EP3160790A1

EP3160790A1 - Electric cable with earthing wires

Info

Publication number: EP3160790A1
Application number: EP15729412.5A
Authority: EP
Inventors: Daniel Chatroux; Olivier GUILLERMIN; Daniel MERMIN; Jérémy Dupont
Original assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2014-06-27
Filing date: 2015-06-10
Publication date: 2017-05-03
Also published as: WO2015197360A1; FR3023071A1; FR3023071B1

Abstract

The invention relates to an electrical connection device comprising: a cable having at least four conductors (41, 42, 43, 44) insulated from one another; and, at a first end of the cable, a plug (5b) having one fewer connector than there are conductors in the cable.

Description

ELECTRIC CABLE WITH GROUNDWIRES

The present patent application claims the priority of the French patent application FR14 / 56069 which will be considered as an integral part of the present description.

Field

The present description generally relates to electrical connection systems and, more particularly, to a cable connection system. The present description applies more particularly to a cable connection system of a motor vehicle battery or the like to recharge.

State of the art

The connection for charging a battery or a set of batteries for a motor vehicle to an electricity distribution system (electricity distribution network, photovoltaic panels, etc.) generally comprises a cable connected to a part to an electronic circuit managing the charge of the battery on the vehicle side and on the other hand to a power supply installation. Most often, the cable is located at the charging station. Most often, a cable having a plug at each end is connected, on the one hand, to the installation and, on the other hand, to the vehicle. Sometimes the cable is permanently connected to the vehicle. With the development of electric vehicles, we see appear solutions in which the cable is stored in the trunk of the motor vehicle. The user plugs both ends of the cable, respectively to the vehicle and to the charging station.

Whatever the solution adopted, the connection cable often tends to drag on the ground, which is particularly inconvenient and messy for the user.

In addition, for safety reasons, it must be ensured that the battery is connected to the ground when charging. This now generates the need for specific plugs dedicated to this application.

Moreover, current systems are not suitable for recharging on home networks, where the plugs and electrical circuits used are not dedicated to such recharging.

summary

One embodiment aims to overcome all or part of the disadvantages of conventional systems for connecting a battery to a charging facility.

Another embodiment aims to propose solutions that do not require any modification or intervention on the installation supplying electrical energy.

One of the constraints related to the charging of a battery for a motor vehicle is that the charging current is likely to cause a heating of the charging cable. Except to provide sections of conductors incompatible with economic constraints and space requirements, the use of cable ^ho¬¬ their cable is prohibited, the usual techniques of ventilated reels not being compatible with the needs of a load of battery for a motor vehicle.

According to a first aspect, an embodiment aims to provide an electric cable compatible with a wound operation. Another embodiment of this first aspect aims to propose a cable winder.

Another embodiment of this first aspect aims to propose a solution optimizing the section of conductors to be used for the electric cable.

Another problem encountered with the charging of electric vehicles is related to the safety of the user against electrocutions, in particular due to the metal parts of the vehicle carcass.

In a dedicated installation, such as a charging station, the station checks the connection of the battery by means of control signals exchanged with it. Such a solution, however, is incompatible with the use of charging plugs in domestic installations that are not specifically provided for such a refill.

According to a second aspect, an embodiment aims to electrically secure a connection to a recharging installation and, in particular, to ensure that the connection includes a connection to the ground.

When recharging a motor vehicle and, more particularly, by using an installation not specifically provided for such a refill, sometimes the plug on which the charger is connected is heated up on the electrical installation side. Such a problem usually does not arise in dedicated charging stations that are sized to provide the required current. However, when a user is supposed to charge his vehicle at home (on a standard outlet), the nature and capacity of the electrical installation can not be guaranteed, and sometimes there is dangerous heating up at the connections.

Temperature detectors are sometimes provided at the battery to control its charge, or even at the dedicated installation of a service station. However, such solutions are incompatible with a need for connection to domestic installations. According to a third aspect, an embodiment aims at securing the use of domestic plugs for recharging a battery for electric vehicles.

Thus, an embodiment provides an electrical connection device, comprising:

a cable having at least four conductors isolated from each other; and

at one end of the cable, a plug having a connector of less than the number of conductors of the cable, a first and a second conductor being connected to separate parts of one of the connectors and the plug being adapted to, when is engaged in a taken, connect these first and second drivers.

According to one embodiment, the device comprises at a second end of the cable, an electronic circuit for checking electrical continuity between a first conductor and a second conductor.

According to one embodiment, said circuit is connected to the first conductor by a transformer.

According to one embodiment, said circuit comprises: an element for generating an alternating signal;

an emission element of this signal on the first conductor;

a measuring element of the impedance by measuring the current on the same conductor.

According to one embodiment, said plug integrates at least one temperature sensor.

According to one embodiment, the cable comprises a non-regular external surface sheath surrounding said conductors.

According to one embodiment, projecting portions of the outer surface of the sheath define air circulation spaces between turns of the cable when the latter is wound. According to one embodiment, the air circulation spaces are, over the entire length of the coiled cable, axial and radial.

According to one embodiment, the device further comprises a cable winder having a cylindrical hub, perforated surface and open at at least one of its ends.

According to one embodiment, the device further comprises a fan blowing air in a direction approximately coaxial with the hub.

According to one embodiment, the device further comprises a drive element for rotating the hub.

One embodiment also provides a charging system for at least one battery for a motor vehicle, comprising an electrical connection device.

Brief description of the drawings

These and other features and advantages will be set forth in detail in the following description of particular embodiments in a non-limiting manner with reference to the accompanying drawings in which:

FIG. 1 very schematically represents an exemplary charging system for a battery of a motor vehicle and such a vehicle;

FIG. 2 diagrammatically represents an embodiment of an equipment internal to the vehicle;

Figure 3 is a partial perspective view of an embodiment of a cable according to the first aspect;

Figure 4 is a partial perspective view of the cable of Figure 3 wound;

Figure 5 is another partial perspective view of the cable of Figure 3 wound;

Figure 6 is a partial perspective view of another embodiment of a cable according to the first aspect;

Figure 7 is a schematic representation of an embodiment of an electric cable reel, equipped with an embodiment of a cable according to the first aspect; Figure 8 shows, very schematically, an embodiment of a connection plug and a cable according to the second aspect, associated with a ground connection detection circuit;

FIG. 9 represents a detail of the form of FIG.

8;

Fig. 10 shows an embodiment of a temperature sensing device associated with a plug according to the third aspect; and

FIG. 11 very schematically shows an embodiment of an electrical connection system using a plug of the type of that of FIG. 10.

detailed description

The same elements have been designated with the same references in the various figures. For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been shown and will be detailed. In particular, the production of a battery has not been detailed, the described embodiments being compatible with the usual batteries. In addition, the production of a battery charger has not been detailed otherwise than for the purposes of this description, the embodiments described being, for the rest, again compatible with the usual chargers. In addition, for ease of understanding, the figures are not to scale. Unless otherwise specified, the terms "approximately", "substantially" and "in the order of" mean within 10%, preferably within 5%.

Figure 1 shows, very schematically, an example of a charging system of a battery of a motor vehicle and such a vehicle.

An electric or hybrid vehicle V comprises one or more batteries 1 (BAT) intended to provide it with the energy necessary for its propulsion. These batteries are connected to one or more load management and control devices (chargers) for controlling their load when they are connected to an installation 3 of electricity supply. The installation 3 can be a public charging station of the service station type, a domestic installation (for example, at the vehicle user's home), etc.

In the description that follows, we will simplify the reference to "a" battery. However, the vehicles generally comprise a set of several batteries and all that will be described subsequently applies regardless of the number of batteries that make up the "battery" of the vehicle, these batteries are generally recharged through a battery. common device.

There are essentially two modes of charging a battery for a motor vehicle.

In a so-called "fast charge" mode, the battery is charged under a current of several tens of amperes (for example, of the order of 150A). In this case, the load is carried out from specific installations equipped with a suitable section cable and safety devices. The free end of the cable is then connected to a socket of the vehicle.

The development of electric vehicles, the time required to recharge their battery (compared to the speed of a full tank) and the autonomy they have, generate a need to multiply the possible charging points. In particular, it is desired to be able to connect a battery charger to a standard socket of a domestic installation.

We then resort to a so-called "slow load" mode which is particularly concerned with the embodiments that will be described. The battery is charged under a current of a few tens of amperes at most, typically under a current compatible with the use of plugs of a domestic installation. For example, in France, this amounts to being able to charge the battery from a socket called 16A. The battery connection cable for recharging is no longer necessarily charging station side, but more and more often on the vehicle side. This creates, among other things, constraints in terms of congestion. Today, electric vehicles are usually provided with a cable "bulk", intended to be connected on the one hand to the vehicle and on the other hand to a power supply outlet.

A slow charge can last more than ten hours. It is necessary to facilitate the handling of the user while ensuring its comfort and safety.

Moreover, the fact that the battery is likely to be recharged in other places than dedicated stations leads to the fact that we may wish to equip the vehicle with a longer cable length.

In addition, the need to recharge the battery from domestic installations that are not necessarily provided for this causes many other constraints.

Among these constraints, we note:

- the need for a reliable earth connection for safety reasons, in particular because of the metal casing of the vehicle which, in the event of a fault in the insulation of the vehicle during the charging of the battery, may be carried to a potentially dangerous potential;

- Intensity taken by the battery charge continuously, for a relatively long period (typically several hours) compared to the connection times of domestic equipment, which can cause a heating of the plugs and cables;

the inexperienced character of the user of the vehicle with regard to electrical stresses;

- the impossibility of modifying all the existing electrical installations to equip them with test and safety equipment;

- the need to be able to load a vehicle in different places (eg different countries) where the facilities do not necessarily have the same safety criteria. It would be desirable to have solutions taking into account all or part of these constraints.

In the example of FIG. 1, the charger 2 is connected using a cable 4 provided at its end at the installation end 3 with a plug 5 intended to be engaged in a socket 7 of the 'installation. On the charger side 2, the end of the cable 4 is either permanently connected to the charger (as shown) or is also connected via a plug.

FIG. 2 schematically represents an embodiment of an equipment inside the vehicle V.

According to this embodiment, there is provided on the vehicle side, a cable reel 6 to reduce the size of the latter. One (fixed) end of the cable 4 is connected to the charger 2 (CTRL). The other end, which can be rolled out of the cable, is connected to plug 5.

Due to the intensities involved when recharging a vehicle battery, a common cable can not be used while it is wound up. Indeed, the cable will heat and its heat can not be dissipated, hence the risk of melting or fire. It would then be necessary to force the user to unroll the cable completely for recharging, or to oversize the cable in section to prevent it from heating up too much. In the first case, the cable will drag on the ground and get dirty, which is particularly troublesome when charging in places that are not clean. In addition, the user may not respect this constraint, which involves risks. In the second case, this leads to increase the cost of the cable unrealistically and to increase its size.

Ventilated cable reels have already been proposed in an attempt to overcome this phenomenon in other domestic applications. However, the solutions adopted in these applications can not be transposed to an application for recharging electric vehicle batteries, particularly because of the particular constraints of this application. In particular, in most electrical applications in which the equipment (for example a garden tool) may remain connected long enough to cause a heating of the cable, the user moves this equipment. Therefore, the complete unwinding of the cable is often necessary for reasons other than heating. In addition, the cable is regularly moved and therefore does not remain in a pile. This is not the case of charging a vehicle that is stationary during charging, the length of the cable and its position therefore remain fixed throughout the recharge.

Moreover, the solutions used for vacuum cleaners, which consist of using a powerful fan, or the suction power of the vacuum cleaner itself (which is a depression of the order of 0.3 bar (3.10 ^ Pa )), at the level of the winder are not appropriate. Indeed, when the fan is used in a vacuum cleaner (or a reel used to power a power tool), the engine of the vacuum cleaner or the tool is already making noise and the noise added by the fan is negligible. In addition, this fan does not remain in operation when the vacuum cleaner or tool is not used. However, a vehicle battery is recharged while the vehicle is not in use. The fact that the charger must remain plugged in the absence of the user and in domestic locations generates a strong constraint in terms of noise.

According to a first aspect, an electrical cable of particular structure is provided. The internal structure of the cable comprises as many conductors as necessary, isolated from each other inside a sheath, in the manner of a conventional cable. However, the outer surface of the sheath has a non-regular section.

In other words, the outer surface has projecting portions of a bottom or base. The function of these projections, or irregularities, is to define air circulation spaces through the cable coil when the cable is wound on itself, or through sections of this cable stacked (for example if the cable is laid in piles). Figure 3 is a partial perspective view of an embodiment of a cable 4a according to the first aspect.

For example, the cable 4a comprises three conductors 41 (for example of phase), 42 (for example of neutral) and 43 (for example of earth), individually isolated from each other, and then embedded in an insulating sheath 45a. The sheath 45a has, on the outer surface, preferably at regular intervals, gadroons or rings 452 creating irregularities in this outer surface. Between the rings, the outer surface of the sheath has an inner diameter (or diameter of the base of the sheath). The outer diameter of the rings (or height of the surface irregularities) defines, with respect to the internal diameter, intervals or spaces of air circulation.

The interval between the rings 452 and their external diameter, which determines the size of the air circulation spaces, depend on the application and, in particular, on the amount of heat to be discharged, which depends, among other things, on the section of the conductors. and the amperage to which they must be subjected.

Figure 4 is a partial perspective view in section of the cable 4a of Figure 3 wound.

Figure 5 is another partial perspective view of the cable 4a of Figure 3 wound.

For simplicity, only the outer surface of sheath 45a has been illustrated in FIGS. 4 and 5.

These two figures show that, when the cable 4a is wound on itself, the rings 452 separate the base of the sheath of the different sections that overlap, thereby creating air circulation spaces. In addition, because of the winding, the diameter of the turns of the coil varies from one turn to another so that few rings 452 are found opposite each other. Furthermore, even in the axial direction of the coil, the winding causes the rings 452 to have very little risk of being aligned with several turns. Therefore, the air flow channels follow patterns, both in the radial direction and in the axial direction of the winding. Figure 6 is a partial perspective view of another embodiment of a cable 4b according to the first aspect.

According to this embodiment, the sheath 45b has a projecting portion 454 of its outer face defining a part with non-contiguous turns, wound coaxially around the cable. Thus, there is found between the non-contiguous turns of the portion 454, a base of diameter smaller than the outer diameter of the portion 454. The base of the sheath 45b also has the shape of a winding, coaxial with the cable axis , of non-joined turns. As in the embodiment of Figure 3, the difference in diameter between the inner and outer diameters of the surface of the sheath 45b, and the non-contiguous turn pattern, create air flow channels when the cable is wound. on itself, in the axial and radial directions of the winding.

The interval between the turns 454 and their outer diameter, which determines the size of the air circulation spaces, also depend on the application and in particular the amount of heat to be evacuated.

The embodiment of FIG. 6 illustrates a variation in the composition of the cable which here comprises four conductors 41, 42, 43 and 44. It may be a cable equipped with a control wire or pilot wire or a cable having two earth conductors 43 and 44, isolated from each other, as will be seen in connection with the third aspect which will be described later.

Other forms of surface irregularities may be provided, provided that they define, for the coiled cable, air flow channels in the axial and radial directions of the winding.

In addition, the number of drivers can vary. For example, the cable may include multiple pilot wires. According to another example, for a cable intended for a three-phase connection, five conductors (three phases, one neutral, one earth) or six conductors (three phases, one neutral, two earths) may be provided. Preferably, the assembly of the sheath 45 is made in one piece, for example by spinning plastics material.

Preferably, the difference in thickness between the outer diameter, rings 452 or portion 454, and the diameter of the base of the cable 4a or 4b is greater than about 3 millimeters. Likewise, the interval between rings 452 or between turns of the portion 454 in the axial direction is greater than about 3 mm, preferably greater than about 1 cm. Such minimal dimensions promote the circulation of air by simple natural convection.

As a particular embodiment, for a cable 4 whose conductors 41 to 43, or 41 to 44, are made of copper and have a cross section of approximately 2.5 mm 2, the internal diameter of the base sheath 45 ( 45a or 45b) is about 1 cm and the outer diameter of the rings 452 or the portion 454 is about 1.4 cm.

The representations of Figures 3 to 6 are schematic and functional. The practical realization of such cables is within the reach of those skilled in the art from the functional indications given above, using for the rest of the usual cable manufacturing techniques and as a function of the amperage for which the cable is intended and the conductors section.

For a given section of conductors, such a cable structure allows, for the same heating, the passage of a current of an intensity greater than that of a conventional cable when the cable is wound.

A cable 4 (4a or 4b) thus produced may, in a simplified embodiment, be used with a standard winder, the natural convection through the turns being sufficient to cool it.

However, according to a preferred embodiment, provision is made to associate this cable 4 with a specific winder.

Figure 7 is a schematic representation of an embodiment of a cable reel 6, equipped with an embodiment of a cable 4 according to the first aspect. According to this embodiment the winding device 6 comprises a cylindrical hub 62, openwork surface (openings 622) and open (opening 624) at at least one of its ends. The role of the openings 622 and 624 is to improve the flow of air through the cable 4. The greater the number of openings, the better. A compromise will therefore be made with the desired mechanical strength for the hub 62. Preferably, the openings 622 have a diameter, or are in a diameter, greater than 3 millimeters. The inventors have indeed found that from a diameter of 3 mm, the air flow was improved.

Preferably, the winder 6 further comprises a fan 64 blowing air inside the hub in a direction approximately coaxial with the hub (from the open end 624). Preferably, the hub is then open at one of its ends to force the pulsed air to pass through the openings 622, then to circulate through the cable 4 wound. A significant difference compared to conventional winders is that the air flow channels formed in the cable 4, participate in a power reduction of the fan. Indeed, with a conventional winder, the power of the fan should allow to force the circulation between contiguous coils of the coiled cable, which is in practice almost impossible and incompatible with low noise. Here, thanks to the air flow channels, the resistance to the passage of air is low and the fan can be low power, so silent and less expensive. For example, ventilation can be provided by a fan providing an overpressure of a few mbar (10 ² Pa).

Optionally, the reel 6 comprises a hub rotation drive member 66. This is, for example, a spring device, arming automatically as the user unwinds the cable 4. According to another example, using a rewinding motor of the cable, moved by the energy provided by the battery. Preferably, the reel 6 and its various components are housed in a housing 68 (Figure 2), partially shown in Figure 7. The housing prevents elements that block the operation of the reel. Preferably, the housing 68 comprises, at the bottom, one or more openings 682 for discharging any impurities accumulated around the cable and falling by gravity, or water if the cable 4 is wet during its rewinding.

The representation of Figure 7 is schematic and functional, the practical embodiment of such a reel being within the reach of the skilled person from the functional indications given above.

FIG. 8 very schematically shows an embodiment of an electrical connection device 9 according to the second aspect. This involves, for example, connecting a battery charger 2 of a motor vehicle to a socket 7 of an electricity supply installation (not shown).

FIG. 9 is a partial perspective view of an embodiment of a female connector 53 of a plug 5b of the device of FIG. 8.

The cable 4 (for example, of the cable type 4b, FIG. 6) comprises two conductors 43 and 44 intended to be connected to the ground. These two conductors are individually connected to two distinct portions 533 and 534 of a connector 53 of the plug 5b. The two parts 533 and 534 are not in electrical contact with each other as long as the plug is not engaged in a socket 7. For example, the parts 533 and 534 each constitute a sector of a female connector of cylindrical general shape (Figure 9) for receiving a male connector 73 of a socket 7. Thus, the plug 5b has a connector of less than the number of conductors of the cable 4b.

In the example of Figure 8, the socket 7 has two female connectors 71 and 72 for the connectors (male) 51 and 52 of the plug 5b, and a male connector 73. The connectors 71 to 73 are connected to wires (generally designated by a cable 76) of the electricity supply installation.

When the plug 5b is engaged in the socket 7, the earth connector 73 (dashed side plug 5b in Figure 8) electrically contacts the two parts 533 and 534 and thus connects the conductors 43 and 44.

At the other end of the cable 4b, for example at the charger 2 of battery 1, the conductors 41 and 42 are connected to the charger itself, for example via a rectifier 23. Two conductors 21 and 22 of the charger are connected to the terminals (positive (-) and negative (+)) of the battery 1. One of the conductors 43 and 44 (for example the conductor 43) is connected directly to the mass M (metal frame) of the vehicle. The other earth conductor 44 is also connected to the ground M, but via an electronic circuit 92 for checking electrical continuity between the conductors 43 and 44. Battery side, typically acting as a battery of traction, it is usually isolated.

For example, the circuit 92 generates an alternating signal, preferably at a frequency different from that of the alternating voltage supplied by the electrical network, that it emits on the conductor 44 via a transformer 93. The circuit 92 detects the impedance of the circuit by measuring the current and the voltage supplied.

In the absence of electrical continuity provided by a socket 7, the circuit is open and the impedance is of high value, the current is close to zero. When continuity is assured, a current flows and the impedance is low.

Other continuity detection circuit embodiments may be provided to detect the grounding of at least one of the leads 43 or 44.

An advantage of the solution described in connection with FIGS. 8 and 9 is that it is compatible with standard outlets of existing domestic installations. Another advantage is that all detection (detection electronics) is on the charger side. Thus, no intervention is necessary on the side of the electricity supply installation.

The representation of Figure 8 is schematic and functional. In particular, the practical embodiments of a continuity detection circuit charger side 2, and a connector, female or male, adapted to establish continuity between the two conductors 43 and 44 when the presence of a connector, male or female, ground 83 of a socket 7, are within the reach of the skilled person from the functional indications given above.

In addition, although an example has been described in which one end of the cable is permanently connected to the charger 2, it is possible to provide a cable whose two ends are equipped with a plug 5b, or even a cable whose end is equipped with a plug 5b and the other end is equipped with a socket 7. In addition, although an application to the load of a motor vehicle is an application where such an electrical connection device has many advantages, this The device may be used in other applications where it is desired to check a ground connection.

Fig. 10 shows an embodiment of a temperature sensing device associated with a plug 5a according to the third aspect.

FIG. 11 very schematically shows an embodiment of an electrical connection system using a plug 5a of the type of FIG. 10.

In the example of Figure 10, it assumes a so-called 2P + T plug, that is to say three conductors (phase, neutral and earth). Usually, the plug 5a comprises three connectors 51, 52 and 53 of different shapes and positions according to the standards in force in the different countries. Here, assume a plug 5a whose two connectors 51 and 52 carrying the current are protruding from a front face 55 of the plug (male connectors) and whose ground connector 53 is recessed from this front face (female connector).

Inside the plug 5a, the ends of the conductors 41, 42 and 43 of a cable 4 (for example the cable 4a of Figure 3) are connected (for example, welded, crimped or screwed) to the respective connectors 51 at 53. The assembly is enclosed in an insulating casing 58.

Such a plug is intended for a socket 7 (Figure 11) whose ground connector 73 (male) is protruding from the apparent face of the socket so that the earth is the first connected conductor. The socket 7 is connected, by a cable 76, to a source of electricity supply (not shown), for example the distribution table of a domestic installation.

In the example of FIG. 11, the cable 4 connected, at its other end, to the battery charger 2 of a vehicle is represented by means of a winder 6.

Plug 5a has at least one temperature sensor. In the preferred embodiment shown in FIG. 10, each connector 51, 52 conveying current in normal operation (phase and neutral) is equipped with a temperature sensor 81, respectively 82. In an embodiment where a single sensor is provided, it is placed closer to the connectors, for example, halfway between the two connectors 51 and 52. A simple realization of temperature sensors is to use negative temperature coefficient resistors (CTN). The sensors 81 and 82 are connected to an electronic circuit 85 for interpreting the temperature and, for example, for comparing this temperature with a threshold.

Preferably, the circuit 85 is integrated in the plug 5a and communicates with the battery charger (2, Figure 11). The charger 2 takes into account the temperature detected to allow or interrupt the charging of the battery, or even to control the charging current taken from the installation so that the temperature of the socket 7 remains acceptable and safe. The communication between the circuit 85 and the charger 2 can be carried out via one or more additional conductors 86 (pilot wires) provided in the cable 4. According to another embodiment, this communication is effected by means of carrier current using the conductors 41 and 42 (the plug then comprising a transceiver / carrier connected to the conductors 41 and 42 of the cable 4), which avoids a galvanic isolation of the circuit 85. Alternatively, the circuit 85 controls minus a switch (not shown) integrated in the plug 5a and interposed on the conductor 41 or the conductor 42, which opens the electrical circuit if the temperature exceeds a predetermined threshold.

The fact of proceeding to the detection of the temperature at the plug 5a indirectly detects an excess of temperature at the plug 7 in which the plug is connected. Thus, when the plug 5a is plugged into a domestic installation, it is possible to detect a rise in temperature that would occur at the outlet 7 of the installation. This makes it possible to detect a possible defect in the installation in terms of power accepted by the conductors 76 of this installation or the electrical outlet 7 in which the plug 5a is connected. Such an advantage is particularly advantageous in the application to the charging of electric vehicles insofar as, given the high intensity required for the taking and the duration of the connection, the risk of heating is not negligible.

The representation of Figures 10 and 11 is schematic and functional. The practical realization of such a plug equipped with a temperature detector is within the reach of the skilled person from the functional indications given above. In particular, the determination of the temperature threshold (for example, between 50 and 80 °) depends on the application.

An advantage of the embodiments that have been described is that they make it possible to secure and make practical and comfortable the charging of a battery of an electric vehicle, including from a non-dedicated installation, for example, a domestic installation.

Various embodiments have been described. Various variations and modifications will be apparent to those skilled in the art. In particular, the various embodiments and variants described are combinable when they have not been presented as alternatives.

In addition, the practical implementation of the embodiments that have been described is within the abilities of those skilled in the art from the functional indications given above.

Finally, although the various embodiments have been exposed in connection with a preferred application to the charging of a motor vehicle battery where they bring maximum benefits, they apply more generally to other applications in which we meet all or part of the same problems.

Claims

An electrical connection device, comprising: a cable (4) having at least four conductors (41, 42, 43, 44) insulated from one another; and

at one end of the cable, a plug (5b) having a connector of less than the number of conductors of the cable, a first and a second conductor (43, 44) being connected to portions (533, 534) separate from a connectors and the plug (5b) being adapted to, when engaged in a socket (7), connect these first and second conductors.

2. Device according to claim 1, comprising at a second end of the cable (4), an electronic circuit (92) for checking electrical continuity between the first conductor (44) and the second conductor (43).

3. Device according to claim 2, wherein said circuit (92) is connected to the first conductor (44) by a transformer (94).

4. Device according to claim 2 or 3, wherein said circuit (92) comprises:

an element for generating an alternating signal;

a transmitting element of this signal on the first conductor (44);

5. Device according to any one of claims 1 to 4, wherein said plug incorporates at least one temperature sensor (81, 82).

6. Device according to any one of claims 1 to 5, wherein the cable comprises a sheath (45a, 45b) non-uniform outer surface surrounding said conductors (41, 42, 43, 44).

7. Device according to claim 6, wherein protruding parts (452, 454) of the outer surface of the sheath (45a, 45b) define air circulation spaces between turns of the cable when it is wound.

8. Device according to claim 7, wherein the air flow spaces are, over the entire length of the coiled cable, axial and radial.

9. Device according to any one of claims 1 to 8, further comprising a cable reel (6) having a cylindrical hub (62), perforated (622) surface and open (624) at least at one end thereof .

The apparatus of claim 9, further comprising a fan (64) blowing air in a direction approximately coaxial with the hub (62).

11. Device according to claim 9 or 10, further comprising a member (66) for driving the hub (62) in rotation.

12. System for charging at least one battery (1) for a motor vehicle (V), comprising a device according to any one of claims 1 to 11.