DE102019213055A1 - Charging system and method for conductive charging of an energy store of a vehicle with a safe-to-touch charging voltage - Google Patents

Abstract

The invention relates to a method and a charging system (100) for conductive charging of an energy store (200) of a vehicle with a touch-safe charging voltage. For this purpose, a primary side (110) comprises a primary contact unit (111) with a flat base body (112) which has at least two first and at least one second primary contact areas (113, 114). Furthermore, a secondary side (120) comprises a secondary contact unit (121) with a flat base body (122) which has at least one first and at least one second secondary contact area (123, 124). A contacting device (130) is designed to connect the at least one first secondary contact area (123) to at least one of the first primary contact areas (113) and the at least one second secondary contact area (124) to the at least one second primary contact area (114). Finally, a control device (140) is designed, depending on a connection state of the respective contact areas (113, 114, 123, 124) in a first operating mode of the vehicle, the primary side (110) for providing the safe-to-touch charging voltage via the primary contact areas (113, 114) head for.

Description

The invention relates to a charging system for conductive charging of an energy store of a vehicle with a safe-to-touch charging voltage. The invention also relates to a method for charging an energy store of a vehicle with a safe-to-touch charging voltage. In this context, energy storage means preferably a vehicle battery, in particular a high-voltage battery. This is why the term “high-voltage battery” is used as a synonym for the energy storage system in the following.

In charging systems for conductive charging, complementary contact units, for example a plug and a socket, a transmitter (charging device or charging infrastructure) and a receiver (vehicle) are usually physically connected to one another. When the contact units are correctly connected or connected, an electrically conductive connection is thus created and a charging voltage for transmitting electrical energy can be applied from the transmitter to the receiver.

Such charging systems are often designed as cable-based standardized plug systems. The contact units are usually designed as contact pins and associated contact sockets, so that a point-to-point connection is obtained when the contact units are connected. Well-known examples of wired charging systems are the Combined Charging System (CCS; combined charging system) or the Chademo system. In wired charging systems of this type, charging requires a plug-in process. This can either be carried out manually, for example by an operator, or automatically. The exact positioning of the complementary contact units represents a major challenge in the implementation, especially in the case of an automatically performed plugging process.

Examples for the exact positioning of the contact units to one another are from DE 10 2016 008 982 A1 and the DE 20 2018 100 805 U1 known. The charging system described in each case comprises a charging station which is arranged recessed on the ground. The charging station has an extendable and retractable charging arm as a contact unit for coupling with the vehicle battery. The motor vehicle has, for example, a, for example, funnel-shaped socket, which is designed to be complementary thereto, as a complementary contact unit which can accommodate the loading arm. As an alternative to a funnel-shaped charging socket, an automatic positioning device for adjusting the charging arm in a horizontal xy direction can also be provided. If the vehicle is now in a corresponding position above the charging station, the charging arm can be extended automatically so that it can be coupled to the charging socket.

An alternative embodiment of a charging system for conductive charging, with which positioning is to be achieved as precisely as possible, is shown in FIG WO 2019/052962 A1 known. To transfer a charging voltage, a vehicle contact unit has at least three contact electrons and, for contacting a ground contact unit, can be moved in a contacting direction towards the ground contact unit and rotated about an axis of rotation that runs essentially in the contacting direction. The ground contact unit has a multiplicity of contact electrodes which are designed to be complementary to the three contact electrodes of the vehicle contact unit and which are arranged in a two-dimensional Bravais lattice. This can increase the probability of establishing an electrically conductive connection between the vehicle contact unit and the ground contact unit.

However, the stated prior art has the disadvantage that the connection for transmitting the charging voltage is always a point-to-point connection. This means that the contacts of the two connector systems must always be positioned exactly to one another. Another disadvantage is that the transferred charging voltage is high-voltage. This means that protective measures are always necessary to avoid personal injury. In the present application, the term “high voltage” refers in particular to a voltage or a potential difference ≥ 60 volts for direct voltages (DC) or 25 volts for alternating voltages (AC). The conductive charging systems known from the prior art thus either have a high mechanical, kinematic and electrotechnical complexity or limitations in their robustness due to the transfer of electrical energy in the high-voltage range and the need for the exact positioning of the contact units to one another. These charging systems are therefore usually very complex, which is reflected in increased costs, increased use of materials and an increased size.

An alternative to the aforementioned automated connector systems is the exact positioning of a vehicle on a charging device built into the ground by means of a parking assistance system. However, an exact positioning in the centimeter range of the connector systems is difficult to achieve here as well.

A charging system is now known from the internal prior art, by means of which a safe-to-touch charging voltage can be provided for charging an energy store or a high-voltage battery of a motor vehicle. As a result, the charging system does not require any protection against accidental contact in order to avoid endangering persons, so that the contact units or contacts can, for example, be designed as contact surfaces over a large area. The term “safe to touch” results in particular from the IEC 60449 standard. Accordingly, a voltage is considered safe to touch if the following limit values are adhered to: for alternating voltage ≤ 25 volts and for direct voltage ≤ 60 volts. A safe-to-touch charging voltage can also be referred to as a protective extra-low voltage. With an appropriately designed charging voltage, a high degree of efficiency of the charging device when transmitting electrical energy can be combined at the same time with a low risk for the user or an operator. Furthermore, the complexity of the design of the contacts can also be reduced.

The object of the present invention is to increase user acceptance of charging systems for charging an energy store of a vehicle by simplifying correct connection or contacting of the contact units of such a charging system.

The object is achieved by the subjects of the independent claims. Advantageous developments of the invention are disclosed by the dependent claims, the following description and the figures.

The invention is based on the knowledge that the acceptance of conductive charging systems for transmitting a safe-to-touch charging voltage can be increased if the installation space requirement of a corresponding charging system and the use of materials can be reduced and the costs for a corresponding charging system can be lowered as a result. This can be achieved in that a tolerance area of complementary, flat contact units is optimized, in particular enlarged. The tolerance area means an area within which, when the contact units approach the contact areas to connect, successful or electrically conductive contact is made. For this purpose, a plurality of contact surfaces or contact areas, each of which has two different potentials, are arranged in a contact unit. The contact surfaces represent the electrical connections of a respective contact unit. Complex adjustment or positioning systems, as are known from the general prior art, can thus be dispensed with and the correct connection of the contact units can be simplified. As an alternative to this, the acceptance of conductive charging systems can also be improved by increasing the tolerance area of the contact units with the same installation space requirement. This also increases the likelihood of successful contact.

In order to realize this, the charging system comprises a primary side with a primary contact unit which has a flat base body. The base body can thus, for example, be essentially plate-shaped or disk-shaped. The base body also has at least two first primary contact areas and at least one second primary contact area as electrical connections. The at least two first primary contact areas have a first potential, for example, and the at least one second contact area has a second potential that is different from the first potential. The primary contact areas thus form at least one pole pair, so to speak, via which the safe-to-touch charging voltage can be provided or received. For example, the at least two first primary contact areas can each be designed as a first conductor or plus conductor or phase conductor (outer conductor), while the at least one second primary contact area is designed as a second conductor or minus conductor or neutral conductor (neutral conductor). Similarly, a reverse configuration of the primary contact areas is of course also possible. The main body of the primary side thus comprises three or more primary contact areas which are designed to have at least two different potentials and to provide or receive the safe-to-touch charging voltage.

As a complementary contact unit to the primary contact unit, the charging system also includes a secondary contact unit on a secondary side. This has a flat, in particular plate-shaped or disk-shaped, base body which comprises at least one first secondary contact area and at least one second secondary contact area. The respective first secondary contact area can represent, for example, a first conductor or positive conductor or phase conductor (outer conductor), while the respective second secondary contact area represents, for example, a second conductor or negative conductor or neutral conductor (neutral conductor). The main body of the secondary side thus comprises at least two or more contact areas which form the connections of the secondary side. The at least one first secondary contact area is preferably designed to have a first potential and the at least one second secondary contact area is preferably designed to have a second potential. The first and second secondary contact areas thus preferably form a pole pair, and are designed to provide or receive the safe-to-touch charging voltage.

The primary contact areas and / or the secondary contact areas are advantageously designed as flat contact areas or connections. As an alternative to this, the primary contact areas and / or the secondary contact areas can, for example, also be embedded or incorporated into the respective base body as cylindrical transverse struts, in particular similar to tubes. As a result, at least one of the base bodies can have a three-dimensional surface structure in a side view. They thus preferably represent exposed connections or connection surfaces in which, in contrast to the prior art, no shielding measures, such as a sheathing or a protective conductor, are necessary. The respective contact areas (primary contact areas and secondary contact areas) can preferably be formed alternately or one after the other, for example similar to a zebra stripe pattern, in the respective base body. Thus, for example, a first contact area and a second contact area can alternately be arranged next to one another. The respective contact areas are preferably arranged in their respective base bodies so as to be electrically insulating from one another. For example, they can be arranged physically and electrically conductively separated from one another by an insulating layer or an insulating region. The insulating layer preferably comprises a material with a negligibly low or non-existent electrical conductivity, such as, for example, air or ceramics or thermoplastics, such as, for example, polyethylene. To contact the two contact units, the charging system also includes a contacting device which is designed to connect the at least one first secondary contact area to at least one of the first primary contact areas and the at least one second secondary contact area to the at least one second primary contact area. In this context, “connecting” means physical contact to produce an electrically conductive connection between the respective primary contact areas and the associated secondary contact areas. The contacting device is preferably designed to automatically connect the respective contact areas to one another.

Finally, the charging system also includes a control device which is designed to control the primary side for providing the touch-safe charging voltage via at least one of the first primary contact areas and the at least one second primary contact area as a function of a connection state of the respective primary contact areas with the respective secondary contact areas in a first operating mode of the vehicle . The first operating mode can therefore be, for example, a charging mode of the vehicle for charging the vehicle battery.In the first operating mode of the vehicle, the primary side thus represents, in particular, a transmitter of the safe-to-touch charging voltage, while the secondary side represents a receiver of the safe-to-touch charging voltage. The primary side can thus be part of a charging device or charging infrastructure, for example, and the secondary side can be part of the vehicle, for example, and preferably be connected to the energy store (high-voltage battery). In other words, the control device is designed to enable the charging voltage taking into account the connection state of the respectively assigned contact areas and to determine a transmission direction of the charging voltage depending on or taking into account an operating mode of the vehicle. The connection status can, for example, also be referred to as the contacting status and preferably indicates whether the contact areas assigned to one another are in contact, i.e. are connected in an electrically conductive manner, or not, whether the high-voltage battery is ready for charging and which type of charging (level of voltage and current, AC, DC) can be used for the high-voltage battery.

By designing the contact units (primary contact unit and secondary contact unit) with a plurality of contact areas (primary contact areas and secondary contact areas) each in a base body, i.e. a contact surface, there is the advantage that a size of a corresponding charging system, i.e. in particular a required volume or a required area of the primary contact unit and the secondary contact unit in the vehicle and the charging infrastructure can be reduced. Instead of two contact areas in two separate base bodies, several contact areas are now possible in one base body. As a result, the use of materials and the costs for such a charging system can also be reduced. By reducing costs, user or customer acceptance of the charging system can also be improved. Furthermore, such a configuration of a charging system also results in a reduction in the complexity with regard to making contact with the two contact units. In addition, a tolerance area when contacting the contact units can thus also be optimized, so that correct contacting can take place without the need for an exact positioning of the contact units in the centimeter range.

The invention also includes embodiments which result in additional advantages.

In order to contact or connect the primary contact unit to the secondary contact unit allow, it is provided in one embodiment that the at least one contacting device has an actuator unit which is designed to move the primary contact unit and / or the secondary contact unit for connecting the respective primary contact areas to the respective secondary contact areas along a predetermined contacting direction towards one another. According to the contacting direction, the contact units can preferably be moved towards one another along a perpendicular through their respective base bodies. The actuator unit can preferably be designed as an electrically driven height adjustment mechanism, that is to say as a lifting or lowering mechanism with an electric motor as the drive. Alternatively, a pneumatic or similar mechanical height adjustment mechanism is also conceivable. In the event that the secondary contact unit is embedded, for example, in the underbody of a vehicle, and the primary contact unit is designed, for example, as a floor contact, the contacting direction thus corresponds to a displacement of one or both of the contact units in a z-direction. In this case, the actuator unit can also be referred to as a z-mover.

In order to be able to position the respective first and second primary contact areas with the respective first and second secondary contact areas exactly to one another for contacting, a further embodiment provides that the actuator unit is designed, the primary contact unit and / or the secondary contact unit for connecting the respective primary contact areas to the move or rotate respective secondary contact areas in relation to their base bodies parallel to one another. The actuator unit can thus actively move the primary contact unit and / or the secondary contact unit laterally or vertically and thus in the x-y direction in a two-dimensional plane with respect to one another. For this purpose, the actuator unit can in particular additionally have an electrically driven lateral adjustment mechanism or displacement mechanism with an electric motor as the drive. In this case, the actuator unit can also be referred to as an x-y mover.

In a preferred embodiment, however, the charging system is passively guided or positively guided, so that there is no need to actively move the primary contact unit and the secondary contact unit parallel to one another. For this purpose, the base bodies each have three-dimensional surface structures which are complementary to one another and which are designed to slide against one another into a final contact position when they are brought into contact. In the final contact position, one of the first primary contact areas is connected in an electrically conductive manner to the first secondary contact area and one of the second primary contacts is connected to the second secondary contact area. In order to slide the base bodies against one another, at least one of the base bodies is preferably mounted so as to be movable laterally or vertically, that is, in a two-dimensional plane. In contrast to this, the other of the base bodies is preferably designed to be rigid or immovable in this two-dimensional plane. When the contact units are brought into contact, one of the base bodies can thus shift so that the base bodies can be framed, threaded or meshed into one another due to their surface structures. However, the electrically conductive contact between the primary contact areas and the respectively assigned secondary contact areas is preferably only created when the final contact position has been reached and the base bodies are thus correctly enclosed, threaded or meshed. The surface structures can be, for example, a jagged or triangular surface structure. Each of the base bodies includes a large number of essentially triangular elevations and depressions, so that a surface structure of mountains and valleys is created. When decontacting, that is, when the contact units are physically and electrically detached from one another, the at least one movably mounted base body can then be returned to its original position or zero position.

In this context, in a further embodiment it is preferably provided that at least one of the base bodies, that is to say one or both base bodies, is designed to be resiliently mounted. That is, the above-described movable mounting of the at least one base body can be done, for example, by means of springs. As a result, the respective base body is designed to move in parallel with respect to the respective other base body as a result of the sliding. The spring mounting thus has the effect that the respective base body can be moved in the lateral or vertical direction, that is to say preferably in the x-y direction.

Another embodiment provides that the respective primary contact areas and / or the respective secondary contact areas are designed to be switchable with respect to their respective potential. The respective contact areas therefore no longer have a fixed or predetermined potential. Instead, their respective potential can be switched. This means that each of the contact areas can be designed either as a neutral conductor (minus conductor) or as a phase conductor (plus conductor), depending on a polarity or circuit. This results in the advantage that it is possible to dispense with an active actuator unit for moving or rotating the base bodies parallel to one another or with a configuration of the base bodies with mutually complementary three-dimensional surface structures. The respective contact areas can instead be brought into contact or are switched in the connected state with one another in such a way that at least one of the first primary contact areas is connected to the at least one first secondary contact area and the at least one second primary contact area is connected to the at least one second secondary contact area. In this way, the complexity of the contacting device and the installation space required for the respective base body can be reduced. For switching the respective contact areas, the primary side and / or the secondary side can preferably comprise a switching device or switching device. This circuit device can be designed, for example, as a bridge circuit made up of semiconductor switches, such as, for example, transistors.

The primary contact unit and the secondary contact unit in the vehicle, in particular in the vehicle underbody or in a wall or in the floor, are advantageously designed to be retractable. As a result, the contact units can be stored protected from contamination, in particular from dust or dirt or water deposits, until contacting the contact units is desired. For this purpose, the primary side and the secondary side can each have a protective device, for example with a countersink element and a protective flap, the countersunk element being designed to countersunk the respective contact unit and the protective flap serving as a cover for the respective contact unit.

In an advantageous manner, it can also be provided that the primary contact unit and / or the secondary contact unit is designed to be heatable. In this way, icing or waste water deposits on the respective contact unit can be avoided. For this purpose, the primary side and / or the secondary side can comprise a heating element, such as, for example, a heating wire or a heating coil or a Peltier element.

In the following embodiments, an embodiment of the aforementioned control device will now be described.

In order to be able to recognize the described connection state of the respective contact areas, the control device is designed in one embodiment to evaluate image data that depict a connection process of the respective primary contact areas with the respective secondary contact areas and / or the primary side or the secondary side for providing a test voltage as charging voltage to check the connection of the respective primary contact areas with the respective secondary contact areas. Thus, the charging system can include, for example, an image acquisition device or camera, by means of which the primary contact unit and the secondary contact unit, and in particular the position of the respective contact areas with respect to one another, can acquire and generate image data therefrom. The control device can accordingly use an object or image recognition algorithm and evaluate the image data provided by the image acquisition device. As an alternative or in addition to the image acquisition device, the charging system can also have a test unit in the form of an electrical circuit which is designed to generate and provide the test voltage. The test voltage is preferably a voltage that is much lower than the actual charging voltage. For example, the test voltage can be 5 volts. By activating the test unit, the control device can release the test voltage and thus check whether there is a correct connection between the respective contact areas. In this context, correct connection or contacting means whether the contact areas are actually in the electrically conductive contact and whether the respective contact areas are connected with the correct polarity, i.e. the first primary contact areas are connected to the first secondary contact area and the second primary contact areas are connected to the second secondary contact area . Reverse polarity protection of the contact areas can thus be achieved by the control device. After testing the contact, a four-wire measurement can preferably be carried out in order to check how good the electrical contact is between the respective contact areas. That is to say, when an electrically conductive connection is determined, the primary side or the secondary side can be activated to carry out a four-wire measurement to verify the connection. Carrying out a corresponding four-point measurement is described in more detail below.

A further embodiment provides that the control device is designed to control the contacting device as a function of a position of the primary contact unit and the secondary contact unit with respect to one another in order to connect the respective primary contact areas to the respective secondary contact areas. The control device can thus be designed to determine the position relative to one another, in particular with regard to a lateral or vertical alignment of the base bodies of the primary contact unit and the secondary contact unit. For this purpose, the control device can use the aforementioned image acquisition device or camera, for example. Only when a correct position, in particular a position in which the surfaces of the base bodies of the contact units preferably completely overlap, is determined by the control device, the control device can provide a control signal for activating the contacting device for moving the respective base bodies to one another.

In a further embodiment it is provided that the control device is designed to control the secondary side in a second operating mode of the vehicle to provide the safe-to-touch charging voltage via the at least one first secondary contact area and the at least one second secondary contact area. Thus, in this case, the secondary side can be designed as a transmitter of the safe-to-touch charging voltage and the primary side as a receiver of the safe-to-touch charging voltage. If the secondary side is part of the vehicle and the primary side is part of a charging device or charging infrastructure, the high-voltage battery of the vehicle, for example, can be discharged via the charging infrastructure. That is to say, the second operating mode can represent, for example, a discharging operation of the vehicle for discharging the vehicle battery. Thus, for example, excess energy stored in the high-voltage battery can be fed back into an energy network to which the charging infrastructure is connected. The energy network can be a household energy network, for example, so that household appliances, for example, can be supplied using the excess energy of the high-voltage battery.

With regard to an embodiment of the at least one contacting device, a further embodiment provides that the at least one contacting device has at least one holding unit which is designed to hold the respective primary contact areas detachably in contact with the respective secondary contact areas. The respective contact areas can preferably be held in contact or connected in a non-destructive manner in a detachable manner. This means that the connection can be released without destroying or damaging the respective contact areas. Thus, for example, a holding force can be generated by the contacting device, by means of which the respective contact areas can be held against one another. For this purpose, the holding unit can be designed, for example, as a spring-loaded holding mechanism for the respective primary or secondary contact unit. Accordingly, as is known, for example, from spring-loaded contact pins, the respective contact unit can yield when it is brought into contact with the respective other contact unit. Alternatively, the holding unit can also be designed as a magnetic holding unit, so that a holding force for holding the primary and secondary contact units to one another is generated in a magnetic field.

Since a supply device, such as a public energy supply network, usually provides a supply voltage of 230 volts, and a high-voltage battery also requires a high-voltage voltage greater than 60 volts for charging, a further embodiment provides that the primary side has a primary converter unit and the secondary side has a secondary converter unit which are designed to convert a respective high-voltage voltage external to the charging system into the safe-to-touch charging voltage. The converter units are preferably voltage converters, such as a direct voltage converter (DC / DC converter) or an alternating voltage converter (AC / DC converter) or and / or be designed as a step-down converter or a step-up converter.

The invention also relates to a charging device for charging a high-voltage battery of a vehicle with a touch-safe charging voltage, the charging device comprising the primary side of the charging system, as described above. The charging device and in particular the primary side is preferably connected to a supply network, in particular a public energy supply network.

The invention also relates to a vehicle, in particular a motor vehicle with an electrical energy store, in particular a high-voltage battery, which is designed for charging with a touch-safe charging voltage, the energy store being connected to the secondary side of the charging system, as described above. The motor vehicle is preferably designed as an electrically drivable motor vehicle, that is to say, for example, as an electric vehicle or hybrid vehicle. The motor vehicle is preferably designed as a motor vehicle, in particular as a passenger vehicle or truck, or as a passenger bus or motorcycle.

Finally, the invention also relates to a method for conductive charging of an energy store, which is preferably designed as a high-voltage battery, of a vehicle with a touch-safe charging voltage. The method comprises the following steps: First, a primary side is provided with a primary contact unit, which has a flat base body which comprises at least two first primary contact areas and at least one second primary contact area, and a secondary side with a secondary contact unit which has a flat base body, which comprises at least one first secondary contact area and at least one second secondary contact area. The at least one first secondary contact area is then connected to at least one of the first primary contact areas and the at least one second secondary contact area is connected to the at least one second primary contact area. A connection state of the respective primary contact areas with the respective secondary contact areas is then checked. Farther it is also checked whether the vehicle is in a first operating mode. In the event that the vehicle is in the first operating mode, and depending on a result of the checking of the connection status, the primary side is finally controlled to provide the safe-to-touch charging voltage via at least one of the first primary contact areas and the at least one second primary contact area.

The invention also includes developments of the method according to the invention, the charging device according to the invention and the motor vehicle according to the invention which have features as they have already been described in connection with the further developments of the charging system according to the invention. For this reason, the corresponding developments of the method according to the invention, the charging device according to the invention and the motor vehicle according to the invention are not described again here.

The invention also includes the combinations of the features of the described embodiments.

• 1 eine schematische Darstellung einer Ausgestaltung eines konduktiven Ladesystems mit Toleranzflächenoptimierung;
• 2 eine schematische Darstellung von verschiedenen Ausgestaltungsmöglichkeiten einer Primärkontakteinheit und einer Sekundärkontakteinheit, und
• 3 eine schematische Darstellung von verschiedenen Ausgestaltungsmöglichkeiten einer Oberflächenstruktur der Primärkontakteinheit und der Sekundärkontakteinheit.

Exemplary embodiments of the invention are described below. This shows:

• 1 a schematic representation of an embodiment of a conductive charging system with tolerance area optimization;
• 2 a schematic representation of various design options of a primary contact unit and a secondary contact unit, and
• 3rd a schematic representation of various design options for a surface structure of the primary contact unit and the secondary contact unit.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention which are to be considered independently of one another and which also further develop the invention in each case independently of one another. Therefore, the disclosure is also intended to include combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

In the figures, the same reference symbols denote functionally identical elements.

Previous conductive charging systems are usually based on connector systems in which a plugging process for contacting oppositely or complementarily designed contact units of a charging infrastructure and a vehicle is carried out by a user or automatically. The connections or contacts of such a plug system are usually designed as point connections, such as contact pins and complementary contact sockets, which must be precisely aligned with one another for contacting. In particular in the case of automated plug-in processes, however, there is generally a lack of accuracy to connect the connections or contacts in a correctly electrically conductive manner, or complex adjustment systems have to be used so that the connections can be correctly aligned or positioned with respect to one another. In addition, high-voltage voltages are transmitted with the corresponding connector systems, which means that complex protective measures, such as sheathing the connections or an additional protective conductor, have to be provided. As a result, corresponding automated charging systems are usually expensive and are less accepted by users.

In order to simplify the positioning of the contact units and to reduce installation space and material costs for providing a conductive charging system and thereby to increase the acceptance of users towards such a charging system, as in FIG 1 shown a charging system 100 , which transmits a touch-scissors charging voltage, can be used with an optimized tolerance area of the contact units to one another. By using a safe-to-touch charging voltage or protective extra-low voltage, the connections can be designed as flat and large contact areas in the square centimeter to square meter area instead of as point connections. Instead of a point-to-point connection, a point-to-surface connection or a surface-to-surface connection can thus be implemented, for example. In order to optimize the tolerance area, i.e. an area in which there is correct contact, i.e. an electrically conductive connection between the contact areas of two complementary contact units, several contact areas are also used in one contact unit, each of which has two different potentials, arranged. At least two of these contact areas with different potentials thus represent a pole pair or connection pair via which the safe-to-touch charging voltage can be transmitted. As a result, the installation space and use of material for each of the contact units can be reduced and a tolerance range for correct contacting of the contact units can still be created.

1 now shows an exemplary embodiment of a corresponding charging system 100 . The charging system 100 has a primary side 110 and a secondary side 120 on. The primary side 110 is in 1 for example designed as a charging device or charging infrastructure and connected to an external energy network 300 be connected. On the other hand is the secondary side 120 integrated in a motor vehicle and connected to the high-voltage battery 200 connected as an electrical energy store of the motor vehicle.

Electrical energy can thus be obtained from the external energy supply network 300 via the charging system 100 for charging the high-voltage battery 200 to be provided. The reverse can also be done from the high-voltage battery 200 electrical energy via the charging system 100 to the external energy transfer device 300 to be provided. The primary side is used to transmit the electrical energy 110 with the secondary side 120 coupled, i.e. electrically connected or contacted.

To contact the primary side includes 110 thereby a primary contact unit 111 that have a flat base body 112 having. On this two-dimensional base body 112 are at least two first primary contact areas as electrical connections or connection poles 113 and at least one second primary contact area 114 arranged. The first primary contact areas 113 have a different potential to the second primary contact area 114 on. For example, the first primary contact areas 113 be designed as a positive conductor or phase conductor, while the second primary contact area 114 is designed as a negative conductor or neutral conductor. Between at least one of the first primary contact areas 113 and the second primary contact area 114 the safe-to-touch charging voltage can be applied or made available.

In 1 is the basic body 112 designed as a square plate. The respective primary contact areas 113 , 114 are as longitudinal contact surfaces on the base body 112 arranged alternately or next to one another and are each covered by an insulating layer or an insulating area 115 such as a layer of polypropylene, electrically separated from each other. Thus, as in 1 shown, a zebra stripe pattern of primary contact areas 113 , 114 and isolation areas 115 . Alternatively, the primary contact areas 113 , 114 can also be designed as tubes or half tubes, so that, in particular in a side view, a three-dimensional surface structure of the base body 112 results. This configuration of the primary contact unit 111 is described in more detail later on.

Since from the external energy network 300 , such as the public power supply network, as a rule no safe-to-touch voltage is provided, but rather a high-voltage alternating voltage of approximately 230 volts, has the primary side 110 additionally a primary converter unit 116 on. As in 1 shown, the primary contact unit 111 is via a connection A to the primary converter unit 116 and the external energy network 300 be connected. This primary converter unit 116 is on the one hand designed to be used by the energy network 300 to reduce the high-voltage voltage provided to the safe-to-touch charging voltage. Thus, the primary converter unit 116 for example include a buck converter. On the other hand, the primary converter unit 116 , as in 1 also include an AC / DC converter to power the grid 300 AC voltage provided to DC voltage for charging the high-voltage battery 200 to be able to convert and vice versa. As in 1 shown, the primary side 110 in an advantageous manner still another connection A1 have, via which, for example, a second primary contact unit to the primary converter unit 116 can be connected.

For contacting the primary side 110 , includes said secondary side 120 a secondary contact unit 121 . This also has a flat base body 122 on, which according to the configuration of the charging system in 1 a first secondary contact area 123 and a second secondary contact area 124 includes. The secondary contact areas 123 , 124 thus form the connections or connection poles of the secondary side 120 . The secondary contact areas have different potentials, so that over the secondary contact areas 123 , 124 the touch-safe charging voltage can be transmitted or received. For example, the first secondary contact area 123 be designed as a positive conductor or outer conductor, while the second secondary contact area 124 can be designed as a negative conductor or neutral conductor.

As in 1 shown is the base body 122 as an elongated plate with a smaller area than the base body 111 educated. The secondary contact areas 123 , 124 are in different sections along a longitudinal direction of the main body 122 educated. An insulating layer or area 125 separates or isolates the secondary contact areas 123 , 124 thereby electrically from each other.

The isolation areas 115 , 125 between the respective contact areas 113 , 114 , 123 , 124 can preferably also be designed as grounding contacts or as grounding conductors.

As the high-voltage battery 200 A high-voltage voltage, i.e. a DC voltage greater than 60 volts, is required for charging and a corresponding one for discharging Provides DC voltage, includes the secondary side 120 a secondary converter unit 126 . The secondary contact unit 121 is via a connection A to the secondary converter unit 126 and the high-voltage battery 200 connected. The secondary converter unit 126 comprises, for example, a step-up converter and is designed to convert the safe-to-touch charging voltage into a high-voltage voltage for charging the high-voltage battery 200 raise and vice versa.

To the primary side 110 and the secondary side 120 for conductive charging of the high-voltage battery 200 The charging system 100 furthermore a contacting device 130 on. This is according to the design in 1 from the secondary side 120 includes. The contacting device 130 is formed, the first secondary contact area 123 to be electrically conductively connected to at least one of the first primary contact areas and the second secondary contact area 124 with the second primary contact area 114 to connect electrically conductive. For connecting or contacting the primary contact areas 113 , 114 with the respectively assigned secondary contact areas 123 , 124 can the contacting device 130 for example an actuator unit 131 include. This is designed to move the primary contact unit and / or the secondary contact unit for connecting the respective primary contact areas to the respective secondary contact areas along a predetermined contacting direction R towards one another. The actuator unit 131 can include, for example, an electric motor and a height adjustment mechanism. The height adjustment mechanism can be designed, for example, as a mechanical arm that can be moved by the electric motor. The contacting device can preferably 130 also be formed, the respective contact areas 113 , 114 , 123 , 124 to be positioned in relation to longitudinal and transverse alignment to one another. The actuator unit 131 additionally included a lateral adjustment mechanism by means of which the secondary contact unit 121 parallel in a plane to the primary contact unit 111 to move or rotate.
To the contacting device 130 The charging system tells you to be able to control it 100 also a control device 140 on. The control device can preferably 114 the contacting device 130 for establishing the electrically conductive connection between the respective contact areas 113 , 114 , 123 , 124 depending on a position, i.e. an alignment, of the contact units 111 and 121 to steer towards each other.

The control device 140 is also designed to be dependent on a connection state of the respective primary contact areas 113 , 114 with the respective secondary contact areas 123 , 124 and the primary side as a function of an operating mode of the vehicle 110 or the secondary side 120 to provide or receive the touch-safe charging voltage. In a first operating mode of the vehicle, it can be provided, for example, that the high-voltage battery 200 of the vehicle is to be charged. Accordingly, the control device can use the primary side 110 for providing the safe-to-touch charging voltage via at least one of the first primary contact areas 113 and the second primary contact area 114 drive. In contrast, it can be provided in a second operating mode that the high-voltage battery 200 of the vehicle is to be unloaded. Accordingly, the control device can use the secondary side in the second operating mode 120 to provide the safe-to-touch charging voltage via the first secondary contact area 123 and the second secondary contact area 124 drive. The control device 140 , as in 1 shown, for example, detect an operating mode signal B from the vehicle and then the primary side 110 or the secondary side 120 control a respective control signal F to provide the safe-to-touch charging voltage.

As described above, the provision of the safe-to-touch charging voltage also takes place as a function of a connection state of the respective primary contact areas 113 , 114 with the respective secondary contact areas 123 , 124 . The connection status indicates whether the respective contact areas 113 , 114 , 123 , 124 are electrically connected. Furthermore, the connection status can also indicate which charging type, that is to say an alternating voltage or direct voltage, the vehicle is used to charge the high-voltage battery 200 required, and how large the charging voltage must be. The connection status of the control device 140 , as in 1 shown as a status signal Z capture.

In a preferred embodiment of the charging system 100 can be the state signal Z represent that an electrical contact between the primary contact unit 111 and the secondary contact unit 121 has been made. The control device 140 be formed, the primary side 110 and / or the secondary side 120 for transmitting a respective test voltage as charging voltage for checking the connection of the respective contact areas 113 , 114 , 123 , 124 provide. The test voltage can be much smaller than the charging voltage and can be, for example, 5 volts. The primary converter unit 116 and the secondary converter unit 126 be designed, for example, switchable, so that they are powered by the power grid 300 or the high-voltage battery 200 can convert the high-voltage voltage provided either into the touch-safe charging voltage or into the test voltage. With a correct polarity connection of the respective contact areas 113 , 114 , 123 , 124 This results in a closed circuit, whereby a current flow between the primary side 110 and the secondary side 120 can be determined. This can be done, for example, by means of a corresponding current or voltage sensor in the primary converter unit 116 and / or the secondary converter unit 126 respectively. The test voltage can thus be used both for a touch test and for a test with regard to a correct or correct polarity connection of the contact areas 113 , 114 , 123 , 124 respectively.

After testing or checking whether the electrically conductive connection between the respective contact areas 113 , 114 , 123 , 124 is established, a quality or goodness of the electrical connection can also be checked. For this purpose, for example, a four-wire measurement can be used to establish a contact resistance on the respective contacted surfaces of the contact areas 113 , 114 , 123 , 124 determined or determined. For example, the control device 140 one of the converter units 116 , 126 to provide a known and constant current (for charging with very low voltage and power). This electricity can then be fed into the charging system 100 fed in. become. With a four-wire measuring arrangement, for example in the respective transducer unit 116 , 126 can be integrated, then the resulting voltage between at least two differently polarized contact areas 113 , 114 , 123 , 124 measured. The contact resistance can then be determined using Ohm's law from the known current and the measured voltage. In this case, the control device 140 then the determined contact resistance as a status signal Z record and compare, for example, with a resistance limit value. If, during the comparison, it is found, for example, that the contact resistance is less than the resistance limit value, the electrically conductive contacting of the respective contact areas can be made 113 , 114 , 123 , 124 be confirmed and the control device 140 can provide said control signal F. If, on the other hand, the contact resistance is greater than the resistance limit value, the electrically conductive contacting of the respective contact areas can 113 , 114 , 123 , 124 be answered in the negative and the control device 140 can, for example, the contacting device 130 for a new contact attempt. Alternatively, the control device can also output a warning signal to a user of the motor vehicle via a screen. The user can then park or move his motor vehicle so that a new contacting process can be carried out.

In an alternative embodiment of the charging system 100 can be the state signal Z the control device 140 also from a primary communication unit 118 and a secondary communication unit 128 to be provided. These communication units 118 , 128 can in particular be designed as wireless communication units and the status signal Z via a generally known wireless communication link K to the control device 140 send. At least one of the communication units can do this 118 , 128 comprise a camera by means of which a connection process, that is to say an approaching of the primary contact unit 111 and the secondary contact unit 121 can be captured or filmed. The resulting image data can be sent to the respective communication unit 118 , 128 then preferably wirelessly as the status signal Z to the control device 140 transfer. This can then evaluate the image data in order to check the connection status.

Alternatively, the communication units 118 , 128 be designed for example as near-field communication units. In this case you can pair the primary side for the first time 110 and the secondary side 120 be used. For example, the secondary side 120 an approach signal to the primary side via near field communication or a Bluetooth connection or a WLAN connection 110 send, which announces the approach of the vehicle to the charging infrastructure. When the approach signal is detected, the primary side 110 the control device 140 "Wake up" and, for example, switch from a sleep mode or energy-saving mode to an operating mode. Thus, for example, the control device 140 attention should be drawn to the fact that a contacting process is to take place soon.

The design of the charging system 100 according to 1 could now be based on the following situation as an example. A user of a motor vehicle wants his high-voltage battery 200 load. The motor vehicle has the primary side described above 120 on, wherein the primary contact unit is arranged hidden in an underbody of the motor vehicle. A corresponding charging infrastructure or charging device, which has the aforementioned primary side and, for example, the control device 140 comprises, can accordingly be designed as a ground contact unit. If the user of the motor vehicle drives his motor vehicle to charge the high-voltage battery 200 on the primary contact unit designed as a base plate 111 can the control device 140 a position of the secondary contact unit 121 on the motor vehicle and detect the relative position of the secondary contact unit to the primary contact unit 111 for example by means of a camera in one of the communication units 118 , 128 check. The surfaces of the base bodies overlap 112 , 122 , the primary contact unit 111 and the secondary contact unit 121 preferred for example completely, the control device can 140 the contacting device 130 drive, whereby the secondary contact unit 121 towards the primary contact unit 111 is moved to contact. The contacting process can for example be recorded again by means of the camera and the image data can be sent to the control device for evaluation 140 be transmitted. The contacting process is preferably monitored, however, by means of the transmission of the test voltage described above and the aforementioned multiplicity measurement. That is, the control device 140 can for example be the primary converter unit 116 drive to the test voltage from the primary contact unit 111 to the secondary contact unit 121 transferred to. If a successful transmission of the test voltage is determined, the control device can 140 then the primary converter unit again 116 to perform the four-wire measurement. If a suitably low transmission resistance is found, the control device can 140 finally the primary side 110 , so in particular the primary converter unit 116 , to enable the touch-safe charging voltage. The safe-to-touch charging voltage from the external energy network can thus be conductive 300 via the charging system 100 to the high-voltage battery 200 be transmitted.

To correctly contact the respective contact areas 113 With 123 and 114 With 124 to be able to ensure the primary contact areas 113 , 114 according to 1 designed to be switchable in their potential. That is, the respective potential of a contact area can be adjusted as desired. Thus, for each of the primary contact areas 113 , 114 determine whether it should be designed as a neutral conductor or an external conductor. This includes the primary side 110 in 1 a switching device 117 which is designed to switch or set the primary contact areas as first primary contact areas or as second primary contact areas. The circuit unit 117 can be designed, for example, as a bridge circuit made up of semiconductor switches, such as, for example, transistors. As a result, a complex adjustment of the position of the respective contact units is possible 111 , 121 to each other are waived. The actuator unit described above 140 to move or rotate the secondary contact unit vertically 121 can therefore be omitted.

In 2 are now alternative exemplary design options for the primary contact unit 111 and the secondary contact unit 121 shown. In 2 are the two contact units 111 and 121 shown in a top view or from a bird's eye view

For example, as in 2a be essentially square. The basic body 112 has three first primary contact areas 113 and three second primary contact areas 114 which are arranged as elongated contact surfaces on the base body. The first primary contact areas 113 and the second primary contact areas 114 are arranged alternately next to one another, similar to a zebra crossing, for example, and are provided with isolation areas 115 electrically separated from each other. In contrast, the secondary contact unit 121 a base body 122 on, the area of which is made much smaller than an area of the base body 112 the primary contact unit 111 . The surface of the base body can preferably 122 by at least one factor 2 , preferred by a factor 4th , in particular by one factor 8th , be smaller than an area of the base body 112 . In contrast to the primary contact unit 111 has the secondary contact unit 121 only a first secondary contact area 123 and a second secondary contact area 124 on, which along a longitudinal direction of extension side by side by an insulating region 125 electrically separated from one another on the base body 122 are arranged.

In the in 2 B The embodiment shown has the primary contact unit 111 an elongated, substantially rectangular base body 112 on which three first primary contact areas 113 and three second primary contact areas 114 includes. These are analogous to 2a along a longitudinal extension direction of the base body 112 alternating and through isolation areas 115 formed separately from each other. The secondary contact unit 121 likewise has an elongate, essentially rectangular base body 122 on, with a first secondary contact unit 123 and a second secondary contact unit 124 . The first secondary contact unit 123 and the second secondary contact unit 124 are perpendicular to the direction of longitudinal extent of the base body through the insulating area 125 electrically separated next to each other. Preferably one area corresponds to the base body 112 thereby a surface of the base body 122 . The base bodies are used to optimize the tolerance area 112 and 122 however, rotated by 90 degrees in an xy orientation with respect to one another. When overlaying the primary contact unit 111 and the secondary contact unit 122 a cross pattern would result.

In the design in 2c has the primary contact unit 111 again an elongated, substantially rectangular base body 112 on. This includes two first primary contact areas 113 and two second primary contact areas 114 , each as elongated contact areas in one of the four corners of the base body 112 are arranged. There is a first primary contact area in each case 113 and a second primary contact area 114 along a Longitudinal direction of the base body 112 arranged one after the other. Furthermore, the first are primary contact areas 113 and the second primary contact areas 114 arranged side by side perpendicular to the direction of longitudinal extension of the base body. The primary contact areas 113 , 114 are analogous through a continuous isolation area 115 electrically separated from each other. The secondary contact unit 121 likewise has an elongated, essentially rectangular base body 122 on. The basic body 122 comprises a first secondary contact area 124 and a second secondary contact area 125 on, along a longitudinal direction of extent of the base body 122 are formed in different sections (at different ends). You are through the isolation area 125 electrically isolated from one another, with one surface of the insulating region 125 according to 2c is made much larger than an area of the respective secondary contact area 123 , 124 .

When superimposing the base body 112 , 122 the primary contact unit 111 and the secondary contact unit 121 according to 2c it can be determined that a distance between the first two primary contact areas 113 and the two second primary contact areas 114 is smaller than a longitudinal extension direction of the first secondary contact area 123 and the second secondary contact area 124 . Furthermore, it can be determined that a distance between the respective first secondary contact area 123 and the respective second secondary contact area 124 is greater than a longitudinal direction of one of the respective primary contact areas 113 , 114 . This design of the contact units 111 , 121 it can be avoided that a polarity reversal, i.e. a contact between a phase conductor (positive conductor) and a neutral conductor (negative conductor) occurs.

According to the configuration in 2d can use the primary contact areas 113 , 114 also be designed to be switchable. This means that they can be connected either as a phase conductor (plus conductor) or as a neutral conductor (minus conductor). In 2d includes the primary contact unit 111 for this purpose an elongated and essentially rectangular base body 112 , in which the primary contact areas through a respective insulating area along a longitudinal extension direction 113 are arranged separately alternately one after the other. The secondary contact unit 121 likewise has an elongated, substantially rectangular base body 122 in which a first secondary contact area 124 and a second secondary contact area 125 through an isolation area 125 are arranged separately next to each other. The dimensions of one of the secondary contact areas 124 , 125 in the longitudinal direction are preferably smaller than a distance between two of the primary contact areas 113 , 114 . Now become the basic body 112 , 122 the primary contact unit 111 and the secondary contact unit 121 superimposed and arranged next to one another for electrical connection, the primary contact areas 113 , 114 , depending on which of the secondary contact areas 124 , 125 at the respective primary contact area 113 , 114 is applied, must be switched accordingly.

As an alternative to the in 2 The design options shown can, of course, also have a reverse design of the primary contact unit 111 and the secondary contact unit 121 to be possible.

In 3rd shows a side view of the two contact units 111 and 121 . About the need for an exact positioning of the respective first primary and secondary contact areas 113 , 123 and the respective second primary and secondary contact areas 114 , 124 Avoid using a complex adjustment device, as in 3rd shown, be provided that the respective base body 112 , 122 each have a complementary surface structure O to one another. This allows the primary contact unit 111 and the secondary contact unit 121 when they are brought into contact with one another to slide into a final contact position. In the final contact position, there is exactly a first primary contact area 113 with a first secondary contact area 123 and a second primary contact area 114 with a second secondary contact area 124 electrically connected. 3a to 3c now show exemplary configurations of a respective surface structure O of the base body 112 , 122 . The primary contact unit 111 two first primary contact areas 113 and two second primary contact areas 114 on. These are alternately next to each other by insulating areas 115 separated in the main body 112 educated. The secondary contact unit in each case has a corresponding 111 a first secondary contact area 123 and a second secondary contact area 124 on. These are alternately next to each other through an insulating area 125 separated in the main body 122 educated.

According to 3a can use the basic body 112 , 122 essentially have triangular elevations and depressions which form the surface structure O. The final contact position according to 3a This results in a correct sliding-in or phase-in or threading-in of an elevation of the secondary contact unit 121 into a recess in the primary contact unit 111 and vice versa. Now, for example, the secondary contact unit 121 in a predetermined contacting direction R, for example, in the z-direction onto the primary contact unit 111 moved towards, with an elevation as in 3a shown, not directly above a recess of the primary contact unit 111 is arranged, takes place when the primary contact unit is brought into contact 111 and the secondary contact unit 121 sliding or shifting of the base bodies with respect to one another in a shifting direction V, which is designed here in particular as an x-direction. To move the base body 112 , 122 in the x-direction so parallel to each other, as in 3a shown, for example, the primary contact unit 111 via a spring mechanism 119 be designed to be spring-loaded. Due to the spring mechanism, the base body 112 be moved in one plane, for example in the xy direction. This results in the approach of the contact units 111 , 121 forced guidance of the primary contact unit 111 until the final contact position is reached.

In 3b are the primary contact unit 111 and the secondary contact unit 121 essentially analogous to that 3a educated. In 3b however, are the tips of the essentially triangular elevations of the base body 122 the secondary contact unit 121 cut off or flattened. Thus, when arranging an elevation of the base body 122 into a recess in the base body 112 a cavity in the lower part of the recess. The contacting of the primary contact unit 111 and the secondary contact unit 121 is thus preferably carried out over the side surfaces of the elevations or the depressions. In this cavity, for example, dirt or water can then be deposited without the contact surface of the first contact unit 111 and the second contact unit 121 is reduced.

In 3c include the basic body 112 , 121 a surface structure O which has essentially spherical elevations. The surface structure of the respective base body is between the spherical elevations 112 , 122 thereby formed planar. Here, too, there is the advantage that when contacting the primary contact unit 111 with the secondary contact unit 121 a contact essentially through the side surfaces of the spherical elevations between the primary contact unit 111 and the secondary contact unit 121 will be produced. Furthermore, in this embodiment, when making contact, there are cavities in which dirt and grime can be deposited without the contact, in particular a contact surface, of the primary contact unit 111 or that of the secondary contact unit 121 to affect.

In 3d is an alternative embodiment of the primary contact unit 111 and the secondary contact unit 121 shown. Here only the primary contact unit has 111 a base body 112 with a three-dimensional surface structure O on. The main body 112 in the side view circular (in three-dimensional view cylindrical or tubular) depressions V or recesses. In these depressions V, the four primary contact surfaces are alternating one after the other 113 , 114 embedded or incorporated as essentially circular (in three-dimensional view in particular tubular or cylindrical) connections with an accurate fit or form-fitting. The insulating layer 115 is in this case through the main body 112 , in particular the material of the base body 112 , educated. In contrast to this, there is a surface structure P of the base body 122 the secondary contact unit 121 essentially planar or flat. The two secondary contact areas 123 , 124 are in the side view as rectangular (in three-dimensional view as elongated plates) connections side by side. The insulating layer 125 is formed by air. This results in the flat shape of the base body 122 in this case indirectly through a straight line (shown in dashed lines) or imaginary connection between the secondary contact areas 123 , 124 .

Overall, the examples thus show a multipole tolerance area optimization in automated contact-based charging of electric vehicles or electrified vehicles. The contact areas 113 , 114 , 123 , 124 are designed as surfaces, sliding or touch contacts. Through a mechanically cleverly selected arrangement of the contact areas 113 , 114 to each other and 123 , 124 In relation to one another, a tolerance area with a number of x poles can thus be reduced to a tolerance area of one pole. That means the clever arrangement of the contact areas 113 , 114 , 123 , 124 is selected in such a way that the one contact unit is phased in or threaded in or meshed with the other contact unit, whereby a transverse or longitudinal tolerance must be ensured for correct phasing. This transverse or longitudinal tolerance can be achieved by appropriate mounting, such as, for example, by spring mechanisms on one of the contact units 111 , 121 will be realized. The electrical contact is only established once the phase has been fully phased in, so that the final contact position is reached.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016008982 A1 [0004]
• DE 202018100805 U1 [0004]
• WO 2019/052962 A1 [0005]

Claims (14)

Charging system (100) for conductive charging of an energy store (200) of a vehicle with a safe-to-touch charging voltage, comprising a primary side (110) with a primary contact unit (111) which has a flat base body (112) which comprises at least two first primary contact areas (113) and at least one second primary contact area (114), a secondary side (120) with a secondary contact unit (121) which has a flat base body (122) which comprises at least one first secondary contact area (123) and at least one second secondary contact area (124), at least one contacting device (130) which is designed to connect the at least one first secondary contact area (123) to at least one of the first primary contact areas (113) and the at least one second secondary contact area (124) to the at least one second primary contact area (114), and a control device (140) which is designed, depending on a connection state of the respective primary contact areas (113, 114) with the respective secondary contact areas (123, 124) in a first operating mode of the vehicle, the primary side (110) for providing the safe-to-touch charging voltage via at least to control one of the first primary contact areas (113) and the at least one second primary contact area (114). Charging system (100) Claim 1 , wherein the at least one contacting device (130) has an actuator unit (131) which is designed, the primary contact unit (111) and / or the secondary contact unit (121) for connecting the respective primary contact areas (113, 114) to the respective secondary contact areas (123, 124) to move towards one another along a predetermined contacting direction (R). Charging system (100) Claim 2 , wherein the actuator unit (131) is designed, the primary contact unit (110) and / or the secondary contact unit (120) for connecting the respective primary contact areas (113, 114) to the respective secondary contact areas (123, 124) in relation to their base bodies (112, 122) to move or rotate parallel to each other. The charging system (100) according to any one of the preceding claims, wherein the base bodies (112, 122) each have complementary three-dimensional surface structures (O) which are designed to slide against one another when brought into contact up to a final contact position, wherein in the final contact position in each case one of the first primary contact areas (113) is electrically conductively connected to the at least one first secondary contact area (123) and the at least one second primary contact area (114) is electrically conductively connected to the at least one second secondary contact area (124). Charging system (100) Claim 4 , wherein at least one of the base bodies (112, 122) is designed to be resiliently mounted and is thereby designed to move parallel to the respective other base body (112, 122) as a result of the sliding. Charging system (100) according to one of the preceding claims, wherein the respective primary contact areas (113, 114) and / or the respective secondary contact areas (123, 124) are designed to be switchable with respect to their respective potential. The charging system (100) according to any one of the preceding claims, wherein the control device (140) is designed to detect the connection state, and to evaluate image data which depict a connection process of the respective primary contact areas (113, 114) with the respective secondary contact areas (123, 124) / or to control the primary side (110) or the secondary side (120) to provide a test voltage as charging voltage to test the connection and, in particular when an electrically conductive connection is detected, the primary side (110) or the secondary side (120) to carry out a four-wire measurement for Verify the connection to control. Charging system (100) according to one of the preceding claims, wherein the control device (140) is designed, in a second operating mode of the vehicle, the secondary side (120) to provide the safe-to-touch charging voltage via the at least one first secondary contact area (123) and the at least one second secondary contact area (124) to control. Charging system (100) according to one of the preceding claims, wherein the control device (140) is designed, the contacting device (130) depending on a position of the primary contact unit (111) and the secondary contact unit (121) to each other for connecting the respective primary contact areas (113, 114 ) to be controlled with the respective secondary contact areas (123, 124). The charging system (100) according to any one of the preceding claims, wherein the at least one contacting device (130) has at least one holding unit which is designed to releasably hold the respective primary contact areas (113, 114) in contact with the respective secondary contact areas (123, 124). The charging system (100) according to any one of the preceding claims, wherein the primary side (110) has a primary converter unit (116) and the secondary side (120) has a secondary converter unit (126) which are designed to convert a respective high-voltage voltage external to the charging system into the safe-to-touch charging voltage walk. Charging device for charging an energy store (200) of a vehicle with a touch-safe charging voltage, wherein the charging device comprises the primary side (110) of the charging system (100) according to one of the preceding claims. Motor vehicle with an energy store (200) which is designed for charging with a safe-to-touch charging voltage, the energy store (200) being connected to the secondary side (120) of the charging system (100) according to one of the preceding claims. Method for conductive charging of an energy store (200) of a vehicle with a safe-to-touch charging voltage, comprising the following steps: - Providing a primary side (110) with a primary contact unit (111) which has a flat base body (112) which comprises at least two first primary contact areas (113) and at least one second primary contact area (114), and a secondary side (120) with a Secondary contact unit (121) which has a flat base body (122) which comprises at least one first secondary contact area (123) and at least one second secondary contact area (124), - connecting the at least one first secondary contact area (123) to at least one of the first primary contact areas (113) and the at least one second secondary contact area (124) to the at least one second primary contact area (114), - checking a connection state of the respective primary contact areas (113, 114) with the respective secondary contact areas (123, 124), - Check whether the vehicle is in a first operating mode, and - In the event that the vehicle is in the first operating mode and depending on a result of the checking of the connection status: controlling the primary side (110) to provide the safe-to-touch charging voltage via at least one of the first primary contact areas (113) and the at least one second Primary contact area (124).

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