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: fast charging positive relay and fast charging negative relay, electrically connected in fast charging interface;First diode, first parallel relay and first battery module are connected in series between fast charging positive relay and fast charging negative relay;Second diode, second parallel relay and second battery module are connected in series between fast charging positive relay and fast charging negative relay;Series relay, connected in series between the negative terminal of first battery module and the positive terminal of second battery module;Main positive relay, connected in series between the common terminal of parallel charging circuit and fast charging positive relay and driving interface, main negative relay, connected in series between the negative terminal of second battery module and driving interface;And third parallel relay, connected in series between main positive relay and fast charging positive relay common terminal and first battery module.By the charge-discharge circuit provided by the utility model, the safety of charge-discharge can be improved.

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] When charging new energy vehicles using charging stations, due to limitations in infrastructure construction and battery pack development, there are two types of charging stations on the market: those based on 400V and those based on 800V platforms. When using a 400V charging station, it is not possible to directly charge an 800V platform battery pack. The battery cell modules within the 800V battery pack need to be converted into two parallel 400V platform modules.

[0003] In parallel use of battery cell modules, due to the voltage difference between them, current flows from the higher-voltage cell module to the lower-voltage cell module, forming a parallel circulating current. Simultaneously, internal chemical reactions within the battery also create parallel circulating currents between the parallel battery packs. These parallel circulating currents not only affect battery lifespan and waste energy, but also cause increased battery temperature, raising the risk of fire and explosion. Utility Model Content

[0004] The purpose of this invention is to provide a charging and discharging circuit and vehicle that is compatible with charging piles of different voltages, prevents the formation of parallel circulating currents, and improves the safety of vehicle charging and discharging.

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

[0006] Fast charging interface;

[0007] Driver interface;

[0008] A fast charging positive relay and a fast charging negative relay, wherein the fast charging positive relay is electrically connected to the positive terminal of the fast charging interface, and the fast charging negative relay is electrically connected to the negative terminal of the fast charging interface;

[0009] The first parallel charging circuit includes a first diode, a first parallel relay, and a first battery cell module connected in series between the fast charging positive relay and the fast charging negative relay;

[0010] The second parallel charging circuit includes a second diode, a second parallel relay, and a second battery cell module connected in series between the fast charging positive relay and the fast charging negative relay. The second parallel charging circuit and the first parallel charging circuit are two circuits connected in parallel.

[0011] A series relay, one end of which is electrically connected to the negative terminal of the first battery cell module, and the other end of which is electrically connected to the positive terminal of the second battery cell module;

[0012] A main positive relay and a main negative relay, wherein the main positive relay is connected in series between the first common terminal and the positive terminal of the drive interface, and the main negative relay is connected in series between the second common terminal and the negative terminal of the drive interface; and

[0013] The third parallel relay is connected in series between the first common terminal and the positive terminal of the first cell module;

[0014] Wherein, the first common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging positive relay, and the second common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging negative relay.

[0015] In one embodiment of this utility model, the positive terminal of the first diode is electrically connected to the fast-charging positive relay, the negative terminal of the first diode is electrically connected to one end of the first parallel relay, the other end of the first parallel relay is electrically connected to the positive terminal of the first battery cell module, and the negative terminal of the first battery cell module is electrically connected to the fast-charging negative relay.

[0016] In one embodiment of this utility model, the positive terminal of the second diode is electrically connected to the fast-charging positive relay, the negative terminal of the second diode is electrically connected to one end of the second parallel relay, the other end of the second parallel relay is electrically connected to the positive terminal of the second battery cell module, and the negative terminal of the second battery cell module is electrically connected to the fast-charging negative relay.

[0017] In one embodiment of this utility model, the charging and discharging circuit further includes a third diode, the negative terminal of which is electrically connected to the first common terminal, and the positive terminal of which is electrically connected to the third parallel relay.

[0018] In one embodiment of this utility model, the rated voltage of the first battery cell module and the second battery cell module is 400V.

[0019] In one embodiment of this utility model, the fast charging positive relay, the fast charging negative relay, the first parallel relay and the second parallel relay are closed, and the series relay, the main positive relay, the main negative relay and the third parallel relay are open, and the charging and discharging circuit forms two parallel 400V charging circuits that charge from the fast charging interface.

[0020] In one embodiment of this utility model, the fast charging positive relay, the fast charging negative relay, the first parallel relay and the second parallel relay are disconnected, and the series relay, the main positive relay, the main negative relay and the third parallel relay are closed, and the charging and discharging circuit forms an 800V discharge circuit to discharge to the drive port.

[0021] In one embodiment of this utility model, the charging and discharging circuit includes a pre-charging circuit, which is connected in parallel to the main positive relay.

[0022] In one embodiment of this utility model, the pre-charging circuit includes:

[0023] A pre-charge relay, one end of which is electrically connected to one end of the main positive relay; and

[0024] 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.

[0025] This utility model also provides a vehicle, including the charging and discharging circuit described in any of the above claims.

[0026] In summary, this utility model provides a charging and discharging circuit and vehicle that divides the battery cell modules within a battery pack into at least two parallel cell modules, and sets each cell module in a parallel charging circuit. By setting a parallel relay connected in series with the cell module in each parallel charging circuit, and a series relay connected in series between adjacent cell modules, the series and parallel connection method of multiple cell modules and the charging and discharging process of the cell modules are changed, thereby enabling the vehicle with this charging and discharging circuit to meet the needs of charging stations with different voltages. Each parallel charging circuit also includes a diode connected in series with the parallel relay, thereby avoiding the risk of parallel circulating current between cell modules, which could lead to fire or other hazards. Attached Figure Description

[0027] 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.

[0028] Figure 1 This is a circuit diagram of the charging and discharging circuit in one embodiment of this application.

[0029] Figure 2 This is an equivalent circuit diagram of a 400V charging circuit in one embodiment of the present application.

[0030] Figure 3 This is an equivalent circuit diagram of the 800V charging circuit of the charging and discharging circuit in one embodiment of this application.

[0031] Figure 4 This is an equivalent circuit diagram of the 800V discharge circuit of the charging and discharging circuit in one embodiment of this application.

[0032] Label Explanation:

[0033] 101. Fast charging positive relay; 102. Fast charging negative relay; 103. First parallel relay; 104. Second parallel relay; 105. Series relay; 106. Third parallel relay; 107. Main positive relay; 108. Main negative relay; 109. Pre-charge relay; 111. First cell module; 112. Second cell module; 113. Second current sensor; 114. First current sensor; 201. Fast charging interface; 202. Front drive interface; 203. Rear drive interface; D1. First diode; D2. Second diode; D3. Third diode; F1. First fuse; F2. Second fuse; F3. Third fuse; F4. Fourth fuse; R1. Pre-charge resistor. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] New energy vehicles (NEVs) are popular with consumers due to their excellent energy-saving and emission-reduction effects and high level of intelligence. NEVs use battery packs as their power source, eliminating exhaust fumes produced by internal combustion engines, thus contributing significantly to environmental protection and air quality – virtually "zero pollution." With the continuous growth in NEV ownership and increasingly frequent charging demands, various types of charging stations are widely deployed in high-frequency parking and traffic scenarios such as urban community parking lots, underground garages in commercial complexes, highway service areas, transportation hubs, and office park parking lots, providing core energy replenishment support for the daily use of NEVs. However, due to limitations in infrastructure construction and battery pack development, the market offers two types of charging stations: one based on a 400V platform and the other on an 800V platform. This can lead to a mismatch between the battery pack voltage in the electric vehicle and the charging voltage of the charging station. For example, a 400V charging station cannot directly charge an 800V battery pack. Therefore, vehicles need to be equipped with charging and discharging circuits that can meet different charging voltages. The charging circuit in the charging and discharging circuit can be used to charge the battery pack under different charging voltages, while the discharging circuit can be used to supply power to the outside.

[0038] Please see Figure 1 As shown, the charging and discharging circuit provided by this utility model includes a charging circuit and a discharging circuit. The charging circuit includes a fast charging interface 201, a main charging circuit, and parallel charging circuits. The main charging circuit includes a fast charging positive relay 101 and a fast charging negative relay 102 connected in series between the two voltage input terminals of the fast charging interface 201. By controlling the states of the fast charging positive relay 101 and the fast charging negative relay 102, the on / off state of the charging circuit can be controlled. The charging circuit includes at least two parallel charging circuits connected in parallel, with each parallel charging circuit connected in series between the fast charging positive relay 101 and the fast charging negative relay 102. Each parallel charging circuit includes a battery cell module connected in series and a parallel relay. By controlling the parallel relay in the parallel charging circuit, the connection of the relay in the parallel charging circuit to the charging circuit can be controlled. The discharge circuit includes a drive interface, a main positive relay 107 and a main negative relay 108 connected in series between the cell module and the drive interface. By controlling the states of the main positive relay 107 and the main negative relay 108, the on / off state of the discharge circuit can be controlled. A series relay 105 is provided between the cell modules. The series-parallel connection relationship between at least two sets of cell modules can be changed by controlling the states of the series relay 105 and other relays.

[0039] 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 (BMS), which controls the opening and closing of each relay.

[0040] For details, please refer to Figure 1 As shown, in one embodiment of this utility model, the main charging circuit includes a fast-charging positive relay 101 and a fast-charging negative relay 102. The fast-charging positive relay 101 is electrically connected to the positive terminal of the fast-charging interface 201, and the fast-charging negative relay 102 is electrically connected to the negative terminal of the fast-charging interface 201. By controlling the states of the fast-charging positive relay 101 and the fast-charging negative relay 102, the state of the parallel charging circuit between them can be controlled. When the fast-charging positive relay 101 and the fast-charging negative relay 102 are in an open state, the parallel charging circuit between them is disconnected, and at this time, the battery module in the parallel charging circuit cannot be charged through the fast-charging interface 201. When the fast charging positive relay 101 and the fast charging negative relay 102 are in the closed state, it is necessary to determine whether the battery module in the parallel charging circuit is connected between the fast charging positive relay 101 and the fast charging negative relay 102 based on the state of the parallel relays connected in series with the battery module in the parallel charging circuit.

[0041] Please see Figure 1 As shown, in one embodiment of this utility model, a fast charging interface 201 is provided on the vehicle, and the fast charging interface 201 is the physical connection port between the vehicle and the charging pile. The fast charging positive relay 101 is electrically connected to the positive terminal of the fast charging interface 201, and the fast charging negative relay 102 is electrically connected to the negative terminal of the fast charging interface 201.

[0042] Please see Figure 1 As shown in this application, at least two parallel charging circuits are provided between the fast charging positive relay 101 and the fast charging negative relay 102. The number of parallel charging circuits is specifically set according to requirements. In one embodiment of this utility model, since it is necessary to meet the charging voltage of the vehicle's charging pile (400V and 800V), all battery cell modules are divided into two groups, with two parallel charging circuits corresponding to each group. In other embodiments of this utility model, if the vehicle needs to meet other voltage requirements later, three, four, or five parallel charging circuits can also be provided.

[0043] Please see Figure 1As shown, in one embodiment of this utility model, the parallel charging circuit includes a first parallel charging circuit and a second parallel charging circuit. The two ends of the first parallel charging circuit are electrically connected to a fast-charging positive relay 101 and a fast-charging negative relay 102, and the two ends of the second parallel charging circuit are also electrically connected to the same relay. During charging, the first and second parallel charging circuits are in parallel, forming two parallel circuits.

[0044] Please see Figure 1 As shown, in one embodiment of this utility model, the two controlled terminals of the fast charging positive relay 101 and the fast charging negative relay 102 are defined as the first terminal and the second terminal. When the fast charging positive relay 101 and the fast charging negative relay 102 are connected to the fast charging interface 201 and the parallel charging circuit, the first terminal of the fast charging positive relay 101 is electrically connected to the positive terminal of the fast charging interface 201, the first terminal of the fast charging negative relay 102 is electrically connected to the negative terminal of the fast charging interface 201, the two ends of the first parallel charging circuit are electrically connected to the second terminal of the fast charging positive relay 101 and the second terminal of the fast charging negative relay 102, and the two ends of the second parallel charging circuit are electrically connected to the second terminal of the fast charging positive relay 101 and the second terminal of the fast charging negative relay 102, thereby realizing the series connection of the parallel charging circuit with the fast charging positive relay 101 and the fast charging negative relay 102.

[0045] Please see Figure 1 As shown, in one embodiment of this utility model, the first parallel charging circuit includes a first diode D1, a first parallel relay 103, and a first battery cell module 111. The first diode D1, the first parallel relay 103, and the first battery cell module 111 are connected in series between the fast charging positive relay 101 and the fast charging negative relay 102. Specifically, the positive terminal of the first diode D1 is electrically connected to the fast charging positive relay 101, the negative terminal of the first diode D1 is electrically connected to one end of the first parallel relay 103, the other end of the first parallel relay 103 is electrically connected to the positive terminal of the first battery cell module 111, and the negative terminal of the first battery cell module 111 is electrically connected to the fast charging negative relay 102.

[0046] Please see Figure 1As shown, in one embodiment of this utility model, the second parallel charging circuit includes a second diode D2, a second parallel relay 104, and a second battery cell module 112. The second diode D2, the second parallel relay 104, and the second battery cell module 112 are connected in series between the fast charging positive relay 101 and the fast charging negative relay 102. Specifically, the positive terminal of the second diode D2 is electrically connected to the fast charging positive relay 101, the negative terminal of the second diode D2 is electrically connected to one end of the second parallel relay 104, the other end of the second parallel relay 104 is electrically connected to the positive terminal of the second battery cell module 112, and the negative terminal of the second battery cell module 112 is electrically connected to the fast charging negative relay 102.

[0047] Please see Figure 1 As shown, in one embodiment of this utility model, the first cell module 111 and the second cell module 112 include multiple cells connected in series and / or parallel. Each cell can be any type of cell, such as a lithium iron phosphate cell or a ternary lithium cell. In this embodiment, the rated voltage of the first cell module 111 is, for example, 400V, the rated voltage of the second cell module 112 is, for example, 400V, and the rated voltage across the first cell module 111 and the second cell module 112 connected in series is 800V.

[0048] Please see Figure 1 and Figure 2 As shown, in one embodiment of this utility model, when using a 400V charging pile to charge the first battery cell module 111 and the second battery cell module 112, the charging and discharging circuit is configured as follows: the fast charging positive relay 101, the fast charging negative relay 102, the first parallel relay 103, and the second parallel relay 104 are closed, while the other relays are open. At this time, the equivalent circuit of the charging circuit is as follows: Figure 2 As shown, the charging current enters the battery pack through the fast charging interface 201. Inside the battery pack, the current passes through the fast charging positive relay 101, the first diode D1, the first parallel relay 103, the first cell module 111, and the fast charging negative relay 102 to form a first high-voltage charging circuit. The charging current then passes through the fast charging positive relay 101, the second diode D2, the second parallel relay 104, the second cell module 112, and the fast charging negative relay 102 to form a second high-voltage charging circuit. At this time, the first cell module 111 and the second cell module 112 are connected in parallel, and the charging and discharging circuits form two parallel 400V charging circuits that charge from the fast charging interface 201. The 400V charging pile can charge the first cell module 111 and the second cell module 112.

[0049] Please see Figure 1 and Figure 2As shown in one embodiment of this utility model, when a 400V charging pile is used to charge the first battery module 111 and the second battery module 112, due to the unidirectional conduction characteristics of the first diode D1 and the second diode D2, even if there is a voltage difference between the first battery module 111 and the second battery module 112, mutual charging and discharging between the first battery module 111 and the second battery module 112 can be avoided, eliminating parallel circulating current and ensuring charging safety.

[0050] Please see Figure 1 As shown, in one embodiment of this utility model, a series relay 105 is further provided between the battery cell modules, with the series relay 105 connected in series between the two battery cell modules. One end of the series relay 105 is electrically connected to the negative terminal of one battery cell module, and the other end is electrically connected to the positive terminal of the other battery cell module. When the series relay 105 between the two battery cell modules is closed, the two battery cell modules can be connected in series. In this embodiment, the battery pack is provided with a first battery cell module 111 and a second battery cell module 112, and a corresponding series relay 105 is provided, with one end of the series relay 105 electrically connected to the negative terminal of the first battery cell module 111, and the other end of the series relay 105 electrically connected to the positive terminal of the second battery cell module 112. In other embodiments, in addition to the first cell module 111, other cell modules may be provided, and all other cell modules are connected in series between the first cell module 111 and the second cell module 112. Each other cell module is equipped with a parallel relay and a diode to form a parallel charging circuit. Simultaneously, a series relay 105 can be provided between two adjacent cell modules to connect them.

[0051] Please see Figure 1 and Figure 3 As shown, in one embodiment of this utility model, when using an 800V charging pile to charge the first battery cell module 111 and the second battery cell module 112, the charging and discharging circuit is configured as follows: the fast charging positive relay 101, the fast charging negative relay 102, the first parallel relay 103, and the series relay 105 are closed, and the second parallel relay 104 is open. At this time, the equivalent circuit of the charging circuit is as follows: Figure 3 As shown, the charging current enters the battery pack through the fast charging interface 201, and forms a high-voltage charging circuit by passing through the fast charging positive relay 101, the first diode D1, the first parallel relay 103, the first cell module 111, the series relay 105, the second cell module 112, and the fast charging negative relay 102. At this time, the first cell module 111 and the second cell module 112 are connected in series, and the charging and discharging circuit forms an 800V charging circuit that charges from the fast charging interface 201. The 800V charging pile can charge the first cell module 111 and the second cell module 112.

[0052] Please see Figure 1 As shown, in one embodiment of this utility model, for ease of description, the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging positive relay 101 is defined as the first common terminal, and the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging negative relay 102 is defined as the second common terminal.

[0053] Please see Figure 1 As shown, in one embodiment of this utility model, a current protection device is also provided in the charging circuit. Specifically, a current protection device, such as a fuse, is provided in each parallel charging circuit. In this embodiment, a first fuse F1 is provided in the first parallel charging circuit. A second fuse F2 is provided in the second parallel charging circuit. One end of the first fuse F1 is electrically connected to the negative terminal of the first battery cell module 111, and the other end is the output terminal of the first parallel charging circuit, i.e., the other end is the second common terminal. One end of the second fuse F2 is electrically connected to the common terminal of the second battery cell module 112 and the series relay 105, and the other end is electrically connected to the second parallel relay 104. A current protection device, such as a third fuse F3, is provided in the series circuit of the first battery cell module 111 and the second battery cell module 112. The third fuse F3 is connected in series with the series relay 105. That is, one end of the third fuse F3 is electrically connected to the common terminal of the first battery module 111 and the first fuse F1, and the other end is electrically connected to the series relay 105.

[0054] Please see Figure 1 As shown, in one embodiment of this utility model, a current detection device is also provided in the charging circuit. Specifically, current sensors are provided in the parallel charging circuits other than the first parallel charging circuit. In this embodiment, a first current sensor 114 is provided in the second parallel charging circuit, which can detect the current in the second parallel charging circuit. Another current sensor is also provided at the output terminal of the multiple parallel charging circuits, which can detect the magnitude of the current in all parallel charging circuits. In this application, a second current sensor 113 is provided at the output terminal of the multiple parallel charging circuits. One end of the second current sensor 113 is electrically connected to the first current sensor 114 and the first fuse F1, and the other end is electrically connected to the fast charging positive relay 101 and the main negative relay 108, i.e., the second common terminal, which can detect the charging current and discharging current on the main circuit of the charging circuit and the discharging circuit.

[0055] Please see Figure 1As shown, in one embodiment of this utility model, the discharge circuit includes a main positive relay 107, a main negative relay 108, and a third parallel relay 106. The main positive relay 107 is connected in series between the first common terminal and the positive terminal of the drive interface, and the main negative relay 108 is connected in series between the second common terminal and the negative terminal of the drive interface. One end of the third parallel relay 106 is electrically connected to the positive terminal of the first battery cell module 111, and the other end is electrically connected to the first common terminal.

[0056] Please see Figure 1 As shown, in one embodiment of this utility model, two drive interfaces are provided in the vehicle: a front-drive interface 202 and a rear-drive interface 203. The front-drive interface 202 is electrically connected to the vehicle's front-drive motor, transmitting high-voltage energy from the battery pack to the front-drive motor to power the front wheels. The rear-drive interface 203 is electrically connected to the vehicle's rear-drive motor, transmitting high-voltage energy from the battery pack to the rear-drive motor to power the rear wheels. In other embodiments, only either the front-drive interface 202 or the rear-drive interface 203 may be provided in the vehicle.

[0057] Please see Figure 1 As shown, in one embodiment of this utility model, one end of the main positive relay 107 is electrically connected to the first common terminal, and the other end is electrically connected to the positive terminal of the drive interface. Specifically, one end of the main positive relay 107 is electrically connected to the common terminal of the fast charging positive relay 101, the first diode D1, and the second diode D2, and the other end is electrically connected to the positive terminal of the front drive interface 202 and the positive terminal of the rear drive interface 203. One end of the main negative relay 108 is electrically connected to the second common terminal, and the other end is electrically connected to the negative terminal of the drive interface. Specifically, one end of the main negative relay 108 is electrically connected to the common terminal of the second current sensor 113 and the fast charging negative relay 102, and the other end is electrically connected to the negative terminal of the front drive interface 202 and the negative terminal of the rear drive interface 203.

[0058] Please see Figure 1As shown, in one embodiment of this utility model, one end of the third parallel relay 106 is electrically connected to the positive terminal of the first battery cell module 111, and the other end of the third parallel relay 106 is electrically connected to the first common terminal through the third diode D3. Specifically, one end of the third parallel relay 106 is electrically connected to the positive terminal of the first battery cell module 111, the other end of the third parallel relay 106 is electrically connected to the positive terminal of the third diode D3, and the negative terminal of the third diode D3 is electrically connected to the first common terminal. The series circuit formed by the third parallel relay 106 and the third diode D3 is connected in parallel to the series circuit formed by the first parallel relay 103 and the first diode D1. During discharge, the state of the third parallel relay 106 is controlled to control whether the battery cell module supplies power to the outside. During discharge, the third diode D3 can prevent external current from flowing back into the battery cell module.

[0059] Please see Figure 1 As shown, in one embodiment of this utility model, a pre-charging circuit is further provided in the discharge circuit, and the pre-charging circuit includes a pre-charging relay 109 and a pre-charging resistor R1. The series circuit formed by the pre-charging relay 109 and the pre-charging resistor R1 is connected in parallel to the main positive relay 107. Specifically, one end of the pre-charging relay 109 is electrically connected to one end of the main positive relay 107, the other end of the pre-charging relay 109 is electrically connected to one end of the pre-charging resistor R1, and the other end of the pre-charging resistor R1 is electrically connected to the other end of the main positive relay 107.

[0060] Please see Figure 1 and Figure 4 As shown, in one embodiment of this utility model, when the vehicle is discharging, the charging and discharging circuit is configured such that the fast charging positive relay 101, the fast charging negative relay 102, the first parallel relay 103, and the second parallel relay 104 are always in the open state. When the vehicle is charging externally at 800V, the series relay 105 closes, causing the first battery cell module 111 and the second battery cell module 112 to be connected in series, forming an 800V platform. At this time, the equivalent circuit of the discharging circuit is as follows: Figure 4As shown. Then, the third parallel relay 106, pre-charge relay 109, and main negative relay 108 are closed, while the main positive relay 107 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 controls the main positive relay 107 to close and the pre-charge relay 109 to open. The third parallel relay 106 and the main negative relay 108 remain closed during discharge. At this time, the discharge current passes through the third parallel relay 106, the third diode D3, and the main positive relay 107 to the front drive interface 202 and the rear drive interface 203. The discharge current output from the front drive interface 202 and the rear drive interface 203 drives the external high-voltage components, and then returns to the battery pack through the front drive interface 202 and the rear drive interface 203. The return current flows from the front drive interface 202 and the rear drive interface 203 through the main negative relay 108 and returns to the negative terminal of the cell module.

[0061] Please see Figure 1 As shown, in one embodiment of this utility model, a current protection device is also provided in the discharge circuit. Specifically, the discharge circuit includes a fourth fuse F4, which is connected in series between the common terminal of the main positive relay 107 and the precharge relay 109 and the positive terminal of the drive interface, thereby providing current protection during the precharge and discharge processes.

[0062] In summary, this utility model provides a charging and discharging circuit and a vehicle, including a fast charging interface; a drive interface; a fast charging positive relay and a fast charging negative relay, wherein the fast charging positive relay is electrically connected to the positive terminal of the fast charging interface, and the fast charging negative relay is electrically connected to the negative terminal of the fast charging interface; a first parallel charging circuit, including a first diode, a first parallel relay, and a first battery cell module connected in series between the fast charging positive relay and the fast charging negative relay; and a second parallel charging circuit, including a second diode, a second parallel relay, and a second battery cell module connected in series between the fast charging positive relay and the fast charging negative relay, wherein the second parallel charging circuit and the first parallel charging circuit are connected in parallel. The circuit includes: a series relay, one end of which is electrically connected to the negative terminal of the first battery cell module, and the other end of which is electrically connected to the positive terminal of the second battery cell module; a main positive relay and a main negative relay, the main positive relay being connected in series between the first common terminal and the positive terminal of the drive interface, and the main negative relay being connected in series between the second common terminal and the negative terminal of the drive interface; and a third parallel relay, connected in series between the first common terminal and the positive terminal of the first battery cell module; wherein, the first common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit, and the fast charging positive relay, and the second common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit, and the fast charging negative relay. This allows charging piles with different charging voltages to charge the battery pack, and ensures charging safety during the charging process.

[0063] 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: Fast charging interface; Driver interface; A fast charging positive relay and a fast charging negative relay, wherein the fast charging positive relay is electrically connected to the positive terminal of the fast charging interface, and the fast charging negative relay is electrically connected to the negative terminal of the fast charging interface; The first parallel charging circuit includes a first diode, a first parallel relay, and a first battery cell module connected in series between the fast charging positive relay and the fast charging negative relay; The second parallel charging circuit includes a second diode, a second parallel relay, and a second battery cell module connected in series between the fast charging positive relay and the fast charging negative relay. The second parallel charging circuit and the first parallel charging circuit are two circuits connected in parallel. A series relay, one end of which is electrically connected to the negative terminal of the first battery cell module, and the other end of which is electrically connected to the positive terminal of the second battery cell module; A main positive relay and a main negative relay, wherein the main positive relay is connected in series between the first common terminal and the positive terminal of the drive interface, and the main negative relay is connected in series between the second common terminal and the negative terminal of the drive interface; as well as The third parallel relay is connected in series between the first common terminal and the positive terminal of the first cell module; Wherein, the first common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging positive relay, and the second common terminal is the common terminal of the first parallel charging circuit, the second parallel charging circuit and the fast charging negative relay.

2. The charging and discharging circuit according to claim 1, characterized in that, The positive terminal of the first diode is electrically connected to the fast-charging positive relay, the negative terminal of the first diode is electrically connected to one end of the first parallel relay, the other end of the first parallel relay is electrically connected to the positive terminal of the first battery cell module, and the negative terminal of the first battery cell module is electrically connected to the fast-charging negative relay.

3. The charging and discharging circuit according to claim 1, characterized in that, The positive terminal of the second diode is electrically connected to the fast-charging positive relay, the negative terminal of the second diode is electrically connected to one end of the second parallel relay, the other end of the second parallel relay is electrically connected to the positive terminal of the second battery cell module, and the negative terminal of the second battery cell module is electrically connected to the fast-charging negative relay.

4. The charging and discharging circuit according to claim 1, characterized in that, The charging and discharging circuit further includes a third diode, the negative terminal of which is electrically connected to the first common terminal, and the positive terminal of which is electrically connected to the third parallel relay.

5. The charging and discharging circuit according to claim 1, characterized in that, The rated voltage of the first battery cell module and the second battery cell module is 400V.

6. The charging and discharging circuit according to claim 5, characterized in that, The configuration is as follows: the fast charging positive relay, the fast charging negative relay, the first parallel relay and the second parallel relay are closed, and the series relay, the main positive relay, the main negative relay and the third parallel relay are open, and the charging and discharging circuit forms two parallel 400V charging circuits that charge from the fast charging interface.

7. The charging and discharging circuit according to claim 5, characterized in that, The configuration is as follows: the fast charging positive relay, the fast charging negative relay, the first parallel relay and the second parallel relay are disconnected, and the series relay, the main positive relay, the main negative relay and the third parallel relay are closed, and the charging and discharging circuit forms an 800V discharge circuit to discharge to the drive port.

8. The charging and discharging circuit according to claim 1, characterized in that, The charging and discharging circuit includes a pre-charging circuit, which is connected in parallel to the main positive relay.

9. The charging and discharging circuit according to claim 8, characterized in that, The pre-charging 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.

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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