A cascade battery pack available energy assessment system

Abstract

The utility model provides a kind of energy evaluation system of echelon battery pack, including energy storage cabinet, cooling system and being arranged in several placing devices of energy storage cabinet, battery pack is fixed in placing device, cooling system includes main stream passage and fire extinguishing flow channel;Placing device includes shell, at least two electricity connection sockets are provided on shell, and battery pack is electrically connected with electricity connection socket;The periphery of shell is provided with telescopic baffle, and telescopic baffle is automatically stretched from retracted state to unfolded state when the temperature preset threshold of shell;Main stream passage flows through each shell, and shell is provided with serpentine cooling flow channel and cooling flow channel is connected with main stream passage, and fire extinguishing flow channel includes the outlet above each placing device;Placing device further includes calibration unit electrically connected with battery pack, and calibration unit is used to calibrate battery pack SOC.Through built-in calibration unit, the problem that echelon battery is large in dispersion and difficult to estimate is solved, so as to improve the operating efficiency and safety of entire energy storage system.

Description

Technical Field

[0001] This utility model relates to the field of battery pack management system technology, specifically a cascaded battery pack available energy assessment system. Background Technology

[0002] With the rapid development of the electric vehicle industry, the number of retired power batteries is increasing year by year. These retired power batteries are not completely failed, but their capacity has decayed to less than 80% of their initial capacity, no longer meeting the performance requirements of electric vehicles. However, these batteries still have considerable residual energy, which can be utilized in "second-hand utilization" fields such as energy storage. Applying retired power batteries to energy storage systems can not only effectively improve resource utilization and reduce the total life cycle cost of batteries, but also provide peak shaving and frequency regulation services to the power grid, promoting the consumption of renewable energy.

[0003] Currently, the application of secondary battery packs in energy storage systems faces numerous challenges. One key issue is how to accurately assess the available energy of these packs. Due to the significant performance variability of secondary battery packs—including differences in parameters such as battery capacity, internal resistance, and self-discharge rate—and the further changes these parameters with increasing usage time and environmental factors, the inability to accurately assess the available energy of each pack can lead to inefficient operation of the energy storage system and even safety hazards. For example, over-discharge may accelerate battery aging and shorten battery life; while underestimating the available energy of the batteries results in resource waste.

[0004] Furthermore, the heat dissipation and safety issues of secondary battery packs, which operate for extended periods in energy storage systems, cannot be ignored. Batteries generate heat during charging and discharging; if heat dissipation is inadequate, it can lead to overheating, affecting battery performance and lifespan, and even triggering thermal runaway. Traditional heat dissipation methods may be insufficient to meet the complex and varied thermal management requirements of secondary battery packs. Simultaneously, due to aging and performance differences, the risk of failure is relatively high during secondary use, especially since energy storage cabinets may contain battery packs of different sizes and specifications. If one experiences thermal runaway, effectively isolating the fire source and preventing the fire from spreading between different battery packs presents a pressing technical challenge. Utility Model Content

[0005] This invention aims to overcome the shortcomings of existing technologies and provide a cascaded battery pack available energy assessment system. This system can not only accurately calibrate and assess the available energy of the battery pack, but also provide efficient cooling during daily operation. In extreme situations such as thermal runaway, it can automatically and quickly form physical isolation and perform targeted fire suppression to effectively prevent the spread of fire. In particular, it can meet the fire safety requirements of battery packs of different sizes.

[0006] In order to achieve the above object, the utility model discloses the following technical scheme:

[0007] A kind of echelon battery pack available energy evaluation system, including energy storage cabinet, cooling system and being arranged in the energy storage cabinet several placing devices, the battery pack is fixed in the placing device, cooling system includes main flow channel and fire extinguishing flow channel;

[0008] The placing device includes shell, at least two power connection sockets are arranged on the shell, and the battery pack is electrically connected with the power connection socket;

[0009] The periphery of the shell is provided with telescopic baffle, the telescopic baffle is automatically stretched from the retracted state to the unfolded state when the temperature of the shell reaches the preset threshold value;

[0010] The main flow channel flows through each shell, the shell is provided with a serpentine cooling flow channel and the cooling flow channel is communicated with the main flow channel, and the fire extinguishing flow channel includes a fire extinguishing outlet above each placing device.

[0011] The placing device further includes a calibration unit electrically connected to the battery pack, and the calibration unit is used to calibrate the SOC of the battery pack.

[0012] Further, the calibration unit includes a host computer and an inverter, and the AC side of the inverter is connected to the mains through an AC inlet switch and connected to the station power through a switch. The calibration unit can accurately charge and discharge test the battery pack to obtain accurate capacity and SOC information. Preferably, the calibration unit is connected to at least two series-connected battery packs to simulate actual working conditions and improve calibration efficiency.

[0013] Further, to realize automatic triggering and reliable isolation of the telescopic baffle, the telescopic baffle includes a lower baffle and an upper baffle fixedly connected to the shell, and the lower baffle and the upper baffle are both hinged with a first link and a second link. The first link of the lower baffle is hinged with the second link of the upper baffle, and the second link of the lower baffle is hinged with the first link of the upper baffle, forming a cross-link telescopic mechanism.

[0014] To realize temperature sensing automatic triggering, the upper baffle is slidably provided with a tenon, and the shell is provided with a corresponding tenon hole. A pusher (such as a compression spring) is arranged between the upper baffle and the tenon, so that the tenon has a movement trend of moving away from the upper baffle and inserting into the tenon hole. The tenon is further connected with a shape memory metal wire, and the other end of the shape memory metal wire is connected to the upper baffle. At normal temperature, the shape memory metal wire is in a stretched state, pulls the tenon to overcome the elastic force of the pusher, and makes the tenon out of the tenon hole and keep in a contracted state. When the temperature rises to a preset threshold (such as 80-100 DEG C), the shape memory metal wire shrinks under heat, releases the pulling force on the tenon, and the tenon is automatically popped out under the action of the pusher and out of the tenon hole, thereby triggering the telescopic mechanism.

[0015] To realize complete isolation, the telescopic spring and the flexible shroud are further connected between the upper baffle and the lower baffle. The telescopic spring provides initial power for the expansion of the baffle, and the flexible shroud is stretched at the same time as the baffle is expanded, forming a closed or semi-closed isolation cavity. This design is the key to adapt to different sizes of battery packs. No matter the size of the battery pack, the expanded baffle and flexible shroud can effectively isolate it from the surrounding space to form an independent fireproof unit, preventing heat and flame from spreading to adjacent battery packs.

[0016] Further, to increase the stability of the expanded state, a stable link is further hinged between the two second links, ensuring that the baffle is stable and will not easily deform or collapse after being fully expanded.

[0017] Further, to provide a reliable source of fire extinguishing agent, the top of the energy storage cabinet is provided with a fire water tank or a container for storing other fire extinguishing agents, which is connected with the fire extinguishing flow channel, so that once a fire occurs, the fire extinguishing agent can be quickly transported to the fire extinguishing outlet above the fire point through the fire extinguishing flow channel.

[0018] Compared with the prior art, the utility model has the advantages that:

[0019] 1. Accurate evaluation and efficient operation: through the built-in calibration unit, the capacity of the battery pack can be calibrated offline or online regularly or as needed, the accurate SOC is obtained, the problem of large dispersion of the battery pack and difficult estimation is solved, and the operation efficiency and safety of the whole energy storage system are improved, and overcharging and overdischarging caused by inaccurate estimation are avoided.

[0020] 2. Safety protection combining active and passive: the system integrates active heat dissipation in daily operation and passive safety protection in extreme cases. The winding cooling flow channel can effectively take away the heat generated by the normal operation of the battery; and the telescopic baffle triggered by temperature sensing constitutes the second safety line, and realizes early isolation of faults.

[0021] 3. Intelligent fire isolation and targeted fire extinguishing: when a battery pack shows signs of thermal runaway (abnormal temperature rise), the telescopic baffle on the corresponding placement device will automatically expand, instantly forming a physical isolation cover. It can effectively prevent heat radiation and flame spread to adjacent batteries. At the same time, the fire extinguishing flow channel in the cooling system can spray from above and immerse the battery pack in cooling. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 It is a three-dimensional structural schematic diagram of an embodiment of the present application.

[0024] Figure 2 It is a front view of an embodiment of the present application.

[0025] Figure 3 It is a structural schematic diagram of the telescopic baffle in an embodiment of the present application.

[0026] Figure 4 It is a sectional view of the upper baffle in an embodiment of the present application.

[0027] Figure 5 It is a principle diagram of the calibration unit in an embodiment of the present application.

[0028] EXPLANATION OF REFERENCE NUMERALS:

[0029] 1. Energy storage cabinet;

[0030] 2. Placement device; 21. Shell; 22. Power socket; 23. Clamping hole;

[0031] 3. Battery pack;

[0032] 4. Main flow channel;

[0033] 5. Fire extinguishing flow channel; 51. Fire extinguishing outlet;

[0034] 6. Fire-fighting water tank;

[0035] 7. Telescopic baffle; 71. Upper baffle; 72. Lower baffle; 73. First connecting rod; 74. Second connecting rod; 75. Mortise; 76. Ejector; 77. Shape memory metal wire; 78. Steady-state connecting rod; 79. Telescopic spring;

[0036] 8. Flexible apron. DETAILED DESCRIPTION

[0037] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product.

[0038] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings. The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0039] Reference Figures 1-5 This utility model provides a system for assessing the usable energy of a cascaded battery pack, which is mainly installed inside an energy storage cabinet 1. The energy storage cabinet 1 is equipped with multiple placement devices 2 for placing and securing cascaded battery packs 3 of different specifications. The entire system also includes a cooling system.

[0040] The cooling system includes a main flow channel 4 and a fire extinguishing flow channel 5. The main flow channel 4 runs through and connects each placement device 2, and is used to transport coolant (such as cooling water or insulating cooling oil). The fire extinguishing flow channel 5 is arranged independently, with fire extinguishing outlets 51 located directly above each placement device 2. A fire water tank 6 is installed on the top of the energy storage cabinet 1, which is connected to the fire extinguishing flow channel 5.

[0041] Each placement device 2 is the core of this invention. It consists of a housing 21 made of a metal with good thermal conductivity. The housing 21 has multiple power connection ports 22 to facilitate the connection of battery packs 3 with different interfaces to the system. The interior of the housing 21 is machined with meandering cooling channels, which are connected to the main channel 4. During normal operation, coolant flows from the main channel 4 into the meandering cooling channels, surrounds the battery pack 3, efficiently absorbs the heat generated by battery charging and discharging, and then flows out, thereby maintaining the battery temperature within the optimal operating range.

[0042] Detailed description of preventative measures against the spread of fire:

[0043] Reference Figure 3 Each housing 21 is equipped with a telescopic baffle 7 around its perimeter. In the retracted state, the telescopic baffle 7 fits snugly against the housing 21, without occupying additional space. It mainly consists of an upper baffle 71, a lower baffle 72, and two pairs of cross links (first link 73 and second link 74) hinged between them. To increase the structural strength after deployment, the two second links 74 are connected by a steady-state link 78.

[0044] Its triggering and locking mechanisms are key to achieving automatic protection. For example... Figure 3As shown, the upper baffle 71 has a sliding latch 75, and the housing 21 has a corresponding latching hole 23. An ejector 76 constantly pushes the latch 75, causing it to tend to insert into the latching hole 23. One end of a shape memory metal wire 77 is connected to the latch 75, and the other end is fixed. At room temperature, the shape memory metal wire 77 is in its martensitic phase and is relatively long, so it does not exert any tension on the latch 75. At this time, the telescopic baffle 7 can be retracted and locked.

[0045] When a battery pack 3 malfunctions, the temperature rises sharply, and heat is conducted through the casing 21. When the casing temperature exceeds a preset safety threshold (e.g., 90°C), the shape memory metal wire 77 is heated above its phase transformation temperature, transforming into the austenitic phase, and its length shrinks significantly. This shrinkage releases the tension on the latch 75, causing the latch 75 to disengage from the locking hole 23.

[0046] Once unlocked, the telescopic spring 79 connecting the upper and lower baffles immediately exerts force, pushing the upper baffle 71 upwards. The first link 73, the second link 74, and the steady-state link 78 convert this force into a smooth unfolding action. Simultaneously, the flexible drape 8 (e.g., fiberglass fireproof cloth) sewn to the edge of the baffle is fully expanded, forming a three-dimensional, relatively sealed fireproof enclosure that completely covers the faulty battery pack 3. This confines most of the heat source and flame within the enclosure, preventing its spread to adjacent horizontal units.

[0047] Simultaneously or subsequently, the central control system (host computer) can immediately initiate the fire suppression procedure based on temperature sensor signals or the baffle deployment signal. This involves opening the valve of the fire water tank 6, allowing the extinguishing agent to be sprayed through the extinguishing channel 5 from the extinguishing outlet 51 directly above the burning unit, precisely and efficiently extinguishing the fire within the isolation enclosure. A large amount of water flows into the space formed by the telescopic baffle 7 to submerge the battery pack 3, preventing the significant heat generated by the combustion of the battery pack 3 from affecting the energy storage cabinet 1.

[0048] Reference Figure 5 The system also includes a calibration unit for precise evaluation. This unit consists of a host computer and an inverter. The AC side of the inverter is connected to the mains power and the station's power supply via switches. Its DC side can be connected to one or more battery packs connected in series. The host computer can control the inverter to perform a complete "charge-rest-discharge-rest" cycle on the selected battery pack. During this process, the system accurately records data such as the amount of charge and discharge, and voltage curves, thereby calculating the actual usable capacity of the battery pack in the current state and the accurate SOC-OCV (open circuit voltage) curve. This calibrated data will be updated in the battery management system (BMS) of the energy storage system as the basis for subsequent energy dispatch and operation control, thereby achieving efficient and safe management of the entire cascaded battery energy storage system.

[0049] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A system for assessing the usable energy of a cascaded battery pack, characterized in that, It includes an energy storage cabinet, a cooling system, and several placement devices installed in the energy storage cabinet. The placement devices are equipped with battery packs. The cooling system includes a main flow channel and a fire extinguishing flow channel. The placement device includes a housing, on which at least two power connection ports are provided, and the battery pack is electrically connected to the power connection ports. The shell is provided with telescopic baffles around its perimeter. When the shell reaches a preset temperature threshold, the telescopic baffles automatically extend from a retracted state to an expanded state. The main flow channel flows through each of the housings, and the housings are provided with meandering cooling channels that are connected to the main flow channel. The fire extinguishing channel includes a fire extinguishing outlet located above each of the placement devices. The placement device also includes a calibration unit electrically connected to the battery pack, the calibration unit being used to calibrate the state of charge (SOC) of the battery pack.

2. The available energy assessment system for a cascaded battery pack according to claim 1, characterized in that, The calibration unit includes a host computer and an inverter. The inverter's AC side is connected to the mains power through an AC input switch and to the station power supply through another switch. The calibration unit is connected to at least two of the battery packs in series.

3. The available energy assessment system for a cascaded battery pack according to claim 1, characterized in that, The telescopic baffle includes a lower baffle and an upper baffle that are fixedly connected to the housing. The lower baffle and the upper baffle are both hinged with a first connecting rod and a second connecting rod. The first connecting rod of the lower baffle is hinged to the second connecting rod of the upper baffle, and the second connecting rod of the lower baffle is hinged to the first connecting rod of the upper baffle. The upper baffle is slidably provided with a latch, and the housing is provided with a corresponding latch hole. An ejector is provided between the upper baffle and the latch, and the ejector causes the latch to have a tendency to move away from the upper baffle. The latch is also connected to a shape memory metal wire, and the other end of the shape memory metal wire is connected to the upper baffle. A telescopic spring and a flexible drape are also connected between the upper baffle and the lower baffle.

4. The available energy assessment system for a cascaded battery pack according to claim 3, characterized in that, A steady-state connecting rod is also hinged between the two second connecting rods.

5. The available energy assessment system for a cascaded battery pack according to claim 1, characterized in that, The top of the energy storage cabinet is equipped with a fire water tank that is connected to the fire extinguishing channel.

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