High voltage electrical connector with limited arc risk in high frequency alternating operation

Abstract

The invention relates to an electrical connector (10, 11) having:-a body (12, 21) made of an electrically conductive material,-at least one electrical conductor (13, 23) covered with a layer (15, 25) of electrically insulating material,-at least one electrical terminal (16, 26) electrically connected to one end of the electrical conductor (13, 23), and-an insulating insert (18, 28) intended to electrically insulate the electrical terminal (16, 26) relative to the body (12, 21) of the electrical connector (10, 11), -the insulating insert (18, 28) has a first electrical continuity region (31.1) covered with a layer of electrically conductive material (32, 34) to provide electrical continuity with the body (12, 21), and-a second electrical continuity region (31.2) covered with a layer of electrically conductive material (33, 34) to provide electrical continuity with the electrical terminal (16, 26),-an elastic seal (40) arranged in the space (41), in which the insulating insert (18, 28) has a first electrical continuity region (31.1) covered with a layer of electrically conductive material (32, 34) to provide electrical continuity with the body (12, 21), and a second electrical continuity region (31.2) covered with a layer of electrically conductive material (33, 34) to provide electrical continuity with the electrical terminal (16, 26). The air volume inside the electrical connector (10, 11) may be subjected to a potential difference between the potential of the body (12, 21) and the potential of the electrical terminals (16, 26),-the resilient seal (40) is in contact with the first electrical continuity region (31.1) and the second electrical continuity region (31.2).

Description

Technical Field

[0001] The present invention relates to a high voltage electrical connector with limited risk of arcing in high frequency alternating operation.The invention finds a particularly advantageous, but not exclusive, application in which the connector is used in the electrical power grid of an aircraft. Background Art

[0002] Figure 1 A schematic diagram is shown of an assembly of a male electrical connector 10 and a female electrical connector 11 for use in an aircraft power network according to the prior art.

[0003] The male electrical connector 10 includes a body 12 made of a conductive material, an electrical conductor 13 covered with an electrically insulating material layer 15 , a male electrical terminal 16 , and an insulating insert 18 for electrically insulating the male electrical terminal 16 from the body 12 .

[0004] The female electrical connector 11 includes a body 21 made of a conductive material, an electrical conductor 23 covered with an electrically insulating material layer 25 , a female electrical terminal 26 , and an insulating insert 28 for electrically insulating the female electrical terminal 26 from the body 21 .

[0005] The increase in electrification of aircraft has resulted in an increase in the voltage applied to the actuation system in order to minimize the mass and electrical losses of the actuation system. The voltage achieved on the power grid is on the order of 800V, with a maximum DC voltage approaching 1000V.

[0006] In order to support high voltage levels, it is known to increase the thickness of the solid dielectric of electrical connectors made of thermoplastic or thermosetting materials. However, the ambient air contributes to the electrical insulation of different equipotential areas from each other.

[0007] Figure 2 An equivalent diagram of a dielectric link between two equipotential areas (eg, electrical conductors 13, 23 and bodies 12, 21 of electrical connectors 10, 11) is shown. S and R S Cg and Rg represent the capacitance and resistance of a solid dielectric, respectively. Cg and Rg represent the capacitance and resistance of a gas dielectric (such as ambient air), respectively.

[0008] In DC (direct current) operation, the potential is distributed only by the inherent resistance in the insulator (no capacitors are involved). Furthermore, the resistivity of solid dielectrics is much higher than that of air. In practice, the voltage is largely distributed in the solid insulator, which is sized to withstand the voltage.

[0009] In AC (alternating current) operation, the potential is distributed primarily by the inherent capacitors in the insulators, especially at higher frequencies relative to resistors. These capacitors are sized in farads, and their values ​​are defined by the relative surface area, the distance between equipotential regions, the dielectric constant of the vacuum (ε0), and the relative dielectric constant of the dielectric (εr).

[0010] The value of the capacitor is given by the relationship C = S ε0εr / L gives:

[0011] - C is the value of the capacitor in Farads,

[0012] -S is in m 2 is the relative surface area per unit,

[0013] - L is the distance between the opposing surfaces in meters, and

[0014] -ε0 is the relative permittivity of vacuum = 8,854×10–12F / m. The relative permittivity of air is close to 1, while the relative permittivity of commonly used solid dielectrics is between 3 and 5.

[0015] In AC operation, most of the voltage change is applied to air, which has a much lower dielectric strength (20 to 50 times) than that of solid dielectrics (1 kV / mm to 3 kV / mm for air, 20 kV / mm to 150 kV / mm for solid dielectrics).

[0016] Under these conditions, phenomena of ionization of the air are observed, which give rise to the risk of electric arcs. In particular, this phenomenon occurs during the remote powering of multiphase motors via PWM (Pulse Width Modulation) voltage signals which exhibit significant voltage-time variations (dV / dt) due to short switching times and high voltages. This results in power losses and heat dissipation that can degrade the solid dielectrics in the electrical connectors. Summary of the invention

[0017] The object of the present invention is to effectively solve the above disadvantages by providing an electrical connector, the electrical connector comprising:

[0018] - a body made of an electrically conductive material,

[0019] - at least one electrical conductor covered with a layer of electrically insulating material,

[0020] - at least one electrical terminal electrically connected to one end of the electrical conductor, and

[0021] - an insulating insert for electrically insulating the electrical terminal from the body of the electrical connector,

[0022] - the insulating insert comprises a first electrical continuity area covered with a layer of conductive material ensuring electrical continuity with the body, and

[0023] - a second electrical continuity area covered with a layer of conductive material ensuring electrical continuity with the electrical terminal,

[0024] - an elastic gasket arranged in a gap in which an internal air volume of the electrical connector may be subjected to a potential difference between the potential of the body and the potential of the electrical terminals,

[0025] - the elastic gasket is in contact with the first area of ​​electrical continuity and with the second area of ​​electrical continuity.

[0026] The invention thus allows to remove ambient air inside the connector acting as electrical insulation by minimizing or even eliminating significant potential differences that may be applied to the air inside the electrical connector. The invention thus minimizes the risk of arcing when the electrical connector is used for high frequency and high voltage operation.

[0027] According to an embodiment of the present invention, the elastic gasket is made of silicone material.

[0028] According to one embodiment of the invention, the layers of conductive material in the first area of ​​electrical continuity and in the second area of ​​electrical continuity are solid layers.

[0029] According to one embodiment of the invention, the conductive material layers in the first electrical continuity area and the second electrical continuity area are mesh layers.

[0030] According to one embodiment of the invention, the conductive material layers in the first electrical continuity region and the second electrical continuity region are made of carbon.

[0031] According to one embodiment of the invention, the conductive material layers in the first electrical continuity area and the second electrical continuity area are made of metal.

[0032] According to an embodiment of the invention, the layers of conductive material in the first region of electrical continuity and in the second region of electrical continuity each have a thickness between 20 nm and 100 nm.

[0033] According to an embodiment of the invention, the electrical conductor and the layer of electrically insulating material are covered by a shielding.

[0034] According to an embodiment of the present invention, the electrical connector is of male type and / or female type.

[0035] The invention also relates to an assembly of two connectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be better understood and other characteristics and advantages will emerge by reading the following detailed description, which includes embodiments given for illustrative purposes with reference to the accompanying drawings, which are presented by way of non-limiting examples and which may serve to complete the understanding of the description of the invention and its implementation, and ultimately contribute to its definition, in which:

[0037] [ Figure 1 ] has been described Figure 1 is a schematic diagram of an assembly of a male electrical connector and a female electrical connector according to the prior art;

[0038] [ Figure 2 ] has been described Figure 2 An equivalent diagram of a dielectric link between two equipotential regions in an electrical connector according to the prior art is shown;

[0039] [ Figure 3 ] Figure 3 is a schematic diagram of an assembly of a male electrical connector and a female electrical connector according to the present invention;

[0040] [ Figure 4a ][ Figure 4b ] Figure 4a and Figure 4b Showing top views of a conductive material layer on an insulating insert having a solid configuration and a mesh configuration, respectively;

[0041] [ Figure 5 ] Figure 5 is a schematic diagram of the voltage gradient distribution inside the elastic gasket of the electrical connector according to the present invention;

[0042] [ Figure 6a ] Figure 6a is a schematic diagram of a male-female electrical connector according to the present invention;

[0043] [ Figure 6b ] Figure 6b is a schematic diagram of an assembly of two male and female electrical connectors according to the present invention. DETAILED DESCRIPTION

[0044] It should be noted that common structural elements and / or functional elements of different embodiments have the same reference numerals. Therefore, unless otherwise specified, these elements have the same structural characteristics, dimensional characteristics and material characteristics.

[0045] Figure 3 A male electrical connector 10 is shown establishing electrical contact with a female electrical connector 11. The electrical connectors 10 and 11 may be used in a high voltage electrical network in an aircraft, for example.

[0046] The male electrical connector 10 comprises a body 12 made of a conductive material and provided with at least one conductor passage opening 14. The body 12 of the male electrical connector 10 has a shape complementary to the shape of the body 21 of the female electrical connector 11. At least one electrical conductor 13 is inserted into the conductor passage opening 14. The electrical conductor 13 can be made of a conductive material, such as copper, aluminum or any other conductive material suitable for the application. If necessary, the electrical conductor 13 can be covered with a thin finishing layer for improving its conductivity, such as a layer of palladium, gold, silver, tin, nickel or any other conductive material suitable for the application.

[0047] The electrical conductor 13 may consist of a single wire having a circular cross section, a flat surface or any other form suitable for the application. Alternatively, the electrical conductor 13 may be of the multi-strand type, i.e. it may consist of a plurality of wires arranged side by side. The electrical conductor 13 is covered by a layer 15 of electrically insulating material. The electrically insulating material of the layer 15 may consist of a dielectric sheath covering the electrical conductor 13 or possibly of an enamel layer.

[0048] The electrical conductor 13 and the layer of electrically insulating material 15 are covered by a shield 19. The shield 19 is made of an electrically conductive material. The shield 19 is electrically connected to the body 12 of the male electrical connector 10.

[0049] At least one male electrical terminal 16 is electrically connected to one end of the electrical conductor 13. The connection between the male electrical terminal 16 and the electrical conductor 13 can be achieved by crimping, welding (with or without adding material), or any other electrical connection technology suitable for the application. The male electrical terminal 16 has a shape that complements the shape of the female electrical terminal 26.

[0050] The insulating insert 18 is provided to electrically insulate the male electrical terminal 16 from the body 12 of the electrical connector 10. The insulating insert 18 also has the function of electrically retaining the male electrical terminal 16. The insulating insert 18 is arranged in a housing 20 in the body 12. The insulating insert 18 extends at least partially around the male electrical terminal 16. The insulating insert 18 has a shape that matches the complementary shape of the insulating insert 28 of the female electrical connector 11. The insulating insert 18 can be made of any rigid dielectric material, such as a thermoplastic material or a thermosetting material.

[0051] The insulating insert 18 comprises a first electrical continuity area 31 . 1 covered with a layer of conductive material 32 ensuring electrical continuity with the body 12 of the electrical connector and a second electrical continuity area 31 . 2 covered with a layer of conductive material 33 ensuring electrical continuity with the male electrical terminal 16 .

[0052] The first region of electrical continuity 31.1 and the second region of electrical continuity 31.2 are different from each other, ie there is no material continuity between the conductive material layer 32 of the first region of electrical continuity 31.1 and the conductive material layer 33 of the second region of electrical continuity 31.2.

[0053] In addition, the female electrical connector 11 comprises a body 21 made of a conductive material and provided with at least one conductor passage opening 24. The body 21 of the female electrical connector 11 has a shape complementary to the shape of the body 12 of the male electrical connector 10. At least one electrical conductor 23 is inserted into the conductor passage opening 24. The electrical conductor 23 can be made of a conductive material, such as copper, aluminum or any other conductive material suitable for the application. If necessary, the electrical conductor 23 can be covered with a thin finishing layer for improving its conductivity, such as a layer of palladium, gold, silver, tin, nickel or any other conductive material suitable for the application.

[0054] The electrical conductor 23 may consist of a single metal wire having a circular cross section, a flat surface or any other shape suitable for the application. Alternatively, the conductor may be of the multi-strand type, i.e. it may consist of a plurality of metal wires arranged side by side. The electrical conductor 23 is covered with a layer 25 of electrically insulating material. The electrically insulating material of the layer 25 may consist of a dielectric sheath covering the electrical conductor 23 or possibly of an enamel layer.

[0055] The electrical conductor 23 and the layer of electrically insulating material 25 are covered by a shield 29. The shield 29 is made of an electrically conductive material. The shield 29 is electrically connected to the body 21 of the female electrical connector 11.

[0056] At least one female electrical terminal 26 is electrically connected to one end of the electrical conductor 23. The connection between the female electrical terminal 26 and the electrical conductor 23 can be achieved by crimping, welding (with or without adding material), or any other electrical connection technology suitable for the application. The female electrical terminal 26 has a shape that is complementary to the shape of the male electrical terminal 16.

[0057] The insulating insert 28 is provided to electrically insulate the female electrical terminal 26 from the body 21 of the electrical connector 11. The insulating insert 28 also has the function of electrically retaining the female electrical terminal 26 of the electrical connector 11. The insulating insert 28 is arranged in a housing 30 in the body 21. The insulating insert 28 extends at least partially around the female electrical terminal 26. The insulating insert 28 has a shape that matches the complementary shape of the insulating insert 18 in the male electrical connector 10. The insulating insert 28 can be made of any rigid dielectric material, such as a thermoplastic material or a thermosetting material.

[0058] The insulating insert 28 comprises a first electrical continuity area 36 . 1 covered with a conductive material layer 34 ensuring electrical continuity with the body 21 of the electrical connector 11 and a second electrical continuity area 36 . 2 covered with a conductive material layer 35 ensuring electrical continuity with the female electrical terminal 26 .

[0059] The first region of electrical continuity 36.1 and the second region of electrical continuity 36.2 are different from each other, ie there is no material continuity between the conductive material layer 34 of the first region of electrical continuity 36.1 and the conductive material layer 35 of the second region of electrical continuity 36.2.

[0060] When the male electrical connector 10 and the female electrical connector 11 are assembled together, there is electrical continuity between the first electrical continuity area 31.1 of the male electrical connector 10 and the first electrical continuity area 36.1 of the female electrical connector 11. There may also be electrical continuity between the second electrical continuity area 31.2 of the male electrical connector 10 and the second electrical continuity area 36.2 of the female electrical connector 11.

[0061] Therefore, the air volume V1 extending radially between the outer surface of the insulating insert 18 and the inner surface of the body 12 is affected on both sides by the potential of the bodies 12, 21 of the electrical connectors 10, 11, which prevents parasitic currents from occurring in high-voltage alternating operations in this area. Similarly, the air volume V2 is affected on both sides by the potential of the electrical terminals 16, 26 of the electrical connectors 10, 11, which prevents parasitic currents from occurring in high-voltage alternating operations in this area.

[0062] like Figure 4a As shown, the conductive material layers 32, 33, 34 and 35 of the first electrical continuity region 31.1, 36.1 and the second electrical continuity region 31.2, 36.2 may be solid layers.

[0063] Alternatively, if Figure 4b As shown, the conductive material layers 32, 33, 34 and 35 of the first 31.1, 36.1 and second 31.2, 36.2 electrical continuity regions can be mesh layers comprising alternation of empty regions 38 (i.e. regions without any conductive material) and arms 39 defining the mesh of the layer.

[0064] The layers 32, 33, 34 and 35 of the electrically conductive material of the first 31.1, 36.1 and second 31.2, 36.2 regions of electrical continuity are preferably made of carbon. Alternatively, the layers 32, 33, 34 and 35 are made of metal.

[0065] The layers 32, 33, 34 and 35 of conductive material may be deposited by ultrasonic welding, plasma deposition or any other technique for depositing thin layers of conductive material onto an element made of dielectric material. The type of conductive material is selected according to its compatibility with the material of the insulating insert 18, 28 onto which the layers 32, 33, 34 and 35 are deposited.

[0066] The layers 32, 33, 34 and 35 of the first and second regions of electrical continuity 31.1, 31.2 each have a thickness between 20 nm and 100 nm.

[0067] exist Figure 3 The resilient gasket 40 visible in the figure is arranged in a gap 41, wherein the internal air volume of the electrical connector may be subjected to a potential difference between the potential of the body 12, 21 and the potential of the electrical terminals 16, 26. The resilient gasket 40 is arranged between the male electrical connector 10 and the female electrical connector 11. The gap 41 extends axially between the insulating insert 18 of the connector 10 and the insulating insert 28 of the connector 11. The gap 41 extends radially between one of the electrical terminals 16 or 26 and one of the insulators 18 or 28.

[0068] The elastic gasket 40 is made of a material capable of supporting the maximum internal voltage to which the electrical connector is subjected. The elastic gasket 40 is preferably made of silicone, but any other material suitable for the application is also possible. When the connectors 10 and 11 are assembled together, the elastic gasket 40 is compressed to expel the air inside the gap 41. Thus, the air is replaced by the elastic gasket 40, which is an electrical insulator. Therefore, the elastic gasket 40 allows a significant increase in dielectric strength by a ratio of at least 10 relative to air.

[0069] As in Figure 5 As can be seen more precisely in FIG. 4 , the gasket 40 is in contact with the first electrical continuity area 31.1 and the second electrical continuity area 31.2 of the electrical connector 10, in particular with one end of the first electrical continuity area 31.1 and one end of the second electrical continuity area 31.2 of the electrical connector 10. The gasket 40 is also in contact with the first electrical continuity area 36.1 and the second electrical continuity area 36.2 of the electrical connector 11, in particular with one end of the first electrical continuity area 36.1 and one end of the second electrical continuity area 36.2 of the electrical connector 11.

[0070] On the first face 42 of the gap 41 defining the air volume, the ends of the first electrical continuity area 31 . 1 and the ends of the second electrical continuity area 31 . 2 of the electrical connector 10 maintain a distance from each other, for example a distance of millimeters.

[0071] On the second face 43 of the gap 41 defining the air volume, the ends of the first electrical continuity area 36.1 and the second electrical continuity area 36.2 of the electrical connector 11 are kept at a distance from each other, for example a distance of millimeters.

[0072] In this example, a first face 42 and a second face 43 of a gap 41 are shown, wherein the ends of the electrical continuity region are adjacent to each other. Alternatively, the first face 42 and the second face 43 may be opposite to each other.

[0073] Therefore, a voltage gradient gradV between the potential of the terminal and the potential of the bodies 12 , 21 is distributed inside the elastic gasket 40 .

[0074] Figure 6a An example of an implementation of the invention with a hermaphroditic electrical connector 50 (i.e. a connector that is a combination of a male and female connector) is shown. This type of connector is used for economies of scale or when the assembly operation on a device (wiring harness or housing) is irreversible to avoid assembly errors.

[0075] More specifically, the electrical connector 50 includes a body 51 made of a conductive material, an electrical conductor 52 covered with an electrically insulating material layer 53, and a shield 54 electrically connected to the body 51. The connector 50 also includes an electrical terminal 55 having a male portion and a female portion, and an insulating insert 56 for electrically insulating the electrical terminal 55 from the body 51.

[0076] Similar to the previous embodiment, the insulating insert 56 includes a first electrical continuity area 57.1 and a second electrical continuity area 57.2, wherein the first electrical continuity area 57.1 is covered with a conductive material layer ensuring electrical continuity with the body 51 and the second electrical continuity area 57.2 is covered with a conductive material layer ensuring electrical continuity with the electrical terminal 55.

[0077] The first region of electrical continuity 57.1 and the second region of electrical continuity 57.2 are different from each other, ie there is no material continuity between the conductive material layer of the first region of electrical continuity 57.1 and the conductive material layer of the second region of electrical continuity 57.2.

[0078] like Figure 6b As shown, when the two male and female electrical connectors 50 and 50' are assembled together, the male portion of the electrical terminal 55 of the connector 50 mates with the female portion of the electrical terminal 55 of the connector 50', and the female portion of the electrical terminal 55 of the connector 50 mates with the male portion of the electrical terminal 55 of the connector 50'.

[0079] There is electrical continuity between the first electrical continuity area 57.1 of the electrical connector 50 and the first electrical continuity area 57.1 of the electrical connector 50'. There is also electrical continuity between the second electrical continuity area 57.2 of the electrical connector 50 and the second electrical continuity area 57.2 of the electrical connector 50'.

[0080] Alternatively, the electrical connectors 10, 11 and 50 are multi-pin connectors including two or more electrical terminals 16, 26 and 55. In this case, an electrical continuity area is provided for each electrical terminal 16, 26 and 55 of the electrical connectors 10, 11.

[0081] Of course, the different features, variants and / or embodiments of the present invention may be associated with each other in various combinations, as long as they are compatible with or not exclusive of each other. In addition, the present invention is not limited to the above-described embodiments, which are provided only as examples. The present invention encompasses various modifications, alternative forms and other variants that may be conceived by those skilled in the art in the context of the present invention, and in particular, any combination of the above-described various operating modes may be adopted individually or in combination.

Claims

1. An electrical connector (10, 11, 50), the electrical connector (10, 11, 50) comprising: - a body (12, 21), said body (12, 21) being made of an electrically conductive material, - at least one electrical conductor (13, 23), said at least one electrical conductor (13, 23) being covered with a layer (15, 25) of electrically insulating material, - at least one electrical terminal (16, 26) electrically connected to one end of the electrical conductor (13, 23), and - an insulating insert (18, 28) for electrically insulating an electrical terminal (16, 26) from a body (12, 21) of the electrical connector (10, 11), characterized in that the insulating insert (18, 28) comprises a first electrical continuity area (31.1) covered with a layer of conductive material (32, 34) ensuring electrical continuity with the body (12, 21), and - a second electrical continuity area (31.2) covered with a layer (33, 35) of electrically conductive material ensuring electrical continuity with the electrical terminals (16, 26), - an elastic gasket (40) arranged in a gap (41), wherein an internal air volume of the electrical connector (10, 11) may be subjected to a potential difference between the potential of the body (12, 21) and the potential of the electrical terminal (16, 26), - the elastic gasket (40) is in contact with the first area of ​​electrical continuity (31.1) and the second area of ​​electrical continuity (31.2).

2. The electrical connector according to claim 1, characterized in that: The elastic gasket (40) is made of silicone material.

3. The electrical connector according to claim 1 or 2, characterized in that: The layers (32, 33, 34, 35) of the first area of ​​electrical continuity (31.1, 36.1) and the second area of ​​electrical continuity (31.2, 36.2) are solid layers.

4. The electrical connector according to claim 1 or 2, characterized in that: The conductive material layers (32, 33, 34, 35) of the first area of ​​electrical continuity (31.1, 36.1) and the second area of ​​electrical continuity (31.2, 36.2) are mesh layers.

5. The electrical connector according to any one of claims 1 to 4, characterized in that: The layers (32, 33, 34, 35) of the first area of ​​electrical continuity (31.1, 36.1) and the second area of ​​electrical continuity (31.2, 36.2) are made of carbon.

6. The electrical connector according to any one of claims 1 to 4, characterized in that: The conductive material layers (32, 33, 34, 35) of the first electrical continuity region (31.1, 36.1) and the second electrical continuity region (31.2, 36.2) are made of metal.

7. The electrical connector according to any one of claims 1 to 6, characterized in that: The layers of electrically conductive material (32, 33, 34, 35) of the first area of ​​electrical continuity (31.1, 36.1) and the second area of ​​electrical continuity (31.2, 36.2) each have a thickness between 20 nm and 100 nm.

8. The electrical connector according to any one of claims 1 to 7, characterized in that: The electrical conductor (13, 23) and the layer of electrically insulating material (15, 25) are covered by a shield (19, 29).

9. The electrical connector according to any one of claims 1 to 8, characterized in that: The electrical connector is of male type and / or female type.

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