resistor R2 connected in series.

[0049] Please see Figure 1As shown, in one embodiment of this utility model, when the vehicle is charging, the fast charging positive relay 101, fast charging negative relay 102, main positive relay 104, main negative relay 105 and pre-charge relay 111 can be controlled to open and close according to the magnitude of the charging current and the specifications of the charging connector 201 and the discharging connector 202, thereby controlling the charging and discharging of the battery module 103.

[0050] Please see Figure 1 As shown, in this application, Ia is defined as the rated current of the discharge connector 202, Ib is defined as the rated current of the charging connector 201, Ic is defined as the charging current of the main circuit, Id is defined as the threshold current, Ie is defined as the current of the discharge circuit, and If is defined as the current of the charging circuit.

[0051] Please see Figure 1 and Figure 2 As shown, in one embodiment of this utility model, when the charging current of the main circuit is greater than or equal to the threshold current, i.e., Ic ≥ Id, and the rated current of the discharge connector 202 and the rated current of the charging connector 201 are equal, the range of the rated current of the discharge connector 202 and the rated current of the charging connector 201 is: 0.4Id ≤ Ia = Ib ≤ 0.7Id. When the rated current of the discharge connector 202, the rated current of the charging connector 201, and the charging current of the main circuit satisfy: Ia + Ib ≥ 0.8Ic, the fast charging positive relay 101, the fast charging negative relay 102, the main positive relay 104, and the main negative relay 105 are closed, and the pre-charge relay 111 is open. At this time, Figure 1 The equivalent circuit diagram of the charging and discharging circuit is as follows: Figure 2As shown, a portion of the current flows through the charging connector 201, the fast-charging positive relay 101, the first fuse 110, the current sensor 106, the battery module 103, the smart fuse 107, the shunt 108, and the fast-charging negative relay 102 back to the charging connector 201 to charge the battery module 103. The other portion of the current flows through the discharging connector 202, the main positive relay 104, the second fuse 109, the current sensor 106, the battery module 103, the smart fuse 107, the shunt 108, and the main negative relay 105 back to the charging connector 201 to charge the battery module 103. Even when both the charging and discharging circuits are used to charge the battery module 103 simultaneously, the charging current in the main circuit is equal to the sum of the currents in the charging and discharging circuits, i.e., Ic = If + Ie. At this time, the larger charging current of the main circuit is divided into the current of the charging circuit and the current of the discharging circuit. The charging connector 201 and the discharging connector 202 each bear a part of the current, which reduces the current flowing through the charging connector 201 when charging with a large current, thereby avoiding the safety hazards caused by the large current. It also reduces the current carrying capacity of the charging connector 201 and lowers the charging cost.

[0052] Please see Figure 1 and Figure 2 As shown in a specific embodiment of this utility model, the value of the threshold current Id is, for example, 500A. The condition for simultaneously charging the battery module 103 using both the charging and discharging circuits is that the charging current of the main circuit is greater than or equal to the threshold current, i.e., Ic ≥ 500A. Simultaneously, the rated current of the discharging connector 202 is equal to the rated current of the charging connector 201. The range of the rated currents of the discharging connector 202 and the charging connector 201 is: 200A ≤ Ia = Ib ≤ 350A. The rated currents of the discharging connector 202, the charging connector 201, and the charging current of the main circuit satisfy: Ia + Ib ≥ 0.8Ic.

[0053] Please see Figure 1 As shown, in one embodiment of this utility model, when the charging current of the main circuit is less than the threshold current, i.e., Ic < Id, and the rated current ranges of the discharge connector 202 and the charging connector 201 are: Ia < 0.4Id, 0.4Id ≤ Ib ≤ 0.7Id, and the rated current of the charging connector 201 and the charging current of the main circuit satisfy: Ib ≥ 0.7Ic, the fast charging positive relay 101 and the fast charging negative relay 102 are closed, and the main positive relay 104, the main negative relay 105, and the pre-charge relay 111 are open. At this time, Figure 1 The equivalent circuit diagram of the charging and discharging circuit is as follows: Figure 3As shown, the charging current of the main circuit passes through the charging connector 201, the fast-charging positive relay 101, the first fuse 110, the current sensor 106, the battery module 103, the smart fuse 107, the shunt 108, and the fast-charging negative relay 102 before returning to the charging connector 201 to charge the battery module 103. That is, only the charging circuit is used to charge the battery module 103, and the charging current of the main circuit is equal to the current of the charging circuit, i.e., Ic = If. At this time, the charging current of the main circuit is relatively small, and the rated current of the discharge connector 202 is also relatively small. If the discharge circuit were used to charge the battery module 103, it might damage the discharge connector 202. Therefore, only the charging circuit is used to charge the battery module 103.

[0054] Please see Figure 1 and Figure 2 As shown, in a specific embodiment of this utility model, the value of the threshold current Id is, for example, 500A. Therefore, the condition for using only the charging circuit to charge the battery module 103 is that the charging current of the main circuit is less than the threshold current, i.e., Ic < 500A. Simultaneously, the rated current ranges of the discharge connector 202 and the charging connector 201 are: Ia < 200A, 200A ≤ Ib ≤ 350A. The rated current of the charging connector 201 and the charging current of the main circuit satisfy: Ib ≥ 0.7Ic.

[0055] Please see Figure 1 As shown, in one embodiment of this utility model, when the charging current of the main circuit is less than the threshold current, i.e., Ic < Id, and the rated current ranges of the discharge connector 202 and the charging connector 201 are: 0.4Id ≤ Ia = Ib ≤ 0.7Id, and the rated currents of the discharge connector 202, the charging connector 201, and the charging current of the main circuit satisfy: Ia + Ib ≥ 0.8Ic, then the battery module 103 can be charged simultaneously using both the charging and discharging circuits, or only the charging circuit can be used to charge the battery module 103. That is, it is possible to use both the charging and discharging circuits simultaneously. Figure 2 As shown and as Figure 3 The equivalent circuit shown is for charging battery module 103.

[0056] Please see Figure 1 and Figure 2As shown, in a specific embodiment of this utility model, the threshold current Id is, for example, 500A. The condition that the battery module 103 can be charged simultaneously using both the charging and discharging circuits, or only using the charging circuit, is that the charging current of the main circuit is less than the threshold current, i.e., Ic < 500A. Simultaneously, the rated current ranges of the discharging connector 202 and the charging connector 201 are: 200A ≤ Ia = Ib ≤ 350A. The rated currents of the discharging connector 202, the charging connector 201, and the charging current of the main circuit satisfy: Ia + Ib ≥ 0.8Ic.

[0057] Please see Figure 1 and Figure 4 As shown, in one embodiment of this utility model, when the vehicle is discharging, the fast charging positive relay 101 and the fast charging negative relay 102 are always in the off state. At this time, Figure 1 The equivalent circuit of the charging and discharging circuit is as follows: Figure 4 As shown. First, the pre-charge relay 111 and the main negative relay 105 are closed, while the main positive relay 104 is open. Based on the size of the external vehicle's X-capacitor and the pre-charge strategy, the battery management system detects that the pre-charge time has been met and then controls the main positive relay 104 to close and the pre-charge relay 111 to open. At this time, the discharge current passes through the current sensor 106, the second fuse 109, and the main positive relay 104 to the discharge connector 202. The discharge connector 202 outputs a discharge current to drive the external high-voltage components, and then returns to the battery pack through the discharge connector 202. The return current flows through the main negative relay 105, the shunt 108, and the main positive relay 104, returning to the negative terminal of the battery module 103. During the transition from pre-charge to discharge, the main negative relay 105 remains closed during discharge. Using the pre-charge circuit for pre-charge before discharge avoids the impact of large currents on the vehicle load and relays.

[0058] In summary, this utility model provides a charging and discharging circuit and a vehicle, wherein the charging circuit includes a main circuit, a charging sub-circuit, and a discharging circuit. The main circuit includes a battery module. The charging sub-circuit forms a charging circuit with the main circuit, and includes a fast-charging positive relay, a charging connector, and a fast-charging negative relay. The fast-charging positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the charging connector, and the fast-charging negative connector is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the charging connector. The discharging circuit forms a discharging circuit with the main circuit, and includes a main positive relay, a discharging connector, and a main negative relay. The main positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the discharging connector, and the main negative relay is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the discharging connector. When the charging current of the main circuit is greater than or equal to the threshold current, the fast-charging positive relay, the fast-charging negative relay, the main positive relay, and the main negative relay are closed, and the charging circuit and the discharging circuit simultaneously charge the battery module.

[0059] The embodiments of this utility model disclosed above are merely illustrative of the present utility model. The embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Obviously, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A charging and discharging circuit, characterized in that, At least including: The main circuit includes the battery module; A charging sub-circuit forms a charging loop with the main circuit. The charging sub-circuit includes a fast charging positive relay, a charging connector, and a fast charging negative relay. The fast charging positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the charging connector. The fast charging negative connector is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the charging connector. as well as The discharge circuit forms a discharge loop with the main circuit. The discharge circuit includes a main positive relay, a discharge connector, and a main negative relay. The main positive relay is connected in series between the positive input / output terminal of the main circuit and the positive voltage terminal of the discharge connector. The main negative relay is connected in series between the negative input / output terminal of the main circuit and the negative voltage terminal of the discharge connector. Specifically, when the charging current of the main circuit is greater than or equal to the threshold current, the fast charging positive relay, the fast charging negative relay, the main positive relay, and the main negative relay are closed, and the charging circuit and the discharging circuit charge the battery module simultaneously.

2. The charging and discharging circuit according to claim 1, characterized in that, The main circuit also includes a current detection device, which includes a current sensor and / or a shunt, and the current sensor and / or the shunt is connected in series with the battery module.

3. The charging and discharging circuit according to claim 2, characterized in that, The main circuit also includes a smart fuse, which is connected in series with the battery module and is controlled by the battery management system.

4. The charging and discharging circuit according to claim 1, characterized in that, The charging electronic circuit also includes a first fuse, which is connected in series between the fast charging positive relay and the positive input / output terminal of the main circuit. The first fuse is a thermal fuse.

5. The charging and discharging circuit according to claim 1, characterized in that, The discharge circuit also includes a second fuse, which is connected in series between the main positive relay and the positive input / output terminal of the main circuit. The second fuse is a thermal fuse.

6. The charging and discharging circuit according to claim 1, characterized in that, The discharge circuit further includes a pre-charge circuit, and the pre-charge circuit includes: A pre-charge relay, one end of which is electrically connected to one end of the main positive relay, and A pre-charge resistor, one end of which is electrically connected to the other end of the pre-charge relay, and the other end of which is electrically connected to the other end of the main positive relay.

7. The charging and discharging circuit according to claim 1, characterized in that, When the charging current of the main circuit is greater than or equal to the threshold current, and the rated current of the discharge connector and the rated current of the charging connector satisfy: 0.4Id≤Ia=Ib≤0.7Id and Ia+Ib≥0.8Ic, the fast charging positive relay, the fast charging negative relay, the main positive relay and the main negative relay are closed, and the charging circuit and the discharging circuit charge the battery module simultaneously. Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

8. The charging and discharging circuit according to claim 1, characterized in that, When the charging current of the main circuit is less than the threshold current, and the rated current of the discharge connector and the rated current of the discharge connector satisfy: Ia < 0.4Id, 0.4Id ≤ Ib ≤ 0.7Id and Ib ≥ 0.7Ic, the fast charging positive relay and the fast charging negative relay are closed, and the main positive relay and the main negative relay are open, and the charging circuit charges the battery module; Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

9. The charging and discharging circuit according to claim 1, characterized in that, When the charging current of the main circuit is less than the threshold current, and the rated current of the discharge connector and the rated current of the discharge connector satisfy: 0.4Id≤Ia=Ib≤0.7Id and Ia+Ib≥0.8Ic, the fast charging positive relay, the fast charging negative relay, the main positive relay and the main negative relay are closed, and the charging circuit and the discharging circuit charge the battery module simultaneously; or the fast charging positive relay and the fast charging negative relay are closed, and the main positive relay and the main negative relay are open, and the charging circuit charges the battery module. Wherein, Ia is the rated current of the discharge connector, Ib is the rated current of the charging connector, Ic is the charging current of the main circuit, and Id is the threshold current.

10. A vehicle, characterized in that, Includes the charging and discharging circuit as described in any one of claims 1 to 9.

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