DE102020211162A1 - Charging station for charging an electricity storage device of an electric vehicle - Google Patents

Abstract

The invention relates to a charging station (12) for charging an electricity storage device (8) of an electric vehicle (2), with a gas connection (26) for a natural gas network (32), which is downstream of a unit (34) for increasing a hydrogen concentration in terms of fluid technology. The unit (34) for increasing a hydrogen concentration is followed fluidly by a unit (44), which has a current outlet (46), for converting hydrogen into electricity.

Description

The invention relates to a charging station for charging a power storage device of an electric vehicle.

A charging station is usually used to charge a power storage device of an electric vehicle, in particular a high-voltage battery. This has a charging connection on the outside, which is plugged into a corresponding plug of the electric vehicle, for example. As an alternative to this, the charging connection itself is designed as a plug into which a line is plugged, which in turn is connected to the electric vehicle. Depending on the type of charging port, different standards are used.

The charging station is usually designed to be stationary and electrically connected to a power grid. An essentially unlimited number of charging processes can therefore be carried out using the charging station, and maintenance is essentially not required or is only required to a comparatively small extent. In this case, however, it is necessary that there is a corresponding connection to the power grid at the desired point of use of the charging station, so that construction work usually has to be carried out first. This increases assembly costs.

If several charging stations are newly installed, it is possible that one motor vehicle is electrically connected to all of the charging stations at the same time, the battery of which is to be charged. As a result, a power draw from the power grid is comparatively large. If the power grid is not adapted to this, it is possible that the electrical voltage carried by the power grid collapses and that it is no longer possible to supply the charging stations and other consumers connected to the power grid. In this case at least, however, there are comparatively large fluctuations in the electrical voltage that is provided by the power grid, with the result that at least some of the consumers cannot be operated correctly. It is therefore necessary to provide sufficient buffer capacity in the power grid and to prepare it for any increased energy consumption. This also increases assembly costs as well as investment and operating costs. However, since not all charging stations are usually in operation at the same time, the buffer capacity provided in this way is only used temporarily, which is why efficiency is therefore reduced. For these reasons, the assembly of a new charging station is comparatively expensive, so that a supply network that has the charging stations is comparatively thin.

The invention is based on the object of specifying a particularly suitable charging station, with assembly costs being advantageously reduced and/or economic efficiency being increased.

According to the invention, this object is achieved by the features of claim 1. Advantageous developments and refinements are the subject of the subclaims.

The charging station is used to charge the battery of an electric vehicle. The charging station is suitable for this, in particular provided and set up. The electric vehicle is, for example, a bicycle that includes an electric motor. In particular, the bicycle is designed as a so-called pedelec. As an alternative to this, the electric vehicle is, for example, an electrically powered scooter or an electrically powered motorcycle. However, the electric vehicle is particularly preferably an electrically operated motor vehicle, in particular a commercial vehicle, such as a truck (lorry) or bus, or a passenger car (car). This expediently has an electric motor which is operatively connected to the wheels of the motor vehicle. Here, the electric motor at least partially forms a main drive of the motor vehicle.

The power storage device is formed, for example, by means of one or more capacitors or includes them. However, the power storage device particularly preferably comprises one or more (electrochemical) batteries and is expediently formed by means of these. Such a battery is in particular a Li-ion battery. The power store is preferably a so-called high-voltage battery, ie a high-voltage energy store, by means of which an electrical voltage greater than 200 V is provided. In particular, the electrical voltage provided is between 400 V and 800 V.

The charging station has a gas connection for a natural gas network. The gas connection is therefore suitable, in particular intended and set up, to be connected to the natural gas network. In the installed state, the charging station is connected to the natural gas network, so that natural gas is introduced into the charging station. In other words, the charging station is supplied with natural gas. For example, the gas connection has a single line, so that only natural gas can be routed to the charging station. However, the gas connection particularly preferably comprises at least one second line, by means of which natural gas or another gas can also be fed back into the natural gas network. In the assembled state, the two lines are expediently fluidly connected to a main line of the natural gas network.

Natural gas, which includes hydrocarbons, preferably methane, is routed through the natural gas network. Here, the methane content is, for example, greater than 50%, 70% or 90%. The natural gas also contains hydrogen, with the hydrogen concentration expediently being greater than 1%, 5%, 10% or 20%. In other words, the natural gas network serves to conduct natural gas that contains at least a fraction of hydrogen. However, it is also possible to only carry hydrogen using the natural gas network, so that the natural gas network is a hydrogen-carrying gas network.

A unit for increasing a hydrogen concentration is connected downstream of the gas connection in terms of fluid technology. In other words, during operation, the natural gas carried by means of the natural gas network is routed via the gas connection to the unit for increasing a hydrogen concentration. A gas is discharged by the hydrogen concentration increasing unit, this gas having a higher hydrogen concentration than the natural gas. By means of the unit for increasing a hydrogen concentration, a gas is thus forwarded which has an increased hydrogen concentration compared to the natural gas used and which was produced using the natural gas. For example, the hydrogen concentration is 100% and the gas consists only of hydrogen. If the natural gas already consists only of hydrogen, no further function is carried out by means of the unit for increasing a hydrogen concentration. The remaining components of the natural gas that are not converted into the gas are expediently, for example completely or at least partially, reintroduced into the natural gas network via the gas connection.

In summary, by means of the unit for increasing a hydrogen concentration, for example, only the proportion of hydrogen conducted to the unit via the gas connection is passed on, or at least to an increased extent. The unit for increasing a hydrogen concentration is suitable for this, in particular provided and set up. The unit for increasing a hydrogen concentration is expediently connected directly to the gas connection in terms of fluid technology, so that it is easier to return the components of the natural gas that are not passed on to the natural gas network.

The unit for increasing a hydrogen concentration is followed fluidically by a unit for converting hydrogen into electricity. For example, the two units are directly connected to one another in terms of fluid technology, so that the gas emitted by means of the unit for increasing a hydrogen concentration is fed directly into the unit for generating electricity from hydrogen. Electricity is generated by means of the unit for converting hydrogen into electricity, for which at least the hydrogen provided by means of the unit for increasing a hydrogen concentration is used. The unit for generating electricity from hydrogen is suitable for this purpose, in particular provided and set up. The electric power generated by the hydrogen power generation unit is output from a power outlet of the hydrogen power generation unit. In particular, the current output has two different electrical poles, via which the electrical current can be output, and at which an electrical voltage is present during operation of the unit for generating electricity from hydrogen, preferably an electrical direct voltage or an electrical alternating voltage.

When the charging station is in operation, electricity is generated at least partially using natural gas. Since the natural gas network is usually comparatively extensive, only comparatively minor construction work is required to connect the charging station to the natural gas network. Thus assembly costs and investment costs are reduced. Furthermore, the additional load can be compensated comparatively inexpensively by means of appropriate buffers, even with several charging stations that are connected to the natural gas network, which is why extensive adaptation of the natural gas network is not necessary. In addition, the electricity is essentially generated from the hydrogen contained in the natural gas, so that no environmentally harmful substances are produced during the conversion to electricity, and the water produced in this way can be discharged directly into the environment or into a sewage system, with a sewage system usually also already being used is comparatively comprehensive. In this way it is also possible to feed hydrogen into the natural gas network during operation, which hydrogen is generated for example using regenerative energy sources, for example using photovoltaic modules or wind power plants. As a result, intermediate storage of the energy provided by means of this is also made possible, with no expansion of an infrastructure or the provision of batteries being required. Since this hydrogen is converted into electricity by means of the charging station, electric current generated essentially from regenerative energy sources is used to charge the electricity storage device of the electric vehicle by means of the charging station.

The charging station preferably has a housing that is made of a metal, for example. This prevents damage to components arranged in the housing. Preferably the housing is under assembly condition is electrically connected to ground, preferably to earth. The housing expediently has corresponding connections for this. Thus, in operation, the electrical potential of the housing is equal to ground. Consequently, injury to persons is excluded if they touch the housing. The housing of the charging station itself is expediently rigidly connected to a floor when assembled. For the purpose of connection, the charging station expediently has corresponding mechanical connection elements.

For example, all components of the charging station are arranged in the housing, at least the two units. In this case, the housing expediently has a housing wall into which the gas connection is at least partially introduced. It is thus possible to feed the natural gas into the housing. In one embodiment, the current output is likewise introduced into such a housing wall, for example. With the exception of the components of the charging station introduced into the housing walls, all remaining components are preferably arranged inside the housing so that it is designed as a unit. Thus, assembly is simplified. In this way, it is also possible to manufacture the charging station in a comparatively compact manner and, for example, to already certify it as a complete system, so that any existing requirements can be met without additional effort.

In an alternative embodiment, the charging station has a plurality of housings, with different components being arranged in the different housings. Here, in particular, the unit for increasing a hydrogen concentration is arranged in one of the housings and the unit for generating electricity from hydrogen is arranged in the other. Thus, these units can be mounted separately from each other. The connection between these takes place, for example, by means of a corresponding line. In this way it is possible to spatially separate comparatively sensitive components of the charging station from other components of the charging station with which a possible user has contact. Thus, security is increased. Since the charging station has a plurality of components that are arranged separately from one another, maintenance and replacement of these if one of them is defective is also made easier.

The charging station suitably comprises a control unit. The control unit expediently comprises a number of electrical and/or electronic components, by means of which a circuit is implemented so that a specific function is carried out during operation. The control unit has a processor, for example, which is designed in particular to be programmable. For example, the control unit is formed by the processor. Suitably the control unit comprises or is formed by means of an application specific integrated circuit (ASIC). The charging station is expediently operated and/or certain functions are carried out by means of the control unit. For example, any valves, the gas connection and/or at least one of the units are adjusted by means of the control unit.

In one development, the charging station has, for example, a number of units for increasing a hydrogen concentration, which are assigned to a common unit for generating electricity from hydrogen, and which is thus fed by means of a number of units for increasing a hydrogen concentration. In this case, a corresponding gas connection is expediently assigned to each unit for increasing a hydrogen concentration, or they are fed by means of the same gas connection. In an alternative to this, there are, for example, several units for generating electricity from hydrogen, which are fed by means of the same unit for increasing a hydrogen concentration.

For example, the unit for converting hydrogen into electricity includes an internal combustion engine, by means of which a generator is driven. In this case, the hydrogen is burned by means of the internal combustion engine, in particular with the addition of ambient air, and is thus converted into kinetic energy. This is converted into electrical energy by the generator. Thus, manufacturing costs are comparatively low.

However, the unit for generating electricity from hydrogen particularly preferably comprises a fuel cell. Since there are essentially no moving parts here, there is essentially no noise pollution, which is why the charging station can also be operated in inhabited areas. In particular, a polymer electrolyte fuel cell (PEM), preferably a polymer electrolyte membrane fuel cell, is used as the fuel cell, with this working, for example, in the low-temperature range or in the high-temperature range. This type of fuel cell has a comparatively high current density and comparatively good dynamic behavior. Specifically, the type of fuel cells is considered when the gas discharged by the hydrogen concentration increasing unit is at least 90% or more, such as 99.999%, hydrogen. In an alternative, a solid oxide fuel cell (SOFC) is used as the fuel cell, in particular if only one comparatively by means of the unit for increasing a hydrogen concentration there is a slight increase in the hydrogen concentration, or the proportion thereof in the gas discharged by the hydrogen concentration increasing unit is below 90%, or 99%, or 99.999%. In particular, the unit for converting hydrogen into electricity has a number of fuel cells which, for example, are structurally identical to or different from one another. As an alternative to this, the unit for generating electricity from hydrogen is formed by means of a single fuel cell.

A charging connection is expediently connected electrically downstream of the current output. The charging connection includes in particular a charging plug, and the charging connection is used to charge the battery of the electric vehicle. The charging connection is suitable for this, in particular provided and set up. The charging connection, in particular any charging plug, preferably meets a certain standard, expediently type 1, type 2 or CHAdeMo. Alternatively, the charging port is or at least includes a GB/T connector. For example, an electrical AC voltage or an electrical DC voltage is present at the charging connection during operation. In this case, the electrical voltage present at the charging connection is expediently adapted to the power storage unit of the respective electric vehicle. For example, the charging station has only a single charging connection, so that only one electric vehicle can be charged at a time using the charging station. The charging station particularly preferably comprises a plurality of charging connections, all of which are electrically connected downstream of the power output, or wherein there are a plurality of units for converting hydrogen into electricity, each of which has a power output, and wherein each of the power outputs is assigned at least one respective electrical charging connection, so that at least the same many charging connections such as units for generating electricity from hydrogen are available. This makes it possible to charge several electric vehicles at the same time using the same charging station.

For example, the same electrical voltage is present at the charging connection as is also provided at the current output. Particularly preferably, however, a DC voltage converter is connected between the current output and the charging connection, in particular if a DC voltage is provided by means of the unit for converting hydrogen into electricity, ie in particular if this is or at least includes a fuel cell. By means of the DC voltage converter, the electrical (DC) voltage provided by the unit for converting hydrogen into electricity is changed to a value that is matched in particular to the electricity storage device of the electric vehicle and is therefore optimized for it. As a result, it is possible to operate the unit for generating electricity from hydrogen at its optimum working point without taking the electric vehicle's electricity storage into account. The corresponding adjustment to this is done by means of the DC voltage converter. Consequently, efficiency, in particular overall efficiency, is increased. If the unit for converting hydrogen into electricity includes the internal combustion engine and the generator, by means of which an alternating current is provided, a rectifier is expediently connected downstream of the generator, so that the DC-DC converter can be operated safely.

For example, with the exception of the charging connection, no other component of the charging station is in electrical contact with the current output. Thus, manufacturing costs and investment costs are reduced. However, the charging station particularly preferably has an energy store which is electrically connected between the current output and the charging connection. The energy store makes it possible to store electrical energy so that, if necessary, more electrical energy can be delivered via the charging connection than is/can currently be made available by means of the unit for generating electricity from hydrogen. As a result, a charging time for charging the power storage device of the electric vehicle is shortened, which increases convenience for a user. A mechanical store or an electrical capacitor is used as the energy store, for example. The energy store particularly preferably comprises an electrical (electrochemical) battery, such as a lithium-ion battery, which is adapted in particular to the electrical voltage delivered by means of the charging connection. The battery expediently has a capacity of more than 100 kWh.

The charging station particularly preferably has two DC voltage converters, one of which is assigned to the current output, so that the energy store can be charged with a suitable electrical DC voltage. Another DC-DC converter is assigned to the charging connection, so that the electrical voltage provided by means of the energy store is adapted to the power store of the electric vehicle. This DC-DC converter is preferably formed by means of a converter, by means of which an AC voltage can also be output, so that the electric vehicle can also be charged with AC. In summary, an electrical intermediate circuit, which includes at least the energy storage device, is thus formed between the two DC-DC converters or the one DC-DC converter and the converter.

A power connection to a power grid is particularly preferred for the electrical power output downstream. The power connection is suitable for this, in particular provided and set up. For example, it is possible to feed electrical energy into the charging station via the power connection. If the charging connection is present, this is expediently in electrical contact with the power connection, so that electrical energy can be released from the unit for generating electricity from hydrogen and from the power grid via the charging connection. It is also possible to charge any energy storage via the power connection, if this is available. If both the energy store and the power connection are available, it is also possible to charge the power store of the electric vehicle via the energy store, the power connection and the unit for generating electricity from hydrogen, so that a charging time is further reduced.

Alternatively or particularly preferably in combination with this, it is possible to feed electrical energy from the charging station into the power grid via the power connection. The electrical energy is provided here by means of the unit for generating electricity from hydrogen. As a result, it is possible to use the charging station to at least partially absorb any peaks in the power grid and therefore to reduce the load on the power grid. In particular, this is only carried out when the charging station is not being used to charge the battery of the electric vehicle.

For example, the power connection is in direct electrical contact with the power output, the charging connection, any energy store or any other component of any intermediate circuit. However, a converter, for example a DC voltage converter or rectifier, is particularly preferred, by means of which the electrical voltage provided by the power grid is adapted to the electrical voltage required in each case within the charging station, preferably that of any intermediate circuit. It is thus possible to always operate the charging station internally with essentially the same electrical voltage, which is why the individual components can be adapted to this, which increases efficiency.

For example, the unit for increasing a hydrogen concentration includes a hydrogen purifier (“hydrogen purifier”), which has a palladium membrane, for example. In an alternative to this, the unit for increasing a hydrogen concentration comprises a palladium catalyst, expediently a palladium membrane, and works, for example, according to the principle of PEM/palladium diffusion. Alternatively or in combination with this, the unit for increasing a hydrogen concentration has a PEM/pressure swing adsorption (PSA) absorber and/or is operated according to a PEM/process with silicon oxide desiccant, ie in particular silica. In another alternative, a combination palladium electrolyzer/cleaner system is used.

An electrochemical filter is particularly preferably used as the unit for increasing a hydrogen concentration, or the unit at least includes this. The (electrochemical) filter is designed here, for example, as a membrane or ceramic and/or expediently acts as a proton pump. There are no moving parts in the electrochemical filter, which means that wear and tear and maintenance are reduced. In addition, noise formation is avoided in this way, and such a filter has comparatively high dynamics, which is why operation is simplified. Furthermore, a continuous flow of the gas through the unit for increasing a hydrogen concentration is possible, so that there are essentially no pressure fluctuations in the gas discharged therewith. Thus, a constant operation of the charging station is possible.

In one development, a compressor is connected between the unit for increasing a hydrogen concentration and the unit for converting hydrogen into electricity. The compressor is, for example, a mechanical compressor or designed chemically, in particular electrochemically. Thus, noise is avoided. By means of the compressor, the gas delivered by means of the unit for increasing a hydrogen concentration is adapted to the operating pressure of the unit for generating electricity from hydrogen, or at least approximated to it, so that it can be operated comparatively efficiently.

Alternatively, or particularly preferably in combination with this, a reformer is connected in terms of fluid technology between the unit for increasing a hydrogen concentration and the unit for generating electricity from hydrogen. The reformer is used to convert hydrocarbons, expediently methane, into hydrogen and is suitable for this purpose, in particular provided and set up. The reformer works, for example, according to the steam reforming process. Due to the reformer, the amount of hydrogen is thus increased, which is why the electrical energy provided by the unit for generating electricity from hydrogen is increased, even if a hydrogen concentration in the natural gas is currently comparatively low in the natural gas network, for example for a short time or due to other conditions. For example, the reformer is only switched on when a hydrogen concentration in the natural gas is comparatively low at the current time, or the reformer is always operated.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. The only drawing therein shows a schematically simplified view of an electric vehicle and a charging station that is connected to a natural gas network and an electricity network.

The figure shows an electric vehicle 2 in the form of a passenger car (car) in a schematically simplified manner. The electric vehicle 2 has an electric motor 4, by means of which at least one or more of a number of wheels 6 of the motor vehicle 2 is driven. The wheels 6 are used for the contact of the electric vehicle 2 with a floor that is not shown in detail. The electric motor 4 is operated by means of a power storage device 8, which is designed as a high-voltage battery. By means of the power accumulator 8, a converter (not shown in detail) is supplied with current, by means of which the electric motor 4 is operated. An electrical DC voltage of 800 V is provided by means of the electricity storage device 8 and is transformed by the converter into an AC voltage which is adapted to the power requirement of the electric motor 4 . The electric vehicle 2 also has an electrical plug 10 which is electrically connected to the power storage device 8 . It is possible to feed electrical energy into the electric vehicle 2 via the plug 10 and thus to charge the power storage unit 8 .

Furthermore, in 1 a charging station 12 is shown, which has a housing 14 . The housing 14 is made of a metal and is electrically connected to ground by means of a protective conductor in the assembled state. Furthermore, the housing 14 is fastened to the floor by means of fasteners that are not shown in detail. Two charging connections 16 are introduced into a housing wall of the housing 14 , and it is possible by means of a cable 18 to electrically connect the plug 10 of the electric vehicle 2 to one of the charging connections 16 . In this case, the charging connections 16 differ in the example shown based on the electrical voltage provided by them. Electrical energy is fed from the charging station 12 into the power storage device 8 of the electric vehicle 2 via the respective charging connection 16 and the cable 18 . The charging station 12 is thus used to charge the power storage device 8 of the electric vehicle 2 . Furthermore, a power connection 20 is introduced into a housing wall of the housing 14 and is electrically connected to a power grid 22 . A corresponding power line 24 is electrically connected to the power connection 20 for this purpose. A three-phase current, for example, which has an alternating voltage of 400 V, is conducted by means of the power supply system 22 .

In addition, the charging station 12 has a gas connection 26 which is also introduced into a wall of the housing 14 . The gas connection 26 has a first line 28 and a second line 30 which are each fluidly connected to a natural gas network 32 . The natural gas network 32 carries natural gas that contains a composition of different gases, mainly methane and a proportion of hydrogen. The natural gas is conducted by means of the first line 28 to a unit 34 for increasing a hydrogen concentration, which is thus downstream of the gas connection 26 in terms of fluid technology. The unit 34 for increasing a hydrogen concentration is an electrochemical filter, and the natural gas provided by means of the natural gas network 32 is conducted to the unit 34 for increasing a hydrogen concentration by means of the first line 28 . By means of the electrochemical filter, mainly the hydrogen is passed on from the natural gas via an outlet 36 as gas 38, the gas 38 also containing hydrocarbons, ie methane, depending on the configuration of the electrochemical filter. However, the main part of the methane is fed back into the natural gas network 33 by means of the second line 30 . In summary, the gas 38 has a higher concentration of hydrogen than the natural gas provided by means of the natural gas network 32 .

A reformer 40 is connected downstream of the unit 34 for increasing a hydrogen concentration in terms of fluid technology, so that the gas 38 is routed to the reformer 40 . The reformer 40 works according to the method of steam reforming, and by means of the reformer 40 part of the methane still contained in the gas 38 is converted into hydrogen, with the resulting carbon dioxide being released into the environment. The hydrogen concentration within the gas 38 is thus further increased by means of the reformer 40, and the gas 38 processed in this way is routed to a compressor 42, which is thus downstream of the reformer 40 in terms of fluid technology. Consequently, the compressor 42 is also connected downstream of the unit 34 for generating electricity from hydrogen. The compressor 42 is an electrochemical compressor, by means of which a pressure of the gas 38 is increased. For this purpose, the compressor 42 has appropriate membranes and/or ceramics.

A unit 44 for converting hydrogen into electricity is connected downstream of the compressor 42 in terms of fluid technology and has a current outlet 46 . In summary, the unit 34 for increasing a hydrogen concentration is fluidically connected downstream of the unit 44 for generating electricity from hydrogen, which has the current output 46 , and the reformer is between the unit 34 for increasing a hydrogen concentration and the unit 44 for generating electricity from hydrogen 40 for converting hydrocarbons into hydrogen and the compressor 42 is fluidically connected.

The unit 44 for generating electricity from hydrogen comprises one or more fuel cells, each of which is designed as a polymer electrolyte membrane fuel cell, preferably as a low-temperature polymer electrolyte membrane fuel cell. The unit 44 for converting hydrogen into electricity thus converts the gas 38 or at least the proportion of hydrogen present therein into electricity, which is discharged via the electricity outlet 46 so that an electrical voltage is present at the electricity outlet 46 . The resulting water is discharged either into the environment or into a sewage system via a connection that is not shown in detail. In a variant that is not shown in detail, a solid oxide fuel cell (SOFC) is used as the fuel cell, namely when the gas 38, by means of which the unit 44 for generating electricity from hydrogen, continues to contain a comparatively large proportion of methane.

A DC voltage converter 48 is connected to the current output 46, by means of which the electrical voltage present at the current output 46 is modified. In this case, the electrical voltage is increased to 800 V and this is fed into an intermediate circuit 50 . An electrical DC voltage of 800 V is thus conducted with the intermediate circuit 50 . The intermediate circuit 50 is connected to the power connection 20 , the power connection having a converter (not shown) so that the electrical voltage provided by the power grid 22 can also be converted to the electrical voltage prevailing in the intermediate circuit 50 . It is also possible to adapt the electrical voltage of the intermediate circuit 50 to the electrical voltage of the power supply system 22 by means of the converter.

The intermediate circuit 50 also has an energy store 52 which is in the form of a high-voltage battery and which is therefore in electrical contact both with the DC-DC converter 48 and with the current output 48 . Furthermore, a converter 54 is electrically connected to the intermediate circuit 50, by means of which one of the charging connections 16 is fed. The other charging connection 16 makes direct electrical contact with the intermediate circuit 50 . Thus, the DC voltage converter 48 and the energy store 52 are connected between the power output 46 and the charging connections 16 , and the power connection 20 to the power grid 22 is electrically connected downstream of the power output 46 of the unit 44 for converting hydrogen into electricity.

Furthermore, the charging station 12 has a control unit 56, by means of which some or all of the components of the charging station 12 can be adjusted and/or controlled. It is also possible to use the control unit 56 to actuate valves that are not shown in more detail, so that a flow rate/pressure of the natural gas used and/or the gas 38 can be set. All components of the charging station 12 are arranged in the housing 14 with the exception of the gas connection 16 and the charging connections 16 and the power connection 20 so that they are protected by the housing 14 .

During operation of the charging station 12 , the gas 38 is created by means of the unit 34 to increase a hydrogen concentration 34 , which gas is further modified by means of the reformer 40 and is compressed by means of the compressor 42 . The unit 44 for converting hydrogen into electricity uses the hydrogen contained in the gas 38 to generate the electric current, which is fed into the intermediate circuit 50 via the DC voltage converter 48 and by means of which the energy store 52 is charged. Since there are no mechanically moving parts, noise is comparatively low, so that charging station 12 can also be operated in inhabited areas and at any time. Also, no environmentally harmful substances are produced during operation, which is why complex exhaust gas cleaning is not necessary. If an emission of carbon dioxide is prohibited at the installation site of the charging station 12, the reformer 40 is not used or is not available.

If the charging station 12 is to be used to charge the electricity storage device 8 of the electric vehicle 2, the cable 18 is electrically contacted with the corresponding charging connection 16, and electrical energy is transferred from the charging station 12 via the cable 18 to the electricity storage device 8 the electric current provided by means of unit 44 for converting hydrogen into electricity is conducted via DC converter 48 and intermediate circuit 50 to charging connection 16 directly or via converter 54 . Depending on the requirements and configurations of the power storage device 8, the electrical direct voltage present in the intermediate circuit 50 is transformed by means of the converter 54 to a lower electrical direct voltage or to an electrical alternating voltage. If the charging time of the power storage device 8 is to be shortened, additional electrical energy is drawn from the energy storage device 52 and conducted to the power storage device 8 of the electric vehicle 2 via the charging connection 16 that is used. For further shortening, additional electrical energy can be taken from the power grid 22 via the power connection 20 and the intermediate circuit 50 to the respective charging connection 16 .

It is also possible to charge two electric vehicles 2, in which case they are then assigned to different charging connections 16. If no electric vehicle 2 is to be charged, or if this is only to be done comparatively slowly, the electrical energy provided by the unit 44 for converting hydrogen into electricity is conducted into the energy store 52, and the latter is thus charged. As a result, the electrical energy stored there is available for a subsequent rapid charging process. In addition, if the electrical energy provided by unit 44 for generating electricity from hydrogen is not to be fed into energy store 52 or into power store 8 of electric vehicle 2 , it can be fed into power grid 22 via power connection 20 . In this way, a peak load on the electricity network 22 can be reduced, and this is thus stabilized by means of the charging station 12 .

If a power plant that produces electrical energy using renewable energy sources, such as a photovoltaic system or a wind power plant, produces electricity that is not required at the current time and/or in the vicinity of the power plant, it can be used to produce hydrogen are used. For this purpose, the hardware components are adapted/expanded accordingly, and a separate electrolyzer and/or a reversible fuel cell is used, for example. The hydrogen produced in this way is subsequently fed into the natural gas network 32, which is why the hydrogen concentration of the natural gas located there is increased. This hydrogen is taken from the charging station 12 . As a result, the power storage device 8 of the motor vehicle 2 is charged and the motor vehicle 2 is therefore operated using electrical power provided by means of regenerative energy sources.

The invention is not limited to the embodiment described above. On the contrary, other variants of the invention can also be derived from this by a person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

Reference List

2

electric vehicle

4

electric motor

6

wheel

8th

power storage

10

plug

12

charging station

14

housing

16

charging port

18

cable

20

power connection

22

power grid

24

power line

26

gas connection

28

first line

30

second line

32

natural gas network

34

Unit for increasing a hydrogen concentration

36

exit

38

gas

40

reformer

42

compressor

44

Hydrogen power generation unit

46

current output

48

DC converter

50

intermediate circuit

52

energy storage

54

converter

56

control unit

Claims (9)

Charging column (12) for charging an electricity storage device (8) of an electric vehicle (2), with a gas connection (26) for a natural gas network (32), which is downstream of which a unit (34) for increasing a hydrogen concentration is fluidically connected, which fluidically has a current output ( 46) having unit (44) for the conversion of hydrogen into electricity is connected downstream. charging station (12) after claim 1 , characterized in that the unit (44) for generating electricity from hydrogen comprises a fuel cell. charging station (12) after claim 1 or 2 , characterized in that the current output (46) is electrically connected downstream of a charging connection (16). charging station (12) after claim 3 , characterized in that a DC voltage converter (48) is connected electrically between the current output (46) and the charging connection (16). charging station (12) after claim 3 or 4 , characterized in that an energy store (52) is connected electrically between the current output (46) and the charging connection (16). Charging column (12) according to one of Claims 1 until 5 , characterized in that the power output (46) is electrically connected downstream of a power connection (20) to a power supply system (22). Charging column (12) according to one of Claims 1 until 6 , characterized in that the unit (34) for increasing a hydrogen concentration is an electrochemical filter. Charging column (12) according to one of Claims 1 until 7 , characterized in that fluidically between the unit (34) for increasing a hydrogen concentration and the unit (44) for converting hydrogen into electricity, a compressor (42) is connected. Charging column (12) according to one of Claims 1 until 8th , characterized in that fluidically between the unit (34) for increasing a hydrogen concentration and the unit (44) for converting hydrogen into electricity, a reformer (40) for converting hydrocarbons into hydrogen is connected.

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