BATTERY STORAGE SYSTEM

Abstract

A battery system includes a battery receiving device and a plurality of battery units. Each battery unit can be coupled bidirectionally and inductively to one another and/or to the receiving device for charging/discharging. The receiving device can be connected to an external electrical energy source and/or sink. Each battery unit includes a coil unit. The receiving device has a storage seat for each battery unit removable with a magnetically complementary connectable coil unit for inserting/removing a battery unit without tools. The coil unit has a single coil which is substantially shaped as an elliptical, elongated flat coil, arranged in a half-shell housing and embedded in a ferrite core half-shell of ferrite elements, with a coil unit ratio of thickness to length/width of at least 1:5. The coil unit of the battery unit and receiving device are formed mechanically separable with a maximum distance between the coil units of 110 mm.

Claims

1. A battery system comprising a battery receiving device and a plurality of battery units, wherein each battery unit can be coupled bidirectionally and inductively to one another and/or to the battery receiving device for charging and discharging, and the battery receiving device can be connected to an external electrical energy source and/or an energy sink, the each battery unit comprises a coil unit, and the battery receiving device has a storage seat for each battery unit removable with a magnetically complementary connectable coil unit for inserting and removing a battery unit without using a tool, wherein the coil unit comprises a single coil which is substantially shaped as an elliptical, elongated flat coil, arranged in a half-shell housing and embedded in a ferrite core half-shell consisting of ferrite elements, so that the coil unit has a ratio of thickness to length/width of at least 1:5, preferably 1:8, in particular 1:10 or higher, and the coil unit of the battery unit and the coil unit of the battery receiving device are formed mechanically separable with a maximum distance between the coil units of 110 mm.

2. The battery system according to claim 1, wherein at least one non-ferromagnetic coil coupling plate being arranged as a cover for the coil unit of the battery unit, in particular having ferromagnetic areas for guiding magnetic flux.

3. The battery system according to claim 1, wherein the maximum distance between the coil units is 100 mm, particularly preferably 10 mm, in particular 1 mm.

4. The battery system according to claim 1, wherein a coil winding of the coil unit consists of a high-frequency braid and the coil unit is optimized in terms of its mechanical dimensions and electromagnetic parameters for a frequency range of 50-100 kHz, in particular for an operating frequency of 70 kHz.

5. The battery system according to claim 1, wherein a near field coupling (NFC) unit is included in the coil unit.

6. The battery system according to claim 1, wherein the battery unit is mechanically closed, and has no switches or openings to the outside, and can only be charged and discharged via induction.

7. The battery system according to claim 1, wherein the battery unit and/or a storage seat of the battery receiving device comprises a mechanical and/or magnetic locking unit which enables an insertion in a correct position and/or prevents unintentional removal of the battery unit preferably in a charging and/or discharging phase.

8. The battery system according to claim 1, wherein several battery units of the plurality of battery units accommodated in a battery receiving device provide a total electrical capacity of 1.5 kWh to 1700 kWh.

9. A system complex comprising at least two or more battery systems according to claim 8, wherein the two or more battery systems are connected to form a larger system complex.

10. A battery receiving device for use in a battery system according claim 1, wherein the battery receiving device has at least one storage seat, preferably two or more storage seats with at least one magnetic complementary connectable coil unit, preferably one coil unit per storage seat for inserting and removing a battery unit toolless.

11. The battery receiving device according to claim 10, wherein a pressing unit, in particular a spring element, is arranged in a storage seat for applying a spring-loaded pressing force to the battery unit in an insertion state.

12. A battery unit for use in a battery system according to claim 1, wherein the battery unit is encapsulated in a battery housing, and including at least one, in particular a plurality of battery cells, a coil unit, a battery management system and a near field coupling (NFC) unit for an at least monodirectional, preferably bidirectional data communication.

13. The battery unit according to claim 12, wherein the coil unit and the NFC unit are structurally integrated in a front side of the battery housing which is smaller regarding areas of other side surfaces of the battery housing.

14. The battery unit according to claim 13, wherein a pressing unit, in particular a spring element, is arranged on a surface opposite the front side for applying a spring-loaded pressing force in the insertion state in a storage seat on the front side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Further advantages result from the present description of the drawings. Exemplary embodiments of the invention are shown in the drawings. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations. Thereby show:

[0059] FIG. 1 is a schematic circuit diagram of an embodiment of a battery system 10 with two battery units 30 and a battery receiving device 20 according to the invention;

[0060] FIGS. 2a to 2g are several detail and sectional views of an embodiment of a battery unit 30 with inductive coupling possibility with a battery receiving device 20;

[0061] FIGS. 3a-3c are several partial views of an embodiment of a mobile battery receiving device 20 for receiving one, two or more battery units 30;

[0062] FIG. 4 is a view of an embodiment of a container battery system 100 (Power-MRack) for highenergy storage and delivery as well as charging of a large number of battery units 30 and for 16 supplying larger energy consumers or storing energy from larger regenerative energy producers; and

[0063] FIG. 5 is a view of an embodiment of a column battery receiving device 110 for a publicly accessible charging and replacement of battery units 30.

DETAILED DESCRIPTION OF THE INVENTION

[0064] In the figures, similar elements are numbered with the same reference numerals. The figures show only examples and are not to be understood as restrictive.

[0065] The attached drawings and illustrations contain data from sample designs. All information in the figures is part of this description.

[0066] A circuit diagram of a first embodiment of a battery system 10 is shown schematically in FIG. 1. The battery system 10 is composed of a battery receiving device 20 for charging two inductively coupled battery units 30, which are received mechanically guided in storage seats 50 of the battery receiving device 30. Each battery unit 30 includes a plurality of series-connected battery cells 40 which provide a DC voltage of approximately 10V-16V in a battery cell voltage circuit 82. Energy can be exchanged between the battery cell voltage circuit 82 and a battery intermediate circuit 84 via a bidirectional DC/DC converter which has both a step-up and a step-down capability. The battery intermediate circuit 84 can operate with a DC voltage of 32 V, for example. A two- or multi-stage inverter 32 with, in particular, two half bridges can be arranged on the battery intermediate circuit 84 in order to provide an alternating voltage in a battery coil circuit 84 for operating an inductive coil unit 42. By means of a PWM control, the frequency and energy of the alternating current supply in the coil circuit 84 can be adjusted for inductive reception or delivery of electrical energy via the coil unit 42. The coil circuit 84 is preferably operated in a frequency range of approximately 70 kHz, the electromagnetic properties of the coil unit 42 being optimized for this frequency range.

[0067] In parallel with the coil unit 2, an NFC unit 38 is arranged, in particular spatially adjacent on a housing wall of the battery unit 30. This can exchange bidirectional data with a corresponding NFC unit 28 of the battery receiving device 20, regardless of the energy transfer state of the coil unit 42. It is thus possible to read in or read out data even when there is no other current in the intermediate circuits 82, 84, 86, so that the battery unit 30 does not suffer any loss of power in stand-by mode and can still be addressed. For this purpose, a small amount of energy input into the NFC unit 38 can be sufficient to provide its communication capability. The NFC unit 38 is advantageously arranged in a common antiferromagnetic housing, for example in an aluminum half-shell housing together with the coil unit 42, which is covered by a coil coupling plate, which represents a wall area on the housing side. The NFC unit 38 is connected to a battery management system 36 which monitors and controls a charging and discharging process of the battery cells 36 as well as provides data for identifying the battery unit 30, the type, state of charge (Coulomb counting), service life and other diverse data preferably via an RS 485 and controls the charging electronics.

[0068] The battery receiving device 20 has a separate coil unit 26 in a storage seat 50 for each battery unit 30, and spatially adjacent to it an NFC unit 28 for data exchange, and is controlled by a higher-level battery management system 52 as well as the respective coil units 26 serving inverters 24 and the input and output side DC/DC converter 22 for feeding, for example of energy from fuel cells or photovoltaic systems and converters 48 for feeding in and feeding out alternating or three-phase energy. For this purpose, the bidirectional converter can comprise two inverter units for rectifying or inverting a DC intermediate circuit voltage. The inverters 24 arranged to operate the coil units 26 for each battery unit 30 operate a coil circuit 88 at a frequency that is matched to the battery-side coil circuit 86. The frequency and details of the energy transfer in charging or discharging operation can be negotiated with the battery-side NFC unit 38 via an NFC unit 28 arranged spatially adjacent to the coil unit 26 and can be communicated to the superordinate battery management system 52 of the battery receiving device 30, that determines and controls the required parameters. The battery management system 52 can advantageously establish a gateway interface to the Internet, for example via a GSM-based radio interface, WLAN, Bluetooth or via powerline communication (PowerLAN) in order to be able to access an external cloud application and tariffing. A DC intermediate circuit 90 with a high-voltage voltage level of 400V-800V can be provided within the battery receiving device 20, so that the required voltage of up to 400V for AC power grid operation and for a direct DC feed of PV-voltage up to 800V or supply of DC-battery management system 52 provide high-voltage vehicle electrical systems up to 800V can be provided. In this respect, the split transformer arrangement of the battery-side coil unit 42 and the receiving-side coil unit 88 can advantageously already carry out a voltage transformation in a transmission ratio of 1:10 to 1:20.

[0069] In the sub-FIGS. 2a to 2g, the structural design of an embodiment of a battery unit 30 is described in detail in side and sectional views. For this purpose, FIG. 2a shows a front view and FIG. 2b shows a side view of a housing 44 of a battery unit 30. On an front side, which is opposite a front face having a coil unit 42, a battery handle 76 is provided for carrying, and for sliding in and out the battery unit 30, the housing 44 having a essentially cuboid shape and being completely encapsulated, and essentially comprising a metal jacket. On a side surface opposite the handle side, the coil unit 42 is arranged, which is covered by a coil coupling plate made of plastic, in which preferably segmented ferromagnetic partial areas are provided on contact surface areas, where ferrite yokes of the two coil units 26, 42 face each other in order to maximize the flow the magnetic flux and minimize wastage. NFC data communication via the NFC unit 38 with the battery-side battery management system 36 can also take place through the coil coupling plate 42.

[0070] On the handle side, one or more pressure relief valves 74 can be arranged adjacent to the handle 76, so that in the event of a defect in the battery cells 40, excess pressure can escape from the housing 44. The pressure relief valves 74 can be designed in the form of check valves.

[0071] In the side view of FIG. 2b, the plane of the coil unit 42 is shown in a side view, in FIGS. 2a and 2b sectional lines of the other FIGS. 2c to 2g are shown.

[0072] FIG. 2c shows, in a sectional view C-C of FIG. 2b, the construction of a coil unit 42 in detail, which is structurally and functionally complementary to the coil unit 26 and follows a basic concept of a generalized coil unit 60. The coil unit 60 comprises a non-ferromagnetic half-shell housing as an aluminum half-shell housing 92, which comprises a receiving area 78 for receiving an NFC unit 28, 38 and a coil receiving area. In the coil receiving area there are a large number of platelet-shaped, mutually electrically isolated ferrite elements 66 arranged to form a ferrite core half-shell 64, the ferrite core half-shell 64 has protruding contact surfaces 68 and a recessed return area 70 which forms a shell area 72 for receiving an induction coil 62. The contact surfaces 68 serve to transfer the magnetic flux that forms into corresponding contact surfaces 68 of a complementarily opposite coil unit 60 without scattering losses. The induction coil 62 can be constructed from a substantially elliptical elongated flat coil, wherein the coil line can be constructed, for example, from a twisted high-frequency strand. The entire coil arrangement 70 is optimized in terms of its mechanical dimensions and electromagnetic parameters for a frequency range of 50-10 kHz, in particular for an operating frequency of 70 kHz. High-frequency strands are twisted like a rope from many (isolated) individual wires, so that a skin effect can be counteracted. For this purpose, a twist angle of the high-frequency braid, the radius size and the effective length and width of the flat coil shape and the number of turns can be matched to the desired frequency range. The coil 62 is connected to the coil circuit 86 of the battery unit 30 or to the coil circuit 88 of the battery receiving device 20, the complementary coil arrangements 42, 26 advantageously being able to differ in their winding ratios in such a way that desired voltage levels of the intermediate circuits 84 of the battery unit 30 or the intermediate circuit 90 of the battery receiving device 20 can be provided.

[0073] FIG. 2d shows in a sectional illustration A-A a longitudinal side cross section and FIG. 2e shows a transverse side cross section B-B of FIG. 2a through the battery unit 30. It comprises four battery cells 40, which are delimited on an upper side by a circuit board arrangement of the battery management system 36. A spring element 46 is shown on the right-hand side of the sectional illustration in FIG. 2d (in FIG. 2e on the left-hand side). A storage seat 50 of a battery receiving device 20 receives the battery unit 20 in the transverse direction, so that the coil arrangement 42, which is shown on the left in FIG. 2d, rests against a side wall of the storage seat 50 under spring pressure. On this side wall, the coil unit 26 of the battery receiving device 20, which is also shown in FIG. 2d on the left and FIG. 2e, comes into frictional surface contact with the coil unit 42 of the battery unit 30 for minimizing the stray field of a magnetic field exchange coupling.

[0074] The battery management system 36 includes power switching elements for charging and discharging, a PWM driver circuit as a chopper or inverter 32 for operating the coil circuit 86 through the inverter 32 and a DC/DC converter 34 for the bidirectional conversion of the 10V-16V battery voltage circuit 82 into the 32V intermediate circuit 84. In addition, the battery management system 36 provides a communication device of the NFC unit 38 for the bidirectional exchange of control and status data, which is supported by a processor and storage system. The exchangeable data via the NFC interface includes a unique identification of the battery unit 30, type information, life cycle information, current charge status, current and voltage levels, a history of the energy status (Coulomb counting) and other data. The NFC interface can be activated passively from a stand-by mode by approaching a reader de-energized, so that the battery unit does not consume any energy in the idle state.

[0075] In the further partial representations D and D * of FIGS. 2f and 2g, an inductively coupled state (FIG. 2f) and decoupled state (FIG. 2g) of the coil units 42 and 26 is shown. The coil units 26, 42 are constructed as shown in FIG. 2c and can differ in terms of the winding ratio or can be identical. The opening areas of the half-shell housings 92 accommodating the coil units 26, 42 are separated by thin coil coupling plates 80. The thickness of the thin coil coupling plates 80 and the defined alignment of the ferrite core half-shells 64 to one another determine the leakage losses and the energy transmission efficiency of the inductive coupling. The coil coupling plates 80 can advantageously have ferromagnetic inserts in some areas segmented from one another for guiding magnetic flux between the contact surfaces 68 of the ferrite half-shells 64, which provide the transformer core. FIG. 2f shows an inductively coupled state of the battery unit 30, FIG. 2g an inductively separated state of the battery unit 30 for the storage seat 50 of a battery receiving device 20, as e.g. in the case during an exchange during charging or discharging to provide hot-swap capability.

[0076] FIGS. 3a, 3b and 3c show a front, side and sectional view E-E through an exemplary embodiment of a battery system 10 with a mobile battery receiving device 20 which can be equipped with three battery units 30. The battery receiving device 20 is equipped with feet and transport rollers 58 in the manner of a trolley case. Carrying handles 56, which can also be extended to form a telescopic handle or lowered into the housing 54, can facilitate the transport of the battery system, which can weigh between 35 to 60 kg when fully equipped. The higher-level battery management system, which is described in detail in FIG. 1, is arranged in the upper region of the housing 54, and the temperature can be controlled with a passive cooling structure or an active cooling system. By opening a cover plate or cover door, three storage seats 50 can be exposed, into which battery units 30, as shown in FIG. 2b, are inserted in a transverse direction, so that their coil unit 42, arranged on a narrow side surface, is in contact with a coil unit 26 of the storage seat 50. In this case, a spring element (not shown) or a pressing unit can provide a specific alignment of the two opposite coil units 26, 42 which is loaded by spring pressure. The storage seat 50 and/or the housing 44 of the battery unit can ensure correct positioning and alignment of the battery unit 30 in the storage seat 50 by structures of complementary shape. A touch control panel 112 for retrieving data from the battery units 30 and for retrieving and setting charging and discharging specifications and, if relevant, payment details can be arranged on a side wall of the housing 54.

[0077] FIG. 3c is a sectional illustration E-E of FIG. 3b with three received battery units 30, which are shown in a sectional view. The respective four battery cells 40 are also shown. Each battery unit 30 is pressed onto the contact surface of the coil unit 26 of the storage seats 50 by means of spring elements 46, so that an optimized inductive coupling of the coil units 26, 42 can be provided. Various power supply and extraction connections for USB low voltage, bidirectional 48V DC protective voltage interface for feeding and withdrawing 48V voltage, 800V DC high-voltage input, mains input by means of an IEC connector and Schuko-sockets for providing 230V AC mains voltage are not shown. By means of this embodiment of a battery system 10, an energy supply e.g. for a celebration in nature or for tool processing in a construction site, can be provided, but also battery units of vehicles, tools or the like can be charged, whereby maximum personal protection is given and incorrect operation is excluded.

[0078] One embodiment of the battery unit 20 (power cell) can preferably be equipped with a lithium iron phosphate or lithium ion battery cells. The LiFe cell technology impresses with its high depth of use, constant voltage during the entire use, short charging times and an optimal ratio between space consumption and performance.

[0079] The battery unit 20 (power cell) can be modularly expanded by being connected in parallel and can be integrated into an energy network of any size. When charged, a single cell can provide energy of up to 2 kWh with a cell efficiency of over 95% and an output power of up to 2.4 kW. The battery unit 20 can offer minimal self-discharge, long service life, high depth of discharge and cycle stability, and can be safely changed during operation (“hot” swappable) without an arc occurring, electrical connections having to be disconnected or connected or electrical components can be harmed due to overcurrent. Active current regulation as a function of cell voltage and cell temperature (derating) can be provided in the internal battery management system 36. The housing 44 can be designed as a metallic, closed, contactless battery cell housing that also fulfills a transport test according to UN38.3. This is because special regulations apply since 2003 for the transport of lithium rechargeable batteries. These UN transport regulations (e.g. UN 3090, UN 3480, UN 3481) were issued by the UN and apply to transport by land, water and air.

[0080] A battery holder 20 (power pack), which is mobile by means of transport rollers 58 and transport handles 56, can accommodate two, three or more battery units 20 in storage seats 50. External supply connections and operating options can be 230V socket at 50 Hz, USB output, Ql charger, or a touch pad. An amount of energy for e.g. watching TV for 20 hours, listening to the radio for 70 hours or having a refrigerator available for 24 hours can be provided. The maximum output power can be up to 3.6 kW, the amount of energy that can be stored can be up to 6 kWh.

[0081] Building on the concept of a mobile battery receiving device described above, a larger, preferably stationary, e.g. in a residential or office building arranged battery receiving device 20 (power rack) offer a plurality of storage seats 50 for receiving up to ten battery units 30 and can thus store energy up to 20 kWh, preferably fed by a photovoltaic or wind energy source, and when required provide again with an output power of up to 10.8 kW. Both the charging and the discharging of the battery units 30 are carried out by means of effective and safe induction technology. For charging such a larger battery receiving device 20 can be charged with sustainable energy sources such as photovoltaics, wind energy or also by the power supply network by 3-phase with 50 Hz or also with 48V DC or DC high voltage with 400-800V DC. Such a battery receiving device 20 can be used, for example, as an emergency power supply for computer servers or in hospitals in a cost-effective and space-saving manner.

[0082] FIG. 4 shows a container battery system 100 (Mega-Rack/Power-MRack), a shelf battery receiving device 102 being arranged in a container housing, and a plurality of battery units 30 in shelf storage seats 50 of the shelf battery receiving device 102 can be arranged in parallel. These are connected to one another via an energy bus and a data bus, each storage seat 50 having a coil unit 26 and an NFC unit 28. A battery management system 52 (not shown) is connected opposite an opening side of the container for connection to an external power grid, a photovoltaic or wind energy device for power supply, in order to operate the plurality of battery units 50 in parallel and independently of one another, i.e. to be able to charge, or to be able to feed energy back into a power supply network for short to medium-term energy supply. The output power can be up to 0.75 MW and the storable total output can reach up to 1.7 MWh per container. A mains-side supply and withdrawal can be a three-phase AC with voltages between 380-480 V AC, also 48V DC or high-voltage supply with up to 800V being possible. A battery system 100 can thus provide the supply of a building or a larger network or stores energy obtained on site for later industrial use. It thus represents a modern battery system with a high degree of efficiency, wherein the capacity can be expanded modularly and is designed for high cycle efficiency. The relationship between volume, performance and reliability is suitable for high security of supply and flexible use.

[0083] FIG. 5 provides a pillar battery system 110 (power charge) with a battery receiving device 20 for a plurality of battery units 30, the individual storage seats 50 being lockable by doors. A user can control a charging or discharging process of a battery unit 30 by means of an operating panel 112 and, in particular, can control a desired amount of energy, tariffing and lending and return of a battery unit 30 for a pay charging system. The pillar battery system thus provides a concept of a public charging station that offers a convenient way of charging a battery unit 30. Stationed at frequented and barrier-free accessible urban places, the pillar battery system enables users to exchange used battery units 30 for freshly charged ones. An intuitive touchscreen display of the control panel 112 is easy to use and offers simple and cashless payment options. For example, the user can choose between suitable subscriptions or payment by credit card or smartphone. This pillar battery system 110 combines a supply and charging station for battery units 30 in a sustainable energy cycle.

LIST OF REFERENCE SIGNS

[0084] 10 battery system [0085] 20 battery unit [0086] 22 DC/DC converter on the storage seat side [0087] 24 inverter on the storage seat side [0088] 26 coil unit on the storage seat side [0089] 28 NFC unit on the storage seat side [0090] 30 battery unit [0091] 32 battery-side inverter [0092] 34 battery-side DC/DC converter [0093] 36 battery-side battery management system [0094] 38 battery-side NFC unit [0095] 40 battery cell [0096] 42 battery-side coil unit [0097] 44 battery housing [0098] 46 spring element [0099] 48 converter on the storage seat side [0100] 50 storage seat [0101] 52 battery management system on the storage seat side [0102] 54 housing of the battery holder [0103] 56 transport handle [0104] 58 transport wheels [0105] 60 coil unit [0106] 62 coil [0107] 64 ferrite core half-shell [0108] 66 ferrite element [0109] 68 contact surface [0110] 70 inference area [0111] 72 shell area [0112] 74 pressure relief valve [0113] 76 battery grip [0114] 78 NFC board area [0115] 80 coil coupling plate [0116] 82 battery cell voltage circuit [0117] 84 battery intermediate circuit [0118] 86 battery coil circuit [0119] 88 coil circuit [0120] 90 intermediate circuit [0121] 92 coil unit half-shell housing [0122] 100 container battery system [0123] 102 shelf battery holder [0124] 110 pillar battery system [0125] 112 control panel