System for producing a conductive connection

Abstract

The invention relates to a system (25) for producing a conductive connection, comprising multiple contacts having at least one protective conductor contact and power contacts (32). The at least one protective conductor contact is hard wired. The power contacts (32) are associated with at least two different potential layers (34) which comprise a first potential layer (34) and a second potential layer (34). A switch unit (56) is provided which is associated with at least first power contacts (32-1) of the power contacts (32). The switch unit (56) is designed to connect at least the first power contacts (32-1) selectively to the first potential layer (34) or the second potential layer (34).

Description

[0001] System for establishing a conductive connection

[0002] The invention relates to a system for establishing a conductive connection, in particular between a vehicle contact unit and a ground contact unit.

[0003] In vehicles that are at least partially electrically powered, such as plug-in hybrid vehicles and fully electric vehicles, the batteries must be charged regularly, preferably after every trip. To do this, the vehicle is connected to a suitable power source, typically using a plug, such as a Type 2 plug, which must be manually inserted into a corresponding socket on the vehicle by a person. This also ensures that the plug is guided so that contact is made in a defined manner.

[0004] Ground contact units for vehicle battery charging systems, which are provided on the ground, are also known from the prior art, for example, WO 2019 / 052962 A1. The ground contact units can automatically establish a conductive connection with a corresponding vehicle contact unit provided on the vehicle to be charged in order to charge the vehicle. The vehicle contact unit can be provided on the underbody of the vehicle, where it moves downwards to establish electrical contact with the ground contact unit.

[0005] For example, the ground contact unit is designed as a so-called matrix charging pad, as shown in WO 2019 / 052962 A1. For this purpose, the ground contact unit comprises a plurality of contacts arranged in a matrix, wherein the contacts can be contacted by means of the vehicle contact unit to establish an electrical connection between the ground contact unit and the vehicle contact unit.

[0006] It can be provided that the vehicle contact unit is precisely aligned with the ground contact unit before a connector of the vehicle contact unit contacts the ground contact unit at a defined location. Alternatively, it can be provided that no guidance for the vehicle contact unit and / or no precise contact is provided, in which case a contact point of the connector of the vehicle contact unit on the ground contact unit must be detected. Depending on the contact point, the correspondingly assigned contacts of the ground contact unit are switched on to establish the electrical connection via these contacts.

[0007] Typically, the occupied contacts are connected using separate relays assigned to each contact of the ground contact unit. This creates a so-called matrix relay, which, among other things, ensures the safety-relevant requirements regarding the insulation distance. However, this is associated with high costs, as each contact has its own relay.

[0008] In this respect, the systems known from the state of the art for establishing a conductive connection are complex and / or associated with high costs.

[0009] The task is to provide a system for establishing a conductive connection with which the conductive connection can be established easily and cost-effectively.

[0010] The object is achieved according to the invention by a system for establishing a conductive connection, in particular between a vehicle contact unit and a ground contact unit. The system has a plurality of contacts, which comprise at least one protective conductor contact and power contacts, wherein the at least one protective conductor contact is hard-wired. The power contacts are assigned to at least two different potential levels, which comprise a first potential level and a second potential level. In addition, a switching unit is provided, which is assigned to at least first power contacts of the power contacts, wherein the switching unit is configured to connect at least the first power contacts selectively to the first potential level or the second potential level.

[0011] The basic idea of ​​the invention is to collectively assign several power contacts, namely the first power contacts, to a specific potential level by having the switching unit connect the corresponding power contacts, i.e., the first power contacts, either to the first potential level or the second potential level. In other words, depending on its switching position, the switching unit ensures that the first power contacts are connected either to the first potential level or the second potential level. Depending on the switching position of the switching unit, all first power contacts are therefore connected either to the first potential level or the second potential level. All first power contacts are assigned to a first power contact level.

[0012] Basically, the power contacts are the contacts through which a charging current is conducted when a motor vehicle, in particular its battery storage, is charged.

[0013] In addition, the contacts include at least one protective conductor contact, which, unlike the first power contacts, is permanently wired. In other words, the at least one protective conductor contact is permanently wired, meaning it is not connected to or assigned to the switching unit. Therefore, it is also not possible for the protective conductor contact to be connected to a potential layer, for example, as is the case in the prior art, where all contacts are connected to the switching unit.

[0014] The position of at least one protective conductor contact is therefore fixed and cannot be changed. In contrast, the positions of the contacts assigned to the first potential level or the second potential level are variable, since at least the first power contacts can be connected to either the first potential level or the second potential level.

[0015] In particular, the contacts also have second power contacts, which can also be connected via the switching unit to either the first potential level or the second potential level. All second power contacts are assigned to a second power contact level.

[0016] In particular, the switching unit is accordingly also assigned to at least the second power contacts, wherein the switching unit is configured to selectively connect the second power contacts to the first potential level or the second potential level. In principle, it can be provided that the switching unit has a first switching position in which the first power contacts are connected to the first potential level and the second power contacts are connected to the second potential level. In addition, the switching unit has a second switching position in which the first power contacts are connected to the second potential level and the second power contacts are connected to the first potential level. In this respect, the first power contacts and the second power contacts can selectively be connected to the two potential levels, i.e. the first potential level and the second potential level.This ensures that the first power contacts and the second power contacts are never connected to the same potential level.

[0017] The two potential positions can be two potential positions in a direct current or an alternating current application, for example, a positive pole and a negative pole in the case of a direct current application, or a neutral position (N) and a phase position (L1, L2, or L3), or two phase positions in the case of an alternating current application. For example, the first potential position is the neutral position (N).

[0018] Due to the hard-wired protective conductor contact and the first power contacts, which are optionally connected to the first potential level or the second potential level, the number of relays used can be reduced.

[0019] Furthermore, the at least one protective conductor contact can be configured to provide a magnetic contact, via which the connection between the vehicle contact unit and the ground contact unit can be maintained. In other words, the at least one protective conductor contact is magnetizable.

[0020] The switching unit may comprise a plurality of switches, for example two switches, which ensure that the first power contacts are connected to the first potential level or the second potential level.

[0021] The system can have a controller configured to control the switching unit, in particular the respective switching position of the switching unit. In particular, the controller controls the plurality of switches, for example jointly and / or simultaneously. One aspect provides that a plurality of power contacts are each assigned to a power contact level. The switching unit is configured to connect all power contacts of the assigned power contact level optionally to the first potential level or the second potential level. In this respect, the power contacts are switched in groups via the switching unit, since all power contacts of a corresponding power contact level are jointly connected or switched on to the first potential level or the second potential level.

[0022] In particular, all power contacts are assigned to four power contact levels, which can be connected to a neutral position and three phase positions. This can be a three-phase connection with a neutral position N and three phase positions L1, L2, and L3. However, if only two power contact levels are provided, it can be a direct current application, i.e., a DC application.

[0023] For example, the power contacts are each connected to the assigned power contact level via a contact switch. This ensures that only those power contacts of the corresponding potential level that are used for the charging process are connected. In other words, the corresponding contact switches make it possible to switch the individual power contacts to potential-free status if, in the case of a conductive connection, they are not in contact with other power contacts, for example, power contacts of the other contact unit.

[0024] In particular, the contact switches are each designed as a mirror contact, with the contact switches having a main contact and a monitoring contact that are mechanically coupled but galvanically isolated from each other. The main contact and / or the monitoring contact of the contact switch can be a switch that has an open position and a closed position. In this respect, the main contact or the monitoring contact is designed as an on / off switch. This means that the main contact or the monitoring contact can be adjusted between an open position and a closed position.Since the main contact is designed as a switch with an open position and a closed position, the main contact cannot weld when it opens if it changes from its closed position, in which the charging current flows through the main contact, to a second position that does not correspond to an open position but to a closed position with a different counterpart, for example ground. When opening, an arc can be created which would then cause the main contact to weld in the second (closed) position, making it impossible to adjust the main contact and thus the entire contact switch. This is effectively prevented if at least the main contact is designed as a switch that has an open position and a closed position.

[0025] However, it can also be provided that the main contact and / or the monitoring contact can be switched back and forth between two or more different closed positions.

[0026] In any case, the main contact and the monitoring contact are galvanically isolated from each other, so that a common (closed) circuit is not formed across the two contacts, i.e., the main contact and the monitoring contact. Therefore, the two contacts are not used to provide charging functionality in one switching position of the contact switch and sensor functionality or similar in the other switching position. Rather, the main contact and the monitoring contact are assigned to two independent circuits that are galvanically isolated from each other.

[0027] Monitoring can generally occur during the charging process, but also before and / or after a charging process, particularly in connection with a self-test. Furthermore, monitoring can occur at cyclical intervals.

[0028] If an incorrect or false switch position is detected, a warning can be issued, for example a visual warning, an acoustic warning and / or a warning via a remote signaling contact. It can also be provided that charging is not possible, i.e. no charging process can be started, if an incorrect or false switch position was detected during the check. A further aspect provides that the power contacts comprise second power contacts, third power contacts and fourth power contacts in addition to the first power contacts. The four types of power contacts are assigned to a neutral position and three phase positions. In particular, each of the four types of power contacts is assigned to a corresponding power contact level of the four power contact levels.In the case of four different power contact levels, the power contacts thus comprise first power contacts, second power contacts, third power contacts, and fourth power contacts, each of which is assigned to a corresponding power contact level, so that the different power contacts can be connected either to the neutral position or to one of the three phase positions. The corresponding system is therefore designed for use with a three-phase connection, so that the conductive connection for charging the motor vehicle, in particular its battery storage, can be established via three-phase current.

[0029] The four different power contact levels each have multiple power contacts, each of which, i.e., all power contacts of an assigned power contact level, can be connected to a different potential level via the assigned switching unit. This means that, for example, the first power contact level, i.e., the first power contacts, can be connected either to the first potential level or to the second potential level. This results, for example, in at least the second power contacts, i.e., all power contacts of the second power contact level, being connected to the correspondingly different potential level, so that the four power contact levels, i.e., the respective power contacts of these power contact levels, are each connected to different potential levels.

[0030] In principle, it can be provided that all power contact levels can be connected to all available potential levels via the switching unit, thus ensuring maximum flexibility.

[0031] In a simple system design, the switching unit can be assigned to only two power contact levels, i.e., two types of power contacts, in order to be able to switch the first power contacts and the second power contacts back and forth between the first potential level and the second potential level as required. This means that the switching unit is configured to connect the first power contacts either to the first potential level or to the second potential level, while simultaneously connecting the second power contacts to the corresponding other potential level. This ensures that the first power contacts and the second power contacts are always connected to different potential levels.

[0032] The third power contacts and the fourth power contacts can be hard-wired. Alternatively, the switching unit can also be assigned to the third power contacts and the fourth power contacts. In the simple embodiment, as already explained, only the first and second power contacts can be switched back and forth between different potential levels via the switching unit. In contrast, the third and fourth power contacts, i.e., all power contacts of the third and fourth power contact levels, are hard-wired, as is also the case for at least one protective conductor contact.

[0033] In a more flexible design of the system, however, it is possible for the third power contacts and the fourth power contacts to be connected to different potential levels, which in principle makes it possible for all types of power contacts to be connected to different potential levels.

[0034] It can be provided that one power contact of each of the four types of power contacts is arranged in a rectangle. This means that the four types of power contacts together form a rectangle in one plane, with the respective corners of the rectangle being occupied by the different types of power contacts. For example, a first power contact is provided in an upper right corner of the rectangle, whereas the second power contact is provided in the lower right corner of the rectangle. The third power contact can be provided in a lower left corner of the rectangle, whereas the fourth power contact is provided in an upper left corner of the rectangle. In this respect, the four types of power contacts together form a rectangle in the corresponding plane, which can also be referred to as the charge plane or charge area.

[0035] In particular, the at least one protective conductor contact is arranged in the center of the rectangle. Accordingly, the protective conductor contact is equidistant from the various types of power contacts arranged around it.

[0036] The rectangle formed by the four types of power contacts can be a square.

[0037] In principle, multiple protective conductor contacts can be provided. In particular, the protective conductor contacts are arranged in the center of a rectangle, the corners of which are formed by the four types of power contacts.

[0038] The contacts may be arranged in such a way that a plurality of rectangles are formed, the respective corners of which are formed by the four types of power contacts.

[0039] It can also be provided that the at least one protective conductor contact is formed by a continuous surface that provides a protective conductor plane that is interrupted by the power contacts. The corresponding protective conductor plane is also referred to as a PE plane (“PE plane”). In other words, a connection surface, for example a charging surface of the ground contact unit, can be formed largely by the protective conductor contact, wherein the corresponding power contacts are arranged in the plane formed by the protective conductor contact, in particular with an annular insulating region to electrically insulate the power contacts from the protective conductor contact, i.e., the corresponding protective conductor plane.

[0040] According to one embodiment, the switching unit consists of four switches, ten switches, or sixteen switches. The number of switches depends on how flexible the corresponding system is designed and how many power contact levels can be flexibly connected to different potential levels. In a simple design, in which only the first power contacts and the second power contacts can be flexibly connected to different potential levels, it is sufficient if four switches are provided, since one switch is provided between each power contact level and two potential levels, so that two power contact levels are each connected to two potential levels via two switches.In other words, the first power contact level is connected to the first potential level and the second potential level via two switches, and the second power contact level is connected to the first potential level and the second potential level via two switches.

[0041] With four switches, for example, the neutral position can be switched with one phase position or two phase positions can be switched with each other or the positive pole can be switched with the negative pole.

[0042] With ten switches, for example, the neutral position can be switched to any desired phase position. The direction of rotation would not be maintained.

[0043] With twelve switches, the clockwise rotation field can also be maintained.

[0044] With 16 switches, the phase position used for a single-phase transmission can also be freely selected, and a parallel transmission of one phase position to two power contacts can optionally be realized.

[0045] In particular, the switches are each designed as a mirror contact and have a main contact and a monitoring contact that are mechanically coupled but galvanically isolated from each other. The main contact and / or the monitoring contact (each) can be a switch that has an open and a closed position. In this respect, the main contact or the monitoring contact is designed as an on / off switch. This means that the main contact or the monitoring contact can be adjusted between an open and a closed position.Because the main contact is designed as a switch with an open position and a closed position, the main contact cannot weld upon opening if it moves from its closed position, in which the charging current flows through the main contact, to a second position that does not correspond to an open position, but rather to a closed position with a different counterpart, such as ground. However, it can also be provided that the main contact and / or the monitoring contact can be switched back and forth between two or more different closed positions.

[0046] In any case, the main contact and the monitoring contact are galvanically isolated from each other, so that a common (closed) circuit is not formed across the two contacts, i.e., the main contact and the monitoring contact. The two contacts are therefore not used to provide charging functionality in one switching position and sensor functionality or something similar in the other switching position. Rather, the main contact and the monitoring contact are assigned to two independent circuits that are galvanically isolated from each other.

[0047] Monitoring can generally occur during the charging process, but also before and / or after a charging process, particularly in connection with a self-test. Furthermore, monitoring can occur at cyclical intervals.

[0048] If an incorrect or faulty switch position is detected, a warning can be issued, for example, a visual warning, an acoustic warning, and / or a warning via a remote contact. It can also be specified that charging is not possible, i.e., no charging process can be started, if an incorrect or faulty switch position is detected during the check.

[0049] A further aspect provides that the system has an input interface that is connected at least to the first potential level and the second potential level, in particular to all potential levels, wherein the system has an output interface that is connected to the power contacts. The switching unit is arranged between the input interface and the output interface. In this respect, the available potential levels are connected to the input interface of the system via the switching unit. Depending on the switching position, the switching unit switches the corresponding power contacts to the corresponding potential levels, thereby ensuring that all power contacts of a corresponding power contact level, i.e. all power contacts of the same type, are connected to a defined potential level. In addition, the contacts can also comprise at least one control contact for detecting contact.The at least one control contact is formed separately from the power contacts and separately from the at least one protective conductor contact. The control contact can be used to determine whether contact is established. In particular, it is also possible to use the control contact, in particular two control contacts, to determine the orientation with which the vehicle contact unit and the ground contact unit have formed the conductive connection, thereby connecting the corresponding power contacts to potential layers via the switching unit.

[0050] Furthermore, the at least one control contact can also be configured to provide a magnetic contact, via which the connection between the vehicle contact unit and the ground contact unit can be maintained. In other words, the at least one control contact is magnetizable.

[0051] In principle, the magnetic contact, for example the magnetizable control contact, can ensure that the vehicle contact unit and the ground contact unit form the conductive connection in a defined manner, in particular via at least two magnetic contacts that are provided on both the vehicle contact unit and the ground contact unit and interact. The at least two magnetic contacts can be provided via two protective conductor contacts, two control contacts, or via one protective conductor contact and one control contact.

[0052] At least one control contact can be hard-wired.

[0053] According to a further aspect, the system comprises a vehicle contact unit comprising the plurality of contacts, and / or a charging infrastructure with a ground contact unit having a plate-shaped base body with a charging surface on which the plurality of contacts are arranged and against which the vehicle contact unit can come into contact. In this respect, the system can be provided both on the vehicle side and on the charging infrastructure side. In other words, the power contacts can be connected to the respective potential position on both the vehicle side and the charging infrastructure side. In principle, it can also be provided that one power contact of each of the four types of power contacts is arranged in the corners of a common rectangle, in particular on the charging surface of the base body. In other words, a different type of power contact is provided in each corner of the rectangle. The rectangle can be a square.

[0054] The at least one control contact can be arranged in the center of the rectangle. It can therefore be provided that, instead of the at least one protective conductor contact, the at least one control contact is arranged in the center of the rectangle. This can be the case, in particular, if the protective conductor contact is designed as a protective conductor plane that is penetrated by both the power contacts and the at least one control contact.

[0055] In any case, a magnetic contact can be provided in the center of the respective rectangle. This ensures that defined contact points are provided for establishing the conductive connection.

[0056] A centered square pattern can therefore be provided for the power contacts. This is more advantageous than a hexagonal pattern because it reduces the number of relays required to ensure transmission at each contact position of the vehicle contact unit on the ground contact unit.

[0057] To enable the connection between the vehicle contact unit and the ground contact unit ("snap-in") at two adjacent protective conductor contacts in the centered-square pattern, it can be provided that the power contacts assigned to the neutral position, for example, the first power contacts, are designed to be interchangeable with at least one phase position. This ensures that the position of the power contacts assigned to the neutral position matches both connection positions ("snap-in positions").

[0058] Ultimately, the maximum required relative rotation of the vehicle contact unit can be limited to 180°, allowing the vehicle contact unit to be designed with a correspondingly less complex design compared to a vehicle contact unit requiring a 360° relative rotation. Further advantages and features of the invention will become apparent from the following descriptions and drawings, to which reference is made. In the drawings:

[0059] Figure 1 is a schematic overview of a vehicle battery charging system with a system according to the invention,

[0060] Figure 2 is a schematic plan view of a ground contact unit of an electrical charging infrastructure of a system according to the invention according to an embodiment,

[0061] Figure 3 is a schematic plan view of a ground contact unit of an electrical charging infrastructure of a system according to the invention according to a further embodiment,

[0062] Figure 4 is a schematic representation of the electrical connection of the power contacts of the system according to a first embodiment of the system according to the invention,

[0063] Figure 5 is a schematic representation of the electrical connection of the power contacts of the system according to the invention according to a second embodiment of the system according to the invention, and

[0064] Figure 6 is a schematic representation of the electrical interconnection of the power contacts of the system according to the invention according to a third embodiment of the system according to the invention.

[0065] Figure 1 shows a vehicle battery charging system 10, which includes an electrical charging infrastructure 12 and an at least partially electrically powered vehicle 14.

[0066] The vehicle 14 has a vehicle contact unit 16, which can establish a conductive connection with a ground contact unit 18 of the electrical charging infrastructure 12 in order to charge a battery of the vehicle 14 (not shown in detail here).

[0067] The electrical charging infrastructure 12 has a monitoring circuit 20 and a shutdown device 22, which can be fully integrated into the ground contact unit 18. Alternatively, the monitoring circuit 20 can be arranged partially in the ground contact unit 18 and partially in a monitoring unit 24 that is designed separately from the ground contact unit 18. Furthermore, it can be provided that the monitoring circuit 20 and the shutdown device 22 are both arranged entirely in the separately designed monitoring unit 24.

[0068] The separately formed monitoring unit 24 is therefore optional, which is why it is shown in dashed lines in Figure 1. Likewise, the monitoring circuit 20 and the shutdown device 22 are shown in dashed lines, since their respective positions may vary depending on the design.

[0069] In any case, the separately formed monitoring unit 24 would be electrically connected to the ground contact unit 18, as indicated in Figure 1.

[0070] Alternatively, it can also be provided that the monitoring circuit 20 and / or the shutdown device 22 are provided on the vehicle side, as will be explained below.

[0071] In principle, both the charging infrastructure 12 and the vehicle contact unit 16 can have a system 25 for establishing a conductive connection, as will be explained below with reference to Figures 2 to 6. In particular, the corresponding system 25 is provided to form a conductive connection between the vehicle contact unit 16 and the ground contact unit 18.

[0072] The monitoring circuit 20 and the shutdown device 22, in particular also the separately designed monitoring unit 24, can therefore be part of the corresponding system 25.

[0073] In Figure 2, the ground contact unit 18 is shown in a plan view according to an embodiment variant.

[0074] The ground contact unit comprises a plate-shaped base body 26 having a loading surface 28, which is exposed prior to the establishment of the conductive connection. The loading surface 28 is an exposed loading surface when contact is established between the ground contact unit 18 and the vehicle contact unit. However, the loading surface can generally be covered by a cover (not shown here) when not in use, so that the loading surface 28 is protected from environmental influences, among other things. The corresponding cover can be removed manually or automatically, making the loading surface 28 freely accessible.

[0075] On the loading surface 28, several contacts 30 are provided, which are different contact types.

[0076] In any case, the contacts 30 include, among other things, a plurality of power contacts 32, which are used for charging the battery of the vehicle 14. When charging the vehicle 14, in particular when charging the battery of the vehicle 14, a charging current flows through at least some of the power contacts 32. For this purpose, the corresponding power contacts 32 are generally assigned to at least one potential layer 34, as will be explained below.

[0077] In the illustrated embodiment, the ground contact unit 18 is designed as a three-phase ground contact unit 18, which means that the individual power contacts 32 can be assigned to four different potential positions 34, namely the neutral position N and the phase positions L1, L2, and L3. The neutral position N is also referred to as the neutral conductor. These are therefore the corresponding potential positions N, P1, P2, and P3.

[0078] As can be seen from Figure 2, a corresponding three-phase connection 35 is therefore provided.

[0079] The power contacts 32 are therefore divided into power contact levels P1, P2, P3, P4 or assigned to the power contact levels, which are also referred to as “pin layers”.

[0080] In this respect, there are four types of power contacts 32, namely first power contacts 32-1, which are assigned to the first power contact level P1, second power contacts 32-2, which are assigned to the second power contact level P2, third power contacts 32-3, which are assigned to the third power contact level P3, and fourth power contacts 32-4, which are assigned to the fourth power contact level P4. This is clearly shown in Figures 4 to 6, which will be referred to below when describing the interconnection of the power contacts 32.

[0081] It is already clear from Figure 2 that the four types of power contacts 32 are arranged in a rectangle, in particular in a rectangle on the loading surface 28.

[0082] In the illustrated embodiment, the first power contact 32-1 is provided in an upper right corner of the rectangle, whereas the second power contact 32-2 is provided in the lower right corner of the rectangle. The third power contact 32-3 is provided in a lower left corner of the rectangle, whereas the fourth power contact 32-4 is provided in an upper left corner of the rectangle. Thus, the four types of power contacts 32 together form the rectangle in the corresponding plane.

[0083] In addition to the power contacts 32, the contacts 30 also include at least one protective conductor contact 36, i.e., a PE contact. In the embodiment shown in Figure 2, several protective conductor contacts 36 are provided, which are arranged separately and insulated from the power contacts 32 on the charging surface 28.

[0084] Furthermore, it can be seen from the embodiment shown in Figure 2 that the protective conductor contacts 36 are each arranged in the center of the rectangles.

[0085] The rectangles are designed, in particular, as squares, so that the protective conductor contact 36 arranged in the center has the same distance from each of the power contacts 32. In this respect, a centered square pattern is provided in Figure 2 with regard to the power contacts 32 and the protective conductor contacts 36.

[0086] As an alternative to the embodiment shown in Figure 2, the ground contact unit 18 can have a continuous protective conductor plane 38, which accordingly essentially corresponds to the area of ​​the base body 26 or the base area of ​​the loading area 28, as shown in Figure 3.

[0087] The individual power contacts 32 then break through the corresponding protective conductor level 38, wherein the power contacts 32 are each arranged insulated from the protective conductor level 38, for example by annular insulating sections 39 which insulate the power contacts 32 from the protective conductor level 38.

[0088] In addition, the contacts 30 can in principle comprise at least one control contact 40, which is used to carry out a contact check, i.e. to determine whether the vehicle contact unit 16 contacts the ground contact unit 18.

[0089] In the embodiment shown in Figures 2 and 3, several control contacts 40 are provided.

[0090] In principle, the control contacts 40 and / or the protective conductor contacts 36 can be designed as magnetic contacts 41, i.e., they can be magnetizable. This makes it possible for the conductive connection established to occur only in a defined manner, namely such that at least one magnetic contact 41 of the vehicle contact unit 16 couples with a magnetic contact 41 of the ground contact unit 18.

[0091] The defined connection is ensured because the magnetic contacts 41 are each arranged centrally in an associated rectangle, in particular a square, in whose corners a type of power contact 32 is provided, i.e., a first power contact 32-1, a second power contact 32-2, a third power contact 32-3, and a fourth power contact 32-4. Consequently, either a protective conductor contact 36 or a control contact 40 can be provided in the center of the respective rectangle.

[0092] In particular, the contacts 30 are generally distributed on the loading surface 28 and arranged relative to one another in such a way that at least two control contacts 40 are located in a contact area A of the loading surface 28, which is covered by the vehicle contact unit 16 when the conductive connection is established. The orientation in which the ground contact unit 18 has been contacted can then be determined via the two control contacts 40 in the contact area A.

[0093] By knowing the geometry of the vehicle contact unit 16, it is also possible to determine which contacts 30 have been contacted, i.e. which of the contacts 30 belong to the subset of the contacted contacts 30 that are located in the contact area A of the loading area 28.

[0094] Based on this information, the corresponding power contacts 32 can then be switched to assign a specific potential position 34 to the different power contact levels P1 to P4.

[0095] Figure 4 shows, using an example of a variant, how the power contacts 32 are connected. This generally applies to the connection of the power contacts 32 of the vehicle contact unit 16 as well as to the connection of the power contacts 32 of the ground contact unit 18.

[0096] The individual power contacts 32 can each be connected to a corresponding power contact level P1 to P4 via contact switches 42, so that the individual power contacts 32 can be switched on or off via the contact switches 42. This makes it possible to only switch on the power contacts 32 of a corresponding potential level 34 that are located in contact area A, so that exposed power contacts 32 are potential-free.

[0097] Figure 4 further shows that the respective contact switches 42 are designed as mirror contacts, so that the contact switches 42 have a main contact 44 and a monitoring contact 46. Due to the mirror contact design, it is ensured that the main contact 44, which functions as a relay, is mechanically coupled to the monitoring contact 46, so that the respective switching positions of the main contact 44 and the monitoring contact 46 are mutually dependent or interdependent. However, the main contact 44 and the monitoring contact 46 are galvanically isolated from one another, so that both contacts 44, 46 are not assigned to a common circuit. Rather, both contacts 44, 46 are assigned to different circuits that are independent of one another and also galvanically isolated from one another.

[0098] In this respect, there is no switching position of the contact switch 42 in which a closed circuit is formed in which both the main contact 44 and the monitoring contact 46 are integrated, so that a current could flow through both contacts 44, 46 of the contact switch 42. The main contact 44 is, as shown in Figure 4, designed as a normally open contact, i.e., an NO contact, whereas the monitoring contact 46 is designed as a normally closed contact, i.e., an NC contact.

[0099] Figure 4 therefore shows the initial position of the contact switches 42, since the contact switches 42 are each in a corresponding switching position in which the main contacts 44 are open, so that no current flow to the power contacts 32 is possible. In other words, the power contacts 32 are not connected to any potential layer 34, thus ensuring contact protection.

[0100] The corresponding contact protection can be monitored by the monitoring circuit 20 monitoring, among other things, the respective switching position of the monitoring contacts 46 of the corresponding contact switches 42.

[0101] The monitoring takes place at least at the contact switches 42 which are assigned to power contacts 32 which are not contacted when the conductive connection between the ground contact unit 18 and the vehicle contact unit 16 is present, i.e. at power contacts 32 which do not belong to the subset of the plurality of contacts 30 of the ground contact unit 18 which are contacted.

[0102] The monitoring circuit 20 controls the shutdown device 22 if the monitoring circuit 20 detects that an incorrect switching position is present at one of the monitoring contacts 46, which results in one of the main contacts 44 also having an incorrect switching position, since the monitoring contacts 46 and the main contacts 44 are mechanically coupled to one another.

[0103] The incorrect switching position corresponds to an open switching position of the monitoring contact 46, which is accompanied by a closed switching position of the associated main contact 44, which would mean that a freely accessible power contact 32 would be assigned to a potential position 34, although this is not desired since the corresponding power contact 32 is exposed.

[0104] The shutdown device 22 changes its state due to the control by the monitoring circuit 20, which can be accompanied by a complete shutdown or complete disconnection. In other words, the shutdown device 22 can be designed such that a galvanic isolation of all power contacts 32 is performed, whereby all power contacts 32 would be switched to a potential-free state.

[0105] In this respect, the shutdown device 22 can comprise a main switch 51a or a contactor, which carries out the corresponding galvanic isolation.

[0106] Alternatively, the shutdown device 22 can comprise an electronic power control 51b, which is designed to reduce the voltage associated with the potential level 34 accordingly, so that the applied voltage is limited to a non-critical value, thereby ensuring contact protection. In other words, the voltage applied to the respective power contact 32, which is coupled to the incorrectly closed main contact 44 of the contact switch 42, is so low that no danger exists.

[0107] In addition, the system 25 comprises an input interface 52 which is assigned to the connection 35 and the potential levels 34.

[0108] Furthermore, the system 25 comprises an output interface 54 which is connected to the power contacts 32, in particular the power contact levels P1 to P4.

[0109] The system 25 also includes a switching unit 56, which is provided between the input interface 52 and the output interface 54.

[0110] The switching unit 56 has a plurality of switches 58 which are basically designed to selectively switch the power contacts 32, each belonging to a power contact level P1 to P4, together between a first potential position 34 and a second potential position 34, for example between the neutral position N and the first phase L1.

[0111] The switching unit 56 ensures, for example, that at least the first power contacts 32-1, i.e. the power contacts 32 assigned to the first power contact level P1, can be connected optionally to the first potential position 34 (neutral position N) or to the second potential position 34 (first phase position L1).

[0112] In the embodiment shown in Figure 4, the system 25 is designed such that all power contact levels P1 to P4, i.e. the respective power contacts 32 in groups, can be selectively connected to each of the existing potential levels 34, so that maximum flexibility is ensured.

[0113] The section shown in Figure 4 shows the four different types of power contacts 32, i.e., a first power contact 32-1, a second power contact 32-2, a third power contact 32-3, and a fourth power contact 32-4. In other words, power contacts 32 are shown that are assigned to the first power contact level P1, the second power contact level P2, the third power contact level P3, and the fourth power contact level P4, or are connected to them via the corresponding contact switches 42.

[0114] In principle, the switches 58 - like the contact switches 42 - can also be designed as mirror contacts, so that the switches 58 have a main contact 60 and a monitoring contact 62.

[0115] In contrast to the power contacts 32, the at least one protective conductor contact 36 is hard-wired, which means that the at least one protective conductor contact 36 or the protective conductor level 38 is fixed, i.e. cannot be connected to one of the potential layers 34.

[0116] This also applies to the control contacts 40, which are also hard-wired.

[0117] In Figure 5, however, a simplified embodiment of the system 25 with regard to the interconnection of the power contacts 32 is shown.

[0118] The power contacts 32 of the third power contact level P3 and those of the fourth power contact level P4, i.e. the third power contacts 32-3 and the fourth power contacts 32-4, are hard-wired. Only the power contacts 32 of the first power contact level P1 and those of the second power contact level P2, i.e. the first power contacts 32-1 and the second power contacts 32-2, can be selectively switched back and forth between two potential positions 34 via the switching unit 56. In the present case, these are the neutral position N and the first phase position L1. According to the embodiment shown, the switching unit 56 comprises four switches 58, with two switches 58 being assigned to the first power contact level P1 and two further switches 58 to the second power contact level P2.The first power contact level P1 and the second power contact level P2 are each assigned via a switch 58 to the first potential position 34, which in this case is formed by the neutral position N, and via a switch 58 to the second potential position 34, which in this case is formed by the first phase position L1.

[0119] In this respect, it is possible to switch the first power contacts 32-1 selectively back and forth between the neutral position N and the first phase position L1, while at the same time the second power contacts 32-2 are selectively connected to the neutral position N or the first phase position L1.

[0120] The switching unit 56 is designed such that the individual switches 58 are controlled such that each of the power contact levels P1 to P4 is assigned precisely to a potential level 34. This prevents, among other things, the first power contact level P1 and the second power contact level P2 from both being connected to a common potential level 34.

[0121] Figure 6 shows a further embodiment in which the switching unit 56 comprises a total of ten switches 58.

[0122] The first power contacts 32-1 , i.e. the power contacts 32 of the first power contact level P1 , can be connected to each of the four potential levels 34 via the switching unit 56, since the first power contact level P1 is assigned four switches 58, each of which is assigned to one of the four potential levels 34, i.e. the neutral position N and the three phase levels L1, L2 and L3.

[0123] In contrast, only two switches 58 are provided for each of the three further power contact levels P2 to P4, so that the corresponding power contacts 32 of the second power contact level P2 to the fourth power contact level P4 can only be switched back and forth between two different potential levels 34, one of which is always the neutral level N. In the embodiment shown in Figure 6, it is therefore possible for the neutral level N to be switched at each of the corners of the corresponding rectangle in the contacting area A.

[0124] In principle, the switching unit 56 is designed to switch the different power contacts 32, i.e., the respective types of power contacts 32, in groups. In this respect, all power contacts 32 belonging to a power contact level P1-P4 are connected together to a specific potential level 34 via the switching unit 56, so that the corresponding power contacts 32 are connected to the selected potential level 34, i.e., for example, all first power contacts 32-1, all second power contacts 32-2, all third power contacts 32-3, or all fourth power contacts 32-4.

Claims

Patent claims 1. System (25) for establishing a conductive connection, wherein the system (25) has several contacts (30) comprising at least one protective conductor contact (36) and power contacts (32), wherein the at least one protective conductor contact (36) is permanently wired, wherein the power contacts (32) are assigned to at least two different potential levels (34), comprising a first potential level (34) and a second potential level (34), and wherein a switching unit (56) is provided, which is assigned to at least the first power contacts (32-1) of the power contacts (32), wherein the switching unit (56) is configured to selectively connect at least the first power contacts (32-1) to either the first potential level (34) or the second potential level (34).

2. System (25) according to claim 1, characterized in that several power contacts (32) are each assigned to a power contact level (P1, P2, P3, P4), wherein the switching unit (56) is configured to connect all power contacts (32) of the assigned power contact level (P1-P4) selectively to the first potential level (34) or the second potential level (34), in particular wherein the power contacts (32) are assigned to four power contact levels (P1-P4) which can be connected to a neutral position (N) and three phase positions (L1, L2, L3).

3. System (25) according to claim 2, characterized in that the power contacts (32) are each connected to the associated power contact level (P1-P4) via a contact switch (42), in particular wherein the contact switches (42) are each designed as mirror contacts and have a main contact (44) and a monitoring contact (46) which are mechanically coupled but are galvanically isolated from each other.

4. System (25) according to one of the preceding claims, characterized in that the power contacts (32) comprise, in addition to the first power contacts (32-1), second power contacts (32-2), third power contacts (32-3) and fourth power contacts (32-4), wherein the four types of power contacts (32) are assigned to a neutral position (N) and three phase positions (L1-L3), in particular wherein each of the four types of Performance contacts (32) are assigned to a corresponding performance contact level (P1-P4) of the four performance contact levels (P1-P4).

5. System (25) according to claim 4, characterized in that the third power contacts (32-3) and the fourth power contacts (32-4) are permanently wired or that the switching unit (56) is also assigned to the third power contacts (32-3) and the fourth power contacts (32-4).

6. System (25) according to claim 4 or 5, characterized in that one power contact (32) of each of the four types of power contacts (32) is arranged in a rectangle, in particular wherein the at least one protective conductor contact (36) is arranged in the center of the rectangle or wherein the at least one protective conductor contact (36) is formed by a continuous surface that provides a protective conductor plane (38) which is interrupted by the power contacts (32).

7. System (25) according to one of the preceding claims, characterized in that the switching unit (56) consists of four switches (58), ten switches (58) or sixteen switches (58), in particular wherein the switches (58) are each designed as mirror contacts and have a main contact (60) and a monitoring contact (62) which are mechanically coupled but galvanically isolated from each other.

8. System (25) according to one of the preceding claims, characterized in that the system (25) has an input interface (52) which is connected to the first potential level (34) and the second potential level (34), wherein the system (25) has an output interface (54) which is connected to the power contacts (32), and wherein the switching unit (56) is arranged between the input interface (52) and the output interface (54).

9. System (25) according to one of the preceding claims, characterized in that the contacts (30) also comprise at least one control contact (40) for detecting a contacting, wherein the at least one control contact (40) is designed separately from the power contacts (32) and separately from the at least one protective conductor contact (36).

10. System (25) according to one of the preceding claims, characterized in that the system (25) comprises a vehicle contact unit (16) which comprising several contacts (30), and / or a charging infrastructure (12) with a ground contact unit (18) comprising a plate-shaped base body (26) with a loading surface (28) on which the several contacts (30) are arranged and on which the vehicle contact unit (16) can be attached.

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