The present invention relates to an electrical connector, configured to connect two electrical devices with each other using at least two connection terminals. The invention also relates to an electrical system comprising such an electrical connector, as well as a railway vehicle comprising such an electrical system.
In the field of power converters, particularly in the field of on-board power converters in rail vehicles, it is known to have electrical devices connected to each other to ensure the conversion of electrical energy received from an external source, such as a catenary, into energy usable by other equipment in the rail vehicle. Some electrical equipment, e.g. on the roof of the rail vehicle, can be exposed to the weather without requiring special protection, while other, more sensitive equipment needs special protection against water and/or dust. More generally, such electrical equipment may be subject to various protective measures against water and/or dust. In order to facilitate access to these electrical devices, especially during maintenance operations, a modular structure of the power converters is preferred. The electrical devices are then housed in a number of different compartments, each compartment offering a level of protection appropriate to the electrical devices housed therein, and the electrical devices are separated by watertight bulkheads while being jointly electrically connected to each other, this connection being reversible.
It is known to use connectors comprising a conductive rod embedded in a block of rigid insulating material, such as a polymeric plastic. The conductive rod is connected to the electrical equipment on both sides of a bulkhead and has a cross-section adapted to the electrical current carried. The block of insulation material is tightly mounted on the wall by means of sealing elements.
However, electrical converters nowadays operate at higher frequencies, for example above 10 kHz, in order to limit energy losses during conversion. In these so-called "medium-frequency" ranges between 10 kHz and 150 kHz, electrical conductors are subject to a so-called "skin effect", i.e. electrons only pass through a surface layer of the conductors, which reduces the effective cross-section of the electrical conductors, causes heating, and degrades the performance of the power converters. Moreover, when two separate conductors are placed close to each other and carry the same current in the same direction, an effect known as the

"proximity effect" is added to the skin effect, which limits the useful cross-section of the electrical conductors even more.
To limit the skin effect, it is known to use cables with several twisted wires of small cross-section that are insulated from each other. Such cables are sometimes called "Litz wires". To pass through a leaktight bulkhead, the ends of the Litz wires are each crimped onto a specific end cap, the leaktightness of the bulkhead crossing being ensured by an additional end cap mounted on a cable gland. These end caps are complex in structure and relatively fragile, while the assembly and disassembly of such a system, for example during maintenance, is time-consuming, and Litz wires are also more bulky and fragile than conventional cables.
FR-1 423 398-A describes, for example, welding machine electrodes which comprise conductive strips, which are associated in pairs and which each comprise a central portion and connection lugs distributed on opposite sides of the central portion. The central portions are superimposed and are separated by insulating sheets. The electrodes are exposed, with no special sealing device provided.
These problems are specifically addressed by the invention, which provides a robust electrical connector that allows a sealed wall passage, easy connection and disconnection with terminals of electrical devices, while limiting skin and proximity effects when operating at certain frequencies.
To this end, the invention relates to an electrical system, comprising a first electrical device and a second electrical device separated by a bulkhead parallel to a transverse plane, each of the first and second devices comprising at least two connection terminals, the first electrical device being electrically connected to the second electrical device via an electrical connector, wherein the electrical connector comprises a pair of plates, comprising a first electrically conductive plate and a second electrically conductive plate. Each plate has a central portion and two connection lugs. The connection lugs of each plate extend longitudinally in line with the central portion from opposite edges of the central portion, the opposite edges being portions of the contour of the central portion, located on either side of the transverse plane, the connection lugs of each plate being laterally offset from each other. The first and second plates are stacked on top of each other, with the central portions superimposed and separated by a gap. The connection lugs of the first and second plates are, on the side of each of said opposite edges, laterally

offset from each other. The electrical connector further comprises an insulating structure comprising an interlayer of electrically insulating material housed in a gap between the central portions of the first and second plates.
According to the invention, the electrical connector is configured to mate with sealing members so as to pass through the bulkhead in a sealed manner, two of the terminals of the first device being connected to two of the connection terminals of the electrical connector located on one of the sides of the corresponding bulkhead, while two of the terminals of the second device are connected to two of the connection terminals of the electrical connector located on the other of the sides of that bulkhead.
With the invention, skin effects are reduced thanks to the conductive elements in a plate. The connection lugs can be connected to any type of cable or connection bar, not limited to Litz cables. Assembly and disassembly are easy. The crossed configuration of the connection lugs of a conductor element, combined with the alternating configuration of the connection lugs of two consecutive conductor elements, minimises proximity effects, reduces the inductance of the connection and thus reduces electrical losses.
Several pairs of conductive elements are provided depending on the electrical power flowing through the electrical connector.
According to advantageous but not mandatory aspects of the invention, such an electrical system may incorporate one or more of the following features, taken in any combination that is technically feasible:
the electrical connector comprises at least a second pair of plates, comprising a third plate and a fourth electrically conductive plate, each plate of the second pair having a central portion and two connection lugs. The connection lugs of each plate extend longitudinally from opposite edges of the central portion and are laterally offset from each other. The third and fourth plates are stacked on top of each other, with the central portions superimposed and separated by a gap. The connection lugs of the third and fourth plates are, on the side of each of the opposite edges, laterally offset from each other. All the plates of the electrical connector are stacked on top of each other, with all the central portions overlapping, while the insulation structure comprises intermediate layers of electrically insulating material accommodated in each gap between two immediately

adjacent central portions, and that for two immediately adjacent plates, the connection lugs located on the side of one of the opposite edges are laterally offset from each other. - All the connection lugs located on the side of one of the opposite edges and belonging to plates separated from each other by an odd number of plates are superimposed and are electrically connected to each other by connecting members.
The insulating structure comprises a body which jointly receives the central portions of each plate, the body being made by overmoulding the central portions of the plates in an electrically insulating material, with only the connection lugs projecting from the body.
The insulation structure is made of a single piece of polymer material. The insulation structure is configured to mate with sealing members to sealingly separate the opposite-edge side connection lugs from each other. The plates have an identical structure to each other. The plates are made of metal with a thickness of between 0.1 mm and 5 mm, preferably between 0.5 mm and 2 mm, the metal preferably being chosen from copper and its alloys or aluminium and its alloys. According to another aspect, the invention relates to a railway vehicle, which comprises an electrical system as described above.
The invention will be better understood and advantages beyond these will emerge more clearly in light of the following description of an embodiment of an electrical connector, electricity treatment subassembly, and railway vehicle comprising such an electricity treatment subassembly given solely by way of example and made with reference to the accompanying drawings, in which:
[Fig 1] Figure 1 is a schematic view of a device comprising an electrical
system with an electrical connector according to the invention;
[Fig. 2] Figure 2 is a perspective view of an electrical connector, in
accordance with the invention, belonging to the electrical system of Figure
1, with some elements omitted for ease of reading, and
[Fig. 3] Figure 3 is a schematic view of a detail of the device of Figure 1,
marked with a frame III in Figure 1, comprising the electrical connector of
Figure 2.

Figure 1 shows an electrical system 1. The electrical system 1 can be integrated into a railway vehicle. The electrical system 1 comprises an electrical converter 2, which is an example of an electrical system. The electrical converter 2 is designed to convert electrical energy collected from an external source, for example a catenary, into electrical energy for use by the other electrical equipment in the system 1.
The converter 2 comprises a first electrical circuit 4, a second electrical circuit 6 and a transformer 8. The first circuit 4, second circuit 6 and transformer 8 are shown schematically in Figure 1.
The first and second circuits 4 and 6 each have two connection terminals, while the transformer 8 comprises two coils located around a ferromagnetic core, each of the coils comprising two connection terminals. One of the two coils of the transformer 8 is connected to the first circuit 4 by an electrical connector 10, the other coil of the transformer 8 being connected to the second circuit 6 by another electrical connector 10.
It is understood that each of the connectors 10 is jointly connected to the two terminals of one of the first or second electrical circuits 4 or 6 on the one hand, and to the two terminals of one of the respective coils of the transformer 8 on the other hand. In Figure 1, the electrical connectors 10 are shown schematically. In particular, the connection of the terminals of the first and second circuits 4 and 6 is not detailed in Figure 1. The connection of the terminals of the first and second circuits 4 and 6 can be deduced from the structure of the electrical connectors 10, detailed later in this description, in particular with the aid of Figures 2 and 3.
The first or second electrical circuit 4 or 6 is an example of a first electrical device comprising at least two terminals, while the transformer 8 is an example of a second electrical device comprising at least two terminals.
The first circuit 4, the transformer 8 and the second circuit 6 are each subject to different environmental protection requirements. These protection requirements may relate to water and/or dust and are often indicated in the form of a standardised protection index, known as an "IP code", for example defined by the I EC 60529 standard. The IP code is usually accompanied by two numbers, one for protection against solids and one for protection against water.

Thus, in the example shown in Figure 1 for illustrative purposes, the first and second circuits 4 and 6 are subject to a protection code of IP65, while the transformer 8 is subject to a protection code of IP20.
To ensure a level of protection in accordance with the required IP codes, the first circuit 4, second circuit 6 and transformer 8 are each located in respective zones Z1, Z3 and Z2 which delimit volumes in which the corresponding IP codes are maintained, by external means not detailed.
To maintain adequate levels of protection in each of the zones Z1 to Z3, Z1, zones Z2 and Z3 are separated by leaktight bulkheads. Zones Z2 and Z3 are separated by a bulkhead 56, while zones Z1 and Z2 are separated by a bulkhead 57. The bulkheads 56 and 57 are shown schematically as mixed lines in Figures 1 and 3.
Each of the connectors 10 is designed to be connected, through one of the bulkheads 56 or 57, to two respective electrical devices each having at least two respective terminals. Each of the connectors 10 thus comprises an insulation structure 58, which cooperates with sealing and/or fixing members to ensure the mechanical retention of the electrical connector 10 with respect to the respective bulkhead 56 or 57. The sealing and/or fixing members are not shown in the figures.
For example, the at least two terminals of said electrical devices correspond to polarities, or phases in case of an AC signal, the polarities being related to the design and operation of said electrical devices.
In the example shown, one of the connectors 10, located on the left in Figure 1, connects the first circuit 4, located in the zone Z1, to a primary winding of the transformer 8 located in the zone Z2, while the other of the connectors 10, located on the right in Figure 1, connects a secondary winding of the transformer 8, located in the zone Z2, to the second circuit 6 located in the zone Z3. One of the connectors 10 in the example thus connects two terminals of the first circuit 4 to the two corresponding polarities of the primary winding of the transformer 8, while the other connector 10 connects two terminals of the second circuit 6 to the two corresponding polarities of the secondary winding of the transformer 8.
Each connector 10 comprises four connection terminals, referenced 46, 48, 50 and 52, which are integral with the insulation structure 58.
The internal structure of the electrical connector 10 is detailed in the following.

The two electrical connectors 10 shown in Figure 1 have the same structure and function in the same way. The following description is made with reference to the right-hand connector 10 in Figure 1.
Terminals 46 and 48 are each connected to a respective terminal of the second circuit 6, while terminals 50 and 52 are each connected to a respective terminal of the secondary winding of the transformer 8.
In other words, two of the terminals of the second circuit 6 are connected to the two connection terminals 46 and 48 of the connector 10 which are located on a same first side of the bulkhead 56, while the two terminals of the transformer 8 are connected to the two connection terminals 50 and 52 of the connector 10 which are located on a same second side of the bulkhead 56.
Figures 2 and 3 show in more detail a connector 10 according to certain embodiments.
The connector 10 comprises at least two electrically conductive plates. Advantageously, the connector 10 comprises at least four electrically conductive plates, the plates being "crossed", i.e. between two plates connected to the same terminals, another plate connected to the other terminals is inserted. Crossing the plates reduces the proximity effects between the plates and thus increases the overall efficiency of the connector 10, for reasons that are detailed later in this description.
In this illustrative example, the electrical connector 10 has four electrically conductive plates referenced 12, 14, 16 and 18. However, alternatively, the number of plates may be different. It is therefore understood that everything described here is applicable to these embodiments.
The plates 12 to 18 are parallel to each other and to a longitudinal geometric plane P1.
Plates 12 and 14 are adjacent to each other, i.e. consecutive to each other, and define a first pair of plates 20. Plate 12 is thus a first plate of the first pair 20, while plate 14 is a second plate of the first pair 20. Similarly, plates 16 and 18 are consecutive to each other and define a second pair of plates 22. Plate 16 is thus a first plate of the second pair 22, while plate 18 is a second plate of the second pair 22.
The plates 12 to 18 are made of an electrically conductive material.

Advantageously, the plates 12 to 18 are made of metal, such as copper or aluminium, or an alloy thereof, or any other suitable material.
Advantageously, the plates 12 to 18 have an identical structure to each other.
Each plate 12 to 18 has a central portion 24 which is flat and defines a centre 26. For each central portion 24, an axis A24 is defined as an axis orthogonal to the central portion 24 and passing through the centre 26. The axis A24 is thus orthogonal to the longitudinal plane P1.
Each central portion 24 has a first edge 28 and a second edge 30, opposite the first edge 28. In the example shown, the central portion 24 is rectangular in shape and also has side edges 31. The side edges 31 are opposite and parallel to each other, while the first and second edges 28 and 30 are also parallel to each other.
A geometric median plane P2 is defined as a plane orthogonal to the longitudinal plane P1, passing through the centre 26 and being orthogonal to the edges 28 and 30.
A transverse geometric plane P3 is also defined as a plane passing through the centre 26 and being jointly orthogonal to the planes P1 and P2. The plane P3 is thus orthogonal to the side edges 31.
Alternatively, not shown, the central portion 24 of each plate 12 to 18 may be circular or elliptical in shape. In such a case, the opposite edges defined above refer to portions of the contour of the central portion, located on either side of the transverse plane P3 and cut by the median plane P2. In a similar way, the lateral edges designate the portions of the contour of the central portion, located on either side of the median plane P2 and cut by the transverse plane P3.
The plates 12, 14, 16 and 18 are stacked in pairs with spacers 36 between them, as explained below. In other words, none of the plates 12 to 18 are in electrical contact with an immediately adjacent plate.
For example, the central portions 24 of each plate 12 to 18 are superimposed, with the axes A24 of each plate 12 to 18 coinciding, and the edges 28 and 30 of each plate 12 to 18 being parallel to each other.
Advantageously, all the edges 28 of the plates 12 to 18 are located in the same geometric plane parallel to the axis A24. Similarly, all edges 30 are also located in the same geometric plane parallel to the axis A24. Similarly, all the side

edges 31 located on the same side of the median plane P2 are also located in the same geometric plane parallel to the axis A24. Thus, as illustrated in Figure 2, all the central portions 24 of the plates 12 to 18 are contained in a cylinder with a rectangular cross-section and a generatrix parallel to the axis A24, which gives the connector 10 a compact structure while allowing proximity effects between the plates to be reduced.
The first and second pairs of plates 20 and 22 are thus superimposed parallel to the axis A24.
Each of the plates 12 to 18 further comprises a first connection lug 32 and a second connection lug 34. The connection lugs 32 and 34 are designed to be connected to the terminals of the electrical devices connected by the connector 10.
In the example shown, the connection lugs 32 and 34 have a rectangular shape with a width less than the width of the central portion 24. The lugs 34 are longer than the lugs 32.
For each plate 12 to 18, the connection lug 32 extends longitudinally from the first edge 28 in line with the central portion 24 and in line with one of the side edges 31, while the connection lug 34 extends longitudinally from the second edge 30 in line with the central portion 24 and in line with of one of the side edges 31.
That is, the connection lugs 32 and 34 of each plate 12 to 18 extend longitudinally in line with the central portion 24 of a respective one of the plates 12 to 18, from opposite edges 28 and 30.
In other words, the connection lugs 32 and 34 are located on either side of the transverse plane P3.
For each plate 12 to 18, the lugs 32 and 34 are located on either side of the median plane P2. In other words, the connection lugs 32 and 34 are laterally offset from each other in a direction orthogonal to the median plane P2.
For any two of the plates 12 to 18 in succession, i.e. for the immediately adjacent plates 12 and 14, or 14 and 16, or 16 and 18, the connection lugs 34 are located on either side of the median plane P2. In other words, the lugs 34 are laterally offset from each other in a direction orthogonal to the median plane P2.
Similarly, the connection lugs 32 of two immediately adjacent plates 12 to 18 are also located on either side of the median plane P2. In other words, the lugs 32 are laterally offset from each other in a direction orthogonal to the median plane P2.

More generally, for two of the immediately adjacent plates 12 to 18, the connection lugs 32 and 34 located on the side of one of the respective opposite edges 28 and 30 are laterally offset from each other in a direction orthogonal to plane P2.
It is understood that the lugs 32 and 34 of plate 12, which is the first plate of the first pair 20, and the lugs 32 and 34 of plate 16, which is the first plate of the second pair 22, are respectively superimposed parallel to the axis A24. In other words, the first plate 16 of the second pair 22 is obtained by translation parallel to the axis A24 of the first plate 12 of the first pair 20, and the first plates 12 and 16 of the first and second pairs 20 and 22 are separated from each other by the second plate 14 of the first pair 20.
Likewise, lugs 32 and 34 of plate 14, which is the second plate of the first pair 20, and the lugs 32 and 34 of plate 18, which is the second plate of the second pair 22, are respectively superimposed parallel to the axis A24. In other words, the second plate 18 of the second pair 22 is obtained by translation parallel to the axis A24 of the second plate 14 of the first pair 20, and the second plates 14 and 18 of the first and second pairs 20 and 22 are separated from each other by the first plate 16 of the second pair 20.
Two immediately adjacent central portions 24 define a gap 36 between them. The spacers 36 each have the shape of a flattened parallelepiped, which extends parallel to the longitudinal plane PL
Advantageously, the insulating structure 58 comprises interlayers of electrically insulating material, which are accommodated in each of the gaps 36 between two immediately adjacent central portions 24. The interlayers of the insulating structure 58 are capable of electrically insulating the immediately adjacent central portions 24 from each other. The interlayers are not shown, to facilitate the reading of the figures.
Advantageously, the interlayers accommodated in the spaces 36 are capable of mechanically holding the adjacent central portions 24 in relation to each other.
The lugs 32 located on the same side of the median plane P2 are superimposed in a direction parallel to the axis A24.
Likewise, the lugs 34 located on the same side of the median plane P2 are superimposed in a direction parallel to the axis A24.

The lugs 32 and 34, which are superimposed on each other, are also mechanically and electrically connected to each other by connecting members 38.
In the illustrated example, each connecting member 38 comprises a first outer plate 40, an intermediate plate 42 and a second outer plate 44. The outer and intermediate plates 40, 44 and 42 are rectangular in shape and are attached to the respective lugs 32 or 34 by fasteners 45 which are located in the corners of the plates 40 to 44. In a non-limiting fashion, the fasteners 45 may be screws or rivets, and are preferably made of a metallic or at least electrically conductive material.
Advantageously, the plates 40 to 44 are made of an electrically conductive material, such as a metal, compatible with the material of the plates 12 to 18.
The lugs 32 and 34, connected by respective connecting members 38, form the four terminals 46, 48, 50 and 52. In the example shown in Figures 2 and 3, the four terminals 46 to 52 are each parallelepipedic in shape.
Advantageously, the terminals 46 to 52 may have different or even specific shapes in order to facilitate recognition of the terminals when connecting the connector 10 to an electrical device.
It is understood that terminal 48 is electrically connected to terminal 52, while terminal 46 is electrically connected to terminal 50.
The terminals 48 and 52 are located on either side of the median plane P2, in a so-called crossed configuration. Together, terminals 46 and 50 are also located on either side of the median plane P2 in the crossed configuration.
Alternatively, not shown, the terminals 48 and 52 may be located on the same side of the plane P2, in which case the lugs 32 and 34 of each of the plates 12 to 18 are also located on the same side of the plane P2, in a so-called straight configuration.
In the example shown, the lugs 32 and 34 are arranged along their length parallel to the median plane P2.
Alternatively, not shown, one or more of the lugs 32 or 34 may diverge from the plane P2 away from the central portion 24, while maintaining the superposition of the lugs 32 or 34, parallel to the axis A24.
Each of the terminals 46 to 52 further comprises fixing bores 54. The bores 54 are configured to receive connection members of the electrical devices to which the connector 10 is connected. These connection members, not shown, may be

cables or conductor bars which mate with the terminals 46 to 52 in such a way as to reversibly connect said electrical devices to the terminals 46 to 52 while ensuring good electrical contact and mechanical strength.
Figure 3 is a bottom view of the connector 10 in Figure 2, with the connector 10 shown connected to the transformer 8. One of the coils of the transformer 8, shown partially and schematically, is here connected to terminals 52 and 50 of the connector 10. Transformer 8 is an example of an electrical device subject to a first specific IP protection constraint, transformer 8 being housed in zone Z2 here.
The terminals 46 and 48 of the connector 10 are connected to a second electrical device, which is not shown in Figure 3, the second electrical device being subject to a second IP protection requirement and being housed here in the Z3 area.
Zones Z2 and Z3 are separated by the bulkhead 56.
The insulation structure 58 comprises, in addition to the interlayers housed in the gaps 36, a body 60, a peripheral tongue 62 and a positioning relief 64.
The insulation structure 58 is made of an electrically insulating material. In the example shown, the insulation structure 58 is made of polymeric plastic. The body 60 completely covers the central portions 24 of the plates 12 to 18, thereby ensuring the electrical insulation of the central portions 24 and the spatial immobilisation of the plates 12 to 18 relative to each other. In other words, the body 60 jointly receives the central portions 24 of each of the plates 12 to 18.
In the example shown, the central portions 24, superimposed on each other, are each rectangular in shape, while the body 60 has a parallelepiped shape.
Advantageously, the body 60 ensures electrical insulation continuity and mechanical holding continuity with the interlayers housed in each of the gaps 36.
Advantageously, the body 60 and the interlayers housed in each of the spaces 36 are made of the same material. Even more advantageously, the body 60 and the intermediate layers are manufactured by overmoulding the central portions 24, with only the lugs 32 and 34 projecting from the body 60. During overmoulding, the insulating material of the body 60 is in a viscous state and is shaped by moulding, preferably under pressure, around the central portions 40. The insulating material of the body 60 is preferably a thermoplastic material, with the overmoulding being carried out under heat. During cooling, the insulating material solidifies.

As a result of the overmoulding process, the central portions 24 of the plates 12 to 18 are embedded in the body 60 of the insulation structure 58, with only the connection lugs protruding from the body 60 of the insulation structure 58, as shown in Figure 3.
Preferably, the insulation structure 58 is made in one piece. For this purpose, during the manufacture by overmoulding, the plates 12 to 18 are kept spaced apart, while the insulating material of the insulating structure, in a viscous state, penetrates between the central portions 24 of the plates 12 to 18, so as to form, after cooling and solidification of the insulating material, the insulating interlayers In other words, the body 60 and the interlayers housed in one of the respective spaces 36 together form a monolithic part.
The peripheral tab 62 projects from the periphery of the body 60 in a plane parallel to the transverse plane P3.
In the example shown, the tab 62 straddles the leaktight bulkhead 56.
The tab 62 has a closed and continuous contour and is configured to mate with sealing and/or fixing members, so as to fix the connector 10 to the wall 56 in a tight and reversible manner. The sealing and/or fixing members are not shown.
The terminals 46 and 48 on the one hand, and 50 and 52 on the other, located on either side of the transverse plane P2 and jointly on either side of the bulkhead 56, are thus separated in a sealed manner by the insulation structure 58 mating with the sealing members. In other words, the connection lugs 32 or 34 on the opposite edge side 28 or 30 are separated from each other in a sealed manner.
The positioning relief 64, connected to the body 60 and the tongue 62, advantageously has an asymmetrical shape with respect to the transverse plane P3, allowing good positioning of the sealing members with respect to the insulation structure 58.
It is understood that the connector 10 allows the connection of two electrical devices located on either side of a leaktight bulkhead 56. Of course, the connector 10 can be mounted on a non-leaktight bulkhead.
More generally, the shape of the insulating structure 58 can thus be freely chosen, in particular for the integration of the connector 10 with the rest of the rail vehicle 1, as long as the central portions 24 are completely covered by the body 60 and only the lugs 32 and 34 protrude from the body 60.

In the example shown, each of the connectors 10 comprises two pairs of plates 20 and 22, which are superimposed parallel to the axis A24 and arranged as described above.
In a variant not shown, only the first pair 20 is present, i.e. only plates 12 and 14 are present.
The connecting member 38 then comprises only the outer plates 40 and 44, and the terminals 46 to 52 are connected to each other by only one of the respective plates 12 or 14.
In another embodiment, three pairs of plates, similar to the pairs of plates 20 or 22, are superimposed.
The first plates of each pair of plates, in particular the lugs 32 or 34 of the first plates of each pair of plates, are superimposed on each other parallel to the axis A24, while the second plates of each pair of plates, in particular the lugs 32 or 34 of the second plates of each pair of plates, are superimposed on each other parallel to the axis A24.
The lugs 32 or 34 of each first plate are laterally offset from the lugs 32 or 34 of each second plate.
The connecting members 38 then comprise two spacer plates of the type of the spacer plates 42, while the terminals 46 to 52 each comprise three lugs 32 or 34.
It is understood that depending on the number of plate pairs of the type of pairs 20 and 22 of the connector 10, the electrical power carrying capacity of the connector 10 varies. This makes it easy to design and manufacture a connector 10 suitable for different electrical power ranges.
In the range of electrical powers considered, i.e. for electrical powers above a few tens of kilowatts, for example above 50 kW, the skin effect starts to be particularly noticeable for frequencies at and above 10 kHz. As the lugs 32 or 34 of the terminals 46 to 52 are each provided in a plate, each lug 32 or 34 has a cross-section with a high perimeter to area ratio. In other words, the lugs 32 or 34 have a high surface area relative to their volume, which is favourable for transporting current under conditions where the skin effect tends to be predominant.
It is understood that the thinner the plates 12 to 18 are, the less the connector 10 is subject to skin effects. On the other hand, plates 12 to 18 that are

too thin are mechanically fragile and unsuitable for an industrial environment such as a railway vehicle.
In practice, the plates 12 to 18 have for example a thickness of between 0.1 mm and 5 mm, preferably between 0.5 mm and 2 mm.
It is thus understood that the geometry of the plates 12 to 18, in particular the thickness of the plates 12 to 18, can be chosen to reduce the influence of the skin effect at the frequencies and powers envisaged in a specific application, while the total number of plates of the type of the plates 12 to 18, in particular the number of plate pairs of the type of the plate pairs 20 and 22, is chosen in accordance with the total electrical power to be transmitted through the connector 10.
In the example shown, the terminals 46 to 52 are connected to the terminals of the electrical devices in a crosswise fashion. Terminals 46 and 50 are linked together, while terminals 48 and 52 are linked together. It is understood that when the connector 10 is connected to electrical devices during operation, the current lines pass through the central portions 24 of each of the plates 12 to 18 in the diagonal connecting the respective lugs 32 and 34.
The current lines passing through two immediately adjacent central portions 24 are therefore crossed in a plane parallel to the longitudinal plane P1, reducing proximity effects such as inductance effects, advantageously reducing the impedance of the connection and thus the energy losses.
In the illustrated example, the central portions 24 of the plates 12 to 18 each have a rectangular shape, the rectangular shape being chosen to reduce proximity effects, reduce the inductance of the connection and thus the heating of the connector 10. Alternatively, the central portions 24 may have other shapes, chosen for example to reduce leakage lines.
In the example shown, the connectors 10 link the first and second circuits 4 and 6 to the transformer 8, with these circuits 4 and 6 and the transformer 8 operating at AC frequencies where the skin effect becomes noticeable, i.e. at frequencies above 10 kHz. Of course, the connectors 10 can be used to connect electrical devices operating at lower frequencies, especially at low frequencies, or even at direct current.
The above-mentioned operating mode and variants can be combined to generate new operating modes of the invention.

I/We Claim:
1. An electrical system (1), comprising a first electrical device (4, 6) and a second electrical device (8) separated by a bulkhead (56, 57) parallel to a transverse plane (P3), each of the first and second devices comprising at least two connection terminals, the first electrical device being electrically connected to the second electrical device via an electrical connector (10), wherein:
the electrical connector comprises a pair of plates (20), including a first electrically conductive plate (12) and a second electrically conductive plate (14), each plate (12, 14) having a central portion (24) and two connection lugs (32, 34),
the connection lugs of each plate extend longitudinally in line with the central portion (24) from opposite edges (28, 30) of the central portion, the opposite edges being portions of the contour of the central portion, the portions of the contour being located on either side of the transverse plane (P3), the connection lugs (32, 34) of each plate (12, 14) being laterally offset from each other,
the first and second plates (12, 14) are stacked on top of each other, with the central portions superimposed and separated by a gap (36), the connection lugs (32, 34) of the first and second plates are, on the side of each of said opposite edges, laterally offset from each other, the electrical connector (10) further com prises an insulation structure (58) comprising an interlayer of electrically insulating material housed in a gap (36) between the central portions (24) of the first and second plates, characterised in that the electrical connector (10) is configured to mate with sealing members so as to pass through the bulkhead (56, 57) in a sealed manner, two of the terminals of the first device (4, 6) being connected to two of the connection terminals (46, 48, 50, 52) of the electrical connector (10) located on one of the sides of the corresponding bulkhead, while two of the terminals of the second device are connected to two of the connection terminals of the electrical connector located on the other of the sides of that bulkhead.

2. The electrical system (1) as claimed in claim 1, wherein the
electrical connector (10) comprises at least a second pair (22) of plates,
comprising a third plate (16) and a fourth plate (18) that are electrically
conductive, each plate (16, 18) of the second pair (22) comprising a central
portion (24) and two connection lugs (32, 34):
the connection lugs of each plate (16, 18) extend longitudinally from opposite edges (28, 30) of the central portion and are laterally offset from each other,
the third and fourth plates are stacked on top of each other, with the central portions superimposed and separated by a gap (36), the connection lugs (32, 34) of the third and fourth plates (16, 18) are, on the side of each of said opposite edges, laterally offset from each other, all the plates (12, 14, 16, 18) of the electrical connector (10) being stacked on top of each other with all the central portions (24) being superimposed, wherein the insulation structure (58) comprises interlayers of electrically insulating material housed in each gap (36) between two immediately adjacent central portions, and
wherein for two immediately adjacent plates, the connection lugs (32, 34) on the side of one of the opposite edges (28, 30) are laterally offset from each other.
3. The electrical system (1) as claimed in claim 2, wherein all the connection lugs (32, 34) located on the side of one of the opposite edges (28, 30) and belonging to plates (12, 14, 16, 18) separated from each other by an odd number of plates are superimposed and are electrically connected to each other by connecting members (38).
4. The electrical system (1) as claimed in any one of claims 1 to 3, wherein the insulation structure (58) comprises a body (60) which jointly receives the central portions (24) of each plate (12, 14, 16, 18), the body being made by overmoulding the central portions of the plates in an electrically insulating material, with only the connection lugs (32, 34) projecting from the body.

5. The electrical system (1) as claimed in any one of claims 1 to 4, wherein the insulation structure (58) is made in one piece from a polymeric material.
6. The electrical system (1) as claimed in any one of claims 1 to 5, wherein the insulation structure (58) is configured to mate with sealing members, so as to sealingly separate from each other the connection lugs (32, 34) located on the side of opposite edges (28, 30).
7. The electrical system (1) as claimed in any one of claims 1 to 6, wherein the plates (12, 14, 16, 18) have an identical structure to each other.
8. The electrical system (1) as claimed in any one of claims 1 to 7, wherein the plates (12, 14, 16, 18) are made of metal with a thickness of between 0.1 mm and 5 mm, preferably between 0.5 mm and 2 mm, the metal being preferably selected from copper and its alloys or aluminium and its alloys.
9. A railway vehicle, comprising at least one electrical system (1) as claimed in any one of claims 1 to 8.