Battery cluster frame and battery pack connection structure and battery energy storage system

Abstract

The utility model belongs to lithium ion battery technical field, concretely relates to a kind of connecting structure of battery cluster frame and battery pack and battery energy storage system, including battery cluster frame, battery pack, bracket and edge beam, the bracket of the battery cluster frame is connected by edge beam with the battery pack, the bushing is embedded in the battery pack edge beam inside, the bushing is equipped with the bolt hole that passes through up and down;Bolt passes through the bolt hole and locks the edge beam, bushing and bracket solidly.This structure can effectively improve structural strength, reduce installation process 3 simultaneously, reduce connection assembly cost about 25%.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery technology, specifically relating to a novel battery pack and cluster frame connection structure and battery energy storage system. Background Technology

[0002] In recent years, MW-level battery energy storage technology has developed rapidly both domestically and internationally. Among them, containerized battery energy storage systems have shown broad application prospects in power grids and other fields due to their advantages such as high capacity, high reliability, high flexibility, and strong environmental adaptability. These systems typically consist of multiple battery pack racks. As a key structure for fixing the energy storage batteries, the battery pack racks must ensure that the battery packs do not slide or collide during transportation and use. Therefore, a high-strength connection method is urgently needed to achieve stable fixation between the battery packs and the racks.

[0003] Existing technical solutions (such as) Figure 7 As shown, the battery system is assembled using a multi-level mechanical fixing structure. Its core feature is that the battery pack 02 is physically connected to the battery cluster frame 01 via a stamped metal connecting piece 04. Both ends of the connecting piece 04 are rigidly locked to the side beam 06 of the battery pack 02, the fixing block 05, and the bracket 03 of the cluster frame 01 via bolt assemblies. This architecture has the following technical defects: 1. Structural redundancy: The fixed block 05, bushing 07 and connecting piece 04 increase the number of parts, raising material costs and assembly complexity; 2. Insufficient dynamic reliability: In the vibration test (5-200Hz random vibration) of GB / T 36276, multi-layer connection structures are prone to bolt loosening or component breakage; 3. Low maintenance efficiency: Module repair requires disassembling the entire fixing block 05 and connecting piece 04, increasing the maintenance time by 1.2 person-hours per maintenance session; 4. Appearance defects: Exposed bolt heads and protruding connecting pieces damage the flatness of the equipment surface, affect the aesthetics, and make it difficult to meet the IP67 protection standard.

[0004] Therefore, there is an urgent need for a battery pack and cluster frame connection solution that is structurally simple, highly vibration-resistant, easy to maintain, and has a flat appearance. Utility Model Content

[0005] The purpose of this utility model is to provide a connection structure between a battery cluster frame and a battery pack, as well as a battery energy storage system, to solve the problem of complex structure in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: One of the objectives of this utility model is to provide a connection structure between a battery cluster frame and a battery pack, including a battery cluster frame, a battery pack, a bracket, and a side beam. The battery pack is connected to the bracket of the battery cluster frame through the side beam. A bushing is embedded inside the side beam of the battery pack, and the bushing has bolt holes that extend vertically. Bolts pass through the bolt holes to lock the side beam, bushing, and bracket.

[0007] Preferably, the mating surface between the bushing and the side beam is provided with a welding area, the welding area including double-sided vertical welds and top continuous fillet welds.

[0008] Preferably, the weld leg height of the double-sided vertical weld is 5mm, and the weld leg height of the top continuous fillet weld is 6mm.

[0009] Preferably, the side beam and the bushing are fitted together, and the block structure of the bushing is adapted to the shape of the internal cavity of the side beam.

[0010] Preferably, the bushing is a rectangular metal block with bolt holes of φ9mm on its upper and lower end faces, suitable for M8 grade bolts.

[0011] Preferably, the bushing is fully embedded inside the battery pack side beam, and its outer surface is flush with the contour of the side beam.

[0012] Preferably, the bushing has a positioning step at the bottom, and the positioning step abuts against the bottom surface of the inner cavity of the battery pack side beam.

[0013] Preferably, the battery cluster frame, battery pack, bracket, side beam, bushing, and bolts constitute a three-dimensional positioning and locking structure, and the bolt hole axis of the bushing is perpendicular to the length direction of the side beam.

[0014] Preferably, the clearance between the bushing and the battery pack edge beam is ≤0.2mm.

[0015] Preferably, the bolt is a high-strength galvanized bolt with a mechanical strength grade of not less than M8.

[0016] The second objective of this utility model is to provide a battery energy storage system, which includes the novel battery pack and cluster frame connection structure described above.

[0017] The beneficial effects of this utility model are: This structure achieves three-dimensional positioning and locking of the side beam, bushing, and bracket by embedding bushings inside the side beam and using M8 high-strength galvanized bolts passing through the bolt holes of the bushings. Argon arc welding is used at the mating surface between the bushing and the side beam for double-sided vertical welding and continuous top fillet welding, forming multiple stress transfer paths and creating a composite connection structure. This structure effectively improves structural strength (verified by finite element analysis combined with experiments), while reducing installation steps by three and lowering the cost of connection components by approximately 25%.

[0018] This structure eliminates the traditional exposed connecting pieces, reducing installation steps and the number of connecting components. The embedded fit and welding process of the side beams and bushings effectively improves the structural strength. The connection interface is a planar fit structure, which improves the overall contour flatness and eliminates the surface protrusions. At the same time, the deformation of key connection parts of the battery cluster frame can be controlled under vibration conditions, and the maximum equivalent stress of each component is lower than the material fatigue strength, meeting the requirements for transportation and use. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 for Figure 1 Exploded view; Figure 4a This is a stress cloud diagram of the present invention; Figure 4b This is the displacement cloud map of this utility model; Figure 5 This is a sweep frequency curve diagram of this utility model; Figure 6 This is a vibration curve diagram of the present invention; Figure 7 This is a schematic diagram of the existing technology; Explanation of reference numerals in the attached figures: 1. Battery cluster frame; 2. Battery pack; 3. Bracket; 4. Bushing; 5. Side beam; 6. Bolt; 7. Welding area; Existing structure: 01, battery cluster frame; 02, battery pack; 03, bracket; 04, connecting piece; 05, fixing block; 06, side beam; 07, bushing. Detailed Implementation

[0020] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0021] like Figures 1-3As shown, a novel battery pack and cluster frame connection structure mainly consists of a battery cluster frame 1, a battery pack 2, a bracket 3, a bushing 4, a side beam 5, and bolts 6. The battery pack 2 is connected to the bracket 3 of the battery cluster frame 1 via the side beam 5. A block-shaped bushing 4 is embedded inside the side beam 5, and the side beam 5 and bushing 4 are fitted together. The block structure of the bushing 4 is adapted to the shape of the internal cavity of the side beam 5 (the bushing 4 is completely embedded inside the side beam 5 of the battery pack, and its outer surface is flush with the contour of the side beam 5). Furthermore, a positioning step is provided at the bottom of the bushing 4, which abuts against the bottom surface of the inner cavity of the side beam 5 of the battery pack. The bushing 4 is a rectangular metal block with bolt holes of φ9mm diameter on its upper and lower end faces, suitable for M8 grade bolts. M8 grade high-strength galvanized bolts 6 pass through the bolt holes, rigidly locking the side beam 5, bushing 4, and bracket 3. The battery cluster frame 1, battery pack 2, bracket 3, side beam 5, bushing 4, and bolts 6 constitute a three-dimensional positioning and locking structure. Furthermore, the clearance between the bushing 4 and the battery pack edge beam 5 is ≤0.2mm.

[0022] The mating surface between the bushing 4 and the side beam 5 is welded using an argon arc welding process. Specifically, a welding area 7 is provided on the mating surface between the bushing 4 and the side beam 5. The welding area 7 includes double-sided vertical welds and a continuous top fillet weld. The weld leg height of the double-sided vertical welds is 5mm, and the weld leg height of the continuous top fillet weld is 6mm, forming the welding area 7. This welding process makes the bushing 4 and the side beam 5 form an integral structure, enhancing the connection strength. The bracket 3 is provided with mounting grooves that fit the side beam 5 and the bushing 4. Bolts 6 pass through the mounting holes of the bracket 3 and connect to the bolt holes of the bushing 4 to achieve three-dimensional positioning.

[0023] When the battery pack 2 is subjected to vibration or external force, the load is transferred through the side beam 5 to the embedded bushing 4, and then through the bolts 6 to the bracket 3 and the battery cluster 1. Since the bushing 4 and the side beam 5 are welded together to form a rigid whole, and the bolts 6 are made of high-strength material, the load can be evenly distributed through the path of "side beam → bushing → bolt → bracket", avoiding the single-point stress defect of traditional connecting pieces.

[0024] The multiple stress transmission paths in welded area 7 can effectively disperse vibration loads and reduce the risk of component fracture. Finite element analysis verified that under the random vibration conditions of 5-200Hz according to GB / T 36276 standard, the maximum equivalent stress of each component of battery cluster frame 1 is 72MPa (lower than the material fatigue strength), and the deformation of key connection parts is controlled within 1mm, meeting the strength requirements for transportation and use.

[0025] Because this structure eliminates exposed connecting pieces, it reduces three installation steps and the number of connecting components. Maintenance can be performed without disassembling multiple layers of components; assembly and disassembly can be done directly using bolts 6, reducing assembly complexity and maintenance time.

[0026] To comprehensively verify the reliability of the battery cluster structure designed in this patent during transportation and use, this patent employs the finite element analysis method based on the vibration condition standard GB36276-2023 "Lithium-ion Batteries for Electric Energy Storage" to conduct a strength simulation verification of the battery cluster structure under random vibration conditions simulating highway transportation. Through comprehensive evaluation using stress cloud diagrams, displacement deformation, and modal analysis results, it is ensured that the maximum equivalent stress is lower than the material's fatigue strength, and the deformation of key connection parts is controlled within 1 mm. Figure 4a and Figure 4b The diagrams shown are the stress cloud diagram and displacement cloud diagram of the structure of this patent. The maximum equivalent stress of each component of the battery cluster is 72 MPa, which is lower than the fatigue strength of the materials of each component, ensuring that it meets the strength requirements during transportation and use. The maximum displacement of the battery cluster is 2.4 mm, and the maximum deformation is the cover plate of the battery pack. The deformation of the key connection parts is less than 1 mm, which meets the requirements. To further verify the reliability of the design and simulation, experimental verification was conducted on a single-layer cluster frame (with battery pack). For example... Figure 5 The figure shows the frequency sweep curve of the design structure. The natural frequency of the model is 30Hz, which is not much different from the finite element analysis results (mainly because the model is simplified to a certain extent in the finite element analysis). Figure 6 The vibration curve of the module is shown. Experimental verification shows that the strength of the new connection structure design meets the requirements.

[0027] This structure, through the embedded fit between the bushing and the side beam, effectively improves structural strength (verified by finite element analysis and experiments), while reducing installation steps by three and lowering the cost of connecting components by approximately 25%. In terms of appearance, the elimination of exposed connecting pieces improves the overall contour flatness by 0.5 mm / m, and the surface is free of protruding structures, meeting the IP67 protection standard requirements for new energy equipment. This has a positive impact on product quality and compliance.

[0028] It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A connection structure between a battery cluster frame and a battery pack, comprising a battery cluster frame (1), a battery pack (2), a bracket (3), and a side beam (5), wherein the battery pack (2) is connected to the bracket (3) of the battery cluster frame (1) via the side beam (5), characterized in that: The side beam (5) is fitted with a bushing (4), and the bushing (4) has bolt holes that run through the top and bottom; the bolts (6) pass through the bolt holes to lock the side beam (5), bushing (4) and bracket (3).

2. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The bushing (4) and the side beam (5) are provided with a welding area (7), which includes double-sided vertical welding and top continuous fillet welding.

3. The connection structure between the battery cluster frame and the battery pack according to claim 2, characterized in that: The weld leg height of the double-sided vertical weld is 5mm, and the weld leg height of the top continuous fillet weld is 6mm.

4. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The side beam (5) and the bushing (4) are fitted together, and the block structure of the bushing (4) is adapted to the shape of the internal cavity of the side beam (5).

5. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The bushing (4) is a rectangular metal block with bolt holes of φ9mm on its upper and lower end faces, which are suitable for M8 grade bolts.

6. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The bushing (4) is fully embedded inside the side beam (5), and its outer surface is flush with the outline of the side beam (5).

7. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The bushing (4) has a positioning step at the bottom, and the positioning step abuts against the bottom surface of the inner cavity of the side beam (5).

8. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The battery cluster frame (1), battery pack (2), bracket (3), side beam (5), bushing (4) and bolt (6) constitute a three-dimensional positioning and locking structure, and the bolt hole axis of the bushing (4) is perpendicular to the length direction of the side beam (5).

9. The connection structure between the battery cluster frame and the battery pack according to claim 1, characterized in that: The clearance between the bushing (4) and the side beam (5) is ≤0.2mm; The bolts are high-strength galvanized bolts with a mechanical strength grade of not less than M8.

10. A battery energy storage system, characterized in that: The battery cluster frame and battery pack connection structure are described in any one of claims 1-9.

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