ENERGY STORAGE SYSTEM

Abstract

An energy storage system comprises a plurality of cassettes (1; 1a, 1b, 1c), each containing at least one accumulator (14, 18, 22), which are individually interchangeably connected to a common busbar (27) for charging and discharging the cassettes (1; 1a, 1b, 1c). The cassettes (1; 1a, 1b, 1c) comprise an externally identical housing (2) with electrical connections (11) for interchangeably mounting on each of a plurality of connections (26) of the busbar (27), and at least two of the cassettes (1; 1a, 1b, 1c) contain accumulators (14, 18, 22) of different shapes.

Description

[0001] The present invention relates to an energy storage system for electrical energy, in particular an energy storage system with which accumulators which, for example, after a period of use as drive energy storage in an electrically powered vehicle, have lost part of their original charging capacity and are therefore no longer suitable for their original purpose, but are still usable for other applications where a high ratio of storage capacity to volume is less important, such as the stationary intermediate storage of electrical energy from wind power or photovoltaics.

[0002] Such an energy storage system is known, for example, from CN 105977553 B.

[0003] One problem with this type of reuse of used batteries is that they were not specifically designed for this purpose. Rather, their shape, capacity, and other characteristics are initially designed for their initial use in a vehicle. They must be made suitable for this purpose as they arise, in various forms and with different capacities. Furthermore, depending on how they were treated during their initial use, the batteries may contain hidden defects that only become apparent during their reuse and can compromise the operational reliability of a storage system using such batteries.

[0004] An object of the invention is therefore to provide an energy storage system that enables a secondary use of used accumulators of various types with minimal effort and with high resilience against defects of individual accumulators.

[0005] The object is achieved according to the invention in that, in an energy storage system with a plurality of cassettes, each of which comprises at least one accumulator and is connected to a common busbar for charging and discharging the accumulators installed in the cassettes, the cassettes comprise an externally identical housing with electrical connections in order to be interchangeably mountable on each of a plurality of connections of the busbar, wherein at least two of the cells contain accumulators of different shapes.

[0006] Preferably, the energy storage system comprises a frame through which the busbar extends and in which the installation locations are defined.

[0007] Electrical connections can be distributed along the busbar in the form of connectors that interact with complementary connectors on the cassettes.

[0008] The busbar may include conductors for charging and discharging the accumulators and / or signal lines for the exchange of measurement and control information between the cassettes and a control unit.

[0009] Preferably, the busbar extends horizontally and the installation locations are located next to each other horizontally.

[0010] According to a preferred embodiment, the busbar has a continuous contact surface extending across several installation locations in the rack, and the electrical connections of the busbar are part of the contact surface. This allows the cassettes to contact the busbar at any location without being restricted to a grid pattern, as is the case with the aforementioned connectors.

[0011] To facilitate the installation of the cassettes, each installation location can be assigned a guide that defines a guide direction in which one of the cassettes can be moved between an operating position connected to the busbar and a replacement position separate from the busbar.

[0012] The electrical connections of each cassette are preferably movable relative to their housing in the guide direction and, in the operating position, are spring-loaded against the electrical connections of the busbar. This ensures reliable contact despite positioning tolerances in the guide direction.

[0013] For logistical reasons alone, an electric vehicle manufacturer has an interest in limiting the variety of battery types used in its vehicles. For example, if a take-back system operated by such a manufacturer generates used batteries of various types, their largest dimensions will determine the dimensions of a housing in which any battery can be housed. Within the housing, there are a maximum of as many different positions for battery terminals as there are battery types in use. Ideally, if each housing has connectors at the corresponding positions that are connected to the external terminals of the housing, then any battery can be made suitable for use in the energy storage system simply by inserting it into the housing.

[0014] Small-format batteries can also be accommodated in several cases in one housing, in which case several internal housing connectors may be required at the same time to contact the batteries.

[0015] As an alternative to connectors with a predefined plug-in position, it is possible to configure or equip the cassettes with accumulators using flexible cables.

[0016] To ensure safe operation despite high storage density, each enclosure should have an opening for the passage of coolant (air or liquid), preferably on its top. The same or a separate opening can be provided for the passage of extinguishing agent, allowing rapid access to extinguishing agent if necessary, possibly even before the cassette is moved into the replacement position. An opening for exhaust gases should be provided to divert exhaust gases from a fire and prevent their release into the immediate vicinity of the energy storage system, allowing personnel to remain there safely.

[0017] A distribution line for extinguishing agent and / or a distribution line for coolant conveniently runs in the frame.

[0018] Control means can be provided to selectively connect each enclosure to at least one of the distribution lines. This allows individual cassettes to be cooled according to their needs, which vary depending on the type and quality of the battery installed in the cassette, or the use of extinguishing agent can be limited to cassettes where a current need has been identified.

[0019] Flexible lines may be provided between the distribution or collection line and the housing to enable a cassette to be transferred from the operating position to the replacement position without interrupting the supply and removal of media to and from the cassette.

[0020] If a cassette is moved to the replacement position due to a defect, this does not affect the operation of other cassettes remaining in the operating position.

[0021] To prevent the uncontrolled spread of aggressive and / or potentially hazardous gases in the event of a malfunction, the enclosures should be gas-tight, except for any extinguishing, coolant, or exhaust connections. If extinguishing or coolant connections are present, the lines connected to them can be sealed off outside the cassette, as mentioned above, to isolate the interior of the cassette from the environment.

[0022] To allow for the installation and removal of a battery, the housing should have a removable cover. The larger the cover is, or the more completely it fills a side surface of the housing, the easier it is to install and remove the battery. To create a space-saving arrangement despite the large dimensions of the cover, the cover of a housing mounted in a first installation location preferably faces a closed side of a housing mounted in an adjacent second installation location.

[0023] A control unit may be provided to monitor operating parameters of each cassette or its accumulators such as charge capacity, charge level and / or temperature.

[0024] The control unit can further be configured to control the connection of the cassette to the busbar and / or to a distribution line based on measured values of the operating parameters in order to charge and discharge the cassette in a manner adapted to the current power supply or demand, to supply it with coolant or, if necessary, with extinguishing agent.

[0025] Further features and advantages of the invention will become clear from the following description of exemplary embodiments with reference to the accompanying figures. They show: Fig. 1 a cassette of the energy storage system according to the invention in a perspective external view; Fig. 2 the cassette in a schematic section along a plane parallel to the cover of the cassette; and Fig. 3 a schematic section through a series of cassettes in a frame of the energy storage system.

[0026] Fig. Figure 1 shows a cassette 1 of the energy storage system in a perspective view. A housing 2 of the cassette is essentially cuboid-shaped with six sides, which are referred to below as the front, rear, upper and lower narrow sides, or the bottom and lid. In the view of Fig. 1 shows the upper narrow side 3, the rear narrow side 4 and the cover 5. The four narrow sides, together with a closed side wall, form a box 6 that is open on one side; the cover 5 can be removed from the box 6 to make an interior of the box 6 accessible. The cover 5 is fastened to the narrow sides here, for example, with the aid of screws 7, which fasten a sealing ring 8 (hidden in the figure) extending along the edges of the cover 5 between the cover and the narrow sides, which is inserted into a groove (dashed line) that is machined either in the cover or the narrow side and has a lesser depth than the sealing ring's installation cross-sectional height.

[0027] Four openings 9a-d are visible on the upper narrow side 3. Opening 9a allows the interior to be supplied with coolant during normal operation; opening 9b allows extinguishing water, foam, or inert gas to be supplied to extinguish a fire in the event of a fire. Opening 9c is provided for the discharge of gases in the event of a fire. Opening 9d serves to remove coolant heated during normal operation from an accumulator mounted in the interior.

[0028] The openings 9a-d are each surrounded by flanges 10 to enable a hermetic connection to external supply and discharge lines.

[0029] On the rear narrow side 4, several electrical connections 11 are arranged, via which each accumulator in the interior can be charged and discharged or via which signals are transmitted between sensors of the cassette 1 and a control unit 46 (see Fig. 2) can be transmitted. The connections 11 are each mounted in a sleeve perpendicular to the rear narrow side 4 and are held in an extended stop position by a spring within the sleeve.

[0030] Fig. Figure 2 shows a schematic section through the cassette 1 along a plane parallel to the cover 5 through the upper narrow side 3, the rear narrow side 4, the lower narrow side (designated here as 12), and the front narrow side of the housing 2 (designated as 13). The distance between the front and rear narrow sides 4, 13 corresponds to the length of a battery 14 of a first type, the largest battery intended for use in the energy storage system, shown as a dashed outline. The distance between the upper and lower narrow sides 3, 12 is slightly greater than the height of the battery 14, so that, with the cover 5 removed, it can be inserted through the opening of the box 6 into its interior. A connector 15 on the lower narrow side 12 is opposite a complementary connector 16 of the accumulator 14, so that by lowering the accumulator onto the lower narrow side 12, the connectors 15, 16 come into electrical contact with each other.

[0031] The length of a recess 17 on the lower narrow side 12 corresponds to the length of a second, smaller type of battery 18, shown as a dot-dash outline. A connector 19 is positioned in the recess 17 such that it establishes electrical contact with the connector 20 of the battery 18 when the latter is inserted into the recess 17.

[0032] A further connector 21 is placed beyond the recess 17 on the lower narrow side 12 in such a way that two accumulators 22 of a third, again smaller type, connected to one another to form a bundle, can contact the connectors 15 and 21 simultaneously.

[0033] According to a modification, one of the narrow sides 3, 13 can be provided as a stop for the placement of accumulators of each type, and connectors for accumulators of the different types can be placed on the lower narrow side 12 at a suitable distance from the stop in order to come into contact with connectors of the accumulators 14, 18 or 22 when one of them is lowered along the stop against the lower narrow side 12.

[0034] According to yet another alternative, a connector on the lower narrow side 12 can be displaceable to adapt to the different types of accumulators; in particular, each position adapted to a type of accumulator can be marked by a snap-in of the connector.

[0035] Another simple option is to connect the batteries inside the cassettes using flexible cables and connectors of the same type as those with which they were previously installed in a vehicle.

[0036] To secure the various types of batteries in the cassette, type-specific adapters can be used. These adapters are shaped to fit a specific type of battery and can be mounted on a single fastening element of the cassette that is the same for all adapters. Alternatively, the cassette can be provided with a plurality of fastening elements, only a subset of which is required to secure a given type of battery.

[0037] On the outside of one of the narrow sides 3, 12, a guide contour is provided which cooperates with a complementary contour of a frame 24 receiving the cassette 1 to form a guide which defines an installation position of the cassette 1 in the frame such that several cassettes 1 can be mounted next to one another in a compartment 30 of the frame 24 such that the cover 5 of one of the cassettes 1 is directly facing the side wall of an adjacent cassette.

[0038] In the case of Fig. 2, the guide contour comprises two ribs 23 projecting from the lower narrow side and extending in the longitudinal direction thereof, and rollers 25 of the frame 24 engaging in a space between the ribs 23, which guide the cassette 1 into the operating position with low friction despite its considerable weight.

[0039] Alternatively, the rollers are integrated into the lower base 12 of the cassette 1. If the rollers move together with the cassette, a small number of rollers can, in principle, bridge any distance between the operating and exchange positions.

[0040] The terminals 11 on the rear narrow side 4 meet when inserting the cassette 1 into the compartment 30 with complementary terminals 26 of the frame 24 and thus create, in an operating position of the cassette 1, an electrical contact between the accumulator or the accumulators 14, 18 or 22 in its interior and a busbar 27 of the frame 24. The busbar 24 comprises several straight, to the cutting plane of the Fig. Two vertically oriented, rod-shaped conductors, one of which can be externally applied with a charging voltage for charging the batteries, another of which is applied with the output voltage of the batteries to supply an external consumer, and a further one carries ground potential. Additional conductors can be provided for signal transmission between the cassettes 1 and the control unit 46. The conductors each have a continuous contact surface facing the compartment 30. The terminals 11 are designed to abut the contact surface when inserted into the compartment 30 before the cassette reaches the operating position. Thus, in the operating position, they are pressed against the contact surface by their springs, establishing a secure, low-resistance contact.

[0041] In the embodiment shown here, connections for a coolant supply line 31, an extinguishing agent line 32, a degassing line 34, and a coolant discharge line 33 are provided on the top side of the compartment 30. A space between these and the openings 9a-d on the upper narrow side 3 of the cassette 1 provides space for flexible hose lines 49, one of which is shown as an example between the coolant supply line 31 and the opening 9a. Further hose lines are provided between the extinguishing agent line 32 and the opening 9b, the degassing line 34 and the opening 9c, and the coolant discharge line 33 and the opening 9d. The length of the hose lines 49 is such that they can already be connected when the cassette 1 is still in the Fig. 2 is in a replacement position outside the compartment 30, in which the cover of the cassette 1 is freely accessible.

[0042] A latch 50 at the bottom of compartment 30 is movable between two stable positions. In one of these positions, latch 50 engages a complementary recess 51 in cassette 1, thus securing it in the operating position. In the other position, the latch is recessed, allowing cassette 1 to be moved from the operating position to the replacement position. The transition to the other position can be effected manually, e.g., by an employee pushing the cassette beyond the operating position into compartment 30, thereby actuating a locking mechanism; remote control of latch 50 by control unit 46 can also be provided.

[0043] In the operating position, a temperature sensor 28 communicates with a control unit 46 of the energy storage system via a contact of the terminals 11, 26.

[0044] The extinguishing agent line 32 branches off via a control means 37, such as a shut-off valve, from a distribution line 42, which, like the busbar 27, extends transversely of the compartment 30. The control means 37 can be controlled by the control unit 46 in order to selectively supply extinguishing agent to this cassette if measurement data from the temperature sensor 28 indicate a fire in the cassette 1, but not to neighboring cassettes in the compartment 30 whose temperature is safe.

[0045] If the control unit 46 is configured, as mentioned above, to control the locking bar 50, then the cassette 1 can further be assigned a drive element (e.g., acting on the rollers 25), with which the control unit 46 can move an affected cassette 1 into the replacement position in the event of a fire. Thus, the adjacent cassettes are protected from heat emanating from the defective cassette, even if the fire cannot be extinguished quickly.

[0046] A check valve 48 is arranged between the cooling air supply line 31 and a cooling air distribution line 43 as a passive control means 38 to prevent fire gases escaping from a burning cassette from contaminating other cassettes. A further check valve 48 is arranged between the degassing line 34 of each cassette and a manifold line 47 common to all degassing lines. Its orientation is opposite to the check valve 38, so that it is opened by excess pressure in the cassette, allowing smoke gases to escape via the manifold line 47 but not to penetrate into neighboring cassettes. For this purpose, a directional control valve 39, controlled by the control unit 46, is provided between the cooling air discharge line 33 and a manifold line 44. The extinguishing water manifold line 42 is selectively connected via the control valve 37 in the event of a fire.

[0047] Deviating from the presentation of the Fig. 2, the check valves 38, 48 can also be provided in the hose lines 49 connected to the openings 9a, 9c.

[0048] Deviating from the presentation of the Fig. 2, the check valves 38, 48 can also be integrated into the cassette connection pieces of the openings 9a, 9c.

[0049] On the front narrow side 13, which is exposed after the cassette 1 has been inserted into the frame 24, display elements 29 can be provided for indicating the operating status of the rechargeable battery 14, 18 or the rechargeable batteries 22 of the cassette 1. The display elements 29 can be connected directly to the temperature sensor 28 to indicate any overheating; preferably, they communicate with the control unit 46 via the connections 11, 26 in order to be able to display additional information, if necessary, which the control unit 46 derives from monitoring the sensor 28 and from the charging and discharging processes of the cassette 1, such as a reduction in the charging capacity of the cassette 1 below a limit value above which replacement of its rechargeable battery(ies) is indicated, an abnormal heating of the cassette 1 in relation to the charging or discharging current, or the like.By displaying an existing or potential defect directly on the cassette 1 where the control unit 46 detected it, service personnel can quickly identify and replace the affected cassette. Automated disconnection from the power rails is also possible.

[0050] Fig. Figure 3 shows a section through several cassettes 1a, 1b, 1c mounted side by side in compartment 30 of frame 24. Not all of the slots in compartment 30 are occupied; at the bottom of slots 45 to the left of cassettes 1a, 1b, 1c, grooves 35 can be seen between rollers 25. These grooves, together with the ribs 23 on the undersides of the cassettes, guide them into their operating position, in which they are in contact with the busbar 27 on a rear wall 36 of compartment 30.

[0051] According to a further variant, the conductors 27 can be curved around a vertical axis instead of being straight; in particular, they can form a closed circle, or several differently curved segments can be connected to form a wavy line running in a horizontal plane. If the cassettes, in their operating position, each contact the conductors 27 on a convex side, this has the advantage that if several cassettes need to be moved into the replacement position simultaneously, they also move away from each other, which facilitates heat dissipation via the lid and base and improves accessibility to the cassettes, whether for extinguishing from the outside or for repair. Reference symbol 1 cassette 2 housings 3 upper narrow side 4 rear narrow side 5 lids 6 boxes 7 screw 8 Sealing ring 9 Opening 10 Sealing ring 11 Connection 12 lower narrow side 13 front narrow side 14 Accumulator 15 connectors 16 connectors 17 Deepening 18 Accumulator 19 connectors 20 connectors 21 connectors 22 Accumulator 23 rib 24 frame 25 rolls 26 connection 27 Busbar 28 Temperature sensor 29 Display element 30 compartments 31 Cooling air supply line 32 extinguishing agent line 33 Cooling air discharge 34 Degassing line groove 35 Rear wall 36 Control means (directional valve) 37 Control means (check valve) 38 Control means (directional valve) 39 Control means (directional valve) 40 41 Distribution line 42 distribution line 43 Collective line 44 installation space 45 control unit, 46 Collective line 47 Control means (check valve) 48 hose line 49 bars 50 recess QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 105977553 B

[0002]

Claims

[1] Energy storage system with several cassettes (1; 1a, 1b, 1c), each comprising at least one accumulator (14, 18, 22) and connected to a common busbar (27) for charging and discharging the cassettes (1; 1a, 1b, 1c), characterized by that the cassettes (1; 1a, 1b, 1c) comprise an externally identical housing (2) with electrical connections (11) in order to be interchangeably mountable on each of a plurality of connections (26) of the busbar (27), and that at least two of the cells (1; 1a, 1b, 1c) contain accumulators (14, 18, 22) of different shapes. [2] Energy storage system according to claim 1, further comprising a frame (24) through which the busbar (27) extends and in which installation locations (45) for the cassettes (1; 1a, 1b, 1c) are defined. [3] Energy storage system according to claim 2, wherein the busbar (27) has a continuous contact surface extending over a plurality of installation locations (45) of the frame (24) and the electrical connections (26) of the busbar (27) are parts of the contact surface. [4] Energy storage system according to claim 2 or 3, in which each installation location (45) is assigned a guide (23, 35) which defines a guide direction in which one of the cassettes (1; 1a, 1b, 1c) is movable between an operating position connected to the busbar (27) and a replacement position separate from the busbar (27), and in which the electrical connections (11) of each cassette (1) are movable relative to its housing (2) in the guide direction and are spring-loaded against the electrical connections (26) of the busbar (27) in the operating position. [5] Energy storage system according to one of the preceding claims, in which the accumulators (14, 18, 22) are selected from a plurality of accumulator types and each housing (2) has a plurality of connectors (15, 19, 21) inside, each of which is connected to the terminals (11) of the housing (2) and is positioned to be contactable with an accumulator (14, 18, 22) of at least one of the plurality of accumulator types inserted into the housing (2). [6] Energy storage system according to one of the preceding claims, wherein each housing (2) has an opening (7, 8, 9) for the passage of extinguishing and / or cooling agent and / or exhaust gas. [7] Energy storage system according to claim 6 and claim 2, wherein at least one distribution or collecting line (42, 43, 44) for extinguishing agent and / or for coolant runs in the frame (24), which optionally comprises control means (37, 38, 39) for selectively connecting each housing (2) to at least one of the distribution or collecting lines (42, 43, 44), and which further optionally has flexible lines between the distribution or collecting line (42, 43, 44) and the housing (2). [8] Energy storage system according to one of the preceding claims, in which the housings (2) are gas-tight apart from possible openings (7, 8, 9) for extinguishing and / or cooling agent and / or exhaust gas. [9] Energy storage system according to claim 2 or any one of claims 3-8, as far as dependent on claim 2, in which each housing (2) has a cover (5) which can be removed for the installation and removal of an accumulator (14, 18, 22), wherein the cover (5) of a housing (2) mounted at a first installation location faces a side wall of a housing (2) mounted at an adjacent second installation location. [10] Energy storage system according to one of the preceding claims, further comprising a control unit (46) for monitoring operating parameters such as charging capacity and / or temperature of each accumulator installed in a cassette (1; 1a; 1b; 1c), which control unit is configured to control the connection of the cassette (1; 1a, 1b, 1c) to the busbar (27) and / or to a distribution or collecting line (42, 44) based on measured values of the operating parameters.

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