Wireless BDU structure and heat dissipation simulation method

Abstract

The invention provides a wireless BDU structure, which comprises a shell, a component assembly, a busbar assembly, a PCB acquisition circuit board, a conduction assembly and a liquid cooling assembly, and is characterized in that the component assembly is arranged in the shell; the busbar assembly is arranged in the shell in an injection molding mode. The PCB acquisition circuit board is arranged in the shell and close to one side of the opening of the shell, the PCB acquisition circuit board and the component assembly are arranged at an interval, the conduction assembly is arranged between the component assembly and the PCB acquisition circuit board and between the busbar assembly and the PCB acquisition circuit board, and the liquid cooling assembly is arranged on the closed side of the shell and abuts against the surface of the busbar assembly; the busbar assemblies are fixed in the shell through the injection molding process, the stability and reliability of the structure are enhanced, meanwhile, the insulativity between the busbars is guaranteed, the wiring harness-free layout of high-voltage sampling and low-voltage control is achieved by combining the conduction assemblies and the PCB collection circuit board integrated component assemblies, the space utilization rate is increased, and the cost is reduced. And heat on the surface of the busbar assembly is taken away through the liquid cooling assembly, so that an efficient heat dissipation effect is realized, and the reliability and the stability of the BDU are improved.

Description

Technical Field

[0001] The present invention relates to the field of BDU technology, and in particular to a wireless bundle BDU structure and a heat dissipation simulation method. Background Art

[0002] BDU, or battery energy distribution unit, is the core component in the high-voltage circuit of an electric vehicle. This unit is also called a battery cut-off unit, which is responsible for regulating the power-on, power-off, pre-charging and charging of the high-voltage electrical circuit. The internal structure of BDU is quite complex, including relays, fuses, current collection components, and external high-voltage copper busbars, signal and drive connectors, etc. Among them, relays can be divided into high-voltage main positive / main negative relays, pre-charging relays and fast-charging relays according to their functions; fuses are connected in series in the circuit to play an overcurrent protection role. Once the current is too large, the metal components inside will melt, thereby cutting off the circuit.

[0003] A BDU controller, BDU and vehicle with publication number CN210707274U, the BDU controller includes a control circuit and a battery parameter sampling circuit, the control circuit is connected to the battery parameter sampling circuit; wherein the control circuit is used to respectively connect to the upper and lower power actuators and the battery management unit BMU in the BDU.

[0004] In the current BDU controller, the connections between the high-voltage sampling and low-voltage control ends of the relay are all connected by wiring harnesses, which will cause troubles in the wiring in the distribution box and occupy a large amount of internal space, which not only increases the complexity and weight of the system, but also may cause instability and reliability of signal transmission. In addition, the existing BDU controller has poor heat dissipation effect, which reduces the reliability and stability of the BDU. Summary of the invention

[0005] In view of this, the present invention proposes a wireless bundle BDU structure and a heat dissipation simulation method, which reduces the safety risks caused by overheating or electrical failure based on reliable wireless bundle electrical connection and efficient heat dissipation design, and not only improves the space utilization, but also improves the reliability and stability of the BDU.

[0006] The technical solution of the present invention is implemented as follows: In the first aspect, the present invention provides a wireless bundle BDU structure, including a housing, a component assembly, a busbar assembly, a PCB collection circuit board, a conduction assembly and a liquid cooling assembly, wherein:

[0007] The shell is hollow inside, with one side closed and the other side having an opening;

[0008] The component assembly is arranged in the housing and is used to control the opening and closing of the battery circuit;

[0009] The busbar assembly is injection molded in the housing and is used to connect and conduct the high-voltage devices of the component assembly;

[0010] The PCB acquisition circuit board is arranged in the housing, close to one side of the housing opening, and is arranged at intervals with the component assembly, and is used to collect and transmit signals of various high-voltage devices of the component assembly;

[0011] The conducting component is arranged between the component assembly and the busbar assembly and the PCB acquisition circuit board, and is used to connect and conduct each acquisition point on the busbar assembly and the contact points of each high-voltage device of the component assembly with the PCB acquisition circuit board;

[0012] The liquid cooling component is arranged on the closed side of the shell and abuts against the surface of the busbar component. A heat exchange medium flows in the liquid cooling component for cooling and heat dissipation.

[0013] On the basis of the above technical solution, preferably, the component assembly includes a main positive relay, a pre-charge relay, a main negative relay, a fast charge relay, a main fuse, a pre-charge resistor, a shunt and a branch fuse, wherein:

[0014] The main positive relay, the pre-charge relay, the main negative relay, the fast charge relay, the main fuse, the pre-charge resistor, the shunt and the branch fuse are all arranged in the housing;

[0015] The main fuse is arranged near one side edge of the shell, and the main fuse is parallel to the longitudinal horizontal direction of the shell;

[0016] The main positive relay, the pre-charging resistor and the branch fuse are all arranged on the side of the main fuse away from the edge of the shell, and the main positive relay is located between the pre-charging resistor and the branch fuse, and the arrangement direction of the main positive relay, the pre-charging resistor and the branch fuse is perpendicular to the main fuse;

[0017] The pre-charge relay and the fast-charge relay are both arranged on the side of the main positive relay away from the main fuse, and the pre-charge relay is arranged corresponding to the position of the main positive relay, and the fast-charge relay is arranged corresponding to the position of the pre-charge resistor, and the arrangement direction of the pre-charge relay and the fast-charge relay is perpendicular to the main fuse;

[0018] The main negative relay is located on a side of the pre-charging relay away from the main positive relay, and the main negative relay is arranged correspondingly to the pre-charging relay, and the arrangement direction of the main negative relay is perpendicular to the main fuse;

[0019] The shunt is located on one side of the main negative relay away from the pre-charging relay and is arranged close to the edge of the other side of the shell.

[0020] On the basis of the above technical solution, preferably, the busbar assembly includes a first busbar, a second busbar, a third busbar, a fourth busbar, a fifth busbar, a sixth busbar, a seventh busbar and an eighth busbar, wherein:

[0021] One end of the first busbar is fixedly connected to the input end of the main fuse as the input end of the main positive circuit, and the other end of the first busbar passes through and extends to the bottom of the shell;

[0022] One end of the second busbar is fixedly connected to the output end of the main fuse, and the other end of the second busbar is fixedly connected to one end of the contact of the main positive relay;

[0023] The third busbar is fixedly connected to the other end of the contact of the main positive relay and one end of the contact of the fast charging relay, respectively, and the third busbar has three connection ends;

[0024] The first connection end of the third busbar penetrates and extends into the shell and is arranged close to the edge. The first connection end of the third busbar serves as the positive output end of the front drive circuit.

[0025] The second connection end of the third busbar passes through and extends into the shell, and is arranged on both sides of the shell with the first connection end of the third busbar, and is arranged opposite to the first connection end of the third busbar. The second connection end of the third busbar serves as the positive output end of the rear drive circuit.

[0026] The third connection end of the third busbar penetrates and extends into the housing, and is located on the same side and adjacent to the first connection end of the third busbar. The third connection end of the third busbar is fixedly connected to one end of the branch fuse;

[0027] One end of the fourth busbar is fixedly connected to the other end of the branch fuse, and the other end of the fourth busbar serves as the positive output end of the IPS control loop;

[0028] The fifth busbar is fixedly connected to the other end of the contact of the fast charging relay, and the fifth busbar has a connection end, the connection end of the fifth busbar passes through and extends into the housing, and is arranged adjacent to the first connection end of the third busbar on the same side, and the connection end of the fifth busbar serves as the positive output end of the fast charging circuit;

[0029] The sixth busbar is arranged in the shell, one end of the sixth busbar is fixedly connected to the input end of the shunt, and the other end serves as the input end of the main negative circuit;

[0030] One end of the seventh busbar is fixedly connected to the output end of the shunt, and the other end penetrates and extends to the bottom of the housing and is fixedly connected to one end of the contact of the main negative relay;

[0031] The eighth busbar is fixedly connected to the other end of the contact of the main negative relay. The eighth busbar has four connection ends. The connection ends of the eighth busbar pass through and extend into the shell. The first connection end and the second connection end of the eighth busbar are on the same side and adjacent to the second connection end of the third busbar. The first connection end of the eighth busbar serves as the negative output end of the IPS control loop, and the second connection end of the eighth busbar serves as the negative output end of the rear-drive loop. The third and fourth connection ends of the eighth busbar are on the same side and adjacent to the first connection end of the third busbar. The third connection end of the eighth busbar serves as the negative output end of the fast charging loop, and the fourth connection end of the eighth busbar serves as the negative output end of the front-drive loop.

[0032] On the basis of the above technical solution, preferably, the first busbar, the second busbar, the third busbar, the fifth busbar, the seventh busbar and the eighth busbar are all injection molded on the bottom surface of the shell and are at the same plane height as the bottom surface of the shell.

[0033] On the basis of the above technical solution, preferably, the conducting component includes a plurality of inserts and wire posts, wherein:

[0034] The contact ends of the main positive relay, main negative relay and fast charging relay are all in the housing, and the coil ends are all on the housing opening side; the contact end and coil end of the pre-charging relay are both on the housing opening side;

[0035] A plurality of conductor posts are respectively fixed on the second busbar, the third busbar, the fifth busbar, the sixth busbar, the seventh busbar and the eighth busbar, and one end of the plurality of conductor posts penetrates and extends into the housing;

[0036] A plurality of plugs are respectively fixed on the contact ends of the main positive relay, the main negative relay and the fast charging relay, the contact end and the coil end of the pre-charging relay and one end of each wire column extending out of the housing, and the other ends of the plurality of plugs are plugged into the corresponding ports of the PCB acquisition circuit board;

[0037] The two ends of the pre-charge resistor are plugged into the corresponding ports of the PCB acquisition circuit board.

[0038] On the basis of the above technical solution, preferably, it also includes an insulating film and a thermal conductive pad, wherein the insulating film is arranged on the bottom surface of the shell and abuts against the surfaces of the first busbar, the second busbar, the third busbar, the fifth busbar, the seventh busbar and the eighth busbar, and the thermal conductive pad is arranged on the side of the insulating film away from the shell, for introducing the heat dissipated by the busbar into the liquid cooling component.

[0039] On the basis of the above technical solution, preferably, the liquid cooling assembly includes an upper cover, a bottom shell, two outward expansion pipes, a plurality of boss portions and a plurality of extension portions, wherein:

[0040] One side of the upper cover is fixedly connected to the thermal pad, and the other side is fixedly connected to the bottom shell;

[0041] A first flow channel and a second flow channel which are not connected to each other are arranged in the bottom shell, the liquid inlet side and the liquid outlet side of the first flow channel and the second flow channel are connected, and the shapes of the first flow channel and the second flow channel are both U-shaped;

[0042] The two outward expansion pipes are fixed on one side of the upper cover close to the thermal pad and are connected to the inside of the bottom shell and are arranged adjacent to each other. The two outward expansion pipes are respectively located at the connecting parts of the liquid inlet end side and the liquid outlet end side of the first flow channel and the second flow channel;

[0043] One side of the outward expansion pipe is arranged with the upper cover in an inclined plane, and the inclination direction of the inclined plane is consistent with the flow direction of the fluid, so as to reduce the flow resistance of the flow channel;

[0044] A plurality of boss portions are arranged in communication with each other at the liquid inlet end side and the liquid outlet end side of the first flow channel and the second flow channel, and the positions of the boss portions correspond to the positions of the first busbar and the second busbar;

[0045] Several extension parts are arranged on both sides of the inner walls of the first flow channel and the second flow channel, one side of the extension part is extended obliquely toward the flow channel, and the extension parts on both sides are evenly staggered and arranged corresponding to the positions of the third busbar, the fifth busbar, the seventh busbar and the eighth busbar.

[0046] In a second aspect, the present invention further provides a heat dissipation simulation method for a wireless bundle BDU structure, which is implemented using a wireless bundle BDU structure, and the method comprises the following steps:

[0047] S1, modeling the wireless bundle BDU structure in the modeling software;

[0048] S2, obtaining the total power, thermal radiation and thermal convection heat dissipation power of all heat-generating devices inside the wireless bundle BDU structure, and calculating the required heat dissipation of the liquid cooling component based on the total power, thermal radiation and thermal convection heat dissipation power of the heat-generating devices;

[0049] S3, constructing a heat dissipation calculation model according to the internal structure of the liquid cooling component, performing thermal simulation calculation on the liquid cooling component structure, and adjusting the internal structure of the liquid cooling component according to the heat dissipation calculation model to obtain an optimal liquid cooling component structure.

[0050] On the basis of the above technical solution, preferably, it is characterized in that: step S2 includes the following steps:

[0051] Obtain the internal resistance of all heating devices inside the wireless bundle BDU structure, and calculate the total power of all heating devices. All heating devices inside the wireless bundle BDU structure include the high-voltage devices of the component assembly and the busbars of the busbar assembly. The calculation expression is:

[0052] P1=I 2 R

[0053] Where, P1 is the total power of all heating devices inside the wireless bundle BDU structure, I is the current value passing through the BDU, and R is the sum of the internal resistances of the first busbar, the second busbar, the third busbar, the fourth busbar, the fifth busbar, the sixth busbar, the seventh busbar, the eighth busbar, the main positive relay, the pre-charge relay, the main negative relay, the fast charge relay, the main fuse, the pre-charge resistor, the shunt, and the branch fuse;

[0054] Calculate the heat radiation heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is:

[0055] Q1=εAσT 4

[0056] Where, Q1 is the heat radiation power of all devices inside the wireless bundle BDU structure, ε is the emissivity, A is the heat dissipation area, σ is the Stefan-Boltzmann constant, and T is the temperature difference between the wireless bundle BDU structure and the environment;

[0057] Calculate the heat convection heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is:

[0058] Q2=AhΔT1

[0059] Where, Q2 is the heat dissipation power of all devices inside the wireless bundle BDU structure, A is the heat dissipation area, h is the surface heat transfer coefficient, and ΔT1 is the temperature difference between the heating device and the air;

[0060] According to the total power, heat radiation and heat convection heat dissipation power of the heat generating device, the required heat dissipation of the liquid cooling component 6 is calculated, and the expression is:

[0061] Q3=P1-Q1-Q2

[0062] Where Q3 is the required heat dissipation of the liquid cooling component.

[0063] Based on the above technical solution, preferably, step S3 includes the following steps:

[0064] According to the internal structure of the liquid cooling component, a heat dissipation calculation model is constructed, and the expression is:

[0065]

[0066] Where, Q4 is the estimated heat dissipation of the liquid cooling component, q1 is the water inlet flow rate, m is the mass of the heat exchange medium, V1 is the preset cavity volume between the upper cover and the bottom shell, r is the radius of the boss and the extension; h1 is the height of the boss and the extension; n is the total number of the boss and the extension, and ΔT2 is the temperature difference between the two expansion pipes;

[0067] According to the heat dissipation calculation model, the initial size and number of the boss and extension of the liquid cooling component satisfying the condition of 0.9Q4≥Q3 are obtained, and the initial structure of the liquid cooling component is obtained;

[0068] Import the initial wireless bundle BDU structure model into the simulation software, perform initial settings, mesh division and solution, and output the temperature of the high-voltage devices of the component assembly, the temperature difference of the busbar assembly, the insulation film, the thermal pad, the flow resistance of the internal flow channel of the liquid cooling assembly, and the simulated temperature cloud map, simulated velocity section cloud map and simulated pressure section cloud map;

[0069] According to the required heat dissipation of the liquid cooling component and the radius and number of the boss and extension, the temperature difference of the liquid cooling component is calculated and expressed as:

[0070]

[0071] Where DT1 is the temperature difference of the liquid cooling component, L is the heat transfer path, and k is the thermal conductivity;

[0072] According to the temperature difference of the liquid cooling assembly, the temperature of the high-voltage device of the component assembly, the temperature difference of the busbar assembly, the insulation film, the thermal pad, the flow resistance of the internal flow channel of the liquid cooling assembly, and the simulated temperature cloud map, the simulated velocity section cloud map, and the simulated pressure section cloud map, the conditions that meet the optimal liquid cooling assembly structure are preset;

[0073] The conditions are as follows: the sum of the temperature difference of the liquid cooling component, the temperature difference of the busbar component, the insulation film, the thermal pad and the temperature of the heat exchange medium is greater than or equal to the temperature of the high-voltage device of the component assembly, and the temperature of the liquid cooling component is uniform, the flow velocity of the heat exchange medium is uniform, and the pressure distribution of the heat exchange medium is uniform based on the flow resistance of the internal flow channel of the liquid cooling component and the simulated temperature cloud map, simulated velocity section cloud map and simulated pressure section cloud map;

[0074] If all conditions are met, the current optimal solution is output to obtain the final liquid cooling component structure;

[0075] If not, a parametric iterative simulation is performed on the radius and number of the boss and the extension, and the radius and number parameters of the boss and the extension that meet the conditions are output as the optimal solution to obtain the final liquid cooling component structure.

[0076] The wireless bundle BDU structure and heat dissipation simulation method of the present invention have the following beneficial effects compared with the prior art:

[0077] (1) The busbar assembly is fixed in the shell through the injection molding process, which not only realizes the electrical connection between the high-voltage devices, but also enhances the stability and reliability of the structure, while ensuring the insulation between the busbars, improving the safety of the BDU, and adopts the high-voltage sampling and low-voltage control of the conductive components and PCB acquisition circuit board integrated components to realize the wireless beam layout and improve the space utilization. The liquid cooling component is in close contact with the surface of the busbar assembly, and the heat exchange medium effectively absorbs and takes away the heat, achieving an efficient heat dissipation effect. Therefore, the wireless beam BDU structure reduces the safety risks caused by overheating or electrical failure based on the reliable wireless beam electrical connection and efficient heat dissipation design, and improves the reliability and stability of the BDU;

[0078] (2) By directly injecting the busbar on the bottom surface of the shell, the space occupied inside the shell is reduced, making the entire BDU more compact and facilitating heat dissipation. The heat on the busbar can be more effectively transferred to the environment, reducing the temperature inside the BDU. At the same time, the flat bottom surface design facilitates the installation of subsequent liquid cooling components.

[0079] (3) By expanding the external expansion pipe, the contact area between the coolant and the liquid cooling component is increased, which helps to improve the cooling efficiency. The inlet of the external expansion pipe is designed to be inclined at an angle consistent with the flow channel direction, which can reduce the flow resistance of the coolant in the flow channel, allowing the coolant to enter the liquid cooling component more smoothly. The contact area between the heat exchange medium inside the water cooling plate and the high temperature zone is increased by setting the boss part and the extension part, achieving a better cooling effect;

[0080] (4) By calculating the heat dissipation requirements, optimizing the liquid cooling component structure, and comprehensively evaluating the heat dissipation performance and adjusting the radius and number of the bosses, the heat dissipation requirements can be met and the optimal structure can be achieved to ensure the stability and safety of the BDU structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0082] Figure 1 A three-dimensional diagram of the internal structure of the housing of the wireless bundle BDU structure of the present invention;

[0083] Figure 2 A three-dimensional diagram of the component assembly and housing structure of the wireless bundle BDU structure of the present invention;

[0084] Figure 3 A top view of the housing of the wireless bundle BDU structure of the present invention;

[0085] Figure 4 It is a three-dimensional diagram of the component assembly and busbar assembly structure of the wireless bundle BDU structure of the present invention;

[0086] Figure 5 A perspective view of a housing of a wireless bundle BDU structure of the present invention;

[0087] Figure 6 An exploded view of a liquid cooling component of the wireless bundle BDU structure of the present invention;

[0088] Figure 7 It is a circuit schematic diagram of the wireless bundle BDU structure of the present invention;

[0089] Figure 8 It is a circuit diagram of the filter module of the wireless bundle BDU structure of the present invention. DETAILED DESCRIPTION

[0090] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0091] First, as Figure 1-7 As shown, the present invention provides a wireless beam BDU structure, including a shell 1, a component assembly 2, a busbar assembly 3, a PCB acquisition circuit board 4, a conduction assembly 5 and a liquid cooling assembly 6, wherein the shell 1 is hollow inside, and one side is closed and the other side is provided with an opening; the component assembly 2 is arranged in the shell 1, and is used to control the opening and closing of the battery circuit; the busbar assembly 3 is injection molded in the shell 1, and is used to connect and conduct between the high-voltage devices of the component assembly 2; the PCB acquisition circuit board 4 is arranged in the shell 1, and is close to one side of the opening of the shell 1, and is arranged at an interval with the component assembly 2, and is used to collect and transmit signals of each high-voltage device of the component assembly 2; the conduction assembly 5 is arranged between the component assembly 2 and the busbar assembly 3 and the PCB acquisition circuit board 4, and is used to connect and conduct between each acquisition point on the busbar assembly 3 and the contacts of each high-voltage device of the component assembly 2 and the PCB acquisition circuit board 4; the liquid cooling assembly 6 is arranged on the closed side of the shell 1, and is in contact with the surface of the busbar assembly 3, and a heat exchange medium flows in the liquid cooling assembly 6 for cooling and heat dissipation.

[0092] In the current traditional BDU structure, a large number of cables and connectors not only increase the complexity and weight of the system, but may also cause instability and reliability problems in signal transmission. In this embodiment, the busbar assembly 3 is fixed in the shell 1 through the injection molding process, which not only realizes the electrical connection between the high-voltage devices, but also enhances the stability and reliability of the structure, while ensuring the insulation between the busbars, improving the safety of the BDU, and adopts the conduction component 5 and the PCB acquisition circuit board 4 to integrate the high-voltage sampling and low-voltage control of the component assembly 2, realizing a wireless beam layout, saving a lot of space inside the BDU, and, through the set liquid cooling component 6, it is in close contact with the surface of the busbar assembly 3, and the heat is effectively absorbed and taken away by the internal flowing heat exchange medium, achieving efficient heat dissipation effect, so that the wireless beam BDU structure reduces the safety risks caused by overheating or electrical failure according to the reliable wireless beam electrical connection and efficient heat dissipation design, and improves the reliability and stability of the BDU.

[0093] The component assembly 2 in this embodiment includes a main positive relay 21, a pre-charge relay 22, a main negative relay 23, a fast charge relay 24, a main fuse 25, a pre-charge resistor 26, a shunt 27 and a branch fuse 28, wherein the main positive relay 21, the pre-charge relay 22, the main negative relay 23, the fast charge relay 24, the main fuse 25, the pre-charge resistor 26, the shunt 27 and the branch fuse 28 are all arranged in the shell 1; the main fuse 25 is arranged near the edge of one side of the shell 1, and the main fuse 25 is parallel to the longitudinal horizontal direction of the shell 1; the main positive relay 21, the pre-charge resistor 26 and the branch fuse 28 are all arranged on the side of the main fuse 25 away from the edge of the shell 1, and the main positive relay 21 is located between the pre-charge resistor 26 and the branch fuse 28, and the main positive relay 21, the pre-charge resistor 26 and the branch fuse 28 are arranged. The arrangement directions of the charging resistor 26 and the branch fuse 28 are both perpendicular to the main fuse 25; the pre-charging relay 22 and the fast-charging relay 24 are both arranged on the side of the main positive relay 21 away from the main fuse 25, and the pre-charging relay 22 is arranged corresponding to the position of the main positive relay 21, and the fast-charging relay 24 is arranged corresponding to the position of the pre-charging resistor 7, and the arrangement directions of the pre-charging relay 22 and the fast-charging relay 24 are both perpendicular to the main fuse 25; the main negative relay 23 is located on the side of the pre-charging relay 22 away from the main positive relay 21, and the main negative relay 23 is arranged corresponding to the position of the pre-charging relay 22, and the arrangement direction of the main negative relay 23 is perpendicular to the main fuse 25; the shunt 27 is located on the side of the main negative relay 23 away from the pre-charging relay 22, and is arranged close to the other side edge of the shell 1.

[0094] It should be noted that the main positive relay 21 is responsible for the connection and disconnection between the positive pole of the battery pack and the main circuit. The pre-charge relay 22 pre-charges the battery pack through the pre-charge resistor 26 before the battery pack is connected to the main circuit to protect the battery pack and the main circuit from large current shocks. The main negative relay 23 is responsible for the connection and disconnection between the negative pole of the battery pack and the main circuit, and works in conjunction with the main positive relay 21. The fast charge relay 24 is used to control the on and off of the fast charge circuit to achieve the fast charging function of the battery pack. The main fuse 25 is used as an overcurrent protection device. When the current exceeds the set value, the main fuse 25 will melt, cut off the circuit, and protect the battery pack and other components from damage; the pre-charge resistor 26 limits the current in the pre-charging stage to prevent the battery pack and the main circuit from being subjected to excessive shocks. The shunt 27 is used to measure the current of the battery pack, and is usually used in conjunction with a current sensor to provide accurate current data for use by the monitoring and protection system. The branch fuse 28 provides overcurrent protection for one or some branches of the battery pack to ensure the safe operation of the branch.

[0095] In addition, through reasonable layout design, component assembly 2 realizes effective connection and isolation between components, improves the reliability and stability of the circuit; at the same time, it also facilitates the heat dissipation, maintenance and connection with external systems of the components, helps to improve the overall performance of BDU and ensure the safe and efficient operation of the battery system.

[0096] The busbar assembly 3 in this embodiment includes a first busbar 31, a second busbar 32, a third busbar 33, a fourth busbar 34, a fifth busbar 35, a sixth busbar 36, a seventh busbar 37 and an eighth busbar 38, wherein one end of the first busbar 31 is fixedly connected to the input end of the main fuse 25 as the input end of the main positive circuit, and the other end of the first busbar 31 passes through and extends to the bottom of the shell 1; one end of the second busbar 32 is fixedly connected to the output end of the main fuse 25, and the other end of the second busbar 32 is fixedly connected to one end of the contact of the main positive relay 21; the third busbar 33 is fixedly connected to the other end of the contact of the main positive relay 21 and one end of the contact of the fast charging relay 24, respectively, and the third busbar 33 has three connections. end; the first connection end of the third busbar 33 passes through and extends into the shell 1, and is arranged near the edge, and the first connection end of the third busbar 33 serves as the positive output end of the front drive circuit; the second connection end of the third busbar 33 passes through and extends into the shell 1, and is arranged on both sides of the shell 1 with the first connection end of the third busbar 33, and is arranged opposite to the first connection end of the third busbar 33, and the second connection end of the third busbar 33 serves as the positive output end of the rear drive circuit; the third connection end of the third busbar 33 passes through and extends into the shell 1, and is located on the same side as the first connection end of the third busbar 33 and is arranged adjacent to the third connection end of the third busbar 33, and the third connection end of the third busbar 33 is fixedly connected to one end of the branch fuse 28; one end of the fourth busbar 34 is fixedly connected to the other end of the branch fuse 28, and the fourth busbar The other end of 34 serves as the positive output end of the IPS control loop; the fifth busbar 35 is fixedly connected to the other end of the contact of the fast charging relay 24, and the fifth busbar 35 has a connecting end, the connecting end of the fifth busbar 35 passes through and extends into the shell 1, and is arranged adjacent to the first connecting end of the third busbar 33 on the same side, and the connecting end of the fifth busbar 35 serves as the positive output end of the fast charging loop; the sixth busbar 36 is arranged in the shell 1, one end of the sixth busbar 36 is fixedly connected to the input end of the shunt 27, and the other end serves as the input end of the main negative loop; one end of the seventh busbar 37 is fixedly connected to the output end of the shunt 27, and the other end passes through and extends to the bottom of the shell 1 and is fixedly connected to one end of the contact of the main negative relay 23; The eighth busbar 38 is fixedly connected to the other end of the contact of the main negative relay 23. The eighth busbar 38 has four connection ends. The connection ends of the eighth busbar 38 pass through and extend into the shell 1. The first connection end and the second connection end of the eighth busbar 38 are on the same side and adjacent to the second connection end of the third busbar 33. The first connection end of the eighth busbar 38 serves as the negative output end of the IPS control loop, and the second connection end of the eighth busbar 38 serves as the negative output end of the rear-drive loop. The third and fourth connection ends of the eighth busbar 38 are on the same side and adjacent to the first connection end of the third busbar 33. The third connection end of the eighth busbar 38 serves as the negative output end of the fast charging loop, and the fourth connection end of the eighth busbar 38 serves as the negative output end of the front-drive loop.

[0097] It should be noted that the busbars in the busbar assembly 3 are effectively connected together through precise connection points, including the main fuse 25, the main positive relay 21, the fast charging relay 24, the branch fuse 28, the shunt 27 and the main negative relay 23, to form a complete electrical circuit. The layout of the busbar assembly 3 fully considers the space limitations inside the shell 1, so that each busbar can meet the requirements of electrical connection while minimizing the space occupancy, thereby improving the overall integration and reliability of the BDU. The busbars in the busbar assembly 3 are tightly combined with the shell 1 through injection molding and other processes to form a solid protective layer, which effectively prevents external interference and short-circuit risks. At the same time, the setting of the main fuse 25 and the branch fuse 28 provides dual overcurrent protection for the circuit, further improving the safety of the BDU.

[0098] In this embodiment, the first busbar 31 , the second busbar 32 , the third busbar 33 , the fifth busbar 35 , the seventh busbar 37 and the eighth busbar 38 are all injection molded on the bottom surface of the housing 1 and are at the same plane height as the bottom surface of the housing 1 .

[0099] It should be noted that by directly injecting the busbar on the bottom surface of the shell 1, the space occupied inside the shell 1 is reduced, the need for additional mounting brackets or fixings is reduced, space is saved, and the entire BDU is more compact. At the same time, the overall stability of the structure is enhanced, ensuring a firm connection between the busbar and the shell 1, and reducing the risk of loosening or damage due to vibration or impact. Placing the busbar on the bottom surface of the shell helps dissipate heat. The bottom surface is usually more easily in contact with the outside air, so the heat on the busbar can be more effectively transferred to the environment, thereby reducing the temperature inside the BDU. In addition, the flat bottom design also facilitates the installation of the liquid cooling component 6.

[0100] The conduction component 5 in this embodiment includes a plurality of plug-ins 51 and wire posts 52, wherein the contact ends of the main positive relay 21, the main negative relay 23 and the fast charging relay 24 are all in the housing 1, and the coil ends are all in the opening side of the housing 1; the contact end and the coil end of the pre-charging relay 22 are both in the opening side of the housing 1; the plurality of wire posts 52 are respectively fixed on the second busbar 32, the third busbar 33, the fifth busbar 35, the sixth busbar 36, the seventh busbar 37 and the eighth busbar 38, and one end of the plurality of wire posts 52 passes through and extends into the housing 1; the plurality of plug-ins 51 are respectively fixed on the contact ends of the main positive relay 21, the main negative relay 23 and the fast charging relay 24, the contact ends and the coil ends of the pre-charging relay 22 and one end of each wire post 52 extending out of the housing 1, and the other ends of the plurality of plug-ins 51 are plugged into the corresponding ports of the PCB acquisition circuit board 4; the two ends of the pre-charging resistor 26 are plugged into the corresponding ports of the PCB acquisition circuit board 4.

[0101] It should be noted that the plug 51 is a metal sheet with conductive function. The plug 51 and the wire post 52 are provided to achieve reliable electrical connection between the relay contacts, the busbar and the PCB acquisition circuit board 4, and effectively utilize the space inside the shell, making the entire BDU more compact.

[0102] This embodiment also includes an insulating film 7 and a thermal pad 8, wherein the insulating film 7 is arranged on the bottom surface of the shell 1 and abuts against the surfaces of the first busbar 31, the second busbar 32, the third busbar 33, the fifth busbar 35, the seventh busbar 37 and the eighth busbar 38, and the thermal pad 8 is arranged on the side of the insulating film 7 away from the shell 1, and is used to introduce the heat dissipated by the busbar into the liquid cooling component 6.

[0103] It should be noted that the sizes of the insulating film 7 and the thermal pad 8 are the same as the size of the bottom of the shell 1. The insulating film 7 and the thermal pad 8 are laid flat in sequence. The insulating film 7 insulates the busbar assembly 3 to prevent short circuit or leakage between the busbar assembly 3 and the shell 1. The thermal pad 8 effectively introduces the heat generated by the busbar assembly 3 during the conduction process to the liquid cooling assembly 6, and takes away the heat through the circulation of the heat exchange medium of the liquid cooling assembly 6, thereby maintaining the stable operation of the electrical system.

[0104] The liquid cooling assembly 6 in this embodiment includes an upper cover 61, a bottom shell 62, two outward expansion pipes 63, a plurality of boss portions 65 and a plurality of extension portions 66, wherein one side of the upper cover 61 is fixedly connected to the thermal pad 8, and the other side is fixedly connected to the bottom shell 62; a first flow channel 600 and a second flow channel 610 which are not connected to each other are arranged in the bottom shell 62, the liquid inlet side and the liquid outlet side of the first flow channel 600 and the second flow channel 610 are connected, and the shapes of the first flow channel 600 and the second flow channel 610 are both U-shaped; the two outward expansion pipes 63 are fixed on one side of the upper cover 61 close to the thermal pad 8, and are connected to the inside of the bottom shell 62, and are arranged adjacent to each other, and the two outward expansion pipes 63 are respectively located in the first flow channel 600 and the second flow channel 610 The connecting part of the liquid inlet end side and the liquid outlet end side; one side of the outward expansion pipe 63 is arranged with the upper cover 61 in an inclined surface, and the inclination direction of the inclined surface is consistent with the flow direction of the fluid, which is used to reduce the flow resistance of the flow channel; a plurality of bosses 65 are arranged in the connection between the liquid inlet end side and the liquid outlet end side of the first flow channel 600 and the second flow channel 610, and the position of the boss 65 corresponds to the position of the first busbar 31 and the second busbar 32; a plurality of extensions 66 are arranged on both sides of the inner wall of the first flow channel 600 and the second flow channel 610, one side of the extension 66 is arranged to extend obliquely toward the inside of the flow channel, and the extensions 66 on both sides are evenly staggered and distributed, and are arranged corresponding to the positions of the third busbar 33, the fifth busbar 35, the seventh busbar 37 and the eighth busbar 38.

[0105] It should be noted that the two outward expansion pipes 63 serve as the water inlet and outlet of the liquid cooling component 61. The outward expansion pipes 63 are enlarged to increase the contact area between the coolant and the liquid cooling component, which helps to improve the cooling efficiency. The inlet of the outward expansion pipe 63 is designed to be inclined at an angle consistent with the direction of the flow channel, which can reduce the flow resistance of the coolant in the flow channel and allow the coolant to enter the liquid cooling component more smoothly. Two unconnected flow channels are arranged in the bottom shell 62, which can be used to cool different busbars or areas respectively, thereby improving the targetedness and efficiency of cooling. The first flow channel 600 and the second flow channel 610 are both U-shaped, which is conducive to the uniform distribution and flow of the coolant and improves the heat exchange efficiency. The contact area between the heat exchange medium inside the water cooling plate and the high temperature zone is increased by setting a number of bosses 65, thereby achieving a better cooling effect. The contact area between the heat exchange medium inside the bottom shell 62 and another high temperature zone is increased by setting a number of extensions 66, thereby achieving a better cooling effect. The inclined extension 66 can reduce the reflux of the internal heat exchange medium, thereby allowing the coolant to flow more efficiently and improving the cooling efficiency.

[0106] In a second aspect, the present invention further provides a heat dissipation simulation method for a wireless bundle BDU structure, which is implemented using a wireless bundle BDU structure, and the method comprises the following steps:

[0107] S1, modeling the wireless bundle BDU structure in the modeling software;

[0108] It should be noted that the wireless bundle BDU structure is three-dimensionally modeled using SolidWorks or AutoCAD, and the modeling process should take into account the internal layout of the BDU, the position and shape of the component assembly 2 and the busbar assembly 3, and the preliminary design of the liquid cooling assembly 6.

[0109] S2, obtaining the total power, thermal radiation and thermal convection heat dissipation power of all the heat-generating devices inside the wireless bundle BDU structure, and calculating the required heat dissipation of the liquid cooling component 6 according to the total power, thermal radiation and thermal convection heat dissipation power of the heat-generating devices;

[0110] Specifically, step S2 includes the following steps:

[0111] Obtain the internal resistance of all heating devices inside the wireless bundle BDU structure, and calculate the total power of all heating devices. All heating devices inside the wireless bundle BDU structure include the high-voltage devices of component assembly 2 and the busbars of busbar assembly 3. The calculation expression is:

[0112] P1=I 2 R

[0113] Wherein, P1 is the total power of all heating devices inside the wireless bundle BDU structure, I is the current value passing through the BDU, and R is the sum of the internal resistances of the first busbar 31, the second busbar 32, the third busbar 33, the fourth busbar 34, the fifth busbar 35, the sixth busbar 36, the seventh busbar 37, the eighth busbar 38, the main positive relay 21, the pre-charge relay 22, the main negative relay 23, the fast charge relay 24, the main fuse 25, the pre-charge resistor 26, the shunt 27, and the branch fuse 28;

[0114] Calculate the heat radiation heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is:

[0115] Q1=εAσT 4

[0116] Where, Q1 is the heat radiation power of all devices inside the wireless bundle BDU structure, ε is the emissivity, A is the heat dissipation area, σ is the Stefan-Boltzmann constant, and T is the temperature difference between the wireless bundle BDU structure and the environment;

[0117] Calculate the heat convection heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is:

[0118] Q2=AhΔT1

[0119] Where, Q2 is the heat dissipation power of all devices inside the wireless bundle BDU structure, A is the heat dissipation area, h is the surface heat transfer coefficient, and ΔT1 is the temperature difference between the heating device and the air;

[0120] According to the total power, heat radiation and heat convection heat dissipation power of the heat generating device, the required heat dissipation of the liquid cooling component 6 is calculated, and the expression is:

[0121] Q3=P1-Q1-Q2

[0122] Wherein, Q3 is the required heat dissipation of the liquid cooling component 6.

[0123] It should be noted that the detailed parameters of the heat-generating devices, including the total power, thermal radiation coefficient, and thermal convection coefficient, are collected, and the heat that can be dissipated by the component assembly 2 and the busbar assembly 3 through thermal radiation and thermal convection is simulated and calculated. The heat that can be dissipated through thermal radiation and thermal convection is subtracted from the total heat output to obtain the heat dissipation that the liquid cooling assembly 6 needs to bear.

[0124] S3, constructing a heat dissipation calculation model according to the internal structure of the liquid cooling component 6, performing thermal simulation calculation on the structure of the liquid cooling component 6, and adjusting the internal structure of the liquid cooling component 6 according to the heat dissipation calculation model to obtain the optimal structure of the liquid cooling component 6.

[0125] Specifically, step S3 includes the following steps:

[0126] According to the internal structure of the liquid cooling component 6, a heat dissipation calculation model is constructed, and the expression is:

[0127]

[0128] Wherein, Q4 is the estimated heat dissipation of the liquid cooling assembly 6, q1 is the water inlet flow rate, m is the mass of the heat exchange medium, V1 is the preset cavity volume between the upper cover 61 and the bottom shell 62, r is the radius of the boss portion 65 and the extension portion 66; h1 is the height of the boss portion 65 and the extension portion 66; n is the total number of the boss portion 65 and the extension portion 66, and ΔT2 is the temperature difference between the two external expansion pipes 63;

[0129] According to the heat dissipation calculation model, the initial size and quantity of the boss portion 65 and the extension portion 66 of the liquid cooling component 6 satisfying the condition of 0.9Q4≥Q3 are obtained, and the initial structure of the liquid cooling component 6 is obtained;

[0130] Import the initial wireless bundle BDU structure model into the simulation software, perform initial settings, mesh division and solve, and output the temperature of the high-voltage device of the component assembly 2, the temperature difference of the busbar assembly 3, the insulation film 7, the thermal pad 8, the flow resistance of the internal flow channel of the liquid cooling assembly 6, and the simulated temperature cloud map, simulated velocity section cloud map and simulated pressure section cloud map;

[0131] According to the required heat dissipation of the liquid cooling assembly 6, the radius and number of the boss portion 65 and the extension portion 66, the temperature difference of the liquid cooling assembly 6 is calculated and expressed as:

[0132]

[0133] Wherein, DT1 is the temperature difference of the liquid cooling component 6, L is the heat transfer path, and k is the thermal conductivity;

[0134] According to the temperature difference of the liquid cooling assembly 6, the temperature of the high-voltage device of the component assembly 2, the temperature difference of the busbar assembly 3, the insulating film 7, the thermal pad 8, the flow resistance of the internal flow channel of the liquid cooling assembly 6, and the simulated temperature cloud map, the simulated velocity section cloud map and the simulated pressure section cloud map, the conditions for satisfying the optimal structure of the liquid cooling assembly 6 are preset;

[0135] The conditions are as follows: the sum of the temperature difference of the liquid cooling component 6, the temperature difference of the busbar component 3, the insulating film 7, the thermal pad 8 and the temperature of the heat exchange medium is greater than or equal to the temperature of the high-voltage device of the component assembly 2, and the temperature of the liquid cooling component 6 is uniform, the flow velocity of the heat exchange medium is uniform, and the pressure distribution of the heat exchange medium is uniform according to the flow resistance of the internal flow channel of the liquid cooling component 6 and the simulated temperature cloud map, the simulated velocity section cloud map and the simulated pressure section cloud map;

[0136] If all conditions are met, the current optimal solution is output to obtain the final liquid cooling component 6 structure;

[0137] If not, a parametric iterative simulation is performed on the radius and number of the boss portion 65 and the extension portion 66, and the radius and number parameters of the boss portion 65 and the extension portion 66 that meet the conditions are output as the optimal solution to obtain the final liquid cooling component 6 structure.

[0138] It should be noted that by obtaining the total power, thermal radiation and thermal convection heat dissipation power of all heat-generating devices inside the wireless bundle BDU structure, this method can accurately calculate the required heat dissipation Q3 of the liquid cooling component 6. This ensures that the design of the liquid cooling system is based on accurate heat load requirements and avoids excessive or insufficient design; according to the internal structure of the liquid cooling component 6, a heat dissipation calculation model is constructed to estimate the heat dissipation Q4, and the initial size and number of the boss 65 and the extension 66 are determined through simulation calculation and adjustment, thereby obtaining the initial structure of the liquid cooling component 6. Through parametric iterative simulation, the radius and number of the boss 65 and the extension 66 are further optimized to meet the heat dissipation requirements and achieve the optimal structure. This ensures that the liquid cooling component 6 has efficient heat dissipation performance while maintaining the compactness and reliability of the structure.

[0139] After the simulation calculation is completed, the temperature of the high-voltage device of the component assembly 2, the temperature difference of the busbar assembly 3, the insulating film 7, and the thermal pad 8, as well as the flow resistance of the internal flow channel of the liquid cooling assembly 6, the simulated temperature cloud map, the simulated velocity section cloud map, and the simulated pressure section cloud map are output. The data provides a comprehensive evaluation of the overall heat dissipation performance of the BDU, including key indicators such as temperature distribution, flow velocity distribution, and pressure distribution. By judging the relationship between the temperature difference of the liquid cooling assembly 6, the temperature difference of other components and the temperature of the heat exchange medium, as well as the uniformity of the temperature, velocity, and pressure distribution of the internal flow channel of the liquid cooling assembly 6, the stability and safety of the BDU system are ensured, and system failure or safety hazards caused by overheating or uneven temperature distribution are avoided.

[0140] like Figure 8 As shown, the present embodiment also includes a filtering module, and the positive output end of the fast charging circuit and the negative output end of the fast charging circuit are electrically connected to the positive and negative input ends of the filtering module respectively, so as to simultaneously filter out common-mode and differential-mode interference.

[0141] The filtering module in this embodiment includes a relay K3, a first X capacitor, a first Y capacitor, a first magnetic ring, a second X capacitor, a second Y capacitor, a second magnetic ring, discharge resistors R1, R2, R3, R4, capacitors C1, C2, C3, C4, C5, C6, and a relay K2, wherein the positive output end of the fast charging circuit is electrically connected to one end of the contact of the relay K3, the other end of the contact of the relay K3 is electrically connected to one end of the first X capacitor, the first Y capacitor and the first end of the first magnetic ring respectively, the negative output end of the fast charging circuit is electrically connected to the other end of the first X capacitor and the first Y capacitor and the second end of the first magnetic ring respectively, the first magnetic The third end of the ring is electrically connected to one end of the second X capacitor, one end of the second Y capacitor and the first end of the second magnetic ring respectively, the fourth end of the first magnetic ring is electrically connected to the other end of the second X capacitor and the second Y capacitor and the second end of the second magnetic ring respectively, the third end of the second magnetic ring is electrically connected to the discharge resistor R1 and one end of the capacitors C1, C2, C3, C4, C5, C6 and one end of the contact of the relay K2 respectively, the discharge resistors R1, R2, R3, R4 are electrically connected at both ends, and the fourth end of the second magnetic ring is electrically connected to the other end of the discharge resistor R4 and the other end of the capacitors C1, C2, C3, C4, C5, C6 respectively.

[0142] It should be noted that the first X capacitor, the first Y capacitor and the first magnetic ring work together to initially filter out common-mode and differential-mode interference, and the second X capacitor, the second Y capacitor and the second magnetic ring perform further filtering. The third end of the second magnetic ring is also connected to a discharge circuit composed of discharge resistors R1, R2, R3, and R4, and a filtering network composed of capacitors C1 to C6. These components work together to eliminate residual interference signals, thereby effectively suppressing interference signals in the fast charging circuit and providing a strong guarantee for the stable operation of the electrical system.

[0143] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wireless bundle BDU structure, characterized in that: It comprises a housing (1), a component assembly (2), a busbar assembly (3), a PCB collection circuit board (4), a conduction assembly (5) and a liquid cooling assembly (6), wherein: The shell (1) is hollow inside, with one side being closed and the other side being provided with an opening; The component assembly (2) is arranged in the housing (1) and is used to control the opening and closing of the battery circuit; The busbar assembly (3) is injection-molded in the housing (1) and is used to connect and conduct the high-voltage devices of the component assembly (2); The PCB acquisition circuit board (4) is arranged in the housing (1) and close to one side of the opening of the housing (1), and is arranged at a distance from the component assembly (2), and is used to collect and transmit signals of various high-voltage devices of the component assembly (2); The conducting component (5) is arranged between the component component (2) and the busbar component (3) and the PCB collecting circuit board (4), and is used to connect and conduct each collecting point on the busbar component (3) and the contact points of each high-voltage device of the component component (2) with the PCB collecting circuit board (4); The liquid cooling component (6) is arranged on the closed side of the shell (1) and is in contact with the surface of the busbar component (3). A heat exchange medium flows in the liquid cooling component (6) for cooling and heat dissipation.

2. The wireless bundle BDU structure according to claim 1, characterized in that: The component assembly (2) comprises a main positive relay (21), a pre-charge relay (22), a main negative relay (23), a fast charge relay (24), a main fuse (25), a pre-charge resistor (26), a shunt (27) and a branch fuse (28), wherein: The main positive relay (21), the pre-charging relay (22), the main negative relay (23), the fast charging relay (24), the main fuse (25), the pre-charging resistor (26), the shunt (27) and the branch fuse (28) are all arranged in the housing (1); The main fuse (25) is arranged near one side edge of the housing (1), and the main fuse (25) is parallel to the longitudinal horizontal direction of the housing (1); The main positive relay (21), the pre-charging resistor (26) and the branch fuse (28) are all arranged on a side of the main fuse (25) away from the edge of the housing (1), and the main positive relay (21) is located between the pre-charging resistor (26) and the branch fuse (28), and the arrangement directions of the main positive relay (21), the pre-charging resistor (26) and the branch fuse (28) are all perpendicular to the main fuse (25); The pre-charge relay (22) and the fast charge relay (24) are both arranged on a side of the main positive relay (21) away from the main fuse (25), and the pre-charge relay (22) is arranged corresponding to the position of the main positive relay (21), and the fast charge relay (24) is arranged corresponding to the position of the pre-charge resistor (7), and the arrangement direction of the pre-charge relay (22) and the fast charge relay (24) is perpendicular to the main fuse (25); The main negative relay (23) is located on a side of the pre-charging relay (22) away from the main positive relay (21), and the main negative relay (23) is arranged corresponding to the position of the pre-charging relay (22), and the arrangement direction of the main negative relay (23) is perpendicular to the main fuse (25); The shunt (27) is located on one side of the main negative relay (23) away from the pre-charging relay (22) and is arranged close to the other side edge of the housing (1).

3. The wireless bundle BDU structure as claimed in claim 2, characterized in that: The busbar assembly (3) comprises a first busbar (31), a second busbar (32), a third busbar (33), a fourth busbar (34), a fifth busbar (35), a sixth busbar (36), a seventh busbar (37) and an eighth busbar (38), wherein: One end of the first busbar (31) is fixedly connected to the input end of the main fuse (25) to serve as the input end of the main positive circuit, and the other end of the first busbar (31) penetrates and extends to the bottom of the housing (1); One end of the second busbar (32) is fixedly connected to the output end of the main fuse (25), and the other end of the second busbar (32) is fixedly connected to one end of the contact of the main positive relay (21); The third busbar (33) is fixedly connected to the other end of the contact of the main positive relay (21) and one end of the contact of the fast charging relay (24), respectively, and the third busbar (33) has three connection ends; The first connection end of the third busbar (33) penetrates and extends into the housing (1) and is arranged close to the edge. The first connection end of the third busbar (33) serves as the positive output end of the front drive circuit. The second connection end of the third busbar (33) penetrates and extends into the housing (1), and is arranged on both sides of the housing (1) and opposite to the first connection end of the third busbar (33), and the second connection end of the third busbar (33) serves as the positive output end of the rear drive circuit; The third connection end of the third busbar (33) penetrates and extends into the housing (1), and is located on the same side as and adjacent to the first connection end of the third busbar (33), and the third connection end of the third busbar (33) is fixedly connected to one end of the branch fuse (28); One end of the fourth busbar (34) is fixedly connected to the other end of the branch fuse (28), and the other end of the fourth busbar (34) serves as a positive output end of the IPS control loop; The fifth busbar (35) is fixedly connected to the other end of the contact of the fast charging relay (24), and the fifth busbar (35) has a connection end, the connection end of the fifth busbar (35) penetrates and extends into the housing (1), and is arranged adjacent to the first connection end of the third busbar (33) on the same side, and the connection end of the fifth busbar (35) serves as the positive output end of the fast charging circuit; The sixth busbar (36) is arranged in the housing (1), one end of the sixth busbar (36) is fixedly connected to the input end of the shunt (27), and the other end serves as the input end of the main negative circuit; One end of the seventh busbar (37) is fixedly connected to the output end of the shunt (27), and the other end penetrates and extends to the bottom of the housing (1) and is fixedly connected to one end of the contact of the main negative relay (23); The eighth busbar (38) is fixedly connected to the other end of the contact of the main negative relay (23). The eighth busbar (38) has four connection ends. The connection ends of the eighth busbar (38) penetrate and extend into the shell (1). The first connection end and the second connection end of the eighth busbar (38) are on the same side and adjacent to the second connection end of the third busbar (33). The first connection end of the eighth busbar (38) serves as the negative output end of the IPS control circuit, and the second connection end of the eighth busbar (38) serves as the negative output end of the rear drive circuit. The third connection end and the fourth connection end of the eighth busbar (38) are on the same side and adjacent to the first connection end of the third busbar (33). The third connection end of the eighth busbar (38) serves as the negative output end of the fast charging circuit, and the fourth connection end of the eighth busbar (38) serves as the negative output end of the front drive circuit.

4. The wireless bundle BDU structure as claimed in claim 3, characterized in that: The first busbar (31), the second busbar (32), the third busbar (33), the fifth busbar (35), the seventh busbar (37) and the eighth busbar (38) are all injection-molded on the bottom surface of the shell (1) and are at the same plane height as the bottom surface of the shell (1).

5. The wireless bundle BDU structure as claimed in claim 3, characterized in that: The conducting assembly (5) comprises a plurality of inserts (51) and conducting rods (52), wherein: The contact ends of the main positive relay (21), the main negative relay (23) and the fast charging relay (24) are all located inside the housing (1), and the coil ends are all located on the opening side of the housing (1); the contact end and the coil end of the pre-charging relay (22) are all located on the opening side of the housing (1); A plurality of conductor posts (52) are respectively fixed on the second busbar (32), the third busbar (33), the fifth busbar (35), the sixth busbar (36), the seventh busbar (37) and the eighth busbar (38), and one end of the plurality of conductor posts (52) penetrates and extends into the housing (1); A plurality of plug-ins (51) are respectively fixed to the contact ends of the main positive relay (21), the main negative relay (23) and the fast charging relay (24), the contact end and the coil end of the pre-charging relay (22) and one end of each wire column (52) extending out of the housing (1), and the other ends of the plurality of plug-ins (51) are plugged into corresponding ports of the PCB acquisition circuit board (4); The two ends of the pre-charging resistor (26) are plugged into corresponding ports of the PCB acquisition circuit board (4).

6. The wireless bundle BDU structure as claimed in claim 5, characterized in that: It also includes an insulating film (7) and a thermal pad (8), wherein the insulating film (7) is arranged on the bottom surface of the shell (1) and abuts against the surfaces of the first busbar (31), the second busbar (32), the third busbar (33), the fifth busbar (35), the seventh busbar (37) and the eighth busbar (38), and the thermal pad (8) is arranged on the side of the insulating film (10) away from the shell (1) to conduct the heat dissipated by the busbar to the liquid cooling component (6).

7. The wireless bundle BDU structure as claimed in claim 6, characterized in that: The liquid cooling assembly (6) comprises an upper cover (61), a bottom shell (62), two outward expansion pipes (63), a plurality of boss portions (65) and a plurality of extension portions (66), wherein: One side of the upper cover (61) is fixedly connected to the thermal pad (8), and the other side is fixedly connected to the bottom shell (62); A first flow channel (600) and a second flow channel (610) which are not connected to each other are arranged in the bottom shell (62); the liquid inlet side and the liquid outlet side of the first flow channel (600) and the second flow channel (610) are connected; and the first flow channel (600) and the second flow channel (610) are both U-shaped; The two outward expansion pipes (63) are both fixed on a side of the upper cover (61) close to the thermal pad (8), and are connected to the inside of the bottom shell (62) and are arranged adjacent to each other. The two outward expansion pipes (63) are respectively located at the connecting parts of the liquid inlet end side and the liquid outlet end side of the first flow channel (600) and the second flow channel (610); One side of the outward expansion pipe (63) and the upper cover (61) are arranged in an inclined plane, and the inclination direction of the inclined plane is consistent with the flow direction of the fluid, so as to reduce the flow resistance of the flow channel; A plurality of bosses (65) are disposed at the connecting parts of the first flow channel (600) and the second flow channel (610) at the liquid inlet end side and the liquid outlet end side, and the positions of the bosses (65) correspond to the positions of the first busbar (31) and the second busbar (32); A plurality of extension portions (66) are arranged on both sides of the inner wall of the first flow channel (600) and the second flow channel (610), one side of the extension portion (66) is arranged to extend obliquely toward the flow channel, and the extension portions (66) on both sides are evenly staggered and arranged corresponding to the positions of the third busbar (33), the fifth busbar (35), the seventh busbar (37) and the eighth busbar (38).

8. A heat dissipation simulation method for a wireless bundle BDU structure, implemented by using the wireless bundle BDU structure according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1, modeling the wireless bundle BDU structure in the modeling software; S2, obtaining the total power, thermal radiation and thermal convection heat dissipation power of all heat-generating devices inside the wireless bundle BDU structure, and calculating the required heat dissipation of the liquid cooling component (6) based on the total power, thermal radiation and thermal convection heat dissipation power of the heat-generating devices; S3, constructing a heat dissipation calculation model according to the internal structure of the liquid cooling component (6), performing thermal simulation calculation on the structure of the liquid cooling component (6), and adjusting the internal structure of the liquid cooling component (6) according to the heat dissipation calculation model to obtain an optimal structure of the liquid cooling component (6).

9. The heat dissipation simulation method of the wireless bundle BDU structure as claimed in claim 8, characterized in that: Step S2 includes the following steps: Obtain the internal resistance of all heat-generating devices inside the wireless bundle BDU structure, and calculate the total power of all heat-generating devices. All heat-generating devices inside the wireless bundle BDU structure include each high-voltage device of the component assembly (2) and each busbar of the busbar assembly (3). The calculation expression is: P1=I 2 R In the formula, P1 is the total power of all heating devices inside the wireless bundle BDU structure, I is the current value passing through the BDU, and R is the sum of the internal resistances of the first busbar (31), the second busbar (32), the third busbar (33), the fourth busbar (34), the fifth busbar (35), the sixth busbar (36), the seventh busbar (37), the eighth busbar (38), the main positive relay (21), the pre-charge relay (22), the main negative relay (23), the fast charge relay (24), the main fuse (25), the pre-charge resistor (26), the shunt (27) and the branch fuse (28); Calculate the heat radiation heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is: Q1=eAσT 4 Where, Q1 is the heat radiation power of all devices inside the wireless bundle BDU structure, ε is the emissivity, A is the heat dissipation area, σ is the Stefan-Boltzmann constant, and T is the temperature difference between the wireless bundle BDU structure and the environment; Calculate the heat convection heat dissipation power of all heat generating devices inside the wireless bundle BDU structure. The expression is: Q2=AhΔT1 Where, Q2 is the heat dissipation power of all devices inside the wireless bundle BDU structure, A is the heat dissipation area, h is the surface heat transfer coefficient, and ΔT1 is the temperature difference between the heating device and the air; According to the total power, heat radiation and heat convection heat dissipation power of the heat generating device, the required heat dissipation of the liquid cooling component (6) is calculated, and the expression is: Q3=P1-Q1-Q2 Wherein, Q3 is the required heat dissipation of the liquid cooling component (6).

10. The heat dissipation simulation method of the wireless bundle BDU structure according to claim 9, characterized in that: Step S3 includes the following steps: According to the internal structure of the liquid cooling component (6), a heat dissipation calculation model is constructed, and the expression is: In the formula, Q4 is the estimated heat dissipation of the liquid cooling component (6), q1 is the water inlet flow rate, m is the mass of the heat exchange medium, V1 is the preset cavity volume between the upper cover (61) and the bottom shell (62), r is the radius of the boss portion (65) and the extension portion (66); h1 is the height of the boss portion (65) and the extension portion (66); n is the total number of the boss portion (65) and the extension portion (66), and ΔT2 is the temperature difference between the two expansion pipes (63); According to the heat dissipation calculation model, the initial size and number of the boss portion (65) and the extension portion (66) of the liquid cooling component (6) satisfying the condition of 0.9Q4≥Q3 are obtained, and the initial structure of the liquid cooling component (6) is obtained; Import the initial wireless bundle BDU structure model into the simulation software, perform initial settings, mesh division and solve, and output the temperature of the high-voltage device of the component assembly (2), the temperature difference of the busbar assembly (3), the insulation film (7), the thermal pad (8), and the internal flow resistance of the liquid cooling assembly (6), as well as the simulated temperature cloud map, the simulated velocity section cloud map and the simulated pressure section cloud map; According to the required heat dissipation of the liquid cooling component (6) and the radius of the boss portion (65) and the extension portion (66), the temperature difference of the liquid cooling component (6) is calculated and expressed as: Where DT1 is the temperature difference of the liquid cooling component (6), L is the heat transfer path, and k is the thermal conductivity; According to the temperature difference of the liquid cooling component (6), the temperature of the high-voltage device of the component assembly (2), the temperature difference of the busbar assembly (3), the insulating film (7), the thermal pad (8), the flow resistance of the internal flow channel of the liquid cooling component (6), and the simulated temperature cloud map, the simulated velocity section cloud map, and the simulated pressure section cloud map, the conditions for satisfying the optimal structure of the liquid cooling component (6) are preset; The conditions are as follows: the sum of the temperature difference of the liquid cooling component (6), the temperature difference of the busbar component (3), the insulating film (7), the thermal pad (8) and the temperature of the heat exchange medium is greater than or equal to the temperature of the high-voltage device of the component assembly (2), and whether the temperature of the liquid cooling component (6) is uniform, whether the flow rate of the heat exchange medium is uniform and whether the pressure distribution of the heat exchange medium is uniform are determined based on the flow resistance of the internal flow channel of the liquid cooling component (6) and the simulated temperature cloud map, the simulated velocity section cloud map and the simulated pressure section cloud map; If all conditions are met, the current optimal solution is output to obtain the final liquid cooling component (6) structure; If not, a parametric iterative simulation is performed on the radius and number of the boss portion (65) and the extension portion (66), and the radius and number parameters of the boss portion (65) and the extension portion (66) that meet the conditions are output as the optimal solution to obtain the final liquid cooling component (6) structure.

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