Battery pack shell, liquid-cooled battery pack and modular energy storage system

Abstract

The utility model relates to the technical field of energy storage, in particular to a battery pack shell, a liquid-cooled battery pack and a modular energy storage system.The battery pack shell comprises a base, and the base is used for supporting and fixing the battery pack; the upper cover is connected to the base in a covering manner, a containing cavity with an opening in one side is formed in the upper cover, and when the upper cover is fixed to the base, the battery pack is located in the containing cavity; wherein the whole base is a rectangular frame made of aluminum profiles; and the upper cover is integrally formed by injection molding. The energy storage system has the advantage that the overall weight of the energy storage system can be reduced.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a battery pack housing, a liquid-cooled battery pack, and a modular energy storage system. Background Art

[0002] The energy demand of countries around the world continues to increase, but due to the unstable nature of renewable energy, it is necessary to widely install solar photovoltaic, wind turbines and energy storage systems. Among them, energy storage system refers to a system that stores energy in the form of electricity through different media and releases it when needed.

[0003] The energy storage system mainly includes a battery pack and an inverter. The battery pack is composed of multiple battery cells connected in series and is the main carrier for realizing the storage and release of electric energy; the inverter PCS (Power Conversion System, also known as the inverter) connects the battery pack and the power grid (or load) and is a device for realizing the bidirectional conversion of electric energy. It can convert the DC power of the battery pack into AC power and transmit it to the power grid or use it for AC loads; it can also rectify the AC power of the power grid into DC power to charge the battery pack. During the process of power conversion, the inverter can accurately control the amplitude, frequency and waveform of the output current to meet the specific requirements of the power grid (or load). Therefore, the energy storage inverter improves the operating performance and efficiency of the entire energy storage system by realizing efficient, safe and controllable conversion of electric energy, and has become an important part of the field of energy storage technology.

[0004] However, traditional energy storage systems take their own power capacity into consideration, so multiple battery packs are connected as a whole. This results in a heavier overall weight of the energy storage system, making transportation and installation difficult, which needs to be solved urgently. Utility Model Content

[0005] In order to solve the above problems, embodiments of the present application provide a battery pack housing, a liquid-cooled battery pack and a modular energy storage system, which can reduce the overall weight of the energy storage system.

[0006] To this end, the following technical solutions are adopted in the embodiments of the present application:

[0007] In a first aspect, an embodiment of the present application provides a battery pack housing, comprising: a base, the base being used to support and fix the battery pack; and an upper cover, the upper cover being connectable to the base in a covering manner, and a receiving cavity with an opening on one side being formed inside the upper cover, and when the upper cover is fixed to the base, the battery pack is located in the receiving cavity; wherein the base as a whole is a rectangular frame constructed of aluminum profiles; and the upper cover is constructed by integral injection molding.

[0008] In this embodiment, the upper cover is made of plastic instead of traditional metal materials, and is combined with an aluminum base, which can reduce the weight of the entire energy storage unit by about 25kg, reduce the difficulty of transporting and installing the energy storage unit, and also reduce the cost of the energy storage unit. This application reduces the weight of the energy storage system from the perspective of shell design, and can achieve a lightweight design of the energy storage system without affecting the electrical energy capacity of the energy storage system.

[0009] As an achievable implementation, a groove is formed on the base, and the battery pack is installed in the groove. In this way, the battery pack can be fixed more stably on the basis of further reducing the weight of the base.

[0010] In a second aspect, an embodiment of the present application provides a liquid-cooled battery pack, which is installed in a shell as described above, and includes at least two battery cells. A liquid cooling plate is connected to the lower side of the battery cells, and a refrigerant flows in the liquid cooling plate. The refrigerant is used to extract heat from the battery pack.

[0011] In a third aspect, an embodiment of the present application provides a modular energy storage system, comprising: at least one energy storage unit, the energy storage unit comprising at least one energy storage PCS module and a shell for mounting and fixing the energy storage PCS module; wherein the energy storage PCS module comprises a cascaded PCS and a battery pack, the battery pack comprises at least two battery cells; the battery pack is electrically connected to the cascaded PCS.

[0012] In this implementation, the modular energy storage system adopts a cascade solution, integrating the energy storage battery group and the cascade PCS into the energy storage PCS module of an energy storage unit, thereby reducing the minimum particle unit of the energy storage system. Each energy storage unit is integrated with an energy storage PCS module, which greatly reduces the energy storage system's dependence on battery consistency. When an energy storage unit becomes abnormal, the abnormal energy storage unit automatically exits without affecting the continued operation of other energy storage units, thereby fully improving the battery utilization rate, extending the battery life, and improving the overall utilization rate and stability of the system.

[0013] As a feasible implementation method, the battery pack is provided with 28 battery cells, and the 28 battery cells are arranged in series; and the energy storage PCS modules are provided with 4, and the cascaded PCSs in the 4 energy storage PCS modules are connected in series.

[0014] In this embodiment, the embodiment of the present application uses 28 280Ah lithium iron phosphate cells connected in series to form a minimum battery pack, each battery pack is connected to a 12.5kW cascaded PCS, each cascaded PCS (power conversion system, also known as converter) outputs a voltage of 54V, and 4 cascaded PCSs output 220V after cascading, forming a 50kW / 100kWh minimum energy storage unit. Compared with the traditional 100kW / 215kWh energy storage system with 240 cells in a group, this modular energy storage system uses 28 cells in series to form a group, which greatly reduces the number of cells in the energy storage unit, reduces the requirements for cell consistency, improves cell utilization, extends battery life, and improves system stability.

[0015] As an achievable implementation, the shell includes a base for supporting the energy storage PCS module and an upper cover for protecting the energy storage PCS module; the upper cover has a accommodating cavity, and the upper cover is detachably connected to the base, and when the upper cover is fixed to the base, the energy storage PCS module is located in the accommodating cavity.

[0016] In this embodiment, the base in the shell can support the energy storage PCS module, and the upper cover can completely cover the energy storage PCS module, so that the energy storage PCS module is completely fixed on the shell. And the shell can effectively protect the energy storage PCS module and prevent it from being damaged by the external environment, such as dustproof, waterproof, shockproof, etc., thereby improving the reliability and stability of the system, and at the same time preventing the displacement or damage of the energy storage PCS module due to external factors, thereby improving the safety of the system. The upper cover and the base are detachably connected, which can facilitate maintenance and overhaul work, reduce maintenance time and cost, and facilitate the rapid replacement or adjustment of the energy storage PCS module. The upper cover has a accommodating cavity, which can effectively utilize the space, so that the energy storage PCS module can be installed compactly therein, saving system installation space. The shell formed by the upper cover and the base can provide good protection performance for the energy storage PCS module, and is convenient for maintenance, high in space utilization and high in safety performance. It is a more comprehensive energy storage PCS module shell design scheme.

[0017] As a feasible implementation manner, the upper cover is integrally formed.

[0018] In this embodiment, the integral molding of the upper cover can improve the strength of the upper cover, thereby further improving the safety performance of the shell.

[0019] As a feasible implementation manner, the structural material of the upper cover is any one of polypropylene, polycarbonate, polystyrene, polyamide, polyimide and polyvinyl chloride.

[0020] In this embodiment, the above-mentioned material can take into account the structural strength of the upper cover while reducing the weight of the shell, thereby reducing the overall weight of the energy storage unit, reducing transportation and installation costs, and facilitating system movement and handling. Using materials such as polypropylene, polycarbonate, polystyrene, polyamide, polyimide and polyvinyl chloride as the structural material of the upper cover can bring many advantages such as light weight, corrosion resistance, insulation, cost-effectiveness and good processing performance, and is suitable for the design of the upper cover to protect the energy storage PCS module.

[0021] As a feasible implementation, the upper cover is provided with a reinforcement structure, and the reinforcement structure is a concave-convex pattern.

[0022] In this embodiment, the upper cover design using concave-convex patterns as a reinforcement structure has the advantages of enhanced structural strength, anti-deformation ability, beautiful appearance, anti-slip performance and reduced production costs. It is suitable for application in the upper cover design of energy storage PCS modules to improve the overall performance and reliability of the system.

[0023] As a feasible implementation, the energy storage unit further includes a liquid cooling plate, wherein the liquid cooling plate is interconnected with the battery pack, and a refrigerant flows in the liquid cooling plate, wherein the refrigerant is used to extract heat from the energy storage PCS module.

[0024] In this embodiment, the refrigerant flowing in the liquid cooling plate can effectively remove the heat generated by the energy storage PCS module, achieve fast and efficient heat dissipation, reduce the system operating temperature, and ensure stable operation of the system.

[0025] As a feasible implementation, a heat-conducting structural adhesive is provided between the liquid cooling plate and the battery pack.

[0026] In this embodiment, the thermally conductive structural adhesive can fill the tiny gap between the liquid cooling plate and the battery pack, reduce thermal resistance, promote heat conduction, help the liquid cooling plate absorb the heat generated by the battery pack more quickly and evenly, improve heat dissipation efficiency, and ensure that the system operates stably at a lower temperature. The thermally conductive structural adhesive not only has good thermal conductivity, but also can increase the mechanical connection strength between the liquid cooling plate and the battery pack, reduce the risk of failure caused by looseness or vibration, and improve the reliability and stability of the system.

[0027] As a feasible implementation, the thermally conductive structural adhesive may be any one of silica gel or thermally conductive silicone grease.

[0028] In this embodiment, the silica gel or thermal conductive silicone grease has good softness and filling properties, and can fill irregular surfaces and tiny gaps, which helps to improve the thermal conductivity effect.

[0029] As a feasible implementation, a liquid cooling pipeline is connected to one side of the liquid cooling plate, the liquid cooling pipeline is connected to a liquid cooling unit, and the liquid cooling unit inputs and outputs refrigerant to the liquid cooling plate through the liquid cooling pipeline.

[0030] In this embodiment, the liquid cooling plate is connected to the liquid cooling pipeline and the liquid cooling unit, which can realize the circulation of the refrigerant, thereby quickly taking away the heat generated by the energy storage PCS module, improving the heat dissipation efficiency, and ensuring the stable operation of the system at a lower temperature. At the same time, through the control of the refrigerant by the liquid cooling unit, the internal temperature of the liquid cooling plate can be accurately adjusted to maintain it within the appropriate operating temperature range, which is conducive to extending the service life of the system and the battery pack.

[0031] As a feasible implementation, the base is made of aluminum profile.

[0032] In this embodiment, aluminum profiles are used as the base structural material, which has multiple advantages such as lightweight design, good thermal conductivity, strong corrosion resistance, low manufacturing cost, and environmental protection and renewableness. It is suitable for base design in energy storage systems and helps to improve the performance and service life of energy storage systems.

[0033] In summary, the embodiments of the present application have at least one of the following advantages:

[0034] 1. The modular energy storage system provided in the embodiment of the present application can realize the minimum granularity application of energy storage units and reduce the requirements of the energy storage system on the consistency of battery cells;

[0035] 2. The liquid-cooled battery pack provided in the embodiment of the present application can solve the heat dissipation problem of large-capacity battery packs and cascaded PCS;

[0036] 3. The housing provided in the embodiment of the present application can solve the problem of fixing the structure of the energy storage PCS module;

[0037] 4. The shell provided in the embodiment of the present application can realize a lightweight design of the energy storage unit and solve the problem of excessive weight of the energy storage product. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A simplified structural schematic diagram of a modular energy storage system provided in an embodiment of the present application is shown;

[0039] Figure 2 It is a schematic diagram of a partial structure explosion of a housing provided in an embodiment of the present application;

[0040] Figure 3 A schematic diagram of the energy storage PCS module and base installation structure provided in an embodiment of the present application;

[0041] Figure 4This is a schematic diagram of the upper cover structure provided in an embodiment of the present application;

[0042] In the figure, 100, modular energy storage system; 1, energy storage unit; 11, liquid cooling plate; 111, liquid inlet pipe; 112, liquid outlet pipe; 200, power grid or load; 2, energy storage PCS module; 21, cascade PCS; 22, battery pack; 221, battery cell; 222, insulating cover; 223, binding belt; 224, interval fire blanket; 3, shell; 31, base; 311, groove; 312, angle steel; 313, end plate; 314, positive output terminal; 315, negative output terminal; 316, battery management unit; 32, upper cover; 321, accommodating cavity; 322, flange; 323, make way hole; 324, concave and convex texture. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] In order to more completely understand the present application, the following examples are given. These examples are used to specifically illustrate the embodiments of the present application, and should not be understood in any way as limiting the scope of the present application.

[0049] Figure 1 A simplified structural diagram of a modular energy storage system provided in an embodiment of the present application is shown. Figure 1 The modular energy storage system 100 includes a plurality of energy storage units 1. The plurality of energy storage units 1 can increase the capacity of the modular energy storage system 100. The specific number of energy storage units 1 can be adjusted according to design requirements, and this application does not limit this. The energy storage unit 1 is interconnected with the power grid / load 200 to obtain electrical energy from the power grid side and provide electrical energy to the power grid / load 200.

[0050] Continue reading Figure 1 The energy storage unit 1 includes at least one energy storage PCS (power conversion system, also known as converter) module 2 and a housing 3 for mounting and fixing the energy storage PCS module 2. The energy storage PCS module 2 includes a cascade PCS 21 and a battery pack 22, and the battery pack 22 includes at least two battery cells 221; the battery pack 22 is electrically connected to the cascade PCS 21.

[0051] It should be noted that the cascade PCS21 in this embodiment is composed of hardware such as insulated gate bipolar transistors (IGBT), printed circuit boards (PCB), and wires and cables, and is used to provide a cascade multi-level topology circuit for the battery pack 22. Under this topology circuit, the energy storage system can minimize or eliminate the parallel connection of the energy storage units 1, so that each energy storage unit 1 is independent of each other, reducing or eliminating the circulation phenomenon of the battery cells 221 and the battery pack 22, weakening the problems caused by battery consistency in the energy storage system, improving the cycle life of the battery pack 22, and reducing the safety risks of production operations. The implementation of the specific topology circuit of the cascade PCS21 is a prior art and will not be elaborated here.

[0052] It should be understood that the working modes of the cascade PCS21 mainly include grid-connected, off-grid and hybrid modes. In the grid-connected mode, the cascade PCS 21 realizes bidirectional energy conversion between the energy storage battery group 22 and the power grid, charging or discharging the battery group 22. In the off-grid mode, the cascade PCS21 can provide AC power that meets the power quality requirements of the power grid to the local partial load according to actual needs. In the hybrid mode, the cascade PCS21 can switch between the grid-connected mode and the off-grid mode. The main functions of the cascade PCS21 include power smoothing, information protection, protection, etc. The cascade PCS21 determines the output power quality and dynamic characteristics, and also greatly affects the battery life.

[0053] In this way, the modular energy storage system adopts a cascade solution, integrating the energy storage battery group 22 and the cascade PCS 21 into the energy storage PCS module 2 of an energy storage unit 1, thereby reducing the minimum particle unit of the energy storage system. Each energy storage unit 1 is integrated with the energy storage PCS module 2, which greatly reduces the energy storage system's dependence on battery consistency. When an abnormality occurs in a certain energy storage unit 1, the abnormal energy storage unit 1 automatically exits without affecting the continued operation of other energy storage units 1, thereby fully improving the battery utilization rate, extending the battery life, and improving the overall utilization rate and stability of the system.

[0054] See also Figure 2 and Figure 3In a specific embodiment, there are 4 energy storage PCS modules 2, and the 4 energy storage PCS modules 2 are arranged side by side at equal intervals, and the cascaded PCS 21 in the 4 energy storage PCS modules 2 are connected in series. The battery cells 221 in the battery pack 22 are arranged in 28 sections, and the 28 battery cells 221 are arranged in series. It is worth mentioning that since lithium-ion batteries have the advantages of high energy density, fast response rate and long discharge time, the battery cells 221 in this embodiment are 280Ah lithium iron phosphate battery cells 221. Specifically, each battery pack 22 is composed of 28 280Ah lithium iron phosphate battery cells 221 connected in series, and each battery pack 22 is connected to a 12.5kW cascaded PCS 21, and each cascaded PCS 21 outputs a voltage of 54V. After the cascaded 4 cascaded PCS 21 outputs 220V, forming a 50kW / 100kWh minimum energy storage unit 1. Compared with the traditional 100kW / 215kWh energy storage system with 240 battery cells 221 in a group, the battery pack 22 uses 28 battery cells 221 connected in series, which greatly reduces the number of battery cells 221 in the energy storage unit 1, reduces the consistency requirements of the battery cells 221, improves the utilization rate of the battery cells 221, extends the battery life, and improves the stability of the energy storage system.

[0055] In one embodiment, the upper side of the battery pack 22 is covered with an insulating cover 222, so that the battery cells 221 of the same battery pack 22 can be connected in series side by side to form a group. In order to make the battery cells 221 of the same battery pack 22 more stably fixed to each other, two binding bands 223 are tied to the outer periphery of the battery cells 221 of the same battery pack 22 after they are arranged in series and side by side. It should be understood that the binding bands 223 are insulating binding bands 223. At the same time, the battery cells 221 in the same battery pack 22 form a group in pairs, and a spacing fire blanket 224 is provided between the group formed by two battery cells 221 and the group formed by another two battery cells 221. The spacing fire blanket 224 can play a role of heat insulation and flame retardancy, thereby increasing the safety of the battery pack 22 when in use.

[0056] See also Figure 3 and Figure 4 The housing 3 includes a base 31 for supporting the energy storage PCS module 2 and an upper cover 32 for protecting the energy storage PCS module 2. The upper cover 32 has a receiving cavity 321, and the upper cover 32 is detachably connected to the base 31. The upper cover 32 can be connected to the base 31 in a covering manner, and when the upper cover 32 is fixed on the base 31, the energy storage PCS module 2 is located in the receiving cavity 321.

[0057] Exemplarily, the detachable connection between the upper cover 32 and the base 31 can be any one of bonding, clamping or screwing. For example, the upper cover 32 and the base 31 can be bonded together by structural adhesive; or, a hook is provided at the opening edge of the upper cover 32, and a clamping groove is provided at the four edges of the base 31 at the position corresponding to the hook, and the hook and the clamping groove cooperate with each other to clamp the upper cover 32 on the base 31; or, a flange 322 is extended outward from the opening edge of the upper cover 32 toward the base 31, and a threaded hole is provided at the position where the flange 322 and the base 31 contact, and a bolt is screwed into the threaded hole, so that the upper cover 32 is screwed on the base 31.

[0058] See also Figure 3 The upper surface of the base 31 is provided with a groove 311. The four energy storage PCS modules 2 are arranged side by side and fixed in the groove 311 of the base 31. The groove 311 can make the fixation of the energy storage PCS module 2 more stable. In addition, the base 31 is a rectangular frame made of aluminum profiles. Aluminum profiles are light, corrosion-resistant, easy to process, and have good thermal conductivity. It can make the shell 3 have both strength and significantly reduce the weight of the overall energy storage system.

[0059] Optionally, an end plate 313 is detachably connected to the base 31 through an angle steel 312, and the end plate 313 is located on one side of the energy storage PCS module 2. Exemplarily, an insulated output terminal is provided on the end plate 313, and the insulated output terminal is electrically connected to the energy storage PCS module 2 through a cable. The insulated output terminal includes a positive output terminal 314 and a negative output terminal 315, and the energy storage unit 1 is electrically connected to the power grid / load 200 through the positive output terminal 314 and the negative output terminal 315.

[0060] In one embodiment, a battery management unit 316 is provided on the end plate 313, and the battery management unit 316 mainly manages the charging and discharging protection of the battery pack 22. Exemplarily, when the battery pack 22 is charged, the battery management unit 316 can ensure that the voltage difference between each single cell 221 is less than the set value, so as to achieve equal charging of each single cell 221 of the battery pack 22, and effectively improve the charging effect under the series charging mode. At the same time, the battery management unit 316 detects the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single cell 221 in the battery pack 22 to protect and extend the battery life. The specific implementation of the battery management unit 316 can refer to the existing design, and this application will not be repeated here.

[0061] It is worth mentioning that, correspondingly, a clearance hole 323 for partial installation of the end plate 313 is opened on one side of the upper cover 32. The clearance hole 323 allows the structure on one side of the end plate 313 to be displayed on the outside of the accommodating cavity 321 of the upper cover 32, thereby facilitating the staff to operate the various functional parts on the end plate 313.

[0062] See also Figure 4 In one embodiment, the longitudinal section of the accommodating cavity 321 of the upper cover 32 is set to be trapezoidal, so that while accommodating the energy storage PCS module 2, the space can be effectively utilized, so that the energy storage PCS module 2 can be installed compactly therein, saving system installation space. In another possible implementation, the longitudinal section of the accommodating cavity 321 can also be set to be an inverted U-shape, which is not strictly limited in this application, and the designer can specifically design the shape of the accommodating cavity 321 according to the structure of the energy storage PCS module 2.

[0063] In order to make the upper cover 32 have a higher strength, the upper cover 32 is integrally formed. Exemplarily, the upper cover 32 can be integrally formed by injection molding. For example, the upper cover 32 is made of any one of polypropylene, polycarbonate, polystyrene, polyamide, polyimide and polyvinyl chloride. Polypropylene has good mechanical properties, corrosion resistance and high temperature resistance, and is suitable for manufacturing the shell of the energy storage system. Polycarbonate has excellent transparency, impact resistance and heat resistance, and is suitable for battery pack shells 3 that require a transparent appearance or high impact resistance. Polystyrene has good processability and surface gloss, and is suitable for the manufacture of energy storage system shells. Polyamide has excellent mechanical properties, wear resistance and heat resistance, and is also selected for battery pack shells 3 in some occasions where strength and durability are required. Polyimide has extremely high heat resistance, chemical resistance and mechanical properties, and is suitable for battery pack shells 3 in high temperature environments. Polyvinyl chloride has good processability, insulation performance and corrosion resistance, and the manufacturing cost of polyvinyl chloride is low, which can reduce the overall cost of the energy storage system.

[0064] In some examples, the upper cover 32 is provided with a reinforcement structure, and in order to adapt to the one-piece molding structure, the reinforcement structure is a concave-convex pattern 324. The concave-convex pattern 324 can effectively increase the structural strength of the upper cover 32, making it more sturdy and durable, and improving the compression resistance and bearing capacity of the overall shell 3. At the same time, the setting of the concave-convex pattern 324 can effectively disperse external impact or extrusion force, reduce the possibility of structural deformation, maintain the stability of the shape of the upper cover 32, and extend the service life of the shell 3. Moreover, compared with other complex reinforcement structures, the concave-convex pattern 324 is simple in design, suitable for one-piece molding, easy to manufacture, and can effectively reduce production costs and improve production efficiency.

[0065] Thus, the upper cover 32 is made of plastic instead of traditional metal materials, and is combined with the base 31 made of aluminum profiles, which can reduce the weight of the entire energy storage unit 1 by about 25 kg, while also reducing the cost of the energy storage unit 1 and achieving a lightweight design of the energy storage system.

[0066] Since the lithium battery cell 221 has a range requirement for the operating temperature of the energy storage system, it is necessary to control the internal temperature of the energy storage system housing 3. Figure 1 and Figure 2 , the energy storage unit 1 also includes a liquid cooling plate 11, the liquid cooling plate 11 is interconnected with the battery pack 22, and a refrigerant flows in the liquid cooling plate 11, and the refrigerant is used to extract the heat of the energy storage PCS module 2. Exemplarily, the liquid cooling plate 11 is located at the bottom of the battery pack 22 and is installed in the groove 311 of the support. It can be understood that the liquid cooling plate 11 can cover four energy storage PCS modules 2. In another possible implementation, the liquid cooling plate 11 can also be abutted against the side wall of the battery pack 22 or the insulating cover 222 on the upper side of the battery pack 22. Alternatively, a liquid cooling plate 11 is provided on each of the six side walls of the overall structure formed by four energy storage PCS modules 2 arranged side by side. The present application is not limited here, as long as there is sufficient contact area between the liquid cooling plate 11 and the energy storage PCS module 2.

[0067] In one embodiment, in order to further improve the heat exchange efficiency between the liquid cooling plate 11 and the energy storage PCS module 2, a thermally conductive structural adhesive (not shown) is provided between the liquid cooling plate 11 and the battery pack 22. The thermally conductive structural adhesive can fill the tiny gap between the liquid cooling plate 11 and the battery pack 22, reduce thermal resistance, promote heat conduction, and help the liquid cooling plate 11 absorb the heat generated by the battery pack 22 more quickly and evenly, thereby improving heat dissipation efficiency. Optionally, the thermally conductive structural adhesive can be any one of silica gel or thermally conductive silicone grease. Silica gel or thermally conductive silicone grease not only have good thermal conductivity, but also can increase the mechanical connection strength between the liquid cooling plate 11 and the battery pack 22, reduce the risk of failure caused by looseness or vibration, and improve the reliability and stability of the system.

[0068] See also Figure 2 and Figure 3 , a liquid cooling pipeline is connected to one side of the liquid cooling plate 11, and the liquid cooling pipeline is connected to a liquid cooling unit (not shown in the figure, for example, it may include a hydraulic pump and a liquid cooling machine), the liquid cooling pipeline includes a liquid inlet pipe 111 and a liquid outlet pipe 112, the liquid inlet pipe 111 and the liquid outlet pipe 112 are installed on the base 31, and the liquid cooling unit inputs and outputs refrigerant into and out of the liquid cooling plate 11 through the liquid inlet pipe 111 and the liquid outlet pipe 112. Exemplarily, the refrigerant is a coolant, and the coolant flows unidirectionally in the liquid cooling plate 11 and takes away the heat of the battery pack 22, thereby achieving the effect of cooling the energy storage PCS module 2.

[0069] A modular energy storage system provided in the embodiment of the present application is mainly used in the battery energy storage industry, power transmission and transformation industry, oil exploration industry, sewage treatment industry, data center, communication base station industry, etc. For example, it can provide power regulation and balance in the fields of power grid peak regulation, backup power, microgrid, etc. At the same time, the modular energy storage system can provide power for uninterruptible power supply (UPS), charging pile (electric vehicle charger, EVcharger), grid-side power transmission and distribution equipment ((power transmission and distribution equipment: power transmission and distribution equipment, PTD), (medium voltage distribution: medium voltage distribution, MVD), (active power filter: active power filter, APF), (static var generator: static var generator, SVG)), outdoor cabinets, base stations and other equipment.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application. Those skilled in the art should understand that, although the present application is described in detail with reference to the aforementioned embodiments, the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims

1. A battery pack housing, characterized in that: include: A base, the base is used to support and fix the battery pack; as well as An upper cover, the upper cover can be connected to the base in a covering manner, and a receiving cavity with an opening on one side is formed inside the upper cover, and when the upper cover is fixed on the base, the battery pack is located in the receiving cavity; The base is a rectangular frame made of aluminum profiles; the upper cover is an integrally formed injection molded structure.

2. The housing according to claim 1, characterized in that A groove is formed on the base, and the battery pack is installed in the groove.

3. The housing according to claim 1, characterized in that The upper cover is provided with a reinforcement structure, and the reinforcement structure is a concave-convex pattern.

4. The housing according to any one of claims 1 to 3, characterized in that: The structural material of the upper cover is any one of polypropylene, polycarbonate, polystyrene, polyamide, polyimide and polyvinyl chloride.

5. A liquid-cooled battery pack, characterized in that: It comprises a shell as described in any one of claims 1 to 4 and at least two battery cells, wherein the lower side of the battery cell is connected to a liquid cooling plate, a refrigerant flows in the liquid cooling plate, and the refrigerant is used to extract heat from the battery pack.

6. The battery pack according to claim 5, characterized in that: A heat-conducting structural adhesive is arranged between the liquid cooling plate and the battery pack.

7. The battery pack according to claim 5, characterized in that: A liquid cooling pipeline is connected to one side of the liquid cooling plate, and the liquid cooling pipeline is connected to a liquid cooling unit. The liquid cooling unit inputs and outputs refrigerant into and out of the liquid cooling plate through the liquid cooling pipeline.

8. The battery pack according to claim 5, characterized in that: The battery pack is provided with an insulating cover, which is used to fix the plurality of battery cells; and at least one binding strap is provided on the periphery of the battery pack, which is used to fix the plurality of battery cells connected in series.

9. A modular energy storage system, characterized in that: include: At least one energy storage unit, the energy storage unit comprising at least one energy storage PCS module and a shell as described in any one of claims 1-4; wherein the energy storage PCS module comprises a cascaded PCS and a battery pack as described in any one of claims 5-8, the battery pack comprising at least two battery cells; the battery pack is electrically connected to the cascaded PCS.

10. The energy storage system according to claim 9, characterized in that: The battery pack is provided with 28 battery cells, which are arranged in series; and the energy storage PCS modules are provided with 4, and the cascaded PCSs in the 4 energy storage PCS modules are connected in series.

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