CN215185948U

CN215185948U - Low-voltage distribution box and power battery system

Info

Publication number: CN215185948U
Application number: CN202120986517.8U
Authority: CN
Inventors: 龚航; 郑剑
Original assignee: Hubei Eve Power Co Ltd
Current assignee: Hubei Eve Power Co Ltd
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2021-12-14
Anticipated expiration: 2031-05-10

Abstract

The utility model relates to the technical field of batteries, specifically disclose a low pressure block terminal and power battery system. The low-voltage distribution box comprises a base, a positive circuit, a negative circuit, a pre-charging circuit and a heating circuit, wherein the upper end surface of the base is inwards sunken to form a containing groove. The positive circuit includes the main relay and the main fuse of establishing ties, and the main relay sets up adjacent with the main fuse to all be located the one end of holding tank, the main fuse is connected with the anodal output electricity of battery module. The negative circuit comprises a shunt arranged at the other end of the accommodating groove, and the shunt is electrically connected with the negative output end of the battery module. The pre-charging relay and the pre-charging resistor in the pre-charging circuit are arranged adjacent to each other and are positioned on one side of the main relay. The pre-charging relay pre-charging circuit is connected with the main relay in parallel. And a heating relay in the heating circuit is electrically connected with the positive output end and the negative output end of the battery module respectively. The low-voltage distribution box realizes the modularized installation of the electric elements and has higher integration level.

Description

Low-voltage distribution box and power battery system

Technical Field

The utility model belongs to the technical field of the battery, especially, relate to a low pressure block terminal and power battery system.

Background

The lithium ion power battery comprises a battery box, a battery module and an electrical element electrically connected with the battery module, wherein the electrical element mainly comprises a main relay, a main fuse, a shunt, a heating relay, a pre-charging resistor and the like so as to ensure that the lithium ion power battery safely and stably operates.

At present, lithium ion power battery is single-box system and many-box system usually, and in the lithium ion power battery of single-box system, multiple electric elements install in the battery box through the sheet metal component scattered to carry out electrical isolation through the insulated column, the structure is complicated, and the installation is loaded down with trivial details, appears connecting wrong line scheduling problem easily. In the lithium ion power battery of multi-box system, various electrical elements are installed in the high-voltage box, the battery box is electrically connected with the high-voltage box and is electrically connected with the external control unit through the high-voltage box, the multi-box arrangement increases the occupied space of the lithium ion power battery, and the connectors and wire harnesses among the multiple boxes increase the assembly cost and the purchase cost.

Therefore, a low voltage distribution box and a power battery system are needed to solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a low pressure block terminal to realize electric elements's modularization installation, improve installation effectiveness and accuracy, and optimize multiple electric elements's arrangement structure, reduce occupation space.

To achieve the purpose, the technical proposal adopted by the utility model is that:

a low voltage distribution box for electrical connection with a battery module, comprising:

the upper end surface of the base is inwards sunken to form an accommodating groove;

the positive circuit comprises a main relay and a main fuse which are connected in series, the main relay and the main fuse are arranged adjacently and are positioned at one end of the accommodating groove, and the main fuse is electrically connected with the positive output end of the battery module;

the negative electrode circuit comprises a current divider arranged at the other end of the accommodating groove, and the current divider is electrically connected with the negative electrode output end of the battery module;

the pre-charging circuit comprises a pre-charging relay and a pre-charging resistor which are connected in series, and the pre-charging relay and the pre-charging resistor are arranged adjacent to each other and are positioned on one side of the main relay; the positive electrode of the pre-charging relay is electrically connected with the positive electrode of the main relay, and the pre-charging resistor is electrically connected with the negative electrode of the main relay so as to enable the pre-charging circuit to be connected with the main relay in parallel;

and the heating circuit comprises a heating relay positioned between the main relay and the shunt, and the heating relay is respectively electrically connected with the positive output end and the negative output end of the battery module.

Preferably, the low voltage distribution box further comprises an upper cover, the upper cover is arranged on the accommodating groove to form a box body of the low voltage distribution box; the accommodating groove is divided into a first area and a second area, the upper cover comprises a first box cover and a second box cover which are communicated, the first box cover is covered on the first area, the second box cover is covered on the second area, and the height of the first box cover is greater than that of the second box cover; the main relay, the main fuse and the heating relay are located in the first area, and the shunt, the pre-charging relay and the pre-charging resistor are located in the second area.

Preferably, the low-voltage distribution box further comprises an adapter plug installed in the second area, the second box cover is correspondingly provided with a limiting hole, and the adapter plug is arranged in the limiting hole in a penetrating manner; the positive circuit, the negative circuit, the heating circuit and the pre-charging circuit are all in communication connection with an external control unit through the adapter plug.

Preferably, the input row and the output row of the positive electrode circuit, the negative electrode circuit and the heating circuit all penetrate out of the box body, and the input row and the output row of the same circuit respectively penetrate out of two adjacent sides of the box body.

Preferably, the heating circuit shares one said output bank with the negative circuit.

Preferably, the inner wall of holding tank is provided with first boss, second boss and third boss along its circumference at least, main fuse is located first boss with between the second boss, main relay is located the second boss with between the third boss, just positive circuit's input row fixed support in first boss, positive circuit's output row fixed support in the third boss.

Preferably, the inner wall of the accommodating groove is further provided with a fourth boss along the circumferential direction of the inner wall, the input row of the heating circuit is fixedly supported on the fourth boss and is adjacent to the output row of the positive circuit, and the third boss and the fourth boss are connected into a whole to form a combined boss.

Preferably, a partition plate is arranged on the combined boss, and the partition plate is located between the input row of the heating circuit and the output row of the positive circuit.

Preferably, four corner positions of base inwards cave in and form the locking groove, first mounting hole has been seted up to the tank bottom of locking groove, and the fastener is worn to locate first mounting hole, in order to incite somebody to action base installation is in the battery box.

Another object of the utility model is to provide a power battery system to realize electrical component's modularization installation, improve installation effectiveness and accuracy, and optimize multiple electrical component's arrangement structure, reduce occupation space.

the utility model provides a power battery system, includes battery box, battery module and with foretell low pressure block terminal that the battery module electricity is connected, the battery module with low pressure block terminal install in the battery box.

The utility model has the advantages that:

the utility model provides a low pressure block terminal and power battery system, this low pressure block terminal include base and multiple electric elements, and multiple electric elements installs in low pressure block terminal to assemble into positive circuit, negative pole circuit, pre-charge circuit and heating circuit, and according to the series-parallel relation between positive circuit, negative pole circuit, pre-charge circuit and the heating circuit, optimized electric elements's structural configuration, realized electric elements's modularization installation, the integrated level is higher. For single-box system or many casees power battery, the required panel beating support of scattered installation of electrical component, insulating column and the pencil between a plurality of boxes, structures such as high-pressure box have been saved to this low pressure block terminal, have reduced assembly cost, purchasing cost and the probability of wiring mistake, have improved the inner space utilization of installation effectiveness and battery box, are favorable to integrating and the lightweight of battery system.

Drawings

Fig. 1 is a schematic structural diagram of a low-voltage distribution box provided by an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a low-voltage distribution box with an upper cover removed according to an embodiment of the present invention;

fig. 3 is an internal circuit diagram of a low voltage distribution box provided by an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a base according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an upper cover according to an embodiment of the present invention.

The component names and designations in the drawings are as follows:

1. a base; 11. accommodating grooves; 111. a first region; 112. a second region; 121. a first boss; 122. a second boss; 123. a third boss; 124. a fourth boss; 125. a fifth boss; 126. a sixth boss; 127. a seventh boss; 120. a partition plate; 13. a positioning column; 14. a first mounting hole; 2. an upper cover; 21. a first box cover; 22. a second box cover; 221. a limiting hole; 23. a second mounting hole; 24. an avoidance groove; 3. a main relay; 31. a connecting row; 4. a main fuse; 5. a flow divider; 6. heating the relay; 7. a pre-charging relay; 8. pre-charging a resistor; 9. a patch plug; 10. a control unit; 20. a heating plate; 30. a battery module is provided.

Detailed Description

In order to make the technical problem solved by the present invention, the technical solution adopted by the present invention and the technical effect achieved by the present invention clearer, the technical solution of the present invention will be further explained by combining the drawings and by means of the specific implementation manner. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements related to the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings.

The embodiment discloses a power battery system, and this power battery system includes battery box and battery module 30, and this low pressure block terminal is connected with battery module 30 electricity to install jointly in the battery box. In order to realize safe and stable charging and discharging of the battery module 30, the power battery system further comprises a positive electrode circuit, a negative electrode circuit, a pre-charging circuit and a heating circuit which are composed of various electrical elements. The electric elements mainly include a main relay 3, a main fuse 4, a shunt 5, a heating relay 6, a pre-charge relay 7, and a pre-charge resistor 8.

Currently, power battery systems are mainly single-tank systems and multi-tank systems, in which various electrical components are installed scattered. In the multi-tank system, various electric components are mounted in a high-voltage tank, and a battery tank, the high-voltage tank, and an external control unit 10 are electrically connected in this order. The power battery system is complex to install, wiring errors are easy to occur, and the assembly cost and the purchase cost are increased. Moreover, the space utilization rate of the battery box is low.

To solve the above problem, as shown in fig. 1 to 5, the present embodiment further discloses a low voltage distribution box having a positive electrode circuit, a negative electrode circuit, a pre-charge circuit, and a heating circuit. This low pressure block terminal includes base 1 and upper cover 2, and base 1's up end is inwards sunken to form holding tank 11, and holding tank 11 is located to the cover of upper cover 2 to form the box body of low pressure block terminal.

As shown in fig. 2 to 4, the positive circuit includes a main relay 3 and a main fuse 4 connected in series, and the main relay 3 is disposed adjacent to the main fuse 4 and both located at one end of the accommodation groove 11. The main fuse 4 is electrically connected to the positive output terminal of the battery module 30.

The negative circuit comprises a shunt 5 arranged at the other end of the accommodating groove 11, and the shunt 5 is electrically connected with the negative output end of the battery module 30, so that the battery module 30 is connected with the negative circuit and an external electric load through a positive circuit in the low-voltage distribution box.

The pre-charging circuit comprises a pre-charging relay 7 and a pre-charging resistor 8 which are connected in series, wherein the pre-charging relay 7 and the pre-charging resistor 8 are arranged adjacently and are both positioned on one side of the main relay 3. The positive pole of the pre-charging relay 7 is electrically connected with the positive pole of the main relay 3, and the pre-charging resistor 8 is electrically connected with the negative pole of the main relay 3, so that the pre-charging circuit is connected with the main relay 3 in parallel. The precharge circuit is mainly used for protecting the main relay 3.

The heating circuit comprises a heating relay 6 between the main relay 3 and the shunt 5. The heating relay 6 is electrically connected to the positive output terminal and the negative output terminal of the battery module 30, respectively. The heating relay 6 of this embodiment is connected in series with the heating plate 20 to make the switching-on and switching-off of heating relay 6 control heating plate 20, so that the heating plate 20 can heat or stop heating according to the in service behavior of battery module 30, guaranteed that battery module 30 can charge and discharge in invariable environment, improved the safety in utilization of battery module 30.

In this embodiment, the input row and the output row of the positive circuit, the negative circuit and the heating circuit in the low-voltage distribution box all penetrate out of the box body, so as to facilitate the wiring operation.

The low-voltage distribution box comprises a base 1, an upper cover 2 and various electrical elements, wherein the various electrical elements are arranged in the low-voltage distribution box and are assembled into a positive circuit, a negative circuit, a pre-charging circuit and a heating circuit. According to the series-parallel connection relation among the positive circuit, the negative circuit, the pre-charging circuit and the heating circuit, the structural layout of the electric elements in the low-voltage distribution box is optimized, the wiring operation among the electric elements is facilitated, the modularized installation of the electric elements is realized, and the integration level is high. For the power battery system of single-box system or many casees system, the low pressure block terminal of this embodiment has saved the required panel beating support of scattered installation electrical components, insulating column and the pencil between a plurality of boxes, structures such as high-pressure box, has reduced assembly cost, purchasing cost and the probability of wiring mistake, has improved the installation effectiveness. For scattered installation of electric elements, the internal space utilization rate of the battery box is improved, and integration and light weight of a battery system are facilitated.

Since each kind of electric element is different in size and shape, for example, the main relay 3 is large in size and height, and occupies a large internal space of the box body. The diverter 5 is bulky and low in height. The heating relay 6 has small volume and high height. The main fuse 4, the pre-charging relay 7 and the pre-charging resistor 8 are small in size and low in height. In order to facilitate wiring and improve space utilization of the low-voltage distribution box, the housing groove 11 is divided into regions along the length direction thereof, and a plurality of kinds of electric components are selectively mounted in the regions.

Specifically, the housing tub 11 is divided into a first area 111 and a second area 112, the main relay 3, the main fuse 4, and the heating relay 6 are located in the first area 111, and the shunt 5, the precharge relay 7, and the precharge resistor 8 are located in the second area 112. The multiple electrical elements are installed in different regions, and the structural arrangement of the low-voltage distribution box is optimized.

As shown in fig. 1, 4 and 5, the upper cover 2 includes a first cover 21 and a second cover 22 that are connected, the first cover 21 is covered in the first area 111, and the second cover 22 is covered in the second area 112. Since the height of the first section 111 is greater than that of the second section 112 after the assembly is completed, the height of the first cover 21 is greater than that of the second cover 22. First lid 21 and second lid 22 link to each other, form the stair structure for the low pressure block terminal has regular appearance, has reduced the space that the low pressure block terminal occupy, is favorable to improving the inside space utilization of battery box.

Continuing as shown in fig. 2-4, base 1 is the injection molding of rectangle, and the up end of base 1 is inwards sunken to form holding tank 11, and the inner wall of holding tank 11 is provided with a plurality of boss structures along its circumference, and boss structure and the inner wall of holding tank 11 integrated into one piece for the cross section of holding tank 11 is anomalous shape. The input row and the output row support and are fixed in the boss structure, the input row and the output row which penetrate out of the box body are prevented from exceeding the low-voltage distribution box, and the space occupied by the low-voltage distribution box is reduced.

The input row and the output row of the embodiment are both copper rows. In other embodiments, the input row and the output row may also be aluminum rows or other conductive metal rows.

Specifically, the contact knife at the end of the main fuse 4 is used as an input row of a positive electrode circuit, and the copper joint at the end of the shunt 5 is used as an input row of a negative electrode circuit, so that the using amount of a copper bar is reduced, and the purchasing cost and the assembling cost are saved. Because the volume of the shunt 5 is larger, the volume and the weight of the boss structure which is used for installing the shunt 5 and is injected and molded on the base 1 are correspondingly larger, and the weight of the base 1 is increased. Therefore, two positioning columns 13 are arranged in the accommodating groove 11 of the base 1 instead of a boss structure, and copper joints at two ends of the shunt 5 are respectively fixedly connected with the corresponding positioning columns 13 through bolts.

As shown in fig. 2 and 4, the boss structure includes a first boss 121, a second boss 122, a third boss 123, a fourth boss 124, a fifth boss 125, a sixth boss 126, and a seventh boss 127 disposed circumferentially along the inner wall of the receiving groove 11. The low voltage distribution box of the present embodiment is a distribution box of a low voltage 24V standard battery system, and for convenience of description, it is specified that four outer sides of the base 1 are respectively a first side, a second side, a third side and a fourth side which are connected in sequence, the first side and the third side are disposed opposite to each other, and the second side and the fourth side are disposed opposite to each other.

The specific arrangement of the electrical components in the box body is as follows: the main fuse 4, the main relay 3, and the heating relay 6 are sequentially arranged in the first region 111 of the accommodation groove 11 along the length direction of the base 1. The first side of the base 1 has a first boss 121 and a second boss 122, and the middle of the second side of the base 1 has a third boss 123. The main fuse 4 is located between the first boss 121 and the second boss 122, and one contact blade at the end of the main fuse 4 is used as an input row of the positive circuit, and is supported and mounted on the first boss 121 at the upper left of the base 1. The other contact blade of the main fuse 4 is supported and mounted on the second boss 122. The main relay 3 is located between the second boss 122 and the third boss 123, and the main fuse 4 is connected in series with the main relay 3 through the connecting bar 31 to form a positive circuit, so that the input bar of the positive circuit is fixedly supported on the first boss 121, and the output bar of the positive circuit is fixedly supported on the third boss 123.

The connecting bar 31 is a copper sheet metal member, and can serve to fixedly support the main relay 3 by a large current.

The sixth bosses 126 are located at the third side of the base 1 near the corners of the fourth side. The shunt 5 is installed above the second area 112 of the receiving groove 11, one copper joint at the end of the shunt 5 is located at the right position in the middle of the fourth side of the base 1, and the other copper joint at the end of the shunt 5 is connected with the output row to form a negative pole circuit. The input row of the negative pole circuit is located on the fourth side of the base 1, and the output row of the negative pole circuit is located on the sixth boss 126 of the base 1. The positive terminal of the battery module 30 is electrically connected to the input bank of the positive circuit, and the negative terminal of the battery module 30 is electrically connected to the input bank of the negative circuit, so as to perform charging and discharging operations.

The pre-charging relay 7 and the pre-charging resistor 8 are installed in the second area 112, the pre-charging relay 7 and the pre-charging resistor 8 are connected in series to form a pre-charging circuit, and the pre-charging circuit is connected in parallel with the main relay 3 to protect the main relay 3.

The input row of the heating circuit is fixedly supported on the fourth boss 124 and is arranged adjacent to the output row of the positive circuit, and the third boss 123 and the fourth boss 124 are connected into a whole to form a combined boss. The combined bosses reduce the number of boss structures, simplify the structure of the base 1 and facilitate the injection molding of the base 1.

Preferably, the partition plate 120 is arranged on the combined boss, and the partition plate 120 is located between the input row of the heating circuit and the output row of the positive circuit, so that physical insulation between the heating circuit and the positive circuit is realized, and the safety of the low-voltage distribution box is improved.

The input row of the heating circuit is positioned at the right position in the middle of the second side of the base 1, and the heating relay 6 is connected with the output row of the main relay 3 in series by a wire harness to form the heating circuit. It should be noted that the heating circuit and the cathode circuit share one output bar to reduce the usage amount of the copper bar and save the purchasing cost and the assembling cost.

The input row and the output row of the same circuit of this embodiment wear out from the adjacent both sides of box body respectively for can follow four sides of low pressure block terminal and wiring respectively when the assembly personnel wiring, reduced the probability of wiring error, improved wiring efficiency and accuracy. Meanwhile, the wiring harness of the junction box is prevented from being disordered, and the subsequent maintenance operation of the junction box is facilitated.

As shown in fig. 1, 4 and 5, the outer sidewall of the upper cover 2 has a plurality of avoidance grooves 24 for respectively abdicating the first boss 121, the second boss 122, the third boss 123, the fourth boss 124 and the sixth boss 126, and a gap for the input row or the output row to pass through is formed between at least part of the bottom of the avoidance groove 24 and the corresponding boss structure.

The upper cover 2 of this embodiment is integrally formed by a blister process, and the outer side wall of the upper cover 2 has an inward concave avoiding groove 24 at four corner positions and at a position where the first cover 21 is connected to the second cover 22. Specifically, the avoidance groove 24 at the upper left corner of the first box cover 21 offers the input row of the positive pole circuit, and the avoidance groove 24 at the upper left corner and the upper right corner of the second box cover 22 offer the input row and the output row of the negative pole circuit respectively. The position where the first box cover 21 is connected with the second box cover 22 is provided with an avoidance groove 24 for avoiding the output row of the positive circuit on the combined boss and the input row of the heating circuit.

Further, the upper cover 2 is fixedly connected with the base 1 through bolts. Specifically, the diagonal positions (the upper left corner and the lower right corner in fig. 2 and 4) of the accommodating groove 11 are provided with a fifth boss 125 and a seventh boss 127, the diagonal positions of the upper cover 2 are recessed inwards to form an installation groove, the bottom of the installation groove is provided with a second installation hole 23, and the fifth boss 125 and the seventh boss 127 are fixedly connected with the second installation hole 23 through bolts. Of course, the mounting grooves of the upper cover 2 may be disposed at other positions, and the number may be three, four, or more than five. The fifth boss 125 and the seventh boss 127 of the upper cover 2 are supported and fixed on the base 1, and the corresponding position and number of the bosses can be adjusted.

The bottom edge of the upper lid 2 of this embodiment has a skirt extending vertically except for the portion of the escape groove 24 and the mounting groove. When the holding tank 11 is located to upper cover 2 cover, the shirt rim is laminated with the inside wall of holding tank 11 mutually, and the shirt rim plays the effect of location installation to upper cover 2, is favorable to improving the packaging efficiency of low voltage distribution box.

As shown in fig. 1 and 2, the low voltage distribution box further includes an adaptor plug 9 installed in the second area 112, the second box cover 22 is correspondingly provided with a limiting hole 221, and the adaptor plug 9 is inserted into the limiting hole 221. The positive circuit, the negative circuit, the heating circuit and the pre-charging circuit are all in communication connection with the external control unit 10 through the adapter plug 9, so that disorder of internal wiring of the box body is avoided, and the using amount of the wire harness is reduced.

The control unit 10 of this embodiment is a Battery Management System (Battery Management System BMS), and the positive electrode circuit, the negative electrode circuit, the heating circuit and the pre-charge circuit are all communicatively connected to the BMS through the adaptor plug 9, so that the BMS controls the normal use of the Battery module 30 through the above circuits.

As shown in fig. 1, 2 and 4, four corner positions of the base 1 are recessed inwards to form locking grooves, a first mounting hole 14 is formed at the bottom of each locking groove, and a fastener penetrates through the first mounting hole 14 to install the base 1 in the battery box. The low-voltage distribution box is simple and convenient to install and operate and easy to disassemble and assemble. Meanwhile, the locking groove avoids interference between the fixed installation of the base 1 and the assembly of the low-voltage distribution box.

The length, width and height of the low-voltage distribution box are 250x100x80mm, and compared with the installation volume of an electric element of a single-box system, the low-voltage distribution box is 500x200x150mm, the low-voltage distribution box saves 50% of installation space, reduces the use amount of materials such as sheet metal parts, insulating columns and connectors, and reduces the cost by about 40%.

In addition, can also produce or order low pressure block terminal as solitary product, only need to carry out the conduction test to low pressure block terminal and can install it in the battery box after. The conduction test includes that direct current is introduced into each circuit of the low-voltage distribution box to simulate the working condition of the low-voltage distribution box and measure the internal resistance of each circuit, and the electric elements can work normally.

The above embodiments have been described only the basic principles and features of the present invention, and the present invention is not limited by the above embodiments, and is not departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A low voltage distribution box for electrical connection with a battery module (30), comprising:

the device comprises a base (1), wherein the upper end surface of the base (1) is inwards sunken to form a containing groove (11);

the positive circuit comprises a main relay (3) and a main fuse (4) which are connected in series, the main relay (3) and the main fuse (4) are arranged adjacently and are located at one end of the accommodating groove (11), and the main fuse (4) is electrically connected with the positive output end of the battery module (30);

the negative electrode circuit comprises a current divider (5) arranged at the other end of the accommodating groove (11), and the current divider (5) is electrically connected with the negative electrode output end of the battery module (30);

the pre-charging circuit comprises a pre-charging relay (7) and a pre-charging resistor (8) which are connected in series, wherein the pre-charging relay (7) and the pre-charging resistor (8) are arranged adjacently and are both positioned on one side of the main relay (3); the positive electrode of the pre-charging relay (7) is electrically connected with the positive electrode of the main relay (3), and the pre-charging resistor (8) is electrically connected with the negative electrode of the main relay (3), so that the pre-charging circuit is connected with the main relay (3) in parallel;

the heating circuit comprises a heating relay (6) located between the main relay (3) and the shunt (5), and the heating relay (6) is electrically connected with the positive output end and the negative output end of the battery module (30) respectively.

2. The low voltage distribution box according to claim 1, characterized in that it further comprises an upper cover (2), said upper cover (2) being housed in said housing groove (11) to form a box of said low voltage distribution box; the accommodating groove (11) is divided into a first area (111) and a second area (112), the upper cover (2) comprises a first box cover (21) and a second box cover (22) which are communicated with each other, the first box cover (21) is covered on the first area (111), the second box cover (22) is covered on the second area (112), and the height of the first box cover (21) is greater than that of the second box cover (22); the main relay (3), the main fuse (4) and the heating relay (6) are located in the first region (111), the shunt (5), the precharge relay (7) and the precharge resistor (8) are located in the second region (112).

3. The low-voltage distribution box according to claim 2, further comprising an adaptor plug (9) mounted in the second region (112), wherein the second box cover (22) is correspondingly provided with a limiting hole (221), and the adaptor plug (9) is inserted into the limiting hole (221); the positive circuit, the negative circuit, the heating circuit and the pre-charging circuit are all in communication connection with an external control unit (10) through the adapter plug (9).

4. The low voltage distribution box according to claim 2, wherein the input and output lines of the positive and negative circuits and the heating circuit all extend out of the box body, and the input and output lines of the same circuit extend out of two adjacent sides of the box body.

5. The low voltage distribution box of claim 4, wherein said heating circuit shares one said output bank with said negative circuit.

6. The low voltage distribution box according to claim 1, wherein the inner wall of the accommodating groove (11) is provided with at least a first boss (121), a second boss (122) and a third boss (123) along the circumferential direction thereof, the main fuse (4) is located between the first boss (121) and the second boss (122), the main relay (3) is located between the second boss (122) and the third boss (123), and the input bar of the positive circuit is fixedly supported by the first boss (121), and the output bar of the positive circuit is fixedly supported by the third boss (123).

7. The low voltage distribution box according to claim 6, wherein the inner wall of the accommodating groove (11) is further provided with a fourth boss (124) along the circumferential direction thereof, the input row of the heating circuit is fixedly supported on the fourth boss (124) and is arranged adjacent to the output row of the positive circuit, and the third boss (123) and the fourth boss (124) are connected into a whole to form a combined boss.

8. The low voltage distribution box according to claim 7, wherein a divider plate (120) is provided on said combined boss, said divider plate (120) being located between an input row of said heating circuit and an output row of said positive circuit.

9. The low-voltage distribution box according to claim 1, wherein four corner positions of the base (1) are recessed inwards to form locking grooves, a first mounting hole (14) is formed in the bottom of each locking groove, and a fastener is arranged in each first mounting hole (14) in a penetrating mode so that the base (1) can be mounted in a battery box.

10. A power battery system, characterized in that it comprises a battery box, a battery module (30) and a low-voltage distribution box according to any of claims 1-9 electrically connected to the battery module (30), the battery module (30) and the low-voltage distribution box being mounted inside the battery box.